I'd definitely be interested, I know you've comment on some of my posts that you believe you could provide some some insight into this. Note that I've seen this on more than just CV lenses, so it would be interesting to see how this has nothing to do with Sony at all, and it's all on the lens manufacturers.
realVivek wrote:
Is that the final word or would you be interested in reading about what I find? You are the Admin.
Fred Miranda wrote: realVivek wrote:
The problem is with this (50 APO) Cosina lens . Once I have my spectrometer setup again, I will post about this in detail.
tsdevine wrote:
Yes, I believe more than just CV lenses are susceptible. My Tamron 35mm Di III is probably the worst in this regard. Sony has a lower frequency cutoff in their sensor stack than other camera manufacturers. I'm not sure 3rd party lens makers fully realized that difference when they did lens design. If you look in that link to the thread I posted above, I have some links to sites that discuss Sony's sensor stack and at what frequency it starts filtering.
Oddly enough I don't see this problem in pretty much any of my old legacy manual glass.
Fred Miranda wrote: tsdevine wrote:
I'm doing it to solve a specific problem I see with certain lenses. I definitely would never suggest anyone must or absolutely should use a UV filter (a very specific type in this case), especially if they don't see any problems.
But for me, there is enough reason to do it with the CV 50 APO. I also see the same behavior on the CV 65 APO, and expect to see it on the CV 35 APO. Haven't noticed on my CV 110, but I suspect I will see it there as well.
And to be clear, not any UV filter will do. It needs to have a hard cutoff around 410nm or higher to be effective.
I'm not sure CV was trying to get magenta shading on Sony as a feature. Any perceived degradation seems to be outweighed by the reduction in the magenta I see in the corners. But I would not suggest that this is something that would bother the majority.
YMMV (or everyone's really)
Karl Witt wrote:
In regards to the statement of buying a UV filter for this lens.............
Why do we put inferior glass in front of superior glass? Doesn’t any glass degrade the quality of what the manufacturer worked so hard to achieve??
I’ve not fully understood the benefits of filters.
OK now I’m gonna get a lesson
Karl😎
Tim,
It looks like this could be a general phenomenon. (Not restricted to Voigt lenses)
Here is the 35/2 DG DN without the Zeiss filter (left) and with the Zeiss filter (right):
I still think this is a general issue, rather than an isolated ill-effect from the Voigtlander 50/2 APO.
