Originally Posted by
Joseph Kashi
Thanks, Karl. I have 5 different Protar VIIa sets in shutter, with combined FL ranging from 145mm through 300mm. Some though not all of them, are quite sharp, with the Zeiss sets seemingly sharper than the B+L sets.
I have never even seen a Cooke XV or XVa. The extra air-spaces would seem likely to give the individual cells better correction for single cell use. I would expect that a multicoated Cooke XVa set with 8 air-glass surfaces would have better contract than uncoated Protar VIIa sets even though the Protars have only 4 air-glass surfaces, like Dagors.
I have noticed that of my Protar sets, the set(s) with matched same FL, sequentially numbered cells seem to be noticeably sharper than sets with differing FLs, which I attribute to more perfect front-back cell symmetry and hence better cancelling and correction for some aberrations. Is that your experience as well?
While I generally shoot with modern Plasmat/SA pattern lenses, I try to keep an appropriate Protar VIIa with each LF camera bag for those times when they might be right for the image, such as boosting deep shadows.
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