Lens Comparison Test

[OldBikerPete]

I thought you guys might be interested in a little comparison I recently performed.

I printed a couple of copies of the USAF 1951 Optical test target on a laser printer at A4 size then photographed them from a distance equal to 50 times the focal length of the lens in use. The targets were placed so that one was in the centre and one about 90% out along the diagonal towards one corner. The film in use was 5x4 PORTRA 160 (because that's all I have). I then developed the film and examined the negatives with a microscope. Resolution was calculated from the smallest test element which could just be seen to be composed of alternate dark and light bars.

All of the exposures were on a tripod-mounted Wista 5x4 and the lenses were set at F/11 @ 1/30 or 1/50sec. The targets were placed on a flat surface and the lens was focussed on the centre target. It is probable that the edge values may be degraded due to curvature of field of the lenses.

Schneider Xenar f/4.5 210mm Centre 27 lp/mm Edge 3 lp/mm
Schneider Xenar f/4.5 135mm Centre 47 lp/mm Edge 8 lp/mm
Schneider Symmar-S f/5.6 135mm Centre 47 lp/mm Edge 17 lp/mm
Nikkor-W f/5.6 135mm Centre 53 lp/mm Edge 38 lp/mm

All the Schneider lenses were the older, single-coated variety.

[Ron Marshall]

You may be interested in these test results:

http://www.hevanet.com/cperez/testing.html

[OldBikerPete]

You may be interested in these test results:

http://www.hevanet.com/cperez/testing.html

Thanks, Ron. I saw those results ages ago. I needed to test my Symmar-S 135 and Xenar 135 because they don't appear in any on-line tests I've seen. Then I needed to test my Nikkor-W too so as to ensure consistent methodology across all the lenses. On checking Perez & Thalman again, I see that my Nikkor-W results agree with the better of their two sets of results, so I'm happy.

[roteague]

Thanks for the results. I have the same 135mm lens, and I've always thought that it was a sharp lens. Your results show good results with this lens.