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lumens pixel
Joined: 27 Feb 2019
Posts: 883
Expire: 2021-06-25
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 Posted: Sat May 08, 2021 1:32 am Post subject: Adaptall diaphragm |
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lumens pixel wrote:
I bought a nice Adaptall 90mm macro 52bb. Whatever the adapter the diaphragm is somewhat lazy and would not close completely unless you play a little bit with the actuator.
Is there a way to restore proper function without dismantling everything which might be out of my reach.
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Lumens Pixel
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Minolta SR mount: 16 2,8; Sigma SuperWide 24 2,8; 28 2,5; 28 2,8; 28 3,5; 35 2,8; 45 2,0; 50 1,4; 50 1,7; 50 2,0; 58 1,4; 85 2,0; 100 2,5; 100 4 Macro; 135 3,5; 135 2,8; 200 4; RF 250 5,6; 24-35 3,5; 35-70 3,5; 75-150 4; 70-210 4
Canon FD mount: Tokina RMC 17 3,5; 28 2,8; 35 2,8; 50 1,8; 50 3,5 Macro; 55 1,2; 135 3,5; 135 2,5; 200 4,0; 300 5,6; 28-55 3,5 4,5; Tokina SZ-X SD 270; 70-150 4,5; 70-210 f4; 80-200 4L; Tokina SZ-X 845
Tamron Adaptall: 28-80 3,5-4,2 (27A); 70-210 3,8-4 (46A); 60-300 (23A); 90 2,5 (52B); 35-135 3,5-4,5 (40A)
Tamron SP: 20-40 2,7-3,5 (266D) |
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cooltouch
Joined: 15 Jan 2009
Posts: 9096
Location: Houston, Texas
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| Posted: Sat May 08, 2021 4:25 am Post subject: |
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cooltouch wrote:
Inspect your lens's aperture iris blades for any oily residue. This is usually what causes sluggish aperture operation. If the blades show an oily residue, the only option is to open the lens up and clean the iris blades. Granted, this might be something you won't want to do yourself, in which case you should seek professional service.
It's worth noting that, given the used market value of the SP Adaptall-2 90mm macro, it might not be economic to have the service done. Ultimately it would be your call.
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lumens pixel
Joined: 27 Feb 2019
Posts: 883
Expire: 2021-06-25
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| Posted: Sat May 08, 2021 9:42 am Post subject: |
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lumens pixel wrote:
The blades are fine. No oil.
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Lumens Pixel
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Minolta SR mount: 16 2,8; Sigma SuperWide 24 2,8; 28 2,5; 28 2,8; 28 3,5; 35 2,8; 45 2,0; 50 1,4; 50 1,7; 50 2,0; 58 1,4; 85 2,0; 100 2,5; 100 4 Macro; 135 3,5; 135 2,8; 200 4; RF 250 5,6; 24-35 3,5; 35-70 3,5; 75-150 4; 70-210 4
Canon FD mount: Tokina RMC 17 3,5; 28 2,8; 35 2,8; 50 1,8; 50 3,5 Macro; 55 1,2; 135 3,5; 135 2,5; 200 4,0; 300 5,6; 28-55 3,5 4,5; Tokina SZ-X SD 270; 70-150 4,5; 70-210 f4; 80-200 4L; Tokina SZ-X 845
Tamron Adaptall: 28-80 3,5-4,2 (27A); 70-210 3,8-4 (46A); 60-300 (23A); 90 2,5 (52B); 35-135 3,5-4,5 (40A)
Tamron SP: 20-40 2,7-3,5 (266D) |
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marcusBMG
Joined: 07 Dec 2012
Posts: 1318
Location: Conwy N Wales
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| Posted: Sat May 08, 2021 12:36 pm Post subject: |
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marcusBMG wrote:
This seems to be a not uncommon problem with this lens, I have encountered a couple of examples, and I mention it in the lens description on pentax forums. One possible solution is to tweak the iris return spring position. There used to be a descriptive web page here:
http://www.wiratama.net/camera/category/adaptall2a93b47ccbf
But now getting a 404...
In a nutshell, remove the mount, remove the rear optical group and mounting. There is a spring that is fixed by a blob of thread locker type stuff, this needs to be relaxed slightly. Found these pics, which I think were off that site...
My own efforts, one seemed to fix, the other only partially. I have an impresion that the iris mechanics are delicately balanced, so that a bit of dirt or something making the baldes just a touch sticky has this effect.
#1
#2
#3
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Pentax K3-ii; pentax K-S2; Samsung NX 20; Lumix G1 + adapters;
Adaptall collection (proliferating!) inc 200-500mm 31A, 300mm f2.8, 400mm f4.
Primes: takumar 55mm; smc 28mm, 50mm; kino/komine 28mm f2's, helios 58mm, Tamron Nestar 400mm, novoflex 400mm, Vivitar 135mm close focus, 105mm macro; Jupiter 11A; CZJ 135mm.
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Lloydy
Joined: 02 Sep 2009
Posts: 7794
Location: Ironbridge. UK.
Expire: 2022-01-01
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| Posted: Sat May 08, 2021 4:14 pm Post subject: |
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Lloydy wrote:
The original article is there - just use Wayback Machine
https://web.archive.org/web/20210122222349/http://www.wiratama.net/camera/category/adaptall2a93b47ccbf
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lumens pixel
Joined: 27 Feb 2019
Posts: 883
Expire: 2021-06-25
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| Posted: Sat May 08, 2021 5:50 pm Post subject: |
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lumens pixel wrote:
Fantastic information, maybe out of my technical reach.
_________________
Lumens Pixel
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Minolta SR mount: 16 2,8; Sigma SuperWide 24 2,8; 28 2,5; 28 2,8; 28 3,5; 35 2,8; 45 2,0; 50 1,4; 50 1,7; 50 2,0; 58 1,4; 85 2,0; 100 2,5; 100 4 Macro; 135 3,5; 135 2,8; 200 4; RF 250 5,6; 24-35 3,5; 35-70 3,5; 75-150 4; 70-210 4
Canon FD mount: Tokina RMC 17 3,5; 28 2,8; 35 2,8; 50 1,8; 50 3,5 Macro; 55 1,2; 135 3,5; 135 2,5; 200 4,0; 300 5,6; 28-55 3,5 4,5; Tokina SZ-X SD 270; 70-150 4,5; 70-210 f4; 80-200 4L; Tokina SZ-X 845
Tamron Adaptall: 28-80 3,5-4,2 (27A); 70-210 3,8-4 (46A); 60-300 (23A); 90 2,5 (52B); 35-135 3,5-4,5 (40A)
Tamron SP: 20-40 2,7-3,5 (266D) |
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