NikonGear'23

Gear Talk => Lens Talk => Topic started by: Toby on September 03, 2019, 06:55:07

Title: Optical differences between early and late model CRT Nikkor-O 55mm f1.2
Post by: Toby on September 03, 2019, 06:55:07
Since we are dealing with Nikkor lenses, and minutiae concerning them, I thought it might interest some here to compare early and late version CRT Nikkors. The early versions have serial numbers starting with 7; later version numbers start with 8. The later version has the magnification marked on the beauty ring (M=1/5). I have one of each, and they are noticeably different in rendering. I suspect that the earlier version is not optimized to 1/5, but for slightly greater distances, based on the higher negative field curvature of the later version. There is also a difference in size of the center subject, probably resulting from the difference in field curvature. Just for fun, here are two comparison shots. You'll notice that the earlier version is slightly warmer in color, slightly longer in focal length (or at least the center subject is slightly larger, and does not have as much field curvature as its later sibling. Obviously this shot is taken at a much longer distance than that for which the lens is optimized, but it's clear that they are not exactly the same.
Title: Re: Optical differences between early and late model CRT Nikkor-O 55mm f1.2
Post by: KarlMera on September 03, 2019, 19:00:29
I have both lenses and the same experiences. The old lens is a little bit better for my photos.
Title: Re: Optical differences between early and late model CRT Nikkor-O 55mm f1.2
Post by: Akira on September 03, 2019, 21:23:18
Toby, thank you for sharing this intriguing comparison!  I'm happy to know that I have the earlier one.  I prefer the warmer tone as well.

There might be some sample variation, but Nikon should have controlled the quality more tightly than their camera lenses.
Title: Re: Optical differences between early and late model CRT Nikkor-O 55mm f1.2
Post by: Dr Klaus Schmitt on September 04, 2019, 09:57:40
Thanks Toby, I also have the older type.