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ISO Performance: Part II

The D800 is no slouch when shooting at higher ISO values, and when downsized to the resolution of the D700, the performance is even more impressive. The D800’s performance is absolutely inspiring, and comparing the down-sampled files to D700, D3s and even D4 files, is a real eye opener. Noise handling is pretty much on par with the D4 up to roughly ISO 6400, but higher up the D800 falls behind. At ISO 12800, images are excessively noisy, and worst of all, thermal noise often spoils the image.

Compared to the D700, the D800 does very well at higher ISO values.

The flower scene on the right was dimly lit by a constant white light source, needing an exposure of 1/50sec f/11 at ISO 3200. Click on the image to see the comparison between the D800 and the D700.


This scene is technically not a low light situation to properly compare high ISO performance, but it’s sufficient to make at least a few conclusions. The D800, when down-sampled to the D700 resolution, retains more detail, has over a stop better ISO performance, and better colour depth than the D700.

I have been showing some downscaled D800 images mainly for purposes of comparing two different resolution full frame cameras. Down-sampling is an effective method to reduce the apparent noise in an image. Downsampling D800 images to a D700 resolution not only reduces noise, it makes the grain structure finer, and retains better detail than an identically shot D700 file. However, if the higher resolution file is needed for a large print job, it would really be redundant to downscale. For all intents and purposes, downscaling achieves nothing, unless  the final product needs a smaller resolution. In this case, there are various down-sampling techniques available.


Below, the slider shows the difference in apparent noise levels between actual-pixel crops of an original D800 file, and one from a down-sampled file.

First up is an image series of a simulated low light scene, shot at various ISO values. I set up the D800E with my Zeiss Distagon 35/2 ZF.2 with a Heliopan ND3 (11 stops), and the base exposure was 15 seconds at f/2.8, ISO 100. Needless to say, live view was practically useless while the filter was attached. As you can see by the actual pixel crops on the right, the results are pretty impressive.

Below we have a night scene shot at 1sec, f/8, ISO 3200 (LeNR OFF).

On the right are actual pixel crops comparing the D800 (downscaled to D700 resolution) with the D700.


The focus of both cameras were set to match as accurately as live view allowed me. Please keep in mind that this was a D800E!

The exposure was 10 seconds at f/4.5, ISO 3200, with no LeNR. Also, only default LR4 noise reduction was applied.


Both crops have zero sharpening applied.

Click the image below to see it bigger.

At the top of the page I mentioned the D800 performs rather competitively with the D4. While I haven’t shot the two cameras side by side, I do however have access to RAW files that were shot in a comparison conducted by someone else. The cameras in question were the D700, D800, D3X and D4, but for this review I will only show the comparison between the ISO 6400 images of the D800 and D4.

The full review can be found HERE, or by clicking on the full frame image below.

A notable improvement can be observed with long exposures. The D800 shows fewer odd pixels than the D700 for exposures up to two minutes. With the D700, I usually set LeNR ON when doing exposures longer than 30 seconds. The D800 handles one to two minute exposures quite well, showing less odd pixels than I’ve come to expect with 30sec exposures on the D700.


Given the differences in pixel count, I’d say this is a nice improvement, since it effectively saves you the time of doing an in-camera black frame reduction (LeNR), or editing out the odd pixels in photoshop.

 

It’s easy to see that the D800 is an improvement over the D700. Bumping up the ISO has seemingly smaller repercussions on image quality than before. The D800 is already very good when compared to the D700 at native resolution magnifications, but the comparisons become even more impressive when the D800 images are downsized to the D700 resolution.


Below are more sample images. Click to see larger versions with 100% crops.

ISO 100

ISO 100

ISO 100

ISO 400

ISO 3200

ISO 12800

ISO 800

ISO 6400

ISO 200

ISO 3200