Archivi categoria: iso

How to Find the Best ISO for Astrophotography: Dynamic Range and Noise

ISO is one of the three major exposure settings in the exposure triangle of a digital camera — shutter time, f/number, and ISO. Of the three, it is ISO that is probably most misunderstood. Even more so than f/number. In fact, it is a common misconception that higher ISO settings will cause images to be noisier. In fact, the opposite is often true. Wait, what?

That’s right, higher ISO settings alone do not increase image noise and higher ISOs can even be beneficial to low-light photography. In this post, I talk about the craziness surrounding ISO settings, how ISO actually affects exposure, and how to find the optimal ISO setting on your camera for astrophotography.

Introduction

Learning how to optimize exposure settings is one of the most helpful skills when attempting astrophotography. “What exposure settings should I use?” is probably the most common question I get. For beginners who are new at trying astrophotography with their regular digital camera and lens, I usually recommend starting with my Milky Way Exposure Calculator. That calculator will provide an excellent starting point when making your first attempts at shooting the night sky.

Once you’re comfortable making your first exposures, the next thing I recommend learning about exposure is how to optimize your ISO setting. That’s what this article is all about. To begin, here are a couple of glossary items that will hopefully help:

ISO

In digital photography, ISO is a standard (specifically ISO 12232:2006) for exposure brightness developed by the International Standards Organization (ISO). Different camera sensor models have different sensitivities so we need some way to correlate them so like exposures yield like brightnesses. Some people pronounce each letter (aɪ-es-o) but I think it’s easier to just say it like a word (aɪso).

Signal

Signal is the part of the photograph that we want. Light is signal. Signal is the image. Without the signal (without light), we can have no image. The more light that we can gather, the more signal we have. In general, the more signal, the higher the quality of the photo.

Noise

Noise is the part of the photograph that we do not want. Noise is interference appearing as speckled grain that obscures the signal and thus the details of the photograph. Noise is usually generated by heat or imperfections in the behavior of the electronics of our digital cameras. Some noise is random with every shot (shot noise) and some noise is produced consistently by the camera’s sensor (upstream read noise) or produced by the electronics after the sensor’s signal has been amplified (downstream read noise). In general, the more noise, the lower the quality of the photo.

Signal-to-Noise Ratio (SNR)

The ratio of signal to noise in an image. The higher the signal-to-noise ratio, the higher the quality of the image. More light = more signal = good. More noise = bad. Collecting more light is the best way to increase signal-to-noise ratio.

Higher signal-to-noise ratio is the best way to improve image quality. Sony a7S, 55mm f/1.8 @ f/2.8, 48x5s, PP7, ISO 12800

Dynamic Range

The full range of light of a scene, from the darkest darks to the brightest brights. A high dynamic range scene has extremely bright highlights (such as the sun) and extremely dark darks (such as a fully shadowed black rock). A low dynamic range scene has relatively uniform light across the scene where the brightest parts of the image are not much brighter than the darkest parts of the image. Cameras only capture a limited dynamic range of light. If the dynamic range of a scene is high enough, anything outside the range of the camera’s sensor will either be blown out to pure white (in the case of very bright areas) or crushed to pure black (in the case of very dark areas). In general, a camera sensor capable of capturing a higher dynamic range of light is more desirable.

A disclaimer: I’m an engineer, but I’m formally and primarily trained in mechanical engineering. I have some relevant experience, but electrical and computer engineering isn’t my main mode of expertise. My intention with this article is to simplify these concepts in a way that hopefully makes sense to a larger, non-technical audience. If you’re familiar with this topic and you see any glaring mistakes in this article, please feel free to let me know.

Also, all of the points made in this article apply to RAW image files. It’s very important to shoot astrophotos in RAW format to preserve the best data collected by the sensor. Don’t start complaining when you try any of the tests in this article on your JPEGs. Also, much of the benefit of optimizing ISO selection applies primarily to low-light shooting (like astrophotography) where we have a relatively small amount of signal competing with the various noise sources that encroach upon our photographs.

ISO is Amplification or Gain

It’s a (very) common misconception that increasing ISO increases the sensitivity of a camera sensor. ISO doesn’t change sensitivity. Increasing ISO simply increases the brightness of a photo by amplifying the sensor signal. In the electronics world, amplification is sometimes called “gain.” Like we can “gain” weight if we increase our eating, we can “gain” brightness if we increase our ISO.

ISO in no way affects how much signal (light) the camera can collect. If we actually want more sensitivity with a camera, we need to either increase shutter time or aperture size (lower the f/number).

Higher ISOs Don’t Increase Noise

OK, to the main point: Higher ISOs won’t increase the visible noise in a photo.

Read that again, realize that it contradicts what you probably think you know about ISO and then let me elaborate:

All other things being equal, a higher ISO will do the following:

  • A higher ISO will increase the brightness of an image
  • A higher ISO will decrease the total dynamic range of the image
  • And, in many cases (like astrophotography), a higher ISO will actually decrease the visible noise

OK, I know what you’re thinking: “How come when I use a higher ISO, I get more noise?!” Here’s why:

For most imaging situations, photographers will usually use P (Program), A/Av (Aperture Priority/Aperture Variable), or S/Tv (Shutter Priority/Time Variable) modes on their camera. In these exposure modes, using a higher ISO setting will result in an image with more relative noise. What most people don’t realize is that the increase in noise is not because of the increase in ISO.

The increase in relative noise when using a higher ISO in an automatic exposure mode (like P, A/Av or S/Tv) is actually due to the reciprocal decrease in shutter time or the decrease in aperture size as a result of using an automatic exposure mode. Most people are misattributing the increase in noise to the ISO when it’s actually caused by lower signal-to-noise ratio due to the shutter or aperture.

When setting a higher ISO on one of these autoexposure modes, the camera tries to achieve a neutral exposure and compensates for the increase in ISO by decreasing the amount of light entering camera. This reduction in light is done automatically by the camera by either decreasing the time the shutter is open (when in A/Av mode) or by using a higher f/number and thus decreasing size of the lens aperture diaphragm and letting in less light at a time (when in S/Tv mode), or by a combination of both (when in P mode).

So a reduction of light by the shutter or the aperture is the reason that the image appears noisier. It’s not noisier because of the higher ISO. This reduction of light is a reduction of signal and a reduction of signal yields an overall lower signal-to-noise ratio and thus a noisier photo.

How Do Shutter, Aperture and ISO Affect Noise?

A simple comparison test can show that relative noise levels are primarily affected by shutter and aperture and not affected nearly as much by ISO. In these tests, all settings are kept identical except the one that we wish to test which is adjusted by two stops. Then, in post processing, the images are equalized in brightness and compared.

Here’s what one of my complete test image looks like. It’s a RAW shot of Orion from a city suburb, made on a Sony a7S with the Zeiss 55mm/1.8 lens:

Constellation Orion, Sony a7S, 55mm

How Shutter Time Affects Noise

  • 8s, f/2.8, ISO 3200
  • 4s, f/2.8, ISO 3200 (+1 stop in post)
  • 2s, f/2.8, ISO 3200 (+2 stops in post)
How Shutter Time Affects Noise – Sony a7S, 55mm, f/2.8, ISO 3200

Conclusion: Shorter shutter time = less signal-to-noise ratio = noisier photo

How Aperture (f/number) Affects Noise

  • 8s, f/2.8, ISO 3200
  • 8s, f/4.0, ISO 3200 (+1 stop in post)
  • 8s, f/5.6, ISO 3200 (+2 stops in post)
How Aperture (f/number) Affects Noise – Sony a7S, 55mm, 8s, ISO 3200

Conclusion: Higher f/number = less signal-to-noise ratio = noisier photo

How ISO Affects Noise

  • 8s, f/2.8, ISO 3200
  • 8s, f/2.8, ISO 6400 (-1 stop in post)
  • 8s, f/2.8, ISO 12800 (-2 stops in post)
How ISO Affects Noise – Sony a7S, 55mm, f/2.8, 8s

Conclusion: Higher ISO ≠ more relative noise

So of the three tests on my Sony a7S, shutter speed and aperture very obviously directly affect the apparent levels of noise in the photograph while ISO has nearly no effect. This is completely contrary to what many people would expect when they think about higher ISO.

In low-light photography, there is one aspect of ISO that can greatly affect the amount of perceived noise for any given ISO setting: downstream electronic noise. Let’s see how different types of cameras can be affected by downstream electronic noise.

ISO-Invariance and Downstream Electronic Noise

There are variations from sensor to sensor and camera model to camera model in how ISO affects low-light images. Understanding how your camera sensor behaves can help you find the optimal ISO setting for astrophotography. There are two fairly common configurations that we see in most modern digital cameras so we can split most cameras into one of two camps, ISO-variant and ISO-invariant.

ISO-Variant Cameras

Cameras use varied levels of analog amplification to adjust ISO. In a simplification of this case, the amplifier boosts the electronic voltage readout from the sensor by 2x for each ISO: 100, 200, 400, 800, 1600 and so on. Higher ISO means more amplification of the sensor output data.

After the sensor data is amplified by the ISO, it’s sent through some (downstream) electronics (such as an analog to digital convertor) to ultimately change our data from voltages into a digital file of numbers that’s readable by a computer. One of the distinct characteristics with ISO-variant cameras is higher contribution of noise from these downstream electronics.

If there is relatively little signal to begin with (e.g. in low-light situations), the lower ISO settings might not apply enough amplification for the voltages of the sensor data to overcome the contribution of electronic noise made by the downstream electronics. That means that in low-light situations like astrophotography, ISO-variant cameras will actually show more noise at low ISO settings and less noise at higher ISO settings. The Canon EOS 6D, still one of my favorite choices for a DSLR for astrophotography, is highly ISO-variant and actually shows its best low-light noise performance at ISO 6400 and higher!

The Canon EOS 6D is highly ISO-variant and achieves its best low-light noise performance at ISO 6400 and higher.

Most Canon DSLRs are highly ISO-variant. There are a few exceptions to the Canon lineup that are not as ISO-variant including the new Canon EOS 5D Mark IV and the Canon EOS 80D.

ISO-Invariant Cameras

ISO-Invariant cameras have lower downstream read noise such that in low-light shooting conditions, the signal to noise ratio stays more constant as ISO settings change. In a simplification of this case, the sensor data is already amplified above the minimal contribution of downstream read noise sources before being converted to a digital signal. The result is a camera with low ISOs that tend to have less shadow noise and less of a variation between ISO settings. Most of these types of cameras are considered relatively ISOless or ISO-invariant. One camera that shows a great example of ISO-invariance is the Fujifilm X-T1. An example of the X-T1’s ISO-invariance test is available at the end of the article.

Modern digital cameras made by Sony and Fujifilm tend to be relatively ISO-invariant.

Notes and Exceptions

Okay, it’s not all black and white: many ISO-variant cameras eventually act like an ISO-invariant camera above a certain high ISO setting. Above some threshold ISO, these cameras fully overcome their noisy downstream electronics and show minimal difference in signal-to-noise ratio with higher ISOs. Most Canon cameras act this way above about ISO 1600. Knowing what that threshold ISO setting is can help us achieve the best low-light performance.

Similarly, many ISO-invariant cameras may have one or two distinct jumps in gain that will affect the overall read noise contribution to the image. In this case, there may still be a threshold ISO above which it is beneficial to shoot in low-light conditions. The Sony a7S acts this way with changes from approximately ISO 100 to 200 and 1600 to 3200. The Sony a7S’s best low-light performance is actually around ISO 3200 and above. Otherwise, the differences between ISO settings in low-light conditions on the a7S is relatively minimal.

Ultimately, both configurations achieve the same goal of brightening the photo to correspond with the particular ISO setting but the end result can be quite different, especially when shooting in low-light scenarios. ISO-invariance is a distinct enough trait in the behavior of a camera that DPReview has added an ISO-invariance test to most of their latest camera reviews. I personally think it’s very helpful to know how a camera acts in order to find out where it will perform best in low-light photography.

ISO vs. Dynamic Range

One of the distinct negative aspects of using too high of an ISO is reduced dynamic range. The more that we amplify the data that makes up a digital image, the more that we risk brightening it so much that it blows out the brightest parts of the image to pure white and loses detail in those parts of the image.

In the dynamic range test below, I made exposures of the star Antares at the highest ISO settings of my Sony a7S using the same exposure settings and varying only the ISO. As the ISO increases, the star appears to get larger because it’s being gradually more and more overexposed with each higher ISO. In practice, with the Sony a7S, the reduction in dynamic range doesn’t become too much of an issue until about ISO 51200 and higher but the difference in each stop is still apparent.

As a side-note, notice how similar most of the ISO settings between 1600 and 204800 look to each other in terms of noise, especially relative to the Canon EOS 6D sample above. The Sony a7S is a fairly, although not completely, ISO-invariant camera.

ISO Dynamic Range Test on the Star Antares – Sony a7S, 50mm, f/2.8, 8s

In my experience, except for the brightest stars, blowing out any part of an astrophoto to the point where we’re losing a lot of data is very, very rare. The bigger risk of using too high of an ISO in landscape astrophotography occurs when there is a larger, brighter (usually artificial) light source in view of the shot such as a street lamp, light pollution from a nearby town or your buddy’s headlamp.

Since we lose a little bit of highlight data with each higher ISO, choosing the optimal ISO for astrophotography is a little bit of balancing act between using a higher ISO for better noise performance (especially in the case of an ISO-variant sensor) or a lower ISO for better dynamic range.

Finding the Optimal ISO for Astrophotography: The ISO-Invariance Test

Stand back, we’re going to try science! In order to find the best ISO to use for astrophotography, I recommend doing an ISO-invariance test. Most of the samples shown in this article up to this point were made with an ISO-invariance test. It’s a super easy test to run: all we need to do is to take about 7-10 RAW photographs, one at each whole-stop ISO and then we match the exposure brightnesses in post processing. This test is easier to perform in a low-light scenario so I recommend doing this test outdoors at night or in a dimly lit room. Maybe make it an astrophotography trip.

If you’re performing this test while shooting the dark night sky, use my Milky Exposure Calculator to determine the shutter time and aperture setting. If doing the test in a dimly lit room, first use your camera’s (P) Program exposure mode at ISO 3200 to determine your shutter time and f/number.

Example: Canon EOS 700D

For my example, I’ll be testing out the Canon EOS 700D/T5i. Here’s a summary of the test:

  • Shoot in dark conditions: a dimly lit room or outdoors at night
  • Shoot in RAW file format!
  • Use (M) manual exposure mode
  • Set “daylight” white balance (just so it doesn’t drift)
  • Disable all forms of noise reduction (Long Exposure NR, High ISO NR)
  • Shoot one exposure at each whole stop ISO (100, 200, 400, 800, etc.)
  • Keep all other settings the same, change only ISO
  • Match exposures in post processing and compare

For my test on the T5i, here’s what the complete images looked like with the crop of the test area highlighted. I cropped the results of the test to a small area that included some midtones and some shadows.

Straight out of the camera, the crops of the RAWs looked like this:

ISO Comparison – Canon EOS T5i / 700D, 18mm, f/3.5, 25s

In terms of noise, this comparison is deceiving because the brightnesses don’t match between exposures. In order to level the playing field, we need to match the brightnesses. To do so, I used Exposure adjustment slider in Adobe Lightroom to match all of the exposure brightnesses to the ISO 3200 exposure. The ISO 100 image was pushed all the way to the max +5EV setting on the Exposure slider, the ISO 200 +4EV, the ISO400, +3EV and so on…

Here’s the complete summary of how we match all the exposure brightnesses in Adobe Lightroom.

  • ISO 100 gets pushed +5EV
  • ISO 200 gets pushed +4EV
  • ISO 400 gets pushed +3EV
  • ISO 800 gets pushed +2EV
  • ISO 1600 gets pushed +1EV slider
  • ISO 3200 has no adjustments made
  • ISO 6400 gets pulled -1EV

Another way to do this in Adobe Lightroom is to select all of the exposures, then highlight the ISO 3200 exposure and select Photo > Develop Settings > Match Total Exposures or press Command+Option+Shift+M (Ctrl+Alt+Shift+M).

Once equalized, here’s what the exposures look like:

ISO-Invariance Test – Canon EOS 700D / T5i

Upon comparison of the exposures, it’s immediately apparent that the Canon EOS 700D/T5i is not completely ISO-invariant. It appears as if that the camera reaches its best low-light performance at ISO 1600 and higher. ISO 1600, 3200 and 6400 look almost identical meaning that the 700D might be ISO-invariant from ISO 1600 upwards. Below ISO 1600 is a different story: As the ISO lowers, image quality degrades until the point of being nearly unusable at ISO 100. In order to preserve some dynamic range, but still get the best low-light performance on the 700D, it’s clear from the results of the test that ISO 1600 is the optimal setting.

Example: Fujifilm X-T1

Just for comparison, I ran a separate ISO-invariance test on my Fujifilm X-T1, this time at 30 seconds and an aperture of f/2.8. The results are distinctly different from the Canon.

ISO-Invariance Test – Fujifilm X-T1

The difference is that there is no difference… between the ISO 200 setting (the lowest it goes on the X-T1) and the ISO 6400 setting, noise levels are identical. This means that the Fujifilm X-T1 is completely ISO-invariant. The noise levels across the ISO range don’t change in the slightest. This means that it doesn’t really matter which ISO you use on the Fujifilm X-T1 and the optimal setting might even be ISO 200 in order to preserve dynamic range.

That said, there’s also a little bit of impracticality if attempting to shoot astrophoto at ISO 200 as the image preview on the back of the camera would be very dark and evaluation of other important factors like focus and composition would be difficult at ISO 200. Luckily, we’re usually not risking too much dynamic range by bumping ISO up to a moderately high level, assuming there are no bright artificial light sources in the photo. So using ISO a slightly higher ISO might be the more practical choice, keeping in mind our tolerance for reduced dynamic range.

Conclusion

Contrary to popular belief, higher ISOs don’t create more noise and using a higher ISO can actually be beneficial when shooting in low-light scenarios, especially on cameras with ISO-variant sensors. Run an ISO-invariance test on your camera to determine the best ISO setting to use when shooting astrophotography. ISO behavior varies from camera model to camera model and testing out each ISO setting can help determine the best ISO to use for the best noise performance in your astrophotography.

It’s important to understand that ISO-variance or invariance doesn’t necessarily make a camera better or worse at low-light, it’s just different. Knowing how a camera behaves is an important step to achieving the best image quality.

More and more cameras manufacturers tend to be making their cameras more and more ISO-invariant, as they develop sensor technology with reduced downstream read noise and improved dynamic range at low ISO settings.

Do you know which ISO on your camera gives the best low-light performance? Do a test to find out!


About the author: Ian Norman is the co-founder and creator of The Photon Collective and Lonely Speck. Ian is a full-time traveler, photographer and entrepreneur. In February 2013, he called it quits on his 9-to-5 to pursue a lifestyle of photography. Follow Ian’s photography adventures on Instagram. This article was also published here.

How to Develop and Push the ISO on Color Negative Film at Home

I finally did it! After sitting in my fridge for a few months, I managed to developed myself a roll of CineStill 800 pushed to 3200 ISO, and the results look great! The great thing: it’s actually pretty easy to develop pushed C-41 film at home.

If you don’t know what pushing film means, let me introduce this technique.

Basically, you purposely shoot a roll of film at a higher ISO than it’s intended for, in order to gain extra stops of light. This means that you underexpose your film, then compensate this lack of light by extending the developing time.

Why Would I Do This

If you are shooting in low light or need a faster shutter speed to freeze an action shot, this technique can be helpful.

Black & White film photographers are usually familiar with pushing film because most of them are processing their own film at home, and can adjust the developing time at their convenience.

On the other hand, pushing color negative film is not as common, simply because it requires manual development and most labs can’t (or won’t) do it because the machines they use are 100% automatic. It’s convenient for them because, when shot at box speed, all C-41 films require the same developing time regardless of their ISO rating.

But that’s not an issue anymore and, like B&W film, you can develop color film yourself too!

Before we get started, let me introduce our partner in crime: CineStill 800.

Initially, this was a film used to record motion picture, hence its legendary cinematic look from. The Brothers Wright later made this film usable in C-41 chemistry by removing a layer called “remjet”. This allows us (and labs) to develop it without ruining our chemicals.

It performs best when shot under tungsten lights (city lights) but you can also get great results in daylight by using an 85B filter to adjust the light temperature.

Another advantage of this film is that it can be pushed up to 3200 ISO, and that’s what interest us today.

These images were all shot at night when I was in Vienna for my birthday. I wanted to travel light so my tripod stayed at home and this was the perfect excuse to push CineStill to its limits. You may have guessed it already, but I used my Hasselblad Xpan and its loyal 45mm lens.

About the exposure. Usually, you want to expose for the shadows when shooting color film, but here it was impossible… there wasn’t enough light even at 3200 ISO. So instead, I exposed for the highlights and then added 1 or 2 stops when possible just to make sure that the darker areas wouldn’t be completely black.

Most of the photos were shot between f/4 or f/5.6 and 1/15 or 1/30 of a second.

Now, let’s talk about the home development process. I ordered a Tetenal Colortec C-41 kit that comes in the liquid version. It also exists in powder version, but I guess there are very similar in the end.

Basically, you get 3 solutions:

  • The Developer
  • The Bleach/Fixer (aka Blix)
  • The Stabilizer

Each of them has to be used at a specific temperature, which makes it slightly more challenging that developing B&W, but it’s not complicated at all.

On the instructions, you can read that development temperature should be either 30°C or 38°C. Today, we’ll go for the latter as this is the one suggested for pushing film. It says that developing time should be extended by 30 seconds for each stop (no need to extend the fixer or stabilizer time). Here, as the film was pushed by 2 stops, I should have added 1 extra minute on top of the 3 minutes 15 seconds recommended.

Thankfully, Paul from the Facebook group “CineStill Film Users” suggested adding 1 min 15 sec per stop to avoid having negatives too dark. I knew that my images would be very dark anyway, and was afraid to get too much color shifting by extending the developing time for too long, so I went for an average time and developed for 4 min 45 sec total.

The negatives still came out very dark, but I managed to get the grain contained and the colors represented accurately. Then I slightly increased the exposure in Lightroom by 0.5 or 1 stop just to bring back some details.

One last good point for CineStill is that it’s very easy to scan, and the colors look very good straight out of the scanner. That’s not the case with every color film, as you can see in this article where I show you how to correct color negatives scans.

This result are exciting to me. CineStill 800 is a fantastic film that helps to push the boundaries of color film photography in low light, and I will certainly reproduce this experience.

Also, just to be clear with you guys, by no means am I associated with or sponsored by CineStill for this article. I bought everything with my own money, like the grown up adult that I am ;) It’s just an honest opinion on a film that I admire for its characteristics.


About the author: Vincent Moschetti is an Ireland-based photographer who is in the middle of a year-long experiment where he’s shooting only film photography. You can find more of his work or follow along on this adventure by visiting his website or following him on Facebook and Instagram. This post was also published here.

This is Why Ultra High ISO is a Big Deal in Photography

Ultra high ISO with lots of noise… There’s a lot of buzz going around about the new Pentax KP with it’s maximum ISO of 819200. Every comment I read says ‘what’s the point’?

Well, here are two benefits: late night framing and focus.

I love taking landscape shots late at night, but that kind of photography comes with difficulties. It’s extremely hard to focus (your autofocus won’t work) and sometimes you can’t even see what’s in the frame.

My solution to this is to use ultra high ISO to check framing and focus before taking the ‘real’ shot. Here’s an example:

I was shooting a Gannet colony in New Zealand at a place called Muriwai. To capture these nesting birds in this light I needed a 60 second exposure at f/3.5, followed by a 60 second cool down time while my camera performed long shutter noise reduction. That meant 2 minutes for every image!… I’m patient, but I don’t want to wait 2 minutes to find out that I don’t like the composition or I’m out of focus. So I took 2 shots:

The first, at my Panasonic GX8′s maximum ISO of 25600 at 5 seconds just to check that I liked what was in the frame and that the lens was in focus.

Once I was happy with that I took the second image at a much more reasonable ISO 1800 for 60 seconds.

This has had some distortion correction and is ready to publish!


About the author: Charles Brooks is a photographer based in Auckland, New Zealand, who is internationally renowned for his commercial, portrait, and landscape photos. The opinions expressed in this article are solely those of the photographer. You can find more of his work and connect with him on his website, Tumblr, Twitter, Facebook, and Instagram. This article was also published here.

Is a Full Frame Camera Really Worth It? D610 vs D7100 Real World Test

Full Frame Comparison

Since I got my Nikon D7000 camera 6 years ago I’ve used it almost everyday. That is a lot of shutter clicks, 148,558 to be exact. It looks like I will be in the market for a new camera soon as the D7000 is only factory tested to 150,000 clicks. My dilemma is should I go full frame, or stick with my cropped frame?

I keep asking myself, is a full frame camera really worth it? I took a Nikon full frame D610 and a Nikon cropped frame D7100 on a test drive around Paris to see the real world differences.

What exactly is a “full frame” camera?

Film was the unchallenged king for a century and the most popular format was 35mm film. It was sometimes referred to as “small format” to differentiate it from “medium format” or “large format” cameras, but for most of us it was the standard film we used. Although called 35mm, it actually measured 36x24mm.

When they started making digital cameras they used a smaller sensor than their film counterparts, roughly 24x16mm, but the bodies still took advantage of the same 35mm lens. The smaller sensor size meant there was a part of the image that never made it to the smaller sensor. About a decade ago, developers in Japan decided to increase the size of their sensors to the equivalent of 35mm film and as a very cleaver marketing ploy, called them “full frame” renaming their current cameras as merely “cropped frame.”

Makes you feel like you’re missing out right? Lets take a look at some of the key differences.

Full Frame Comparison

Crop Factor

The first thing to understand is what is cropped on a cropped frame camera. A 35mm lens on a full frame camera will look wider and capture more image area than the same lens on a cropped frame camera. Basically, the optics of the two cameras work the same way, an image passes through all of the elements of glass in a lens, but when it hits the sensor, by having a smaller sensor in a cropped frame camera, only part of the image will make it to your sensor. The result will look as if you took a full frame image and then cropped in.

Using the same lens whilst shooting the Column at Bastille, I was able to make the angel larger in my shot in the cropped frame image. This extra zoom is great for wildlife or sports photographers.

D610 left, D7100 right.
D610 left, D7100 right.

ISO performance

To test out the high ISO performance I thought I would slip into the dark underbelly of Paris and visit the Catacombs. Flash and tripods are not permitted in the museum, and with only some low intensity lighting to illuminate the skulls of the over 6 million dead that lay rest there, it was the perfect testing ground.

I shot the two images with the same settings and changed the focal length to mimic the same field of view. From the offset, the D610 looks to have better ISO performance. The D7100 has a pink cast, especially in the shadows as a result of the noise of the image.

D610 left, D7100 right.
D610 left, D7100 right.

The enlargement below is from one of the shadow areas. The full frame is on the left and the cropped frame on the right. I brought up the shadow details and blacks in the processing (the same amount for both images) because grain really starts to look ugly when we do this and I wanted to push them to their limits to check the results.

Whilst they are close at normal exposure, by bringing them up like this you can see clearly that the full frame outperforms the cropped frame here.

Full Frame Comparison

Dynamic Range

Dynamic Rage is the amount of luminance that can be captured in an image. If a scene has bright whites and dark blacks, you want your camera to have a large enough dynamic range to capture both parts of your image without blowing out to pure white, or clipping to complete blacks.

I went down to Port de l’Arsenal for this test and I must admit they look incredibly similar. I feel the full frame image here is a little more contrasty. Looking at the windows and the side of the boat, and then looking at the shadows created by the trees I honestly get confused as to which camera is which.

D610 left, D7100 right.
D610 left, D7100 right.
D610 left, D7100 right.
D610 left, D7100 right.

Then I went into the heart of the Latin Quarter to the Pantheon. At first glance, I thought the same as the port. The full frame appeared to be more contrasty and the cropped image was flatter… unless I looked at the shadows of the column on the doors.

Whilst still very dark, you can still make out the detail of the patterns in the full frame image, whereas they are almost entirely black in the cropped version.

D610 left, D7100 right.
D610 left, D7100 right.
D610 left, D7100 right.
D610 left, D7100 right.

Full frame equivalent

We often hear that a 50mm lens on a full frame camera is the equivalent of a 75mm on a cropped lens. What we are talking about here is field of view.

Field of view of the 50mm on the cropped frame gives me 4 floors of this building in the Latin quarter. If I were to use a 50mm lens on the full frame, I would see the entire 6 floors of the building. So to get the same 4 floors, I need to use a 75mm on my full frame to get the equivalent field of view.

Left: D610 with 50mm f/1.8. Center: D610 with 70-100mm lens @ 75mm. Right: D7100 with 50mm f/1.8.
Left: D610 with 50mm f/1.8
Center: D610 with 70-100mm lens @ 75mm
Right: D7100 with 50mm f/1.8.

Whilst it has the equivalent field of view, a 50mm lens is still a 50mm lens on either camera. In this GIF below you can see the difference between lenses whilst shooting the same field of view. The full frame was shot with a 21mm lens, and the cropped frame with a 14mm lens. Both give the same field of view, but because of the nature of the lens, the 14mm on the full frame distorts the perspective more.

Does a full frame camera have better Depth of Field?

Yes and no. Technically, the depth of field between a full frame 50mm lens and a cropped frame 40mm lens should be identical, their field of view will differ as explained above. So, to get our foreground subject (which, in our example, is our coffee cup) to be the same size within the image we will need to either zoom in, or move closer to our subject.

If we zoom, we will be compressing the background (and the blur with it) making it look more blurry. If we move physically closer to our subject, we will shorten our focal distance and consequently decrease our depth of field.

Left: D610 with 24-70mm f/2.8 @ 34mm and f/5.6 Center: D610 with 24-70mm f/2.8 @ 55mm and f/5.6Right: D7100 with 24-70mm f/2.8 @ 36mm f/5.6.
Left: D610 with 24-70mm f/2.8 @ 34mm and f/5.6
Center: D610 with 24-70mm f/2.8 @ 55mm and f/5.6
Right: D7100 with 24-70mm f/2.8 @ 36mm f/5.6.

Availability of Lenses

Canon and Nikon both make lenses specific for cropped frame cameras. Nikon call theirs FX for full frame and DX for cropped. Canon EF and EF-S. Whilst full frame lens will work with both of the different formats, the cropped body lens won’t always work. They are specifically designed for the smaller sensor and therefore have a smaller area to cover. They consequently use less glass and are usually cheaper to manufacture and will weigh considerably less too.

You can mount a cropped frame lens on a full frame camera, but is it worth it? When you shoot your image, the centre of the image will look perfect, but at the edges you will find black fall off from the smaller lens at the edge of the barrel.

Nikon has a DX mode feature in their FX cameras that essentially just crops your image back to a DX sensor size. On Canon you will just need to crop the image yourself.

D610 with 18-55mm f/3.5 DX lens @ 18mm in FX mode.
D610 with 18-55mm f/3.5 DX lens @ 18mm in FX mode.

When you choose to operate this, way your full frame camera will basically become an expensive cropped frame camera and behave as such with everything else mentioned here. The drawback will be the reduction in megapixels.

The D610 has 24mp but only in FX mode. In the DX mode it will drop down to about 10mp. At this point you are far better off using the DX lens on the D7100 and taking full advantage of the 24mp.

D610 with 18-55mm f/3.5 DX lens @ 45mm in FX mode.
D610 with 18-55mm f/3.5 DX lens @ 45mm in FX mode.

The quality of full frame lenses will be better. Both Nikon and Canon don’t make “professional grade” lens in their cropped frame series. But they will be more expensive and heavier for their quality.

When choosing a lens you should really consider this. Even if you only have a cropped frame camera now, if you think you might upgrade one day or use it on a 35mm film camera, you might want lenses that will continue to be useful with your new camera rather than having to buy a new arsenal of lenses as well.

Is a ‘cropped’ image smaller?

Whilst the field of view is “cropped” there is no cropping of your actual image. Depending on your camera the physical image size might not be smaller at all. The image size is determined by the megapixels in a camera, not the physical sensor size.

So for our test, the 24mp D610 has 24mp, practically the same file dimensions as the 24mp D7100 camera, which, as you guessed, also has 24mp. If you wanted to print images from your camera, they would both be the same maximum size because the dimensions of your image in pixels between this full frame and cropped frame camera are the same.

Photo Credit: Margot Simonney with Nikon D700.
Photo Credit: Margot Simonney with Nikon D700.

So which format should you choose?

I really enjoyed running these tests and analyzing the results from the images around Paris. There were a few surprises in there for me. I expected the full frame camera to outperform the cropped frame hands down, but in reality the differences weren’t as large as I thought. It does appear that the full frame has won the competition, but at what cost? The selection of lens that work with the cropped frame camera is far greater, but the quality of them is far lower. Full frame bodies are by in large more expensive but even this is changing with new cropped frame cameras becoming more professional—it is really hard to make the justification I need to make the switch.

The cropped frame can zoom 1.5 times further, and when I was out shooting the fireworks at Bastille Day, the difference between a 200mm on a cropped frame camera and the same lens on a full frame camera really makes all the difference to my shot. But if you prefer wider for street photography, then maybe you prefer the 1.5 times wider side of your lens.

Joyeux Quatorze Juillet 2015 !

Whilst these two sensors we tested were pretty equally matched, I expect the new nikon D500 cropped frame camera will have a much better sensor than both of them and the results from that will outperform the full frame camera we used here in ISO and dynamic range. Sensors will continue to become better and ISO and dynamic range are both elements that have seen massive improvements. The first full frame cameras would have terrible ISO and dynamic range compared to the modern cropped frame cameras.

So, ultimately, this only leaves Depth of Field as an inherent change in the performance of the two formats. The rest comes down to what feels good in your hand. What other bells and whistles do you want with your camera? The cropped frame D500 offers 4K video whereas the full frame D610, which costs the same price, doesn’t. The D7100 performed remarkably against the D610 and it is half the price.

For now, I think I might keep the cropped format, and spend the extra money in some new higher quality lenses to really get the best from both worlds.


About the author: Alexander J.E. Bradley is the founder of Aperture Tours (formally Paris Photography Tours) and heads up the tours in Paris. A professional photographer for over a decade Alexander enjoys shooting the surreal by mixing dreamlike qualities into his conceptual images.

You can find more photos and articles like this on the Aperture Tours website, or by following Aperture Tours on Facebook, Twitter, and Instagram. This post was originally published here.

A Comprehensive Beginner’s Guide to Aperture, Shutter Speed, and ISO

pyramid

This guide to photographic exposure aims to help you take full control of your camera. I often tell my students that I want them to move away from the idea “taking a photograph” and towards the idea of “making a photograph.” I teach them how to take the camera off auto mode and take full control of the settings themselves in order to create the photograph they want.

Why let the camera decide these things for you? Do you let your mother choose your clothes? Maybe some of you do, I don’t know. Frankly, I don’t want to know.

I hope to do the same for the readers of this tutorial. I want you take control of your camera. In order to do this, it’s essential to understand the 3 components of what we call “The Exposure Triangle”. These are: aperture, shutter speed and ISO. By the end of this tutorial, you should understand what these 3 components are and how they affect the final photograph. You will also learn how to use the 3 main shooting modes on your camera: aperture priority, shutter priority and manual. Finally, I’ll explain how to decide which settings to choose as you prepare to shoot a scene.

What is exposure?

First of all we need to define what we mean by exposure. Exposure refers to the amount of light that enters the camera and hits the digital sensor. Basically, it is a measure of how dark or bright a photograph is.

If the image is too bright, it is overexposed. Too much light has been allowed to hit the sensor. If it is too dark, it is underexposed. Not enough light has been allowed to hit the sensor. We can control how much light reaches the sensor by changing the aperture, shutter speed and ISO settings.

Exposure is measured in ‘stops’. For example, if you find that your photo has turned out too dark (underexposed), you may increase your exposure by a ‘stop’ or two to make it brighter. Conversely, if the image is overexposed, you may need to decrease the exposure by a stop or two. There is no such thing as the ‘perfect’ exposure, only the right exposure for the photograph you are creating. Some photos such as night shots are supposed to be dark while photos taken in the snow for example are supposed to be bright.

Measuring exposure using a histogram

All digital cameras allow you to see a visual representation of exposure using the histogram. Check your camera’s manual to find out how to turn on the histogram feature. There was a member of my photography club who would tell all new members to RTFM. This stood for ‘Read the Manual’. I’ll let you figure out what the ‘f’ stood for yourself.

The histogram is a graph that represents the spread of tones in a photograph, from the shadows, to the mid tones to the highlights. It allows you to check if the photograph has any shadows that are too dark or ‘clipped’ and to see if you have any highlights that are too bright or ‘blown out’.

Clipped shadows are areas of pure black and contain no detail. Blown out highlights are areas of pure white and also contain no detail. Very generally speaking, you will want to avoid both of these. That said, I personally don’t mind a little clipping in the shadows as it adds punch to the image.

If you look at the histogram below, you will see that some of the graph is right up against the left hand axis of the graph. This means that some of the shadows are clipped. If you look at the right, you will see that a very tiny amount of highlights have been blown out as a very small part of the graph is up against the right hand edge. Sometimes this is unavoidable for example with street lights or if the sun in the frame. Remember, that the histogram is only a guide.

histogram

Examples of underexposed and overexposed photographs

Below we have examples of an underexposed photo, an overexposed photo and a correctly exposed photo.

under

Underexposed photograph: This photograph is underexposed by about 3 stops. You can see that the histogram is completely bunched up to the left as a result. There are lots of clipped shadows on the underside of the gondolas.

over

Overexposed photograph: This image is overexposed by about 3 stops and as you can see, the histogram is bunched up to the right as a result. There are a lot of clipped highlights is this photo. In fact, the entire sky is pure white and contains no detail whatsoever.

correct

Correctly exposed photograph: The photo above has the right exposure for the scene in question. You can see on the histogram that there is a good spread of shadows, mid-tones and highlights. It’s quite a bright image as you can see from the fact that the graph spikes on the right of the graph.

There is a little clipping in the shadows which I don’t mind as it adds some punch to the shot. As you can see from the right hand side of the graph, there are some very bright areas but the highlights are not blown out.

Using the highlights warning feature on your camera

It’s always a good idea to check the histogram after you’ve taken a shot in order to prevent too many clipped shadows and blown out highlights. Most digital cameras also have a ‘highlight warning’ feature.

This makes areas of the image that have blown highlights flash on your screen. It’s an incredibly useful feature and I keep it turned on all the time. Below, you can see how the highlight warning looks on the overexposed gondola photo. A huge amount of the photo is flashing because so many of the highlights have been blown out.

What is aperture?

lens-aperture

The aperture refers to the size of the opening in the lens through which the light enters the camera. The size of this opening can be adjusted and the aperture size is measured in f-stops. The image on the right shows you exactly what the aperture on a lens looks like.

When you change the f-stop value, you change the size of the opening. Here’s the weird thing though. The higher the f-stop, the smaller the opening.

Take a look at the chart below to see what different apertures look like at different f-stops. On the far left, you can see that setting an aperture of f16 will result in a small opening. Choosing an aperture of f1.4 will result in a very wide opening.

aperture-chart

How does your choice of aperture affect the photograph?

The most noticeable effect your choice of aperture has on the photograph is the depth of field. What do we mean by this exactly? In very simple terms, depth of field refers to the amount of the image that is sharp. What does this mean in practice?

If you use a wide aperture, the depth of field will be shallow. Only part of the image is sharp and the rest will be out of focus or blurred. Look at the picture on the left below. The cat is perfectly sharp but the background is blurred. Using a wide aperture works well for portrait style photographs as it makes the subject of the shot really stand out against the blurred background.

depth-of-field-diagram

In this case, the depth of field extends from about the tip of the cat’s nose to just behind its head, no more than a few centimeters (from point A to point B in the diagram). Anything not in this range, either in front of it or behind will not be sharp. For this shot, I used a wide aperture of f/3.5.

OLYMPUS DIGITAL CAMERA

When you use a narrow aperture, the depth of field is deep. When the depth of field is deep, all of the photograph from foreground to background is sharp.

Take a look at the photo below taken in the Dublin Docklands. Everything from the dock cleat in the foreground to the bridge in the background is sharp. In this case the depth of field is several hundred metres, extending right from the foreground to the background of the scene. In this case, I used a narrower aperture of f/11.

samuel-beckett-bridge-at-sunset-dublin

Most of the time, we want to achieve a deep depth of field when shooting landscapes. We want all of the image to be pin sharp.

The mid range apertures (around f/8) are good for shooting handheld for example when doing street photography. You get a good balance between having enough depth of field and fast enough shutter speeds to shoot hand held. We’ll discuss shutter speeds in more detail later.

The chart below gives you a good idea how different apertures will affect the depth of field in your photographs. You can see that as the aperture gets wider, the pyramid in the background becomes more blurred.

aperture-effect-chart-2

What is shutter speed?

The shutter speed refers to the length of time the opening in the lens remains open to let light into the camera and onto the sensor. The shutter speed can be as fast as 1/10,000 of a second or as slow as several minutes.

How does your choice of shutter speed affect the photograph?

Fast shutter speeds have the effect of freezing motion in the scene you are photographing. Conversely, slow shutter speeds will blur motion in a scene. Both of these can be used to great creative effect.

The shutter speed settings on your camera provide a great way to experiment with capturing motion in your landscape photography. This is especially the case with moving water.

OLYMPUS DIGITAL CAMERA

fishing-boat-at-sunset-tunisia

By using a slow shutter speed (1/2 second), we can blur the water in a waterfall for example and create a sense of motion even though it’s a still image. You can see this in this photo of a waterfall in Ireland above. When working with slow shutter speeds, it is essential to use a tripod otherwise camera shake will result in a completely blurred photo.

In the second photograph taken in Tunisia, I used an extremely long shutter speed of 160 seconds. To achieve this, I used a 10 stop neutral density filter. This reduced the light entering the camera down to 1/1000th of what it would be without the filter. This, in turn, allowed me to set such a long exposure time.

As you can see, the clouds moved across the sky during the almost 3 minutes it took to take the photo resulting in the blurred effect.

You can also use fast shutter speeds to freeze motion like in this black and white seascape below.

atlantic-coast-donegal-ireland

For this photograph, I wanted to freeze the motion of the waves crashing against the shore. A fast shutter speed of 1/320th of a second ensured that the wave seems to ‘freeze’ in time. Landscapes that include moving water afford great opportunities to experiment with different exposure times.

The chart below shows how different shutter speeds would effect the sense of motion if you were photographing a person running. Fast shutter speeds will freeze the motion. This technique is often used in sports photography. The slower the shutter speed becomes, the more blurred the person running becomes in the photograph.

shutter-speed-effect-chart

How do you know if your shutter speed is fast enough to shoot handheld?

There is a very simple trick to check if your shutter speed is fast enough to shoot hand held. Simply look at the focal length you have zoomed in to on the lens.

On the lens below, the focal length is set at about 30mm. In this case I simply multiply the focal length by 2 and divide it into 1 to get the minimum shutter speed required to shoot hand held. So, 30 x 2 is 60 therefore the minimum shutter speed required to shoot hand held is 1/60 of a second.

camera-lens-focal-length

This means that you can get away with using slower shutter speeds when the angle is wider. It’s obviously harder to keep the camera steady when zooming in. Think of how difficult it is to keep your sights on an object when using binoculars. It’s the same principle.

If you find that the light is low and you can’t get a fast enough shutter speed, you can increase the ISO. In the next section, I’ll explain what ISO is and how it effects the photograph.

What is ISO?

The ISO refers to how sensitive the digital sensor in your camera is to light. The lower the ISO number, the less sensitive it is to light. Setting a higher ISO number increases the sensitivity of your camera sensor to light. Most cameras have ISOs ranging from about 50 or 100 ISO right up to 16,000 ISO or higher.

How does your choice of ISO affect the photograph?

As you increase the ISO value, your camera sensor becomes more sensitive to light. This means that you can achieve higher shutter speeds. This can be extremely useful when shooting in low light without a tripod. You may find that shooting at 100 ISO results in shutter speeds that are too slow to hand hold without camera shake. By increasing the ISO to 800 ISO for example, you may find that your shutter speed is now fast enough to hand hold.

You may be wondering: why not just use a really high ISO every time to ensure a sharp photo? The problem is that there is a trade off when it comes to image quality. The higher the ISO used, the more digital noise will be present in the image. Digital noise results in a graininess that can have a negative effect on image quality. Take a look at the labels of this bottle of wine shot at different ISOs.

The first one was shot at 100 ISO.

iso100

The second photo was shot at a very high ISO 3200. You can see that the graininess has degraded the image quality quite a lot.

iso3200

When I finished taking these shots of the bottle of wine, I of course sampled the contents. I… eh… wanted to learn about French culture. Funnily enough, after I finished the bottle, the image quality from my own eyes degraded somewhat.

The chart below illustrates the effect of ISO on image quality.

iso-effect-chart-1

This does not mean that you should not increase your ISO when the need arises. The example of ISO 3200 above is quite extreme. Most of the newer cameras actually handle higher ISOs very well and retain high image quality. I know that in low light conditions, I prefer to increase my ISO a little to avoid camera shake even it it means a little graininess. It’s usually not enough to seriously degrade the image quality though.

Next, we’re going to take a look at how to actually set the aperture and shutter speed in your camera. There are 3 modes you can use: aperture priority, shutter priority and manual.

How to use Aperture Priority Mode on your camera

aperture-priority

Aperture priority mode is a semi-manual mode. When using this mode, you choose the aperture you want and the camera chooses an appropriate shutter speed in order to achieve a correctly exposed photo. To switch your camera to aperture priority, turn the dial on top of your camera to ‘A’.

This is actually the shooting mode I use 90% of the time when shooting urban landscapes. I usually choose an aperture of around f16 to ensure maximum depth of field and then let the camera choose the correct shutter speed. As I usually use a tripod, I am generally not too concerned about the shutter speed being too slow.

If I am shooting hand held, I always keep an eye on the shutter speed the camera has chosen just to make sure it isn’t too slow. If it is too slow, I use a wider aperture which will give a faster shutter speed as the opening is larger and lets the light in faster. I also have the option of increasing the ISO to get a faster shutter speed.

How to use Shutter Priority Mode on your camera

shutter-priority

Shutter priority is basically the opposite to aperture priority. You set the shutter speed you want and the camera sets the aperture. To switch your camera to shutter priority, turn the dial on top of your camera to ‘S’. On Canon models, this mode is actually called “Tv” mode which stands for “time value”.

I personally don’t use this mode too often. It can be useful if you need to set a minimum shutter speed in order to avoid camera shake. You may also want a specific longer shutter speed in order to create motion blur. I tend to use manual mode in this case as it gives me greater control over the shutter speed and aperture together. More on manual mode later.

How to use the Exposure Compensation feature on your camera

exposure-compensation-button

Sometimes when you use aperture or shutter priority modes, you may find that your images are too bright or too dark. Sometimes the lighting conditions may confuse the camera and it results in the image being underexposed or overexposed. Thankfully, there is a way of fixing this. It’s called exposure compensation. To switch this on, press the button with the plus/minus symbols.

This will bring up a chart that goes from -5 to +5. Sometimes these numbers are different and may only range from -3 to +3 depending on the camera. This chart represents the exposure of your photograph. So how does it work?

When you are using aperture priority mode for example, the camera will set a shutter speed that makes the camera expose at the “0” point of this chart, right in the middle. In theory, this should be the correct exposure. In reality though, this is not always the case. As we said, some photos are supposed to be bright and others are supposed to be dark.

If you find that your photo is too bright or overexposed, you simply dial down the exposure by a stop or whatever you think is needed. When you turn the dial to the left (RTFM to see which dial), you can set the exposure at -1 for example. This will make the photograph 1 stop darker. When you turn the dial to the right, you can make the photo brighter. You may need to experiment a little to get the exposure you want.

exposure-compensation

How does exposure compensation work exactly? If you are using aperture priority mode and dial the exposure down 2 stops for example, the aperture will stay the same but the shutter speed will change to a faster speed so that less light enters the camera and the picture is made darker.

The opposite happens when you dial up the exposure. The aperture stays the same but the shutter speed will get longer to let more light in and make the image brighter. As already mentioned, keep an eye on the shutter speed if you are shooting hand held. Don’t allow it to become too slow in order to avoid camera shake.

Exposure compensation works in the same way when using shutter priority mode except that the shutter speed will stay the same and the aperture will be changed by the camera accordingly.

How to use Manual Mode on your camera

manual-mode

Here comes the scary one: manual mode! When you set the camera to manual mode, you set both the aperture and shutter speed. How do you know what combination to use to ensure the right exposure? It’s actually quite easy. When you switch to manual mode on the dial (M), you again see an exposure chart that is exactly the same as the exposure compensation chart.

You then turn the aperture and shutter speed dials until the exposure is set to 0. Check your manual to see which dials to use.

Here is an example of how I might use manual mode when shooting a landscape:

  1. I decide what aperture I want to use. If it’s a landscape, I might pick an aperture of about f/16 to ensure plenty of depth of field. After all, I want everything to be sharp from the foreground to the background. I turn the aperture dial until, the aperture is set to f/16.
  2. I then turn the shutter speed dial until the marker on the exposure chart is at zero. This in theory should mean that I now have the correct combination of aperture and shutter speed to ensure the right exposure.
  3. I then check that I am happy with both the aperture and shutter speed and make some adjustments if necessary.
  4. If I find that the shot is too bright or too dark I retake it after moving the dial to either minus a stop or plus a stop (or more as the case may be). The ‘right’ exposure may not always be at the “0” point in the middle. As I have said a few times now, some photos are supposed to be bright or dark.

How do I decide which settings to use in manual mode?

This is where your own creativity comes in to play. I usually decide which is the most important element in the photo and set this first.

As I mainly shoot urban landscape photos, this means I usually set the aperture first as ensuring plenty of depth of field is my biggest concern. I then set the shutter speed. It’s basically a balancing act and with practice you will gain an intuition for what settings you need to achieve the vision you have for a particular photograph.

What if the highlights are blown out or the shadows are clipped no matter what settings I use?

Sometimes the contrast in a scene is simply too much for your camera to handle no matter which combination of aperture and shutter speed you use. In this case, bracketing can be used to solve the problem.

When I bracket a photo, I usually take 3 photos of the same scene, one with the exposure set to “0”, another deliberately underexposed by 2 stops and a final one deliberately overexposed by 2 stops. I can then combine these these in post-processing to get the ‘perfect’ exposure. There are several methods of doing this which I will cover in a future tutorial.

In the example below, I took 3 exposures of the Charles Bridge in Prague and blended them in post production to produce a single photograph with plenty of detail in all areas of the frame.

exposurebracketing

exposure-blending-example

The final photograph is a blend of all 3 images, leading to plenty of detail throughout the image. There are also no clipped shadows or blown out highlights. As you can see, I also cropped the final image to create a better composition.


I hope that after reading this tutorial that you will be confident to take your camera off auto mode and take control of the settings yourself. In this way, you can move from merely taking a photography to making a photograph. Don’t be afraid to experiment with all of the settings you have just learnt about. Over time, you won’t even have to think too much about the settings.

I often advise students to go on a photo shoot where they specifically experiment with different apertures, another to experiment with shutter speed and so on.


About the author: Barry O Carroll is a Dublin, Ireland-based photographer specializing in landscape photography with a particular emphasis on urban landscapes, street scenes and architecture photography. You can find more of his work on his website or by following him on Facebook and Twitter. This article was also published here.

Here’s How the Sony a7S II Compares to the Human Eye in Low Light

The Sony a7S II is known to have amazing performance in low light and at high ISO. To see just how powerful its low light capabilities are, a Greek photographer who goes by Boji decided to do a casual test that pits the camera against the human eye. You can see the comparison in the 48-second video above.

Boji says he was searching for dark places to test the camera’s high ISO performance but couldn’t find any place dark enough to challenge the camera.

The test was based on what he could see with his own eyes — Boji adjusted his cameras settings until the resulting footage roughly matched what he was seeing while looking around in the locations. For the “camera’s view,” he shot at between ISO 64,000 and ISO 256,000 (without any noise reduction added in post).

compare1

compare2

“The only thing I know for sure is how much more than me the camera can see in the darkness,” Boji says.

(via VideoArt GR via sonyalpharumors)