didnt Pentax super multicoat all air glass surfaces starting back in the early 70's. including rear elements? jco -----Original Message----- From: Pentax-Discuss Mail List Sent: Jun 17, 2022 11:37 AM To: Subject: Re: sample photos. - smc pentax A 100mm F2.8 MACRO at middle distances w/K-1 On 6/16/2022 10:17 PM, Alan C wrote: > The problem is related to lack of Multi-coating on the rear element > which > was absent on pre-digital lenses. More commonly this gives rise > to ghosting > (back-and-forth reflections) when these old lenses are > used on digital > camera because the sensors are much more reflective > than film. The > difference between the Sigma 170-500 APO & the later DG > version is > indicative. > I suspect that is a possibility, I suspect the "multicoated" lenses of the day may not have been as multicoated on the rear element. I use quite a few legacy glass and the A100/2.8 macro is the only one I've noticed hot spots on, which is why I thought it might be related to the FREE design and the flat rear element. Anyway, according to John, the problem doesn't exist, so it's all good. bill -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to [email protected] to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
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