Archive 2015 · Kolari Mod's Improvements: A Summary of Tests
Steve Spencer Online • • • • • • • Upload & Sell: On
p.11 #1 · Kolari Mod's Improvements: A Summary of Tests
naturephoto1 wrote:
Steve,
I believe that V3 is the thinnest of the sensor stack covers. I think that I finally have some reference color profiles/WB for my V3 sensor stack modified A7r for Daylight, cloudy, and shade conditions. Because my R 50mm Summicron had to go back again to Leica Camera USA (agh!!!) the profiles were run with my R 60mm Macro Elmairt lens using my X-rite color checker and software. I expect to take images later today of amongst other things some flowers.
Rich
Thanks Rich. When Derek posted I thought I likely had it wrong, now I am sure I did. The v3 mod should work best for lenses designed for film as it is thinnest. Sorry, I got that mixed up.
p.11 #2 · Kolari Mod's Improvements: A Summary of Tests
Steve Spencer wrote:
My impression was that v1 and v2 were thinner than v3, but maybe I had that wrong. If v3 is thinner, then it should work better with lenses designed for film. If Leica starts to design newer lenses for a thicker sensor stack, which it looks like they might have for the M 28 lux, then those might work better with thicker cover glass. So, what works best still depends on the lenses, but I very well may have had it wrong about which Kolari versions are thinner.
i believe version 3 is the thinnest. i think v2 was .8mm.
Apr 16, 2016 at 10:05 AM
Steve Spencer Online • • • • • • • Upload & Sell: On
p.11 #3 · Kolari Mod's Improvements: A Summary of Tests
sebboh wrote:
i believe version 3 is the thinnest. i think v2 was .8mm.
I guess that is what confused me too. My understanding is that the M8 was .5mm, the M9 was .8mm, and the M240 was 1mm, and the SL somewhat thicker. So when I heard v3 was the same as the current Leica I thought this meant the M240 and therefore for 1mm. Now I am not sure about any of this other than the M8 being .5mm.
Edit: I just checked Roger's sensor stack thickness database at the lens rentals blog and he has the M8 at .5mm and the M9 at .8mm and I think we know that the M240 is a bit thicker than the M9 and the SL a bit thicker than the M240. So, the exact thicknesses of the Kolari mods would be interesting to know. If v2 is .8mm and v3 is even thinner, then that would mean the v3 is even thinner than the M9. That could be a good thing for lenses designed for film if it doesn't start to cause problems with IR contamination, but it might not be the best option for newer lenses designed for the thicker cover stacks of later developed cameras (a lot of people seem to think the M 28 lux was designed for the SL thickness of cover glass and Lloyd Chambers does report that the lens works better on the SL than the M240).
p.11 #6 · Kolari Mod's Improvements: A Summary of Tests
mdemeyer wrote:
Gents,
The v2 and v3 mods are the same thickness and match the M240. The only difference is the A/R coating. V1 was slightly thicker.
Michael
Hi Miichael,
Due to the coatings the V2 and V3 sensor covers do record color differently. From my observations, the V3 colors appear to be more neutral to my eye (a little shift toward the yellow) while the V2 still tends to be too blue. As I mentioned above, I ran some color Balance Profiles for my V3 A7r camera using my R 60mm Elmarit lens in Daylight, cloudy, and shade conditions using my X-Rite color checker and software a few days ago. Hopefully these profiles will be pretty darn accurate for my camera.
Unfortunatley from my understanding reading the information for the X-Rite color calibration, it is camera specific once completed so each camera requires its own calibration under different conditions.
sebboh wrote:
thanks! so 1mm?
Hi Derek,
I thought they were 0.8mm thick, but I could be in error.
p.11 #7 · Kolari Mod's Improvements: A Summary of Tests
Original was 1.0mm and v2/3 are 0.8mm. The A/R coating also improves the UV cut, which accounts for the slight change in color balance between the v2 and v3 mods, particularly if used without UV filters. That might account for some person-to-person differences noted re: color balance changes.
It should be noted that I am in the camp that does use UV filters on my lenses, so the profiles I have posted are with a UV filter. So my v2 profile is likely to work pretty well with v3 mods.
Michael
Apr 16, 2016 at 11:52 AM
Steve Spencer Online • • • • • • • Upload & Sell: On
p.11 #8 · Kolari Mod's Improvements: A Summary of Tests
mdemeyer wrote:
Original was 1.0mm and v2/3 are 0.8mm. The A/R coating also improves the UV cut, which accounts for the slight change in color balance between the v2 and v3 mods, particularly if used without UV filters. That might account for some person-to-person differences noted re: color balance changes.
It should be noted that I am in the camp that does use UV filters on my lenses, so the profiles I have posted are with a UV filter. So my v2 profile is likely to work pretty well with v3 mods.
Michael
Micaheal,
While we have you, do you know the thickness of the M240 cover glass? Most people suspect it is thicker than the .8mm of the M9, which would make it thicker than the Kolari Mod v2 & v3. I suppose optical thickness might be different from actual thickness, but I wondered if you could clear this up. I have seen people claim the M240 has 1mm cover glass, but I can't recall a solid reference.
Also, if I can get my two cents in I would love to see Kolari develop two sensor cover glass thicknesses. One like v2 & v3 that is as thin as possible without IR contamination for people who want to use lenses designed for film, and one that is as thick as possible but that still works well with lenses designed for digital cameras (e.g., M 28 lux, the just reformulated and released 28 f/2.8, 28 f/2; and 35 f/2, the Zeiss ZM 35 f/1.4, etc.) and that has as few penalties as possible with lenses designed for Sony FE mount. I can easily imagine someone wanting a camera that would work well with the Loxia 21 f/2.8, the Leica M 28 f/2.8 ASPH or 28 f/2 ASPH, the Leica M 35 f/2 ASPH or the Zeiss ZM 35 f/1.4, the Loxia 50 f/2 or the Leica M 50 f/2 APO, etc, and I think a cover glass that is a bit thicker let's say 1.2mm or even 1.4mm might work really well for such a person.
Basically a thin as possible without causing IR contamination solution for film lenses, and a thick as possible while still working reasonably well with lenses designed for digital Leica M solution.
p.11 #9 · Kolari Mod's Improvements: A Summary of Tests
Steve,
While one could, in principle, develop a whole bunch of different mods for different situations, it's just not economically feasible. This is a very small market so it was difficult to get the economics to work just to get a batch of filters A/R coated. So, even if it was technically reasonable, it's certainly not economically feasible. Offering multiple options would just drive the price of the mod up enough that it would be better to just buy another camera for the native lenses (keeping warranty, etc.).
Everyone interested should also read the following to understand the impact of a difference between the 'design target' of the lens and the actual optical stack thickness:
To your questions about the exact data on the Leica stacks, this is not something that Leica publishes (to the best of my knowledge), but I believe the 0.8mm filter in the v2 and v3 mod is close enough to the current Leica design spec so as to be both a good match for their modern lenses (including those just updated in this regard) and a best practical compromise for older film lenses.
Again, one of the biggest problems here is that the market for these modifications is very, very small. On-going development has to be supported by sales. So perhaps the best thing that those in this group can do is to spread the word to others with collections of treasured glass.
Michael
Apr 16, 2016 at 01:22 PM
Steve Spencer Online • • • • • • • Upload & Sell: On
p.11 #10 · Kolari Mod's Improvements: A Summary of Tests
mdemeyer wrote:
Steve,
While one could, in principle, develop a whole bunch of different mods for different situations, it's just not economically feasible. This is a very small market so it was difficult to get the economics to work just to get a batch of filters A/R coated. So, even if it was technically reasonable, it's certainly not economically feasible. Offering multiple options would just drive the price of the mod up enough that it would be better to just buy another camera for the native lenses (keeping warranty, etc.).
Everyone interested should also read the following to understand the impact of a difference between the 'design target' of the lens and the actual optical stack thickness:
To your questions about the exact data on the Leica stacks, this is not something that Leica publishes (to the best of my knowledge), but I believe the 0.8mm filter in the v2 and v3 mod is close enough to the current Leica design spec so as to be both a good match for their modern lenses (including those just updated in this regard) and a best practical compromise for older film lenses.
Again, one of the biggest problems here is that the market for these modifications is very, very small. On-going development has to be supported by sales. So perhaps the best thing that those in this group can do is to spread the word to others with collections of treasured glass.
I do know the article at the lens rentals blog and it has given me pause about getting the conversion. It seems that v2 & v3 of the conversion would make the the sensor cover glass about 1.2mm too thin for the way FE lenses are designed. That will likely lead to some fairly noticeable degradation of performance of native FE lenses. For example, f/1.4 lenses you will probably see something like 10% reduction in contrast on axis wide open and if they make an f/1.2 lens, which I wouldn't be surprised by then the reduction would be more like 15%. This might not seem like a lot but at wide open reduction in contrast is often the most important. Similarly if you have lenses in which the exit pupil is short (less than 50mm) the 1.2mm is probably enough to create noticeable astigmatism off axis. This decrease in performance with native lenses will probably prevent me from getting the mod.
On the other hand, if Kolari offered a thick as possible mod that was something like 1.4mm, then the decline in performance with native lenses would be almost nil. Certainly for fast lenses (even f/1.2) on axis, and probably even off axis for lenses that have greater than a 30mm or so exit pupil (although that is a bit more of a guess). I would be much more interested in this type of a mod. Said another way, offering a second mod might open up a whole new line of business with new people considering and buying the mod. I would fit in that category and I don't think I am the only one, although I could be wrong. I also further expect that as the quality and range of native FE mount lenses grow more and more people will be reluctant to see a drop in performance of some of their valued native lenses even if they want to get the mod. I do wish Kolari the best and I am very happy they offer this service even if at present it isn't for me.
p.11 #11 · Kolari Mod's Improvements: A Summary of Tests
Steve,
Appreciate your thoughtful and well-considered view on this.
To others,
I would appreciate hearing from you (by PM) if you share Steve's view and would commit to purchasing such a modification. Perhaps a group buy could fund such a project. Again, the matter is not technical feasibility but rather the commercial costs of developing and producing this 'dual-compromise' modification. Understand (as Steve does) that the laws of physics mean you can't optimize for both legacy and native. So would you prefer compromises on both for improved versatility?
Personally I own no native Sony lenses and have no intention to buy any - I use Fuji for my modern AF needs because I prefer the ergonomics. If I wanted to use modern Sony glass I would own another stock body so I had one optimized for each lens system. But that's just me... what about you?
p.11 #12 · Kolari Mod's Improvements: A Summary of Tests
I've had the same worry.
Even though I still only have a single native lens, the issue has still held me back. Currently, my plan is to maybe in another year get a second body solely dedicated to the mod. With used A7's moving lower and lower in price, that seems like the best move from my perspective--I'd rather have the thinnest stack possible for the best possible legacy lens IQ than a compromise between the two.
(also: I'm yet to have seen any comment on the CV 35mm f/1.2 Nokton with the mod...is that in this thread anywhere?)
p.11 #14 · Kolari Mod's Improvements: A Summary of Tests
I would not mind even thinner filter stack. For me closed down landscape shooting with 0.8mm filter is OK - with all lenses I have tried. However this represents only <5% of my shooting (maybe not even that much).
On other hand 0.8mm filter stack is clearly too thick for mid-distance boke shooting with film lenses. This kind of scenarios represents >80% of my shooting. Normal lenses I have tested work OK (Contax G45, Zeiss 1.5/50 ZM) or close to OK (Leica Summicron-M 50). All wider lenses show issues on mid-distance boke shooting scenarios with v2 0.8mm.
Example of outward field curvature & astigmatism caused by 0.8mm filter stack - pay attention to how boke on front corners gets more blurred than in bottom of photo and top corners far away branches etc. get into focus. Zeiss Biogon 2/35 ZM @ f/2.8, A7 v2:
Link to 4K-UHD size version
I like rendering of 35mm Biogon, but I can't stand the outward field curvature => I think I need to give up and get the Distagon 1.4 version.
On positive side with 0.8mm v2 filter Contax C/Y mount lenses have all exceeded my expectations. Many of these lenses truly sucked with 2mm filter stack, to a level I considered them "not usable". For example Distagon 2.8/28 C/Y is giving very nice high quality boke @ f/4 (example) - and with 2mm filter stack it had strong outward field curvature.
p.11 #15 · Kolari Mod's Improvements: A Summary of Tests
Made a shot to compare the Zeiss ZM 35mm F1.4 to my vintage Canon FD 35mm F2.8 Tilt-Shift lens in a basic architectural scenario on a v2 modified A7.
The Canon was shot with front rise in the lens and the Zeiss required a slight correction in post to correct the convergence resulting from a tilted-up camera angle. I also had to back up a few feet with the Zeiss to get more in the image, since the convergence adjustment causes a slight crop (only a few percent on the side, although a little more on the bottom for composition reasons). The Canon is full frame as shot.
Since the Canon is an SLR lens with a long exit pupil distance, the mod probably has minimal effect. The Zeiss is optimized for the Leica stack, so should match what's in the Kolari-modified A7.
Processed in Lightroom with my most-recently posted ACR profile (nice blue sky with no hint of red, which you can get with standard camera profiles):
Output sharpening in Photoshop. Since the clouds were rolling by, I picked two that had similar lighting (but not identical) and processed for similar end-result.
Both are uploaded at 50% of original resolution. Full resolution doesn't tell a materially different story.
I always go back and forth about the relative image quality losses between using this older lens but not making convergence adjustments vs. doing it in post. Here the correction to the Zeiss image was slight at -2 Vertical and -1.9 degree Rotation, so the quality loss should be pretty minimal.
p.11 #16 · Kolari Mod's Improvements: A Summary of Tests
Samuli Vahonen wrote:
I would not mind even thinner filter stack. For me closed down landscape shooting with 0.8mm filter is OK - with all lenses I have tried. However this represents only <5% of my shooting (maybe not even that much).
On other hand 0.8mm filter stack is clearly too thick for mid-distance boke shooting with film lenses. This kind of scenarios represents >80% of my shooting. Normal lenses I have tested work OK (Contax G45, Zeiss 1.5/50 ZM) or close to OK (Leica Summicron-M 50). All wider lenses show issues on mid-distance boke shooting scenarios with v2 0.8mm.
I like rendering of 35mm Biogon, but I can't stand the outward field curvature => I think I need to give up and get the Distagon 1.4 version.
On positive side with 0.8mm v2 filter Contax C/Y mount lenses have all exceeded my expectations. Many of these lenses truly sucked with 2mm filter stack, to a level I considered them "not usable". For example Distagon 2.8/28 C/Y is giving very nice high quality boke @ f/4 (example) - and with 2mm filter stack it had strong outward field curvature.
Great example of the nasty field curvature of the ZM lenses. Has the outward curvature been reduced at all compared to the unmodified sensor? I can't remember if you used that ZM35 prior to the modification. I have compared my ZF.2 1.4/35 on a Nikon D600 and unmodified Sony A7, and to my eye the inward field curvature of that lens is reduced on the A7 without visible degradation of corner performance stopped down. It seems like the Sony stack reduced inward curvature and increases outward curvature, which makes logical sense to me at least. I actually like inward curvature for some applications as I get better apparent separation of a centered mid-distance subject from the background, but it's extreme enough on the D600 that stopped down infinity shots suffer at the edges and corners.
Anyway, I'd like to start using my ZM2.8/25 and ZM2.8/35 lenses again on the A7 and have been hemming and hawing about getting the mod done. From your result, it seems that at least the vignetting and smearing are much better, and I think the exit pupil on the 25mm lens is similar to the ZM2/35 Biogon which would bode well for me.
p.11 #17 · Kolari Mod's Improvements: A Summary of Tests
uscmatt99 wrote:
Has the outward curvature been reduced at all compared to the unmodified sensor? I can't remember if you used that ZM35 prior to the modification.
Yes, difference is very dramatic, lens is not at all usable with 2mm filter even one could fix colorcast somehow. I did shoot some photos before I got the two A7 bodies back from Kolari. For me this lens would not be usable at all without 0.8mm filter. I posted photos most likely FE image thread.
uscmatt99 wrote:
I have compared my ZF.2 1.4/35 on a Nikon D600 and unmodified Sony A7, and to my eye the inward field curvature of that lens is reduced on the A7 without visible degradation of corner performance stopped down. It seems like the Sony stack reduced inward curvature and increases outward curvature, which makes logical sense to me at least. I actually like inward curvature for some applications as I get better apparent separation of a centered mid-distance subject from the background, but it's extreme enough on the D600 that stopped down infinity shots suffer at the edges and corners.
Is ZE/ZF really designed for thick filters or film? Almost every film lens has improved due to 0.8mm filter, at least the Contax C/Y lenses. We also need to remember even if 0.8mm filter (or 2mm) would "fix" field curvature it still does add astigmatism.
uscmatt99 wrote:
Anyway, I'd like to start using my ZM2.8/25 and ZM2.8/35 lenses again on the A7 and have been hemming and hawing about getting the mod done. From your result, it seems that at least the vignetting and smearing are much better, and I think the exit pupil on the 25mm lens is similar to the ZM2/35 Biogon which would bode well for me.
I would assume ZM 2.8/35 will have too steep ray angle for boke shots. Closed down to f/11 it might work for landscapes. I hope 25 biogon works well, I have been wanting to get one, but have been busy and no time for photography or eBay browsing...
p.11 #18 · Kolari Mod's Improvements: A Summary of Tests
ZM 35/2 is really superb on M9. Unusable on any stock A7. It is my most problematic often used lens, it was decent on the A7 v1, but I did not like it on the v3. V2 on A7 was better.
But the mod really has a different effect on each A7 model. Here is the Biogon on the A7s.mod v2:
It should be noted this lens is very even across the frame as you stop down, but it's flaw is very deep corners, even on the M9 at f/8.
A7s.mod makes for a spectacular camera, I think. The A7s does a different render than any of the other models, which I really like. ISO performance means you can have some DOF in low light, which is very useful, or you can use very high shutter for long lenses. The MP count is fine if you are not cropping, at least according to my cat: DSC04399-2 by unoh7, 300/2.8
I'd like to see the new M9 spec cover glass on the A7 series. And I have yet to see many shots from a A7r2 mod.
p.11 #19 · Kolari Mod's Improvements: A Summary of Tests
uhoh7 wrote:
ZM 35/2 is really superb on M9. Unusable on any stock A7. It is my most problematic often used lens, it was decent on the A7 v1, but I did not like it on the v3. V2 on A7 was better.
But the mod really has a different effect on each A7 model. Here is the Biogon on the A7s.mod v2:
It should be noted this lens is very even across the frame as you stop down, but it's flaw is very deep corners, even on the M9 at f/8.
A7s.mod makes for a spectacular camera, I think. The A7s does a different render than any of the other models, which I really like. ISO performance means you can have some DOF in low light, which is very useful, or you can use very high shutter for long lenses. The MP count is fine if you are not cropping, at least according to my cat: https://farm8.staticflickr.com/7548/26878861155_6626305f6d_b.jpg DSC04399-2 by unoh7, 300/2.8
I'd like to see the new M9 spec cover glass on the A7 series. And I have yet to see many shots from a A7r2 mod....Show more →
Hi Charlie,
You just did not have the colro balance/color profile for the the A7M V3 sensor cover. I am generally quite pleased with the color rendering that I am getting with my A7rM V3 and my lenses. I used my X-Rite Color Checker and software with LR to create my color profiles. I may want to go back to re-confirm some of my Color Profiels though. I use the color profiles as my starting point though I will still tweak the results to create what I want just as I had done with my stock A7r before the modification. I will also have to work with my newly aquired and previously owned stock A7r.
Before someone asks why I have not posted the Profiles, as I had mentiioned to Michael in a PM the profiles created wth the X-Rite Color Profiles and LR are supposed to be camera specific and when using LR are only available for that camera when I process my images. I might be able to find the profiles, but I doubt that they would prove beneficial to anyone.
p.11 #20 · Kolari Mod's Improvements: A Summary of Tests
Rich,
Profiles are specific to the model but not the individual camera. So please share.
Charlie,
Did you ever resolve your problem getting LR to pick up the A7M v2 1604 profile I posted?
Michael
naturephoto1 wrote:
Hi Charlie,
You just did not have the colro balance/color profile for the the A7M V3 sensor cover. I am generally quite pleased with the color rendering that I am getting with my A7rM V3 and my lenses. I used my X-Rite Color Checker and software with LR to create my color profiles. I may want to go back to re-confirm some of my Color Profiels though. I use the color profiles as my starting point though I will still tweak the results to create what I want just as I had done with my stock A7r before the modification. I will also have to work with my newly aquired and previously owned stock A7r.
Before someone asks why I have not posted the Profiles, as I had mentiioned to Michael in a PM the profiles created wth the X-Rite Color Profiles and LR are supposed to be camera specific and when using LR are only available for that camera when I process my images. I might be able to find the profiles, but I doubt that they would prove beneficial to anyone.
