Fred Miranda wrote:
yes, I want to use it on the CV 28/2 to see if improves the induced field curvature. That's the one that worked best for the previous CV 28/2 ultron.
Superb. I have been curious about this myself. If that CV played friendlier with Sony sensor stack, I would already own one. Will be watching to see your results.
can you please post the pics again on your setup using Kenko 55mm filter. For some reason I cannot see them. By the way, do you know which kenko 55mm UV you are using? How do you lock the pcx (50mm) with the step down 55-67mm? Do you take the kenko filter apart?
coming in a bit late to the party, but this is fantastic work. Looking at your two posts on this forum with 1m Proxar and the 2.5m PCX, am I right in interpreting the 2.5m PCX as being superior?
Also - not wanting to physically change my 25mm 2.8 ZM (i.e. removing shims) since I also use on my Leica...I have seen references to a 'shorter Leica M to NEX adapter' - anyone have any specific information (brand, etc) on one of those that would work??
I have the Zeiss ZM 25mm - picked up and mounted the Zeiss Proxar 1m (B57 Ø50mm), and its not focusing to infinity.
Here's the rub: don't want to remove shims as I want to use it on my Leica camera still...any idea on specific shorter adapters that would work to allow this to focus to infinity??
Thanks Bastian,
There is a clear improvement off-axis but I think this lens performs much better on the M10, especially the corners. I will try the PCX and compare to the M10-R results.
I'm interested in trying a PCX front lens to tame the field curvature from the Voigtlander 50/1 Nokton and other 50mm F/1 lenses.
We usually use PCX front lens with lenses optimized for the rangefinder's thinner sensor so we can lower the induced field curvature when using it on a thicker sensor like Sony's.
This induced field curvature seems to share a similar shape to native 50/1 Nokton's FC when used on a thin sensor.
I just found out that OptoSigma PCX lenses can be custom sized.
The Voigtlander 50/1 has a 62mm filter thread.
Questions:
1) Which diameter should I order? 65mm? I'm assuming I could use:
62-67mm step up ring
65mm PCX
Blank 67mm filter
2) Which strength? 5000PM? This is hard to know and hopefully @HaruhikoT can help figuring this out.
Fred Miranda wrote:
I'm interested in trying a PCX front lens to tame the field curvature from the Voigtlander 50/1 Nokton and other 50mm F/1 lenses.
We usually use PCX front lens with lenses optimized for the rangefinder's thinner sensor so we can lower the induced field curvature when using it on a thicker sensor like Sony's.
This induced field curvature seems to share a similar shape to native 50/1 Nokton's FC when used on a thin sensor.
I just found out that OptoSigma PCX lenses can be custom sized.
The Voigtlander 50/1 has a 62mm filter thread.
Questions:
1) Which diameter should I order? 65mm? I'm assuming I could use:
62-67mm step up ring
65mm PCX
Blank 67mm filter
2) Which strength? 5000PM? This is hard to know and hopefully @HaruhikoT@ can help figuring this out.
Worth a try, but my guess would be that if CV could have tamed the field curvature without other ill effects with just one element they would have. I also wonder for one thing what any successful reduction of the FC at closer distances would do to the infinity FC.
DavidBM wrote:
Worth a try, but my guess would be that if CV could have tamed the field curvature without other ill effects with just one element they would have. I also wonder for one thing what any successful reduction of the FC at closer distances would do to the infinity FC.
Thanks for your thoughts David. Not sure if I will even try this, it was just an idea.
I compared the FC on the Leica vs Sony sensors today and from close distance to infinity the shape gets more wavy with the thicker sensor while flatter with the thinner.
Fred Miranda wrote:
Thanks for your thoughts David. Not sure if I will even try this, it was just an idea.
I compared the FC on the Leica vs Sony sensors today and from close distance to infinity the shape gets more wavy with the thicker sensor while flatter with the thinner.
Don't quote me as I'm no Leica shooter, but I've read a few reports that the sensor cover glass on the new M11 is even thinner still (vs M10), so, perhaps Cosina designed the new 50mm f1 lens for that, and all this stress about field curvature might be for nothing (if you're lucky enough to own an M11!)
Petegh wrote:
Don't quote me as I'm no Leica shooter, but I've read a few reports that the sensor cover glass on the new M11 is even thinner still (vs M10), so, perhaps Cosina designed the new 50mm f1 lens for that, and all this stress about field curvature might be for nothing (if you're lucky enough to own an M11!)
It's possible, I don't think it would make much of a difference here.
Keep in mind there is hype/marketing surrounding the M11 release. One example was that the new BSI sensor was not only thinner but also would reduce vignetting compared to previous versions. Well, I tested this and actually the M11's sensor produces higher vignetting compared to the M10-R. (Leica 28/2 summicron and 35/1.4 FLE tested)
I just got a 28mm Contax G on ebay from Japan. It came with the correct +.5m PCX filter and rings. Am trying to decide whether to keep it. Sharpness stopped down seems not an issue on an a7r4. I love the form factor and the lack of distortion.
What lightroom correction profile are folks using for this lens? Zeiss Loxia 25 or Zeiss ZM Biogon T with distortion set to zero, or something else?
I am getting the green/cyan drift on the edges, and finally figured out how to correctly do the flat field correction and zap it out, but I dislike the "clunkiness" as an earlier poster wrote, of having to create a separate folder and go through this process. I don't understand how Sean Reid uses the lightroom sliders to only correct for the color shift without making a custom mask with the gradient tool.
May I ask, is there new info regarding PCX filter for the VM 28/2 Ultron v2 for use on Sony sensors?
What ist the best PCX value? SLB-50-5000PM PCX (5.0m)? Or better 4000 (4.0m)?
I would like use the VM 28/2 ii on my A7Rv and perhaps on an upcoming A7Cii (A7iv sensor).
@Adl999 No, I have not seen any online info about the Voigtlander Ultron 28mm F2 with a PCX filter, but I can tell you about my experiences with PCX filters:
On my Contax G 28mm f2.8, the Opto Sigma SLB-50-1500PM works great!
I bought the Opto Sigma SLB-50-1200PM for my Voigtlander Snapshot Skopar 25mm f4.0 for use on the Sony A7RIII. I really like the size and rendering of this lens, but it suffers from softness in the outer 1/3 of the image. Even after removing the (2) shims under the mount I could not get the lens to focus to infinity (or even past around 10 meters). I tried the PCX lens in both configurations (concave/convex). At closer distances (1-5m) I noticed a small improvement in sharpness with the PCX (maybe 1/2 stop), but not enough to warrant the cost (~80eur + shipping). The PCX was mounted with double sided tape flush/against the front-element (not sure if this has a negative effect). Has anyone used a PCX filter on this lens? Any tips are greatly appreciated.
