While working hard on reviewing the Nikon D810 DSLR, we are doing our best to continue providing detailed coverage about the camera and its capabilities to our readers. Although we have been very happy with the improvements we see on the D810 (which does deserve high praises for its overall performance), we have identified one issue that probably needs Nikon’s attention sooner than later – the D810 seems to have a thermal noise issue when shooting very long exposures. In certain conditions, the camera seems to be produce very fine grain at low ISOs (even base ISO) that should not be there. Although most photographers probably will not notice it, those that photograph the night sky, architecture, waterfalls and seashores at exposures longer than 20 seconds surely will. The grain appears to be of different color and spread, which means that what we see in images are essentially hot pixels. Please note that these hot pixels are not of the same permanent kind discussed in this article – these hot pixels appear as a result of heat and they appear in different locations of the frame. Although such “thermal” pixels are very common in digital camera sensors and are supposed to show up when shooting long exposures, camera manufacturers usually clean them up, whether you shoot in RAW or JPEG format. This clean up happens in the image processing pipeline, before RAW and JPEG files are generated.
Here is what the Nikon D810 can potentially look like when compared to the Nikon D800E:
Click the above image to see a larger version. Please note that we exaggerated the effect by dialing +50 Clarity and +50 Sharpness in Lightroom. And it is definitely not the RAW processor that’s doing it – the same effect can be observed when looking at the RAW file in Capture NX-D. Both images above were shot at ISO 100, f/8, 30 second exposure. We dialed +2 EV in Lightroom to show a shadow area that clearly demonstrated this problem.
How widespread is this issue?
We did not want to publish this article until we confirmed that several units were tested and the issue was confirmed on every unit. We initially had access to 2 Nikon D810 DSLRs, both of which showed the same problem and yesterday we were able to get a sample image out of a third unit, which was also affected. A few other individuals that recently purchased the D810 also reported the same issue. So far it looks like all Nikon D810 DSLRs are affected.
Is it a manufacturing defect / physical problem?
No, it does not appear to be. Nikon probably missed something in the code that is supposed to clean up the thermal noise in images at long exposures.
Can a firmware update fix the thermal noise issue?
Yes, we strongly believe that a firmware update can fix this particular problem. As stated above, this was probably just an oversight on behalf of Nikon, so the next firmware update should take care of it.
Has this problem been reported to Nikon?
Yes, our team at Photography Life has already reached out to Nikon USA and reported this problem. A trouble ticket has been opened and we are awaiting a reply.
How can one reproduce this issue?
Turn off Long Exposure Noise Reduction by going to Shooting Menu -> Long Exposure NR -> OFF. Take a long exposure of 20-30 seconds at ISO 64 or 100 of a dark subject in RAW format. Import the image into Lightroom or Nikon Capture NX-D. Find a dark / shadow area and recover some shadow details (+2 EV or +100 in Shadow slider will do). Adjust the Clarity slider to +50 and increase Sharpness levels. Look at the shadow area at pixel level (100% zoom). You should notice spots of different colors, as demonstrated above.
How can noise be addressed now?
Turning Long Exposure Noise Reduction ON definitely helps a great deal with removing the noise. If you need to have noise-free images, you will have to use this feature for now. Unfortunately, this may not be a solution for time lapse photographers, as they will have to wait for the camera to complete its noise reduction process after each shot. Plus, it will drain the battery quicker…
How you can help
If you have a Nikon D810, we would love to get more feedback from you! Please try the above test and report your findings below. We would like to find out if all D810 units are affected, or only a small batch. This could be very useful data to report to Nikon, so that its engineering team can address the issue as soon as possible.