mikhail_rezhepp1

<p>Scott,<br>

I understand that prime is better than zoom, and probably Zeiss prime may be better than Nikon. As a matter of fact this prime beat Nikkor in contrast, color rendering and resolution on the borders wide open.<br>

I also understand that metering might be <em>somewhat </em>different. Still difference of 1 stop struck me as surprising and I wanted to understand the root cause of that.<br>

Thanks for input.</p>

<p>Thanks to all for the comments and suggestions. I was not prepared for this difference in metering results, hence, the confusion. :)<br>

I may say that this difference is observed consistently irrespective of the subject (I tried two different scenes), time of day (tried for two days in the row and slightly different time), length of the experiment (2 minutes for the entire set), aperture (stopped down to f11). Focal lengths were set equal. Zeiss lens is a CPU lens.<br>

I may try the same in a totally controlled environment, like, shooting a wall or something similar.<br>

On the side note, thinking that I have a flawed Nikkor [not coming that route to Zeiss yet :) ] I also compared this morning the Nikkor 17-35/2.8 with a Nikkor 35/2.8 at 35mm. There was a minor difference of 1/3 of a stop, but nothing that dramatic.<br>

Time to read books on exposure metering theory. :) Thanks to everyone for stimulating submissions.</p>

<p>Thanks to everyone for all the suggestions.<br>

I took several shots at apertures 2.8, 4.0 and 11.0. The same x2 difference in shutter speed was observed. Matrix metering was used. And I used a tripod - some movement was possible, probably, less than 1mm. The subject was outdoors a shady corner with some sunlight and all shots were taken within 2 minutes. Lighting conditions did not change dramatically (they surely changed to some minor extent).<br>

I have to run some more experiments with other lenses to see which causes this difference. And please note that when I shifted exposure on Nikkor image by -1 the pictures histograms started looking very much the same.<br>

I did not expect the lenses to be :the same" and expected differences in rendering but did not expect that big difference in metering.</p>

<p>I ran a comparison test for Zeiss 25mm/2.8 CPU ZF.2 lens vs. Nikkor 17-35/2.8. Shot the same subject with a tripod and no filters on lenses on D3. What struck me is that Nikkor image came out lighter and less contrast than the Zeiss image.<br>

When I checked the exposure here is what I got:<br>

Zeiss - f2.8, 1/320, ISO 200<br>

Nikkor (on 25mm) - f2.8, 1/160, ISO 200<br>

When I corrected Nikkor by -1 in Photoshop the images' histograms became very much alike. The same 1 stop difference was happening on other apertures as well.<br>

Does anyone have an idea where this difference is coming from?<br>

Thank you</p>