lsds
Member
Some images from testing today : CG 21(PCX 1500 inverse mounted) on Z6 with the new TZG AF adapter.
@f/8
@f/8
@f/2.8
@f/8
@f/8
@f/2.8
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Contax G Lenses - Any happy digital camera users out there?
- Thread starter moranjr
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AdaptedLenses
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Looks decent. A bit more shading than I’d expect but not too bad.
lsds
Member
Thanks! By “shading”, I assume you refer to the darker tones/level?
AdaptedLenses
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Appears to have some color shift into the corners which was largely (but not completely) mitigated with BSI sensors, but then the 21 and 28 are both pretty extreme lens cases.
lsds
Member
Shift & falloff is indeed minimal and mainly seen on the CG 21 rather. Processing RAW normally gets rid of any cast or falloff & renders better results if correction profile is applied.
Some CG 28 shots for reference with TZG. Loved the quick focus & AF-C on the TZG hat lets you now shoot from hip discreetly in street foto style.
CG 28 (PCX 1500 inverse) on Z6 with TZG AF adapter
CG 28 @f/8
CG 28 @f/2.8
CG90 focussing speed was decent in low light. A viewfinder temporary blackout/focus delay is occasionally seen if light is poor(focus hunting lag I assume). Except that, no other issues on the 90 and quite impressive performance .
CG90 @f/2.8 on Z6 with TZG-01 adapter
JW PHOTO
Senior Member
I was wondering how long it took for you to receive your PCX filter from OPTOSIGMA? I ordered mine 9/12/2021 and still haven't received it yet. I contacted them about a month ago and they informed me that my filter was about to be coated. They said they would inform me when it shipped, but no word yet. Not upset, but just curious. JohnWFYI: To correct corner-issues on mirrorless for the Contax G 28mm and 21mm lenses. This works by changing the effective angle of light rays coming out of the lens (makes the angle less less obtuse). Apparently it also affects focal length of the lens slightly (Maybe someone can chime in with some technical background).
Parts needed:
Put it together: The plano-convex lens should be attached reversed (with the curved side towards the camera). You can tell which side is curved by placing the lens on a flat surface. The lens should be sandwiched between the 46mm-55mm step up and 55-52 step down and the inner retaining ring. Make sure it is centered (I used small strips of rubber band around the perimeter).
- EU -> https://www.optosigma.com/eu_en/pla...0mm-focal-length-400-700nm-SLB-50-1500PM.html
- USA -> https://www.optosigma.com/us_en/pla...0mm-focal-length-400-700nm-SLB-50-1500PM.html
- Fotodiox 46mm-55mm step up ring.
- K&F 55mm-52mm step down ring.
- Cheap transparent/UV 52mm filter from Amazon that has an inner retaining ring.
Sample Images:
Landscape at F5.6 or higher. Notice there's still some vignetting at smaller apertures. This is normal for Biogon/Symmetrical designs.
At F2.8 - Excellent 3D pop/microcontrast from this lens.
More info here: https://www.fredmiranda.com/forum/topic/1453834?b=2
JW PHOTO
Senior Member
Well, I guess the holdup must be the coating line then. They probably have to wait for a certain amount of glass to build up before it's worthwhile to operate it. I'll just keep waiting. JohnW
lsds
Member
Where are you based? In Europe, the last time I had ordered(in Belgium) for a friend in 2020, I received it from OS Germany in about 2 weeks. They also had a lot on stock. I now unfortunately see 3-6 weeks delivery time for OS Germany as well!
Another option would be to try a similar focal length Plano convex coated lens from eksma but believe they are slightly thicker and not too many tests/examples out there so will be a trial/error.
https://eksmaoptics.com/optical-com...AISooJaWZB_QBGpoPt6mjKtXp-QvyumcaAgc2EALw_wcB
Another option would be to try a similar focal length Plano convex coated lens from eksma but believe they are slightly thicker and not too many tests/examples out there so will be a trial/error.
https://eksmaoptics.com/optical-com...AISooJaWZB_QBGpoPt6mjKtXp-QvyumcaAgc2EALw_wcB
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lsds
Member
More with the Nikon Z6 & TZG -01 combo
CG45
CG21
CG90
CG45
CG21
CG90
JW PHOTO
Senior Member
I finally got my PCX 1500 from O.Sigma. I followed all the instructions here as to how to assemble the components, but I'm having a slight problem with focus. I think it might be my adapter, but I'm not sure. Anyway, the issue is I can't reach infinity focus. That is using manual focus or AF. Yes, AF since I'm using the latest Techart adapter with my Sony A7RII. If I set the lens to f8 or f11 the DOF will give me adequate infinity focus, but any aperture wider than f8, and it won't give me good infinity focus. Actually, f5.6 is close, but still no cigar. I have another all manual adapter up at my cottage, but that's of no help here right now. I guess my question is do any of you folks have problems reaching infinity focus with Techart adapters or any adapter for that matter. I sure hate to run around at f8 all the time if I don't have to. Other than this problem, the PCX 1500 works great at cleaning up the edges of the scene. JohnW
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R
rich_cx139
Guest
Have had no probs and I have about 4 kipon or clone type adapters ( to sony FE ) and I had a couple of fotodiox ones which I sold. Don’t have the techart.
They all focussed past infinity on the 21,28,45 and 90.
Can you get infinity focus without the pcx ?
Is the pcx reversed as it should be ie flat side towards the world ?
Only thing i can suggest is to get hold of that manual you have or get another cheap manual adapter - amazon usually have some or ebay if you are able to wherever you are.
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Joachim Wulfers
Veteran Member
All my cheap manual adapters focus past infinityI have been using these for some time now and am a satisfied user:
First on the NEX 5N and then on the A6000. I am a satisfied user and also adapt many other lenses. My preferred lenses on the A6000 though are two Voigtänder, the Ultron 35/1.7 and the color Heliar 75/2.5
--
JoWul
JW PHOTO
Senior Member
That's what I wanted to know. It's my Techart adapter that's causing the problems. And, yes, I can get infinity focus without the PC lens in place and I have the flat side toward the world. Thanks much for the help and the answer to my issue. I feel better knowing there is a cure. JohnWAll my cheap manual adapters focus past infinityI have been using these for some time now and am a satisfied user:
First on the NEX 5N and then on the A6000. I am a satisfied user and also adapt many other lenses. My preferred lenses on the A6000 though are two Voigtänder, the Ultron 35/1.7 and the color Heliar 75/2.5
AdaptedLenses
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Sometimes cheap adapters have enough slop you don't run across this issue. But on a decent one, or the Techart you will. Basically along with correcting the field curvature the Optosigma changes Infinity some.
The fix is actually easy, but if you're trying to use the lens on film as well (G1, G2) then bad news...
Basically unscrew the vanity ring, remove 3-4 small screws (get real JIS screwdrivers, it really does make a difference). Now put your hand over the front and carefully invert the lens. The optical block will be loose and will fall out into your hand. Either on the optical block or still on the housing underneath will be thin brass shims. Remove, reinstall and you should be good to go with infinity.
At that step, I've advise checking centering. I don't know if the shims were wedge shaped, but I've found a strip or two of tape to help centering after removing the shims.
Shims:
Edit: if anyone needs shims cause they're trying to use a modified lens on a film camera, I have some extra...
The fix is actually easy, but if you're trying to use the lens on film as well (G1, G2) then bad news...
Basically unscrew the vanity ring, remove 3-4 small screws (get real JIS screwdrivers, it really does make a difference). Now put your hand over the front and carefully invert the lens. The optical block will be loose and will fall out into your hand. Either on the optical block or still on the housing underneath will be thin brass shims. Remove, reinstall and you should be good to go with infinity.
At that step, I've advise checking centering. I don't know if the shims were wedge shaped, but I've found a strip or two of tape to help centering after removing the shims.
Shims:
Edit: if anyone needs shims cause they're trying to use a modified lens on a film camera, I have some extra...
Last edited:
R
rich_cx139
Guest
Well, I hadn't considered that complication ! - very useful post.Sometimes cheap adapters have enough slop you don't run across this issue. But on a decent one, or the Techart you will. Basically along with correcting the field curvature the Optosigma changes Infinity some.
The fix is actually easy, but if you're trying to use the lens on film as well (G1, G2) then bad news...
Basically unscrew the vanity ring, remove 3-4 small screws (get real JIS screwdrivers, it really does make a difference). Now put your hand over the front and carefully invert the lens. The optical block will be loose and will fall out into your hand. Either on the optical block or still on the housing underneath will be thin brass shims. Remove, reinstall and you should be good to go with infinity.
At that step, I've advise checking centering. I don't know if the shims were wedge shaped, but I've found a strip or two of tape to help centering after removing the shims.
Shims:
Edit: if anyone needs shims cause they're trying to use a modified lens on a film camera, I have some extra...
I sold my G2 bodies some time ago so I will only be using them on a Z6 ( previously an A7 ). As you suggested, my Kipon and Fotodiox adapters are / were all short so never had an issue.
I see that putting a 1.5m lens in front of the 28, say, shifts the image plane forward ( for an object at infinity ) by 0.5 mm - quite a lot - hence the need to remove the shim.
I did think of getting the Ta ga3 when I had the Sony but now the TZg-01 is out ( and I haven't seen poor reviews of it - few users ? ) it had occurred to me to get the Z version but it is mighty expensive just for getting AF on lenses that I only use occassionaly and usually for landscapes / city scenes etc where I tend to manually focus anyway.
Incidentally, and I may have said it before, I don't see much of a difference in corner smearing etc etc between an A7 and the Z6.
I still like the Biogons, sometimes, but the vignetting is pretty heavy as well ( more so than I remember on film due to reflectivity differences etc )
JW PHOTO
Senior Member
Altering my 28mm G Biogon is not an option for me, so I just decided to get a manual adapter off the auction site instead. I won't be going back up to my cottage for a while, so just purchased one for use at home. I think I'll use this new manual adapter as a permanent adapter on the 28mm, the Techart AF adapter on the 45mm and the other manual adapter I have permanently on the 90mm. That should solve all my problems, I hope. As to the vignetting on the 28mm? I can live with that, but couldn't live with the edge/corner smearing. I'll let you know how the manual focus adapter works with the 28mm + PCX 1500 when it arrives in a few days. JohnWWell, I hadn't considered that complication ! - very useful post.Sometimes cheap adapters have enough slop you don't run across this issue. But on a decent one, or the Techart you will. Basically along with correcting the field curvature the Optosigma changes Infinity some.
The fix is actually easy, but if you're trying to use the lens on film as well (G1, G2) then bad news...
Basically unscrew the vanity ring, remove 3-4 small screws (get real JIS screwdrivers, it really does make a difference). Now put your hand over the front and carefully invert the lens. The optical block will be loose and will fall out into your hand. Either on the optical block or still on the housing underneath will be thin brass shims. Remove, reinstall and you should be good to go with infinity.
At that step, I've advise checking centering. I don't know if the shims were wedge shaped, but I've found a strip or two of tape to help centering after removing the shims.
Shims:
Edit: if anyone needs shims cause they're trying to use a modified lens on a film camera, I have some extra...
I sold my G2 bodies some time ago so I will only be using them on a Z6 ( previously an A7 ). As you suggested, my Kipon and Fotodiox adapters are / were all short so never had an issue.
I see that putting a 1.5m lens in front of the 28, say, shifts the image plane forward ( for an object at infinity ) by 0.5 mm - quite a lot - hence the need to remove the shim.
I did think of getting the Ta ga3 when I had the Sony but now the TZg-01 is out ( and I haven't seen poor reviews of it - few users ? ) it had occurred to me to get the Z version but it is mighty expensive just for getting AF on lenses that I only use occassionaly and usually for landscapes / city scenes etc where I tend to manually focus anyway.
Incidentally, and I may have said it before, I don't see much of a difference in corner smearing etc etc between an A7 and the Z6.
I still like the Biogons, sometimes, but the vignetting is pretty heavy as well ( more so than I remember on film due to reflectivity differences etc )
AdaptedLenses
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Comparison of what the PCX can accomplish, as you can see it's necessary and useful for the G28, I think you'll be happy. Fortunately the manual adapter should be fine, but at least the TA-GA3 didn't focus the lens quite far enough to retain infinity so you had to mod the rings.
As far as Sony vs Nikon, not surprised, the filter stack difference is 2.5mm Sony vs 2.3mm Nikon. Meaning there's a slight difference but not enough to drastically change the output.
As far as Sony vs Nikon, not surprised, the filter stack difference is 2.5mm Sony vs 2.3mm Nikon. Meaning there's a slight difference but not enough to drastically change the output.
Altering my 28mm G Biogon is not an option for me, so I just decided to get a manual adapter off the auction site instead. I won't be going back up to my cottage for a while, so just purchased one for use at home. I think I'll use this new manual adapter as a permanent adapter on the 28mm, the Techart AF adapter on the 45mm and the other manual adapter I have permanently on the 90mm. That should solve all my problems, I hope. As to the vignetting on the 28mm? I can live with that, but couldn't live with the edge/corner smearing. I'll let you know how the manual focus adapter works with the 28mm + PCX 1500 when it arrives in a few days. JohnWWell, I hadn't considered that complication ! - very useful post.Sometimes cheap adapters have enough slop you don't run across this issue. But on a decent one, or the Techart you will. Basically along with correcting the field curvature the Optosigma changes Infinity some.
The fix is actually easy, but if you're trying to use the lens on film as well (G1, G2) then bad news...
Basically unscrew the vanity ring, remove 3-4 small screws (get real JIS screwdrivers, it really does make a difference). Now put your hand over the front and carefully invert the lens. The optical block will be loose and will fall out into your hand. Either on the optical block or still on the housing underneath will be thin brass shims. Remove, reinstall and you should be good to go with infinity.
At that step, I've advise checking centering. I don't know if the shims were wedge shaped, but I've found a strip or two of tape to help centering after removing the shims.
Shims:
Edit: if anyone needs shims cause they're trying to use a modified lens on a film camera, I have some extra...
I sold my G2 bodies some time ago so I will only be using them on a Z6 ( previously an A7 ). As you suggested, my Kipon and Fotodiox adapters are / were all short so never had an issue.
I see that putting a 1.5m lens in front of the 28, say, shifts the image plane forward ( for an object at infinity ) by 0.5 mm - quite a lot - hence the need to remove the shim.
I did think of getting the Ta ga3 when I had the Sony but now the TZg-01 is out ( and I haven't seen poor reviews of it - few users ? ) it had occurred to me to get the Z version but it is mighty expensive just for getting AF on lenses that I only use occassionaly and usually for landscapes / city scenes etc where I tend to manually focus anyway.
Incidentally, and I may have said it before, I don't see much of a difference in corner smearing etc etc between an A7 and the Z6.
I still like the Biogons, sometimes, but the vignetting is pretty heavy as well ( more so than I remember on film due to reflectivity differences etc )
R
rich_cx139
Guest
Last saw figures for the Z7 and Z6 e.g.Kolari stripdown quoting 1.1 mm for the stack thickness - frankly I didn't believe it ( from the comparisons I did some time ago when I had an A7 and a Z6 ). I resume that estimate has somehow changed now. Anyway it is what it is.
Great comparison of the 28 with various stack thicknesses and PCX / Kolari (?) btw
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AdaptedLenses
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He's talking about the upper layers of Hot Mirror etc. Not the total thickness, which includes an epoxied coverglass that Kolari doesn't usually remove. I've had conversations with numerous folks across the internet including some bloggers etc. that talk to Nikon confirming the 2.3mm number, which also fits what I've seen, ie very slightly better than Sony.
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