p.32 #1 · A thinner sensor stack may be possible after all!
That's good to know, I sold my TSE 24 II after shooting it on my A7R with Metabones adapter and found strange field curvature effects which I couldn't get my head around.
p.32 #2 · A thinner sensor stack may be possible after all!
Phillip Reeve wrote:
good to know. I had a Canon Ef 16-35/4 IS vith the viltrox adapter but I returned it because of inacceptable field curvature and worse than expected corner sharpness. Where do you get your shims from?
I made the shims myself from multiple layers of thin coper foil - they work OK but took me a long time to get it right and wish that the adaptor was close to the right thickness rather than too short.
Have just done the infinity tests and I am amazed at what a difference the shimming has made. The lens now reaches infinity just before the infinity mark. Going further with shimming would have stopped the contacts from communicating with the adaptor.
The terrible field curvature that my previous test showed has disappeared and the lens performs very very well now even when fully shifted right into the corners.
p.32 #3 · A thinner sensor stack may be possible after all!
nicoimages wrote:
I made the shims myself from multiple layers of thin coper foil - they work OK but took me a long time to get it right and wish that the adaptor was close to the right thickness rather than too short.
Have just done the infinity tests and I am amazed at what a difference the shimming has made. The lens now reaches infinity just before the infinity mark. Going further with shimming would have stopped the contacts from communicating with the adaptor.
The terrible field curvature that my previous test showed has disappeared and the lens performs very very well now even when fully shifted right into the corners.
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p.32 #4 · A thinner sensor stack may be possible after all!
Phillip Reeve wrote:
interesting. Maybe I should shim one of my cheaper Minolta SR adapters for correct infinity focus. Esepcially with a Minolta 2.8/24 and as well with my 2.8/35 I noticed a lot of field curvature on my Novoflex adapter which is a bit short.
The 24 f/2.8 is quite likely to improve as it has a floating element, but the 35 f/2.8 is less likely to do so as it doesn't have one. Still shimming is always a good thing because then your focus scale will be a lot more accurate and your infinity stop will be right at infinity focus. So even if it doesn't improve image quality it will improve usability.
p.32 #5 · A thinner sensor stack may be possible after all!
Phillip Reeve wrote:
interesting. Maybe I should shim one of my cheaper Minolta SR adapters for correct infinity focus. Esepcially with a Minolta 2.8/24 and as well with my 2.8/35 I noticed a lot of field curvature on my Novoflex adapter which is a bit short.
I found that infinity focus is an issue with lenses that use internal focusing or have floating elements like the Zeiss 21/2.8 ZF and the Canon TS24MkII - that is why I could not understand initially why the Zeiss Distagon 28 and Olympus lenses where not affected and naively thought that the TS-E lens was just a bad lens. The shim material I used can be bought from ebay - it is self adhesive copper foil sold for shielding electrical circuits - have also tried the aluminium from drinks cans or even multiple layes of aluminium foil but the self adhesive works best as it stops the shims from moving around when you re-assemble the adaptor.
p.32 #6 · A thinner sensor stack may be possible after all!
nicoimages wrote:
The shim material I used can be bought from ebay - it is self adhesive copper foil sold for shielding electrical circuits - have also tried the aluminium from drinks cans or even multiple layes of aluminium foil but the self adhesive works best as it stops the shims from moving around when you re-assemble the adaptor.
p.32 #7 · A thinner sensor stack may be possible after all!
rscheffler wrote:
Not to add more to your plate, but I wonder if at your convenience, you could re-try the TS-E 24 with the correctly shimmed adapter?
nicoimages wrote:
Hello Ron
After seeing how the Zeiss 21/2.8ZF performed when the adaptor had the correct length, I spent a lot of time yesterday re-shimming the Viltrox Canon to FE adaptor.
It turned out to be a bit of a challenge as I had to ensure that the lens contacts still were in contact with the adaptor electronics after shimming.
Happy to say that the performance of the TS-E 24MKII has improved considerably now and the field curvature is almost gone. Will upload images taken at infinity from my roof terrace as soon as the weather improves and I have managed to get the shims even enough.
Great, thank you Nicholas for your efforts! Does seem to be a bit of a hassle to optimize these non-native lenses and is swaying me to stick with my Canon EOS system for this kind of technical work.
Phillip - from my brief trials with the Canon 16-35/4, it should be quite good across the frame right from wide open. Perhaps a challenge with shimming these lenses is determining where proper infinity focus is on the focusing ring, since I believe all of the AF lenses will focus beyond infinity, or at least don't have an infinity hard stop...
p.32 #10 · A thinner sensor stack may be possible after all!
rscheffler wrote:
Great, thank you Nicholas for your efforts! Does seem to be a bit of a hassle to optimize these non-native lenses and is swaying me to stick with my Canon EOS system for this kind of technical work.
Phillip - from my brief trials with the Canon 16-35/4, it should be quite good across the frame right from wide open. Perhaps a challenge with shimming these lenses is determining where proper infinity focus is on the focusing ring, since I believe all of the AF lenses will focus beyond infinity, or at least don't have an infinity hard stop...
Once the adaptor has been adjusted that should be it in theory anyway... and yes it does require a bit of effort to get there. I am very happy now that the problem has been identified and that I have a new - old Canon TS24 to re-discover and start using again as I was very disappointed with the performance originally.
p.32 #13 · A thinner sensor stack may be possible after all!
Makten wrote:
Interesting! The Loxia 35/2 seems much better in the corners wide open on my unmodified a7. Perhaps the ZM Biogon is still affected by the thinner filter stack, compared to film, which it was intended for?
ZM 2/35 far corners performance exhibits slight softness, which even shows on Leica digital bodies. Having thin focus plane at infinity while shooting wide open may not be ideal for this type of images, but luckily at f/8 it becomes fine, for Biogon.
Full res image on the Canon 100mm (worth a peep - amazing lens for something that old, small and light). Look at the texture of what looks like white area in the screen-res image. Others are scaled down about 2x. All are processed to taste (mine).
p.32 #19 · A thinner sensor stack may be possible after all!
Greggf wrote:
I'm sending my new R to them tomorrow!! They'll have it Wednesday. How long is the process?
It should be a week to 1.5-week turn around.
Mine has been there for more than a month mostly because waiting for this darn new, thinner, corrosion resistance filter. I should have mine either on Tuesday or Wednesday. I also have another un-mod A7s to show the before and after deal.
