As with all things photographic there tends to be differences of opinion and the occasional hard-edged viewpoint that people bring to on-line discussions. Shooting in low light is one such subject. Many folks have a strong belief that if you shoot in low light you must use a full frame camera to get good results. Period.

But… is this actually true?

Note: Click on images to enlarge

Of course in situations where a tripod is used any camera, regardless of its sensor size, will operate at its optimal since the lowest possible ISO can be used. Shutter speed and aperture can then be adjusted to achieve the best possible exposure and composition in terms of depth-of-field. So, let’s take tripod shooting off the table and focus on situations where a photographer is forced to shoot hand-held in lower light conditions, and is using a smaller sensor camera like a M4/3 or the Nikon 1 CX format.

If we simply look at sensor test data there is absolute truth to the notion that full frame sensors are better than smaller sized sensors when shooting in low light conditions. Dynamic range and colour depth are both higher. And, the key point for many photographers is that digital noise is much better controlled as higher ISO’s are used.

All we need to do is examine sensor test data on the DxOMark web site to see the facts in black and white. A camera like my Nikon 1 V2 has a ‘sports score’ (i.e. the low light score) on DxO of 403 ISO while a camera like the Nikon D750 scores 2956 ISO. There’s nothing to debate – facts are simply facts. The D750’s sensor scores almost 3 stops better than the sensor in my Nikon 1 V2. And, it is also true that smaller sized sensors ‘top out’ at much lower ISO values than do their full frame brothers. For example, my Nikon 1 V2 doesn’t even have an option to shoot higher than ISO-6400.

So, all things being equal with the exposure triangle – there’s no doubt that a full frame camera will blow the doors off of a small sensor camera like my Nikon 1 V2 when it comes to shooting at higher ISO’s.

What we often overlook with these types of discussions are some practical, everyday shooting considerations. As I illustrated in an earlier article there are some very practical depth-of-field advantages when shooting with a smaller sensor camera system like the Nikon 1.

This difference changes one of the factors in the exposure triangle in terms of aperture setting. Someone using Nikon 1 system gear can create a similar image to someone using full frame gear by using a more wide open aperture and this could allow them to shoot at a lower ISO than the full frame shooter. Obviously this could come in handy when shooting in lower light situations.

Of course, this assumes that the Nikon 1 shooter has an appropriate native CX lens that can be used in that specific situation. While the Nikon 1 lens family is growing there are still a number of gaps that owners need to work around as best they can.

Owners of M4/3 cameras have a better selection of fast prime and zoom lenses available to them. They are currently in a better position to use a more wide open aperture to help reduce the ISO’s at which they shoot, while still achieving their desired depth-of-field when compared to using a full frame camera.

For example, GH4 owners have two very good Panasonic f/2.8 constant aperture zooms available (12-35 mm and 35-100 mm).

Let’s assume that a photographer was using a Nikon D750 full frame camera with a 70-200 mm f/2.8 constant aperture zoom, and was shooting at f/5.6, 1/200, ISO-3200, at 200 mm in order to achieve their desired depth-of-field, exposure and image framing.

Faced with exactly the same lighting conditions, distance from subject, desired field-of-view and depth-of-field, a GH4 owner could shoot at 100 mm at f/2.8, 1/200 and only have to use ISO-800 to get their image. This is because the aperture they are using is 2-stops faster than the one being used by the D750 owner. Since the GH4’s low light score is 791 ISO and the D750’s is 2958 ISO (as rated by DxO) both set-ups would likely produce very similar levels of noise in the images each camera produced under identical low light conditions.

When shooting with a smaller sensor camera it is important to remember that the sensor crop factor can allow us to shoot at more wide open apertures when compared to photographers using full frame gear and that may allow us to use a lower ISO while still getting the desired depth-of-field and framing in our images. This is due to the fact that smaller sensor camera systems can use shorter focal length lenses to achieve the same field-of-view as full frame cameras. And, shorter focal length lenses have deeper depth-of-field characteristics regardless of the sensor size on the camera on which they are used.

Another very important consideration when shooting in lower light conditions is the size and weight of various camera systems and how that can potentially impact a photographer’s ability to effectively shoot hand-held. In the next portion of this article let’s have a look at some hand-held test images.

Some M4/3 cameras (like the GH4) and lenses are not that much smaller than cropped sensor DSLRs and since I haven’t shot very much with M4/3 gear my comments in this section are based on my experience shooting with the Nikon 1 system.

When facing low light situations a photographer’s ability to shoot at slow shutter speeds while using a smaller and lighter camera system can be a distinct advantage and can allow the photographer to shoot at lower ISO’s. This is especially true when photographing static subjects. In order to demonstrate this functionality I did a number of hand-held test images while sitting at my desk. I kept my elbows tucked into my chest and took three images each at various shutter speeds. What you’ll see in the following portion of the article is the best image I captured from each set of three test images.

As you look at these images it is important to remember the rule of reciprocity in photography. While fairly technical in nature the basic thing to remember is to maintain an appropriate minimum shutter speed based on the focal length of the lens with which you are shooting. If you’re using a 400 mm lens the minimum shutter speed is 1/400th. A 200 mm lens would require a minimum of 1/200th and so on. This does NOT include the effects of vibration reduction or image stabilization that may be in your lens or camera body.

When you read that the VR on a particular lens provides a 3-stop advantage it simply means that the lens can be shot hand-held at a shutter speed equivalent to 3 stops of light slower. For example a 400 mm lens would have a minimum recommended shutter speed of 1/400th. If it has VR that provides a 3-stop advantage that lens should be able to be shot hand-held at 1/50th of a second (1/400 / 2 = 1/200 /2 = 1/100 / 2 = 1/50).

Some folks recommend that you apply the crop factor to your lens to determine the minimum shutter speed at which you should shoot when using lenses designed for smaller sensor cameras. I do not agree with this advice at all and will try to demonstrate this with the test images.

Let’s start with some images taken with a Nikon 1 32 mm f/1.2 lens which does not have VR. All images were taken at ISO-200 in aperture priority. Here is the first image taken at f/1.2 1/80…as would be expected it is decently sharp.

Now let’s look at the next one taken at f/1.8 1/40…still pretty sharp.

Now f/2 1/30…still holding (all three test images at this speed were identical).

Here’s f/2.8 at 1/15…we’re still hanging in there (2 of 3 at this speed were identical, 1 a bit soft).

Now f/4 at 1/8…at this point I’m starting to lose it.

Pushing it further at f/5.6 at 1/4 second…the best of three attempts and not very good.

And, finally the best of three attempts at f/8 at 1/2 second…pretty bad.

The important point in all of this is the fact that smaller sensor cameras and their system lenses are much easier to shoot hand-held at slower shutter speeds when compared to full frame gear. Obviously you have to adjust your hand-holding technique quite a bit, especially your finger movement on the shutter.

The Nikon 1 32 mm f/1.2 has an equivalent field-of-view of 86 mm when compared to full frame. I can tell you from personal experience there is absolutely no way that I could have hand-held my Nikkor 85 mm f/1.8 when mounted on my D800 and got anything sharp at 1/30th of a second…and not even remotely close to sharp at 1/15th of a second.

Regardless of what else you may read… a 32 mm lens is always a 32 mm lens in my opinion. I do not believe that you need to apply any kind of crop factor to it to estimate the minimum shutter speed at which you should be able to shoot with it hand held. That’s why I was able to get 3 out of 3 usable images at 1/30 of a second and 2 out of 3 usable images at 1/15 even though the lens does not have VR.

No doubt some folks will disagree with my view on this point. I just base it on what I routinely experience first hand day in and day out when shooting with Nikon 1 cameras. It has been this way since the first day I started shooting with them. Perhaps this is one of those situations where there is a disconnect between photography theory and the real world.

Now let’s look at a few test shots using some Nikon 1 zoom lenses. Again, all images were shot at ISO-200. The first image was taken with a Nikon 1 30-110 f/3.8-5.6 VR lens. This has an equivalent field-of-view of 297 mm when compared to a full frame camera. But remember… it is still only a 110 mm lens and shoots like one in terms of minimum hand-holding shutter speed. This first image was taken at f/5.6, 1/4 second with the lens fully extended to 110 mm.

Hmmm… that looks like about a 4-stop advantage for the VR on that lens. Let’s look at another shot with the same lens fully extended, this time shot at f/8 at 1/2 second…

Let’s think about this for a moment… the 30-110 mm provides an equivalent field-of-view of about 300 mm. If I was shooting with a 300 mm full frame lens with VR that had a 4-stop advantage on a full frame body I’d be able to shoot at about 1/20th of a second best case. Going from 1/20th down to 1/4 of a second is about a 2-stop advantage for the 30-110 mm CX lens. Depending on the situation that could make the difference in shooting at ISO-400 rather than at ISO-1600 with full frame gear.

Now lets look at two test images taken hand-held with the Nikon 1 CX 70-300 f/4.5-5.6 fully extended to 300 mm. Remember, this lens has an equivalent field-of-view of 810 mm but it is still only a 300 mm lens and shoots like one… this image was taken at f/5.6 at 1/10th of a second.

That looks like about a 5-stop advantage from the VR. Same lens, fully extended shot at f/8 at 1/5th of a second…

Now imagine trying to shoot at these shutter speeds with a 70-300 FX lens on a large full frame body, or even worse an 800 mm FX lens!

How slow could someone shoot an 800 mm FX lens hand-held? I have no idea since I’ve never tried it. VR good for a 4-stop advantage could bring the shutter speed down to maybe 1/50th of a second…again about a 2-stop advantage for the CX lens. And, even if a full frame user could shoot the FX 800 mm at 1/50th could they carry it around all day shooting hand-held like a person can with a V2/CX 70-300 combination? Perhaps…if their parents were gorillas.

When people talk about smaller sensor camera systems being smaller and lighter they are often only referring to their physical properties and how much easier they are to carry around, especially on holidays. The real benefit of the smaller size and weight is a photographer’s ability to shoot this gear hand-held at much slower shutter speeds. This is another important way that you can combat shooting in lower light situations.

Obviously there will be times when a full frame camera will still blow the doors off a smaller sensor camera system… such as fast moving sports in low light. When a faster shutter speed is more important than depth-of-field a full frame camera and lens will typically win out over smaller sensor camera systems when shooting in lower light conditions.

Where smaller sensor camera systems can compete more effectively in lower light conditions is when photographing subjects that are more static.

To get the most from your smaller sensor camera system use its strengths to your advantage! The deeper depth-of-field performance that comes from being able to use shorter focal length lenses to get equivalent fields-of-view, and the improved hand-holding performance that comes from its smaller size and lighter weight. When you do you’ll find that you’ll be much more successful shooting in low light situations.

The final factor to consider when shooting a smaller sensor camera system in lower light situations is the noise reduction software you use. Shoot in RAW and learn how to apply noise reduction the best you possibly can given the software you are using. It will pay big dividends in the final look of your images.

Article and all images Copyright Thomas Stirr. All rights reserved. No use, duplication of any kind, or adaptation is allowed without written consent.