Supertelephoto "IQ" thought experiment...

Started Sep 5, 2013 | Discussions thread
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JimPearce Veteran Member • Posts: 9,153
Supertelephoto "IQ" thought experiment...

Let's set up a theoretical comparison between a D7100 with 400 f2.8 VR and a D800 with a 500 f4 VR. Now, according to equivalence let's say we shoot the D7100 at 1/500 f4 ISO 400, and the D800 at 1/500 f5.6 ISO 800 in 1.2x crop mode. I think it's pretty clear that the images will be the same size - about 6000 X 4000 pixels. Now we'll assume that bobn2's (dxomark's) calculations for the DR and SNR loss are accurate, and dxomark's numbers for DR etc. are accurate. So, what we get is:

D800 (uncorrected): SNR 37 dB, DR 12.02 Ev, TR 8.35 bits, CS 21.9 bits

D800 (corrected): SNR 33.26 dB, DR 11.4 Ev, TR 7.63 bits, CS 20.04 bits

D7100: SNR 36.5 dB, DR 12.59 Ev, TR 8.24 bits, CS 22.2 bits

Well, there you go folks. For "reach constrained" wildlife work the D7100 beats the D800 in terms of noise, DR and colour. And it isn't even close.


I inadvertently used DX crop numbers in my original post. Turns out that the D7100 vs. D800 in 1.2x crop mode is a wash except for a half stop advantage to the D7100 in DR. See corrected values down below in the thread.

 JimPearce's gear list:JimPearce's gear list
Nikon D7100 Nikon D500
Nikon D7100 Nikon D800 Panasonic Lumix DMC-F5
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