p.13 #3 · A thinner sensor stack may be possible after all!
"But, again, all glass designed for film (no cover stack) will improve. This is what we are seeing and the only question is 'how much' on any particular lens."
Zeiss, Sony, Canon, Nikon and Zeiss might all be interested - can the evidence for the above be published for them and others to review?
p.13 #4 · A thinner sensor stack may be possible after all!
Ok you might be able to tell something from this one Elmarit 28 V3 f/8. But Derek suspects this lens may be decentered, so another copy may do better. Obviously light is bad and I had to bring up some levels so there is some noise too. A7m_Elmarit28_v3_f8 by unoh7, on Flickr
p.13 #5 · A thinner sensor stack may be possible after all!
philip_pj wrote:
"But, again, all glass designed for film (no cover stack) will improve. This is what we are seeing and the only question is 'how much' on any particular lens."
Zeiss, Sony, Canon, Nikon and Zeiss might all be interested - can the evidence for the above be published for them and others to review?
...or they might not be interested at all since they would rather sell everyone new lenses.
p.13 #6 · A thinner sensor stack may be possible after all!
Charlie, I really like all the shots in your album with the 28 Elmarit V3. I have had the 28 Cron Asph, and yes it is sharp, but I did not like it on the M240. Yet on the M9 it was very good IMO. Of course for landscapes you have a different criteria. I always found the 28 Cron Asph on the streets was almost too harsh, depending on the lighting. In lower level and contrast lighting the 28 Cron Asph was excellent.
I love the rendering and look with the 28 Elmarit V3. I feel this lens will work great for B&W conversions
p.13 #7 · A thinner sensor stack may be possible after all!
uhoh7 wrote:
Ok you might be able to tell something from this one Elmarit 28 V3 f/8. But Derek suspects this lens may be decentered, so another copy may do better. Obviously light is bad and I had to bring up some levels so there is some noise too.
Derek, what do you think?
the lens looks a little bit better, but not as big an improvement some of the more modern lenses.
it still looks worse on the left side than the right. the difference would probably be more noticeable at larger apertures.
p.13 #8 · A thinner sensor stack may be possible after all!
charles.K wrote:
Charlie, I really like all the shots in your album with the 28 Elmarit V3. I have had the 28 Cron Asph, and yes it is sharp, but I did not like it on the M240. Yet on the M9 it was very good IMO. Of course for landscapes you have a different criteria. I always found the 28 Cron Asph on the streets was almost too harsh, depending on the lighting. In lower level and contrast lighting the 28 Cron Asph was excellent.
I love the rendering and look with the 28 Elmarit V3. I feel this lens will work great for B&W conversions ...Show more →
I think many share your view, but I've been very impressed by Ron's work with the 28 Cron on the 240. It's a different lens than with the M9, but seems to perform great right across the frame.
I think the f/8 shot above suggests the v3, esp a great copy, can be pretty respectable, and it's certainly very nice closer in or with shots that don't need the edges.
Here we go around f/8 or even smaller and that one bar is quite crisp right to the edge: DSC01182 by unoh7, on Flickr
p.13 #9 · A thinner sensor stack may be possible after all!
In response to some earlier discussion on this thread about infinity focus on the mod, I suspect most who have alt lens experience understand that there is a dilemma when deciding on the 'proper' infinity focus adjustment. Remember, the sensor does have to be moved in the mod, since the thinner stack has a shorter optical path length.
I normally use the Voigtlander VM-E Close Focus adapter on the A7, and with that adapter my modified A7 does go slightly past infinity on properly calibrated lenses. (This is the same as the camera before the mod.)
However, for the project I recently got a Novoflex NEX/LEM and, with that adapter, the infinity focus is bang-on with three lenses that I know are properly calibrated (two essentially new - a 24mm Elmar 3.8 and 90mm Summarit - and a 50mm Summicron V5 that just came back from Leica for a CLA). I didn't have the Novoflex before the mod, so can't comment on that.
This test shows me that even the two most well-respected adapters don't appear to be the same. (I can't find my micrometer at the moment, but will post the measurements when I put my hands on it.) And let's not even talk about the legions of Ebay cheapies.
So, the dilemma... What should Kolari adjust focus for? The current mod appears perfect with the Novoflex - at least on properly adjusted lenses. It will be interesting to run through my larger collection and see if they are all acceptable with this adapter. I'll report on that when I have time.
With the VM-E there is some room for a lens to be off and still hit infinity. With a lot of 50+ year old lenses out there and in my collection (Leica, Canon, Nikor, etc.) I imagine some might have issues on the Novoflex, so the "safety margin" on the VM-E might be welcome. And, if those lenses are off with the Novoflex (which, again, seems properly calibrated on my A7M), they are going to be off on the Leica rangefinder, too.
So... which adapter are you using? I think a survey would be valuable as we continue to develop these modifications. If people want to PM me with their adapter choices, I'll compile some info and publish he results.
p.13 #10 · A thinner sensor stack may be possible after all!
mdemeyer wrote:
...and with that adapter my modified A7 does go slightly past infinity on properly calibrated lenses
So, the dilemma... What should Kolari adjust focus for?
I noticed that too and I feel it works well for me. See, if a precise focus at 500-->1000 --> ∞ meters is desired for landscaping shots, some degree of framing and focusing precision is required and focus EVF/LCD magnification can very precisely nail it with all lenses (all, as forget the hard stop you had with xxx camera)
p.13 #11 · A thinner sensor stack may be possible after all!
Thank you Michael for the heads up. It seems that Charlie is not having any problem with his adapter. Personally, I am using the Hawk's Factory V3 adapter right now, so I don't think the minor difference would be an issue since I can adjust infinity on this one (same thing of the Phigment adapter). I also have a Kindai (Rayqual) coming in but I can't report back until I get back my A7s.mod, which would be around mid-March . Right now, I'm afraid that the Kindai might not work well after the mod since Kindai adapter tends to get spot-on infinity as-is (better construction/design compared to Novoflex as well).
p.13 #12 · A thinner sensor stack may be possible after all!
To be clear, I don't think there will be any problem after the mod.
My experience is that focus with the VM-E seems to be the same before and after. (FYI, we used the VM-E and adjusted to achieve the same before and after in developing the mod.) I presume that the same statement would be true for the Novoflex, but I didn't own it before, so can't confirm.
So, if you have something that works now, I expect it will work the same after modification.
p.13 #13 · A thinner sensor stack may be possible after all!
mdemeyer wrote:
This test shows me that even the two most well-respected adapters don't appear to be the same. (I can't find my micrometer at the moment, but will post the measurements when I put my hands on it.) And let's not even talk about the legions of Ebay cheapies.
Michael
To complicate matters, I was told by my well known Leica repairman in Los Angeles that some M lenses can never be perfectly calibrated at infinity throughout the aperture range, which wasn't so much of an issue with film. If you want bang on infinity focus wide open, the lens may be a little off stopped down, and vice versa. In my case, it was the 35 Summicron IV that had this issue. My 35 Summicron ASPH seemed to be closer at both ends of the aperture range.
p.13 #14 · A thinner sensor stack may be possible after all!
mdemeyer wrote:
In response to some earlier discussion on this thread about infinity focus on the mod, I suspect most who have alt lens experience understand that there is a dilemma when deciding on the 'proper' infinity focus adjustment. Remember, the sensor does have to be moved in the mod, since the thinner stack has a shorter optical path length.
I normally use the Voigtlander VM-E Close Focus adapter on the A7, and with that adapter my modified A7 does go slightly past infinity on properly calibrated lenses. (This is the same as the camera before the mod.)
However, for the project I recently got a Novoflex NEX/LEM and, with that adapter, the infinity focus is bang-on with three lenses that I know are properly calibrated (two essentially new - a 24mm Elmar 3.8 and 90mm Summarit - and a 50mm Summicron V5 that just came back from Leica for a CLA). I didn't have the Novoflex before the mod, so can't comment on that.
This test shows me that even the two most well-respected adapters don't appear to be the same. (I can't find my micrometer at the moment, but will post the measurements when I put my hands on it.) And let's not even talk about the legions of Ebay cheapies.
So, the dilemma... What should Kolari adjust focus for? The current mod appears perfect with the Novoflex - at least on properly adjusted lenses. It will be interesting to run through my larger collection and see if they are all acceptable with this adapter. I'll report on that when I have time.
With the VM-E there is some room for a lens to be off and still hit infinity. With a lot of 50+ year old lenses out there and in my collection (Leica, Canon, Nikor, etc.) I imagine some might have issues on the Novoflex, so the "safety margin" on the VM-E might be welcome. And, if those lenses are off with the Novoflex (which, again, seems properly calibrated on my A7M), they are going to be off on the Leica rangefinder, too.
So... which adapter are you using? I think a survey would be valuable as we continue to develop these modifications. If people want to PM me with their adapter choices, I'll compile some info and publish he results.
Still awaiting my A7rM When I first received my A7r I measured three of my Novoflex adapters with a micrometer and there were differing tolerances and in some cases I could not focus to infinity(problem) with a few of my older M lenses. There are variations even with the same make of adapters. I also found the Metabones as supplied by Sony did also have variations. The VM-E, IMO have the best overall tolerances and the best fit.
I was about to send my A7r with Novoflex and my WATE to Camera Clinic to ensure the adapter was calibrated, no different than sending my older M lenses and M9/M240 to re-calibrated. All my M lenses have been carefully calibrated and they do drift. The weight of the 50 Nocti f/1.0, 75 Lux and 90 Cron AA does place stress on the mount and after about 1 or 2 years they do need to be checked.
I intend once I have tested and picked my favourite M lenses, I will send the A7rM and select M lenses with my VM-E adapters and have to them fine tuned and calibrated. This only takes about a day and the results are definitive.
Charlie. Very nice shots! Ron's shots with the 28 Cron Asph are great, though I think Ron could make any WA lens shine
p.13 #15 · A thinner sensor stack may be possible after all!
hiepphotog wrote:
Thank you Michael for the heads up. It seems that Charlie is not having any problem with his adapter. Personally, I am using the Hawk's Factory V3 adapter right now, so I don't think the minor difference would be an issue since I can adjust infinity on this one (same thing of the Phigment adapter). I also have a Kindai (Rayqual) coming in but I can't report back until I get back my A7s.mod, which would be around mid-March . Right now, I'm afraid that the Kindai might not work well after the mod since Kindai adapter tends to get spot-on infinity as-is (better construction/design compared to Novoflex as well)....Show more →
Yes this is the adapter I am using. I have not adjusted it for infinity and it goes well past that. I should get off the couch and do that, since I hate focusing for infinity, and am totally spoiled by the M9. But I've never had one adapter since the Nex-5 which had infinity correct so I sort of take this PITA for granted.
I'm shooting fast quite often, and I never thought I would say this: my hit rate is way better with M9! It took a while but now I shoot WO often with fast lenses. Of course I miss with both cameras. The M9 is also faster.
I'm no newbie with A7 focus: I've shot 75K frames MF at least with one version or the other. But now that I like the camera again I will have to train myself better.
Here is the Sonnetar 50 @about 1.3 today: DSC01095 by unoh7, on Flickr
Demonstrating that the M9 is not the only camera to vary Auto WB wildly with light source and color
p.13 #17 · A thinner sensor stack may be possible after all!
douglasf13 wrote:
To complicate matters, I was told by my well known Leica repairman in Los Angeles that some M lenses can never be perfectly calibrated at infinity throughout the aperture range, which wasn't so much of an issue with film. If you want bang on infinity focus wide open, the lens may be a little off stopped down, and vice versa. In my case, it was the 35 Summicron IV that had this issue. My 35 Summicron ASPH seemed to be closer at both ends of the aperture range.
Quirks abound, but I'm surprised how well the infinity stops works on nearly all my M and LTM glass in the situations where I really want it. That's usually stopped down, for sure.
When I made some threads about the 75 lux at MF lenses I heard all kinds of nightmare stories with bad cams, apparently also an issue in some Canandian 90 crons.
But if a quirky lens is used often pretty soon the shooter start to learn it , and pull back a tad or roll out to infinity x amount. I just walk around my yard and chimp to learn my off lenses. Works pretty decent and the "english" stays in your memory if you use the lens. My 135 APO front focuses just a tad: always.
p.13 #19 · A thinner sensor stack may be possible after all!
Reverting to the topic of the former page about bets, I'll make my own based purely on non optical reasoning.
Yes, it seems that if we modify the design of a film era lens ( i.e. Biogon ZM35/2) to perform it's best with a specified glass cover in mind, the resulting lens (Loxia 35) should be as good as the original glass on film -or in a digital camera with a extremely thin cover.
What happens when we translate a page of text from English to another language and the resulting text is translated back to English?. In theory we should get exactly the same original phrases. Experience tell us that this is not true, There's always something lost in the way every time we translate.
I have the strong hunch that the same happens in optics. Yes, in theory it's possible to counteract the additional astigmatism and field curvature induced by a sensor cover, with a negative astigmatism and FC. in order to preserve exactly the original performance of the lens. In the real world though, I suspect that perfection in optics isn't possible and something is always lost in that double interaction.
Therefore, my bet ( make it $0.99 at most ) :
The best Biogon on a Leica M ( or anything with a super thin cover glass) will always be somehow better than the best Loxia on a Sony A7x with a thick cover, no matter how Zeiss tries hard.
p.13 #20 · A thinner sensor stack may be possible after all!
carstenw wrote:
Douglas, if a lens cannot be calibrated at both ends, it should be sent to Leica, who can reshape the cam.
Perhaps I'm not following but I thought Douglas was referring to focus shift, which is a real issue with a number of classic rangefinder lenses. Are you suggesting there is some sort of calibration of the rangefinder that somehow adjusts for focus shift at different apertures?
, and you will be able to get good beer 
. Right now, I'm afraid that the Kindai might not work well after the mod since Kindai adapter tends to get spot-on infinity as-is (better construction/design compared to Novoflex as well).
When I first received my A7r I measured three of my Novoflex adapters with a micrometer and there were differing tolerances and in some cases I could not focus to infinity(problem) with a few of my older M lenses. There are variations even with the same make of adapters. I also found the Metabones as supplied by Sony did also have variations. The VM-E, IMO have the best overall tolerances and the best fit. 