Tirpitz666 wrote:
Seems that the best compact fast 35mm that can be PCXed and TAPed at the same time without requiring any filter stack modification remains the CV Ultron 1.7 at this point right?
Whether the VM 35 1.7 works with PCX on TAP is a question of mount, lens and adapter tolerances.
Lately a reader told me it worked for him, but I remember some people here saying it didn't for them.
ZM 35 1.4 is indeed the safe bet, as you can easily remove the shims.
I agree the ZM is super pricey. When I was getting rid of my medium format digital system it was the one treat I allowed myself in transitioning back to 35mm. If I were buying now the Ultron would likely be my choice for bang for buck.
thrice wrote:
I agree the ZM is super pricey. When I was getting rid of my medium format digital system it was the one treat I allowed myself in transitioning back to 35mm. If I were buying now the Ultron would likely be my choice for bang for buck.
Mine is up for sale on the board if someone wants the whole setup.
I just ordered the Contax G21. Couldn’t resist the 20%off from keh. I also have the g28. So is the consensus for these lenses still the optosigma pcx 1500?
Zplusc3 wrote:
I just ordered the Contax G21. Couldn’t resist the 20%off from keh. I also have the g28. So is the consensus for these lenses still the optosigma pcx 1500?
For standard camera, yes 1500mm PCX reversed.
Mathieu18 wrote:
Stronger than 1500 would be ideal, performance still improves with a thinner cover glass. 1.8mm &1500mm seems similar to 0.9mm and 5000mm.
Matt, in my opinion stronger than 1500mm reversed with standard camera would just make the issues worse; for me the modified camera is better because it does not need so much correction = weaker PCX-lens is enough correction = midfield suffers less. This PCX-method is like correcting progressive curve (caused by thick sensor cover glass) with linear correction (PCX lens effect), optimum PCX for corner and midfield is rarely the same. I have all Optosigma PCX-lenses from 1500mm to 5000mm, and more or less all lenses behave similarly.
I personally don't see difference in G21 corners if I compare
a) std camera + 1500mm reversed
b) Kolari v2 + 2000mm.
Only difference is that the midfield is better with b).
When I use Kolari v2 + 2500mm then corners are little worse than a) or b), but midfield is little bit better than b) and lens draws better on boke scenes, compromises... From Derek's (forum ID sebboh) tests images with Kolari UT I would prefer Kolari UT + 5000mm, put I don't have Kolari UT, so have to survive with what I have.
There are some lenses that I did never get working with standard camera, but work very well with Kolari v2. For example Zeiss Biogon T* 2/35; standard camera w/ 2000mm ruins midfield drawing style & boke completely, but it's still not strong enough for extreme corners. When used with Kolari v2 w/ 3000mm it's really good, but if I would be landscape shooter I would most likely use 2500mm instead, which would improve the corners and f/8-11 would have enough DOF to remove midfield issues (for landscapes Loxia 35 is obvious choice, don't buy ZM 2/35 if you don't shoot boke photos & have modified camera..)
Samuli and Mathieu, thanks for the advice. Will be on a standard sensor so will go with a 1500mm. Once the g21 arrives I’ll try it as is to make sure there aren’t any issues with it and than order the pcx lens.
Still haven't read through all the 100 pages of the old thread, but I was wondering if someone can help me decide whether for the Distagon 35 1.4 ZM would be better to shoot for the Optosigma 5m (where most of the consensus seem to be) or the Eksma 10m (as reading through the comments to Philip Reeve's comprehensive article looks that some users had a higher degree of success with it, especially in reducing the midzone dip).
Another thing that is still not completely clear to me from all the screenshots is if with a PCX filter the amount of blur behind a subject near the center of the frame would be actually be reduced vs sans PCX or not. I understand that the borders will be more blurred with the filter on, but it still not clear to me if through the field curvature correction the blur in the center behind the subject will be actually somewhat reduced (which would be an undesiderable side effect, at least for me).
Tirpitz666 wrote:
Still haven't read through all the 100 pages of the old thread, but I was wondering if someone can help me decide whether for the Distagon 35 1.4 ZM would be better to shoot for the Optosigma 5m (where most of the consensus seem to be) or the Eksma 10m (as reading through the comments to Philip Reeve's comprehensive article looks that some users had a higher degree of success with it, especially in reducing the midzone dip).
Another thing that is still not completely clear to me from all the screenshots is if with a PCX filter the amount of blur behind a subject near the center of the frame would be actually be reduced vs sans PCX or not. I understand that the borders will be more blurred with the filter on, but it still not clear to me if through the field curvature correction the blur in the center behind the subject will be actually somewhat reduced (which would be an undesiderable side effect, at least for me). ...Show more →
I cannot comment on a filter other than the Optosigma PCX, which is what I use. Without the PCX filter, the 35ZM on Sony FF is sharp in the middle, but it has a lot of astigmatism from the mid-field to the corners in apertures faster than f/8. At f/8, everything is sharp, with or without the PCX filter.
To fix the blurriness in faster apertures, you put on the PCX filter. At f/stops faster than f/8, it sharpens up the corner a lot, but the mid-field and center are unaffected, meaning that the center is sharp but the mid-field is soft. At faster apertures, the image looks a lot better with the PCX.
I shoot my 35ZM + PCX as my default walk-around lens, from f/1.4 to f/4 or so, and I have never noticed the mid-field dip in my shots. I haven't used it for landscape, but if I did, I would probably shoot it at f/8 and get the sharpness across the frame plus depth of field.
Ok thanks, seems that downsides (if any) are pretty limited in using a PCX filter with such lens, do the Optosigma filters come coated by default or you have to specify in the order like you have to do for Eksma ones?
Tirpitz666 wrote:
Another thing that is still not completely clear to me from all the screenshots is if with a PCX filter the amount of blur behind a subject near the center of the frame would be actually be reduced vs sans PCX or not.
PCX lens corrects field curvature and astigmatism. Due to thick sensor cover glass in Sony cameras lenses designed for thinner cover glass (or no cover glass=film), and having any ray angle (=angle in which the light hits the sensor is in angle). So the is no difference or very small difference in center of image.
Due to this PCX lens technique can't correct lenses like Leica Summilux-M 50mm, where lens is projecting rays in angle also to center of image. It can correct corners better, but no matter what PCX is used it will not make this kind of lens to render like it renders in Leica M.
Tirpitz666 wrote:
I understand that the borders will be more blurred with the filter on, but it still not clear to me if through the field curvature correction the blur in the center behind the subject will be actually somewhat reduced (which would be an undesiderable side effect, at least for me).
Actually the blur (when talking about boke photos, not focal plane blur - how I understood your question) is same, but due to field curvature focus distance is further away from camera the level of blurriness may appear less blurred. But more importantly when using these rangefinder lenses without PCX the astigmatism causes tangential and sagittal detail to focus at different distances = also blurred boke detail which is sagittal is focused to different distance than the blurred detail which is tangential. So unfortunately it is not as simple as "more blur" or "less blur".
When corner gets optimal the PCX lens is so strong that it "overcorrects" mid-field, which is little bit ruining boke. And naturally modified Sony (thinner sensor cover glass) requires less correction, and therefore has less midfield issues. Of course this is assuming lens itself has no field curvature or astigmatism, which is not true for majority of rangefinder lenses - so one has to evaluate lenses native field curvature and astigmatism together with the correction PCX lens offers.
Personally I would not worry about 5000mm PCX lens negative effects to midfield boke based on experience with other lenses requiring 5000mm PCX for correction. However I don't have 35mm Distagon so I can't say for sure.
Thank you Samuli, I've read all Bastian's excellent articles on the matter and finally sifted through the whole 98 pages of the super impressive thread here, really an amazing research job everyone.
I'm still wondering about the following topic, that apparently looked to have passed a bit under the radars:
In the comment section of Bastian's review of the 35 ZM, a user posted in March 2018 some comparison pics between the naked lens, with OptoSigma 5m and Eksma 10m (link is still there and functional) and, save for the different lightning, it looks to me that the ones taken with the Eksma PCX 10m have a bit more "bite" (especially in the midfield) vs the OptoSigma 5m's ones. Unfortunately they are not downloadable so they cannot be blown up too much for further scrutiny, but at least to my eyes the diffirent in the upper midfield zone) i.e. the patch of grass on the right and the tarmac structure looks anyway quite apparent).
Any thoughts/experience on that? I've seen that previously another user was reporting not being impressed by the Eksma 10m, but unfortunately the pics are no more there to check, while in the other comprehensive article about rangefinder lenses and pcx filters, Bastian itself posted some tests with the Eksma filter claiming he was not satisfied due to a more pronounced midfield dip, but the filter was referred as Eksma 5m, not 10m.
So at the moment the picture is still at bit confusing to me, is the OptoSigma 5m still the best overall solution for the 35 ZM or the Eksma 10m is really worth a try instead?
To tell the truth, I'd take all the time a weaker filter that would preserve more the midfield, even at the expense of some corner quality loss.
Tirpitz666 wrote:
So at the moment the picture is still at bit confusing to me, is the OptoSigma 5m still the best overall solution for the 35 ZM or the Eksma 10m is really worth a try instead?
If you would like to see test shots at 100% resolution with and without the PCX 5m, send me a PM. I'll send you a link to download them. I conducted the tests with the A7R2. I haven't shot with the Eksma, so I can't provide you those.
Thank you, guess there is little doubt that a PCX filter would be overall beneficial to IQ, as the compromises looks to be more than compensated by the advantages it gives at the end.
The issue for me now is just to decide for which PCX filter to shoot, if OS 5m or Eksma 10m (still waiting for a final pricing quote on the latter with coating, while the first according to OS website would be USD 95+shipping).
