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02-10-2011, 02:06 AM   #1
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Convert an m42 to auto-tak like operation?

I would like to focus wide open with my m42s by either pressing or realeasing a 'pin'.I can then immediately meter at my chosen aperature. This would help focus without having to manually turning the ring. Even worse, trying to focus at say f22!

02-10-2011, 02:23 AM   #2
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Use the auto-manual switch, if your lenses have one.
02-10-2011, 03:34 AM   #3
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Mike,
My 135mm f3.5 ISCO has no such switch It's impossible to focus wide and then turn to the aperture I want. It's all metal and very stiff. When I try, the whole camera moves from the effort.Love the lens, has the best warm color and amazing bokeh.
02-10-2011, 04:50 AM   #4
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It almost sounds like a preset lens because a true auto lens won't stop down unless someone has rigged the pin

But if it is a preset the stop down ring shouldn't be that stiff

02-10-2011, 05:26 AM   #5
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It may be one of those auto-only lenses that don't have a switch.
02-10-2011, 05:37 AM   #6
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QuoteOriginally posted by Mike Cash Quote
It may be one of those auto-only lenses that don't have a switch.
I thought about that but it needs the auto aperture pin to be pushed to stop down. The op is complaining about not wanting to turn the aperture ring to stop down, which would not work with an auto only lens unless as I said someone has modified the lens to defeat the auto function
02-10-2011, 06:22 AM   #7
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QuoteOriginally posted by troglodyte Quote
Mike,
My 135mm f3.5 ISCO has no such switch It's impossible to focus wide and then turn to the aperture I want. It's all metal and very stiff. When I try, the whole camera moves from the effort. Love the lens, has the best warm color and amazing bokeh.
It may not be too difficult to carefully disassemble, clean, and lubricate the lens so you can easily turn the aperture ring. Don't lose the little ball that enables the aperture ring clicks.

Dave
02-10-2011, 02:42 PM   #8
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newarts,
The problem is, I would like a lever to push. That opens and shuts. either a push or release to open to f3.5 and the other to say f16. The lens has only one aperature ring. no auto. no auto lever switch. how do they add such on auto-taks?

02-10-2011, 02:46 PM   #9
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I know olympus zuikos on a film slr also work like I said. It should be a simple matter of only adding a spring that if pushed opens the aperture fully? Then once released stops down to the set aperature on the ring like it's already doing?
02-10-2011, 02:57 PM   #10
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QuoteOriginally posted by troglodyte Quote
newarts,
The problem is, I would like a lever to push. That opens and shuts. either a push or release to open to f3.5 and the other to say f16. The lens has only one aperature ring. no auto. no auto lever switch. how do they add such on auto-taks?
Can you send a photo of the mount. An auto only lens should stay wide open all the time
02-10-2011, 04:57 PM   #11
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Lowell, no contacts. It's almost 60 years old m42 lens. Just the bare flat metal that I can see. I can see what I can do to upload.
02-10-2011, 05:21 PM   #12
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QuoteOriginally posted by troglodyte Quote
newarts,
The problem is, I would like a lever to push. That opens and shuts. either a push or release to open to f3.5 and the other to say f16. The lens has only one aperature ring. no auto. no auto lever switch. how do they add such on auto-taks?
They built it into the lens design; it is an integral part of the lens. And you don't want an Auto-Takumar as the lever is only used when shooting with film bodies. On digital you have to open and close the aperture yourself. The Auto-Takumar design was just part of the evolution in the design of lenses to make them more convenient to use.

What would serve you better would be either the Super Takumar, Super-Multi-Coated Takumar, or SMC Takumar type design. Those have an auto-manual switch you can move to go from wide open to your shooting aperture. Personally, I find it less clumsy to just spin the aperture ring and count the clicks. Other brands are alright, of course; just make sure they have an auto-manual switch before you buy them. The preset lens design would also probably suit you quite well. It has two aperture rings. One of them is used to set the aperture you want to shoot at. Then you easily spin the other one from wide open and it stops on your shooting aperture....no clicks. Easy as pie.

And it sounds like your lens is broken or at least in bad shape, by the way. You might consider replacing it with one of the flavors of Takumar in 135/3.5. They're as common as stupidity so the prices are very reasonable. Shouldn't run you over $30~40.
02-10-2011, 05:49 PM   #13
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Mike,
The lens is mint. It's just old. That's how it was made 60 years ago. Done on purpose as not to accidently move the aperture ring. It's like comparing the TOS Enterprise to TNG Enterprise. It's all metal and glass. Works the way it did brand new.
02-10-2011, 05:52 PM   #14
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Have you ever seen an ISCO/Schnieder lens? Wonderful German glass that is on par with Leica. They still make cinema lenses. Guess I'll just have to use it as a specialty lens portrait lens only until I can afford a 135mm A lens. I'll try to upload some pic
02-10-2011, 05:53 PM   #15
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Oh, the lens focuses silky smooth btw. Like buttah!
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