By now you have probably heard of the Nikon D750 issue that some describe as “flare” or “internal reflection issue”. Thanks to some websites and forums, the issue is now blown out of proportion, with some people claiming the D750 to be another “fiasco” from Nikon. Since many of our readers have been requesting feedback from me regarding the issue, I decided to write an article that describes the issue in detail, along with my opinion on the matter. The thing is, I have known about this particular problem for a while now, probably after the very first complaints started rolling in a few months ago. I never wrote about it, because I consider it to be a non-issue for 99.9% of situations and not even applicable for most photographers out there, which is why I never wrote about it. At the same time, I understand there might be concerns from current and future owners of the D750, who are probably wondering about the severity of the problem. In this article, I will show you what the issue looks like, when it occurs and provide my personal feedback on the matter.
Since neither “flare”, nor “internal reflection” correctly describe the issue (as shown below), I went ahead with “flare shading issue” title instead.
UPDATE: Nikon will be servicing all affected Nikon D750 cameras free of charge. See this announcement for more details.
Nikon D750 Flare Shading Issue: What is it?
So what’s all the fuss about? Before I explain the issue, let’s take a look at the following image captured with the Nikon D750:
See that line on the top right side of the frame? That’s basically the problem. Since the issue is caused due to an internal component within the camera chamber blocking portion of the flare that is reflected from the phase detection sensor from reaching the sensor, there is a defined line that can look distracting in photos.
How to Reproduce the Issue
To reproduce the issue, you have to fire up live view (since you won’t see it in the viewfinder as explained above), then find a bright source of light, then angle the camera down a bit, placing the light source above the frame (angle the camera up and down and you will probably see it). At a particular angle, when the light source is hitting the front of the lens from above, you might see a line separating flare as shown in the first image.
Unlike regular lens flare, which you will typically see in the viewfinder, this particular problem will only show up after you take a picture, just like the common red dot flare issue. Although manufacturers do everything they can to prevent light from reflecting inside the camera chamber, light does end up bouncing off a number of different components, whether it is the phase detection sensor, small metal components or the sensor itself. But since those reflections never show up in most images and can only be seen in rare situations when shooting against a bright light source at an oblique angle, manufactures do not bother trying to shield cameras from every possible reflection. The big source of additional flare that every DSLR has is the phase detection sensor. Since it is covered with glass, light ends up bouncing off of it and eventually ends up in images. You might not have been aware of this, but when you shoot against a very bright source of light at particular angles, you might have previously seen it. Take a look at the below images from Nikon D7100 and Canon 7D Mark II, which clearly show the separating line:
That line you see that separates the brighter part of the image from the darker side is the typical flare shading one will see on most DSLRs. Portion of the light is reflected off the phase detection sensor (brighter) and the other portion is not (darker), which is why there is that line that separates the two. How extreme this is depends on a number of factors and one of them is the proximity of phase detection sensors to the bottom surface of the camera chamber. In the case of the D750, those sensors happen to be a bit closer than usual on some units. Why do we only see this problem on the top of the frame? Because light rays are inverted to form an image – the bottom part of the sensor is the top (see this article for more info). And the bottom of the chamber is where the phase detection sensor is located, as illustrated in the below image:
When testing for the shading issue, I compared my Nikon D800E and D810 cameras to the D750. Both showed shading as illustrated below, but the first defined line was not there. And here is the reason why:
I captured both camera chamber bottoms at the same angle. You can see the glass surface of the three areas of the phase detection sensor on the D750 pretty clearly, while the D800E has those located a bit lower in comparison. I suspect that the shading is happening because of this, but there could also be other reasons as well.
Flare / Internal Reflections vs Shading
Please note that the D750 is not the source of lens flare. Flare is a very normal fact of life in lenses and the D750 is not what causes flare to show up in images. This particular issue has nothing to do with lens flare or the additional flare that phase detection sensors generally cause – it is the shading of flare that seems to bother some people.
Issue Severity and Concerns
All right, now let’s get to the real reason why I have not posted anything on this issue so far. The thing is, in most situations and for most people, flare shading is not a problem, so let’s start there. What is the likelihood that you will be shooting at this particular angle against the sun or another bright source of light above your image frame? Looking at my images, I do not find many. When I shoot against a bright source of light, I usually include it in the frame. So if you do landscape photography and love showing off those beautiful sun stars, you do not need to be concerned – you will never see the above problem.
The only case where there could be a problem, is if you shoot in mid-day sun and deliberately decide to use flare as an “effect” in your photos. And even then, it is unlikely that you will come across this particular issue. Like I said, it only happens at certain angles. Also, how bad that line shows depends on the lens and its focal length – some lenses deal with flare better than others and longer focal length lenses are usually worst performers when it comes to handling flare. The first image in this article was shot with a 50mm lens and the effect is somewhat subtle, while the below examples shot with an 85mm lens show significantly more shading.
Next, this particular shading issue is not isolated to the D750. In fact, if you were to look at every DSLR out there, you will probably come across camera bodies that will have similar issue. Take a look at the below images from the D750, D810 and Df that were shot with the same 85mm lens at the same angle:
As you can see, all three show one large shading separation, but both D750 and Df show the other smaller one too. Df is not as extreme in comparison, but the line is definitely there. I remember my D700 showed shading as well and I think it was pretty close to what the D750 shows above.
Hence, additional flare due to phase detection sensors and flare shading are not a new problem – those have always been there on all DSLRs, with some being worse than others.
I have already said it in my detailed Nikon D750 review and I will say it again: the D750 is an amazing camera. Whether some units have this particular issue or not will not matter for most people and most situations, so do not get overly concerned about it. When Nikon deserved negative attention, whether it was for the D800 AF issues or the D600 dust issues, we at Photography Life wrote about those extensively, hoping for Nikon’s response and action. But in the case of the D750, I personally do not consider the flare shading issue to be worthy of a recall or service advisory. Use lens hoods and do not shoot in mid-day sun at weird angles that cause this shading effect. If you see it in your photo, just recompose the image slightly and you will be set. Chances are, your photo will not look good at that particular angle anyway, due to so many internal lens and camera reflections. Above all, enjoy the process of taking pictures and keep on clicking, instead of spending your valuable time reading up on such issues on the Internet, where things are known to quickly get too much attention…