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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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 Posted: Sat Nov 26, 2022 9:43 pm Post subject: |
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stevemark wrote:
I have one of those rare birds too. Sadly it came with a badly fogged lens surface deep within the system. Images taken therefore are very low-contrast. Nevertheless I can confirm that the lens is unusually free from CAs, and unusually sharp over the entire field. The aperture of my lens is stuck wide open, and therfore I assume that the affected lens surface(s) is just where the aperture sits.
Does anyone have experience in dismantling contemporary Sigma zooms? I suspect the general construction of the 50-200 APO would not be that different from other Sigma zooms of its time ...
Thanks for any hints!
S
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Phalbert
Joined: 17 May 2009
Posts: 325
Location: Namibia
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| Posted: Sun Nov 27, 2022 12:09 pm Post subject: |
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Phalbert wrote:
Doesn't the adapter work as an extension tube ? In which case you'd loose infinity focus too. Or your adapter comes with a glass element and these are known to often lack precision and worsen performance.
That lens was originally sold with a dedicated close-up lens.
_________________
🙋 My wishlist: Titan or Idaho 135/1,8; Nikon Df Vivitar 35-85 f2,8 AI Nikkor 105/1,8
My dream lenses: Zuiko 85/1,4 prototype
Zeiss CY: 55/1,2 85/1,2
Astro Berlin 250/2 Canon EF 50/1,0 85/1,2
Nikkor 105/1,4
My favorites:
Zuiko 50/1,2 100/2
Viv S1 70-210/3.5 (v1) + 2.8 - 4 (v3)
FD 55/1,2 SSC
Nikon 20-35/2,8 AF 50/1,4S 50/1,2AIS 55/1,2S 180/2,8AI 300/4,5 H Reflex 500/8 C + 500/8 N 200-400/4 AIS
Sigma 500/4,5 APO Sigma YS 135/1,8
MD 58/1,2
PK Sigma 15/2,8 ATX 150-500
M42 Chinon 55/1,2 Biotar 75/1,5 Polaris 55-300/4,5 Soligor 180/3,5 200/2,8CD Han 23/3,5
Helios 44-2 44-4
CY Planar 50/1,4 85/1,4AEJ
Tamron 35-105/2,8 24/2,5 350/5,6
Yashica 5cm/2
Takumar 50/1,4 - 8 50/1,4 - 7
My stolen stuff: Zuiko 24/2 #106874; Zuiko 35-80/2,8 #102180; Zuiko 35/2 #119168; Zuiko 90/2 macro #102858; Zuiko x1,4 converter #102019; Tamron 17/3,5 #400567; Tamron 400/4 #80407; Soligor 135/2 #17506600 Sigma 28/1,8 #1001124 |
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bp_reid
Joined: 06 Jan 2021
Posts: 57
Location: London, UK
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| Posted: Wed Nov 30, 2022 4:25 pm Post subject: |
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bp_reid wrote:
| stevemark wrote: |
I have one of those rare birds too. Sadly it came with a badly fogged lens surface deep within the system. Images taken therefore are very low-contrast. Nevertheless I can confirm that the lens is unusually free from CAs, and unusually sharp over the entire field. The aperture of my lens is stuck wide open, and therfore I assume that the affected lens surface(s) is just where the aperture sits.
Does anyone have experience in dismantling contemporary Sigma zooms? I suspect the general construction of the 50-200 APO would not be that different from other Sigma zooms of its time ...
Thanks for any hints!
S |
I had a clear-ish one in OM mount a while back and it was really nice, such a shame that fogged element is standard feature for that lens. |
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Phalbert
Joined: 17 May 2009
Posts: 325
Location: Namibia
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| Posted: Wed Nov 30, 2022 6:37 pm Post subject: |
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Phalbert wrote:
I've been eyeing an AIS mount copy for a while. According to seller, very clean, no haze, fog or separation... It looks really good on the pics too. But it's expensive. Has anyone an idea what would be a decent price for such a lens ? I do realize that it's an old lens and even if it's neat now, problems could arise very soon... 🤷♂️ Thanks guys.
_________________
🙋 My wishlist: Titan or Idaho 135/1,8; Nikon Df Vivitar 35-85 f2,8 AI Nikkor 105/1,8
My dream lenses: Zuiko 85/1,4 prototype
Zeiss CY: 55/1,2 85/1,2
Astro Berlin 250/2 Canon EF 50/1,0 85/1,2
Nikkor 105/1,4
My favorites:
Zuiko 50/1,2 100/2
Viv S1 70-210/3.5 (v1) + 2.8 - 4 (v3)
FD 55/1,2 SSC
Nikon 20-35/2,8 AF 50/1,4S 50/1,2AIS 55/1,2S 180/2,8AI 300/4,5 H Reflex 500/8 C + 500/8 N 200-400/4 AIS
Sigma 500/4,5 APO Sigma YS 135/1,8
MD 58/1,2
PK Sigma 15/2,8 ATX 150-500
M42 Chinon 55/1,2 Biotar 75/1,5 Polaris 55-300/4,5 Soligor 180/3,5 200/2,8CD Han 23/3,5
Helios 44-2 44-4
CY Planar 50/1,4 85/1,4AEJ
Tamron 35-105/2,8 24/2,5 350/5,6
Yashica 5cm/2
Takumar 50/1,4 - 8 50/1,4 - 7
My stolen stuff: Zuiko 24/2 #106874; Zuiko 35-80/2,8 #102180; Zuiko 35/2 #119168; Zuiko 90/2 macro #102858; Zuiko x1,4 converter #102019; Tamron 17/3,5 #400567; Tamron 400/4 #80407; Soligor 135/2 #17506600 Sigma 28/1,8 #1001124 |
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eggplant
Joined: 27 May 2020
Posts: 488
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| Posted: Wed Nov 30, 2022 10:22 pm Post subject: |
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eggplant wrote:
Just saying, I have wanted a 50-200mm f3.5-4.5 for a while now, and for a bit more I think I will opt for the Canon 50-200mm f3.5-4.5L.
As nice as the manual focus limiter is on this, and even if a rare deal could come up, the inner issues keep me away from going above £30 territory.
I passed up on one of these recently in decent nick for £15 on eBay before I wanted a 50-200mm  I am still annoyed.
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Phalbert
Joined: 17 May 2009
Posts: 325
Location: Namibia
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| Posted: Thu Dec 01, 2022 11:05 am Post subject: |
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Phalbert wrote:
[quote="eggplant"]Just saying, I have wanted a 50-200mm f3.5-4.5 for a while now, and for a bit more I think I will opt for the Canon 50-200mm f3.5-4.5L.
As nice as the manual focus limiter is on this, and even if a rare deal could come up, the inner issues keep me away from going above £30 territory.
https://www.ebay.com/itm/303280085085
$ 720 🤔 Not exactly cheap... 😕 It seems to be rather rare too...
_________________
🙋 My wishlist: Titan or Idaho 135/1,8; Nikon Df Vivitar 35-85 f2,8 AI Nikkor 105/1,8
My dream lenses: Zuiko 85/1,4 prototype
Zeiss CY: 55/1,2 85/1,2
Astro Berlin 250/2 Canon EF 50/1,0 85/1,2
Nikkor 105/1,4
My favorites:
Zuiko 50/1,2 100/2
Viv S1 70-210/3.5 (v1) + 2.8 - 4 (v3)
FD 55/1,2 SSC
Nikon 20-35/2,8 AF 50/1,4S 50/1,2AIS 55/1,2S 180/2,8AI 300/4,5 H Reflex 500/8 C + 500/8 N 200-400/4 AIS
Sigma 500/4,5 APO Sigma YS 135/1,8
MD 58/1,2
PK Sigma 15/2,8 ATX 150-500
M42 Chinon 55/1,2 Biotar 75/1,5 Polaris 55-300/4,5 Soligor 180/3,5 200/2,8CD Han 23/3,5
Helios 44-2 44-4
CY Planar 50/1,4 85/1,4AEJ
Tamron 35-105/2,8 24/2,5 350/5,6
Yashica 5cm/2
Takumar 50/1,4 - 8 50/1,4 - 7
My stolen stuff: Zuiko 24/2 #106874; Zuiko 35-80/2,8 #102180; Zuiko 35/2 #119168; Zuiko 90/2 macro #102858; Zuiko x1,4 converter #102019; Tamron 17/3,5 #400567; Tamron 400/4 #80407; Soligor 135/2 #17506600 Sigma 28/1,8 #1001124 |
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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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| Posted: Sat Sep 16, 2023 7:48 pm Post subject: |
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stevemark wrote:
Does anyone have the lens section of the Sigma 3.5-4.5/50-200mm APO?
I just have been trying to clean at lest the rear part of the lens (which is easily accessible), but managed to make a mess when re-assembling the rearmost part. It contains of three single lenses spaced with two spacers ... so quite a few possible combinations to try! As usual I was talking images while disassembling, but the one showing the lens stack wasn't properly focused ... and now I have a problem of course!
Thanks for any help ... 
S
S
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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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| Posted: Sat Sep 16, 2023 9:53 pm Post subject: |
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stevemark wrote:
Well, after looking carefully at the pictures above I came to the conclusion ...
1) that I knew the correct relative position of the three lenses (negative lens towards the aperture, thin positive lens in the ,middle, and thick positive lens at the rear)
2) that I knew the position of the spacers (a thin and a thicker one)
3) that I knew the correct orientation of the outermost lens (flat side towards the rear end)
That left only four possible combinations for the orientation of the remaining two lenses.
Trial-and-error did reveal the correct position and orientation of all three lenses (of course only fourth combination I tried aws the correct one).
Here it is - for the records:
So now the aperture is working again (it was oily and stuck wide open), and we know how to clean the rear part of the lens. The tricky part - cleaning the foggy lenses either in the front part of the masterlens or between master lens and compensator - is yet to come. I suspect that I have to open the lens from the front. There are no visible screws, and either one has to remove the front ring, or access is via some screws hidden behind the rubber of the focus/zoom ring. If I manage to open the lens I will publish a repair guid in the "Repair" section.
S
S
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eggplant
Joined: 27 May 2020
Posts: 488
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| Posted: Sat Sep 16, 2023 11:05 pm Post subject: |
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eggplant wrote:
Nice to tackle this, though.
I have a colleague who disassembled theirs on a German language forum I can dig up, I'm not sure I found a diagram at the time of discussion. I can probably find one in an archived magazine, but it's this sort of Sigma literature I'm interested in...
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caspert79
Joined: 31 Oct 2010
Posts: 2546
Location: The Netherlands
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| Posted: Sun Sep 17, 2023 11:33 am Post subject: |
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caspert79 wrote:
Would be nice to see some sample images made with this lens.
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For sale:
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PM for more info |
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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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| Posted: Sun Sep 17, 2023 6:22 pm Post subject: |
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stevemark wrote:
| eggplant wrote: |
Nice to tackle this, though.
I have a colleague who disassembled theirs on a German language forum I can dig up, I'm not sure I found a diagram at the time of discussion. I can probably find one in an archived magazine, but it's this sort of Sigma literature I'm interested in... |
Took me a few hours to complete the job (actually it was 03:40 in the morning when the lens was re-assembled), but it's working now.
| caspert79 wrote: |
| Would be nice to see some sample images made with this lens. |
Yep, I will compare it to the Zeiss CY Vario-Sonnar 4/80-200mm and the Canon nFD 4/80-200mm L. OK?
S
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caspert79
Joined: 31 Oct 2010
Posts: 2546
Location: The Netherlands
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| Posted: Sun Sep 17, 2023 6:49 pm Post subject: |
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caspert79 wrote:
| stevemark wrote: |
| eggplant wrote: |
Nice to tackle this, though.
I have a colleague who disassembled theirs on a German language forum I can dig up, I'm not sure I found a diagram at the time of discussion. I can probably find one in an archived magazine, but it's this sort of Sigma literature I'm interested in... |
Took me a few hours to complete the job (actually it was 03:40 in the morning when the lens was re-assembled), but it's working now.
| caspert79 wrote: |
| Would be nice to see some sample images made with this lens. |
Yep, I will compare it to the Zeiss CY Vario-Sonnar 4/80-200mm and the Canon nFD 4/80-200mm L. OK?
S |
Thanks, that would be great.
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For sale:
- Zeiss Jena T 210mm f/4.5 large format lens on M42 bellows
PM for more info |
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Phalbert
Joined: 17 May 2009
Posts: 325
Location: Namibia
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| Posted: Sun Sep 17, 2023 8:53 pm Post subject: |
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Phalbert wrote:
I have the CY 80-200/4 and I am still thinking of that expensive Sigma someone is "holding" for me, so I'm very excited about you telling us which is best, if there is such thing. You know, one does this and that, and the other does the rest better... Thanks!
_________________
🙋 My wishlist: Titan or Idaho 135/1,8; Nikon Df Vivitar 35-85 f2,8 AI Nikkor 105/1,8
My dream lenses: Zuiko 85/1,4 prototype
Zeiss CY: 55/1,2 85/1,2
Astro Berlin 250/2 Canon EF 50/1,0 85/1,2
Nikkor 105/1,4
My favorites:
Zuiko 50/1,2 100/2
Viv S1 70-210/3.5 (v1) + 2.8 - 4 (v3)
FD 55/1,2 SSC
Nikon 20-35/2,8 AF 50/1,4S 50/1,2AIS 55/1,2S 180/2,8AI 300/4,5 H Reflex 500/8 C + 500/8 N 200-400/4 AIS
Sigma 500/4,5 APO Sigma YS 135/1,8
MD 58/1,2
PK Sigma 15/2,8 ATX 150-500
M42 Chinon 55/1,2 Biotar 75/1,5 Polaris 55-300/4,5 Soligor 180/3,5 200/2,8CD Han 23/3,5
Helios 44-2 44-4
CY Planar 50/1,4 85/1,4AEJ
Tamron 35-105/2,8 24/2,5 350/5,6
Yashica 5cm/2
Takumar 50/1,4 - 8 50/1,4 - 7
My stolen stuff: Zuiko 24/2 #106874; Zuiko 35-80/2,8 #102180; Zuiko 35/2 #119168; Zuiko 90/2 macro #102858; Zuiko x1,4 converter #102019; Tamron 17/3,5 #400567; Tamron 400/4 #80407; Soligor 135/2 #17506600 Sigma 28/1,8 #1001124 |
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RokkorDoctor
Joined: 27 Nov 2021
Posts: 1057
Location: Kent, UK
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| Posted: Mon Sep 18, 2023 9:24 am Post subject: |
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RokkorDoctor wrote:
| stevemark wrote: |
Well, after looking carefully at the pictures above I came to the conclusion ...
1) that I knew the correct relative position of the three lenses (negative lens towards the aperture, thin positive lens in the ,middle, and thick positive lens at the rear)
2) that I knew the position of the spacers (a thin and a thicker one)
3) that I knew the correct orientation of the outermost lens (flat side towards the rear end)
That left only four possible combinations for the orientation of the remaining two lenses.
Trial-and-error did reveal the correct position and orientation of all three lenses (of course only fourth combination I tried aws the correct one).
Here it is - for the records:
So now the aperture is working again (it was oily and stuck wide open), and we know how to clean the rear part of the lens. The tricky part - cleaning the foggy lenses either in the front part of the masterlens or between master lens and compensator - is yet to come. I suspect that I have to open the lens from the front. There are no visible screws, and either one has to remove the front ring, or access is via some screws hidden behind the rubber of the focus/zoom ring. If I manage to open the lens I will publish a repair guid in the "Repair" section.
S
S |
Thanks for documenting this. 
Next time I would recommend also to make a note of the orientation of the spacers, i.e. which way the spacers need to face, which is the front side and which the back side of a spacer. Sometimes it is obvious, other times not so much, but they are rarely truly symmetrical.
Spacers are usually machined for appropriate contact with the lens surface, which can mean a knife-edge contact on the lens surface, or a chamfered full edge contact to match the surface curvature of a convex lens, or e.g. flat machined for rim-contact on concave lens surfaces.
Sometimes this is important for correct mechanical lens centering; some lenses' diameter is machined significantly smaller than the pocket on purpose so it can be centered by circumferential contact with a precision-machined spacer for significantly convex surfaces; other lenses are machined to within about 10 microns of the pocket diameter to be centered by the pocket itself.
"Mounting Optics in Optical Instruments" by Paul R. Yoder Jr., 2nd edition, 2008, SPIE, is an interesting reference to find out about all aspects on lens mounting and mechanical centering arrangements.
_________________
Mark
SONY A7S, A7RII + dust-sealed modded Novoflex/Fotodiox/Rayqual MD-NEX adapters
Minolta SR-1, SRT-101/303, XD7/XD11, XGM, X700
Bronica SQAi
Ricoh GX100
Minolta majority of all Rokkor SR/AR/MC/MD models made
Sigma 14mm/3.5 for SR mount
Tamron SP 60B 300mm/2.8 (Adaptall)
Samyang T-S 24mm/3.5 (Nikon mount, DIY converted to SR mount)
Schneider-Kreuznach PC-Super-Angulon 28mm/2.8 (SR mount)
Bronica PS 35/40/50/65/80/110/135/150/180/200/250mm |
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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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| Posted: Mon Sep 18, 2023 12:46 pm Post subject: |
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stevemark wrote:
| bp_reid wrote: |
I had a clear-ish one in OM mount a while back and it was really nice, such a shame that fogged element is standard feature for that lens. |
Epoxy gone mad ...
| RokkorDoctor wrote: |
Thanks for documenting this.
Next time I would recommend also to make a note of the orientation of the spacers, i.e. which way the spacers need to face, which is the front side and which the back side of a spacer. Sometimes it is obvious, other times not so much, but they are rarely truly symmetrical. |
I'm pretty much aware of that - but I really couldn't see any difference (which of course doesn't mean that there was no difference) ... I may sooner or later decide to re-open that rear lens system (quite easy without having to disassemble anything else), change the orientation of the spacers and see whether it influences performance and/or centering).
| RokkorDoctor wrote: |
Spacers are usually machined for appropriate contact with the lens surface, which can mean a knife-edge contact on the lens surface, or a chamfered full edge contact to match the surface curvature of a convex lens, or e.g. flat machined for rim-contact on concave lens surfaces.
Sometimes this is important for correct mechanical lens centering; some lenses' diameter is machined significantly smaller than the pocket on purpose so it can be centered by circumferential contact with a precision-machined spacer for significantly convex surfaces; other lenses are machined to within about 10 microns of the pocket diameter to be centered by the pocket itself.
"Mounting Optics in Optical Instruments" by Paul R. Yoder Jr., 2nd edition, 2008, SPIE, is an interesting reference to find out about all aspects on lens mounting and mechanical centering arrangements. |
Thanks a lot for that information and the reference!
I'm absolutely aware that my repairing of the Sigma 3.5-4.5/50-200mm APO isn't perfect, especially since the fogging / yellowing was caused by "epoxy gone mad". The whole idea to look closer at the 50-200mm APO came pretty spontaneously (usually I try to avoid repairing zoom lenses), and I wasn't well prepared to be honest. I didn't even assume I would be able to re-assemble the lens; it was more like "hey, let's see how that thing is constructed ...". Anyway - I have to some other work to do now, but I'll publish the entire repair procedure later on in the "Repair" section.
S
EDIT: here are three 100% crops from the corners (24 MP FF), all taken at 200mm and f8. First Canon nFD 4/80-200L:
Now the Sigma 3.5-4.5/50-200mm APO:
And finally the Zeiss CY 4/80-200mm:
I am pretty sure that my preliminary repair of the Sigma isn't perfect (yet). Two things come to my mind:
1) possible hiccup with the spacers in the rear group (as discussed above) and
2) the fogged epoxy-cemented doublet was successfully separated and cleaned, but not re-cemented (and not centered of course).
These two issues may prevent my Sigma to show its full resolution. For time being, this preliminary repair is a huge improvement over its earlier condition . I am sure I will disassemble the lens again, re-cement the doublet and try to find the correct orientation of the two spacers in the rear group.
S
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caspert79
Joined: 31 Oct 2010
Posts: 2546
Location: The Netherlands
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| Posted: Mon Sep 18, 2023 2:25 pm Post subject: |
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caspert79 wrote:
Thanks for your efforts Stephan.
The Zeiss is very sharp and quite affordable I noticed. Its CA could most likely be dealt with in PP.
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For sale:
- Zeiss Jena T 210mm f/4.5 large format lens on M42 bellows
PM for more info |
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stevemark
Joined: 29 Apr 2011
Posts: 3264
Location: Switzerland
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| Posted: Mon Sep 18, 2023 2:50 pm Post subject: |
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stevemark wrote:
| caspert79 wrote: |
Thanks for your efforts Stephan.
The Zeiss is very sharp and quite affordable I noticed. |
Yes, especially wide open at f4 it has visibly sharper corners than e. g. the Canon nFD 4/80-200L. At f=200mm the Zeiss CY 4/80-200mm is as good at f4 as it is at f8 (apart from vignetting of course).
| caspert79 wrote: |
| Its CA could most likely be dealt with in PP. |
Yep. I got mine for about CHF 120.-- several years ago, and I recently noticed several samples going for around CHF 150.--. Ceratinly not too expensive for its build quality and performance. Especially in the 100mm to 120mm range the Zeiss is extremely well corrected*: Tack sharp corners on 43MP FF, no lateral CAs at all, and no visible distortion. And MFD is a mere 1.0 m over the entire range. Certainly an early masterpiece by Lothar Kölsch!
S
* around f=135mm the Zeiss CY 4/80-200mm clearly outperforms any vintage 2.8/135mm lens I'm aware of - Canon nF, Konica AR f2.5 and f3.2, Leica R, Mamiya SX, CS, and E, Minolta MC and MD (6L, 5L and 4L versions), Nikkor AI, Olympus OM, Pentax Yashica ML, Zeiss CY - you name it!
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