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07-31-2011, 06:49 PM   #1
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Super-Tak 200/4 and Vivitar 28/2 won't focus at inifinity. Can I fix them myself?

Amongst my meager collection of lenses, I have two that I think are not focusing at infinity. What I'd like to know is if there's any way that I can fix them.

The Super Takumar is a beautiful lens that I'd really like to be able to use. It appears to be focusing well short of infinity. In particular, I was trying to shoot two white-tail deer at somewhere around 150' or so. WIth the lens at infinity, the in-focus area was probably a good 30' closer to me than the deer. I'm using a genuine Pentax M42 adapter with this lens.

The Vivitar 28 (not a CFWA, just an auto-wide angle or whatever it's called) has the opposite problem. It seems to focus well past infinity, leaving everything out of focus. I was at f/2 and f/2.8 and attempting to focus on some trees at about 200 yards. Nothing in the shot is in focus.

It's very frustrating, because I really like both of these old gems and want them to be part of my regular use kit. Anybody ever successfully adjusted infinity focus on these lenses?

Thanks in advance.

08-01-2011, 04:52 AM   #2
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Depending on the design of the vivitar resetting infinity focus may be simple

I posted a correction for kiron lenses which I performed after changing mounts. Do a search and you will find it. Can't comment on resetting the tak.
08-01-2011, 05:39 AM   #3
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QuoteOriginally posted by Lowell Goudge Quote
Depending on the design of the vivitar resetting infinity focus may be simple

I posted a correction for kiron lenses which I performed after changing mounts. Do a search and you will find it. Can't comment on resetting the tak.
Awesome, Lowell. That's exactly what I needed. Now, if I can just use my search-fu to locate a similar thread related to the ST 200...

If anyone else sees this thread and needs help, here is a link to Lowell's older thread on Kiron lens focus adjustment.
08-01-2011, 08:31 AM   #4
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I think the Super-Takumar 200mm f4 is built like a lot of the other Pentax/Asahi telephotos, with an easily removable front section. I would check that first. Focus to the minimum distance, hold the focus ring in one hand and the projecting front barrel in the other hand, and try to unscrew the front barrel counter-clockwise. You should be able to do this by hand, so if nothing happens, I'm wrong - don't look for a strap wrench.

If the barrel does unscrew, the aperture blades are probably right there. Look for something like the three screws marked with red arrows in this photo:



On a Super-Tak, the outer ring is probably brass and the screws are probably slotted. You may need a long skinny screwdriver to reach them. These screws attach the outer focus ring you turn to the lens's focus. You may find two out of three loose and one wasn't enough to keep the ring in its correct position.

If the front doesn't unscrew, I know the 135/3.5 Takumars are similar to the typical smaller lenses. Unscrew the ring with "Super-Takumar..." via the filter threads, then remove the filter ring and look for the brass ring/ 3 screws as mentioned above. But that means a really long screwdriver, and seems lile a less-likely design. There may be some alternate way to get the focus ring off, possibly some tiny grub screws around the side of the focus ring.

Once you find out how the focus ring attaches to the brass ring that focuses the lens, the adjustment is simply moving the focus ting back into the correct position. Focus as far as you can. Loosen the screws (really annoying to get back in if they come all the way out). Rotate the focus ring a few degrees back from the infinity mark. Tighten one screw and try to focus to infinity again. It's trial and error but easier with a telephoto than a 28mm. I often use an old film camera for this because the viewfinder is larger and brighter. Live view can work too.

08-01-2011, 09:16 AM   #5
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QuoteOriginally posted by Just1MoreDave Quote
I think the Super-Takumar 200mm f4 is built like a lot of the other Pentax/Asahi telephotos, with an easily removable front section. I would check that first. Focus to the minimum distance, hold the focus ring in one hand and the projecting front barrel in the other hand, and try to unscrew the front barrel counter-clockwise. You should be able to do this by hand, so if nothing happens, I'm wrong - don't look for a strap wrench.

If the barrel does unscrew, the aperture blades are probably right there. Look for something like the three screws marked with red arrows in this photo:



On a Super-Tak, the outer ring is probably brass and the screws are probably slotted. You may need a long skinny screwdriver to reach them. These screws attach the outer focus ring you turn to the lens's focus. You may find two out of three loose and one wasn't enough to keep the ring in its correct position.

If the front doesn't unscrew, I know the 135/3.5 Takumars are similar to the typical smaller lenses. Unscrew the ring with "Super-Takumar..." via the filter threads, then remove the filter ring and look for the brass ring/ 3 screws as mentioned above. But that means a really long screwdriver, and seems lile a less-likely design. There may be some alternate way to get the focus ring off, possibly some tiny grub screws around the side of the focus ring.

Once you find out how the focus ring attaches to the brass ring that focuses the lens, the adjustment is simply moving the focus ting back into the correct position. Focus as far as you can. Loosen the screws (really annoying to get back in if they come all the way out). Rotate the focus ring a few degrees back from the infinity mark. Tighten one screw and try to focus to infinity again. It's trial and error but easier with a telephoto than a 28mm. I often use an old film camera for this because the viewfinder is larger and brighter. Live view can work too.
Awesome. Yeah, the front end of the barrel (with the front element) unscrews easily enough from the lens. There are also three very small grub screws evenly spaced around the focus ring. I'll have to take the front off tonight when I get home and see if I can find the three screws that attach it all together. Will the grub screws play any part in this, or are they just holding the outer ring on?
08-01-2011, 09:38 AM   #6
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QuoteOriginally posted by Jason 407 Quote
Awesome. Yeah, the front end of the barrel (with the front element) unscrews easily enough from the lens. There are also three very small grub screws evenly spaced around the focus ring. I'll have to take the front off tonight when I get home and see if I can find the three screws that attach it all together. Will the grub screws play any part in this, or are they just holding the outer ring on?
I don't really know for sure. Those visible screws are typically holding "trim" parts on (like the depth of field scale), not doing something important. You might need to remove the trim parts to access some screws underneath them.
08-01-2011, 06:23 PM   #7
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QuoteOriginally posted by Just1MoreDave Quote
I don't really know for sure. Those visible screws are typically holding "trim" parts on (like the depth of field scale), not doing something important. You might need to remove the trim parts to access some screws underneath them.
OK, so the Takumar ended up being ridiculously easy to adjust. Those three grub screws actually connect the focusing ring to the lens innards, allowing focus. Fixing it is a simple matter of focusing to infinity, backing out the screws, adjusting the ring back a bit, tightening a screw, and focusing back toward infinity. I don't even have to remove the front element and can make the adjustments while the lens is on the camera. Cool stuff. Thanks for the help!
08-02-2011, 04:03 AM   #8
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QuoteOriginally posted by Jason 407 Quote
OK, so the Takumar ended up being ridiculously easy to adjust. Those three grub screws actually connect the focusing ring to the lens innards, allowing focus. Fixing it is a simple matter of focusing to infinity, backing out the screws, adjusting the ring back a bit, tightening a screw, and focusing back toward infinity. I don't even have to remove the front element and can make the adjustments while the lens is on the camera. Cool stuff. Thanks for the help!
Jason, are you near Orlando?

My 200 is a b*tch to focus.

08-02-2011, 05:29 AM   #9
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QuoteOriginally posted by Ira Quote
Jason, are you near Orlando?

My 200 is a b*tch to focus.
Yeah, my mailing address is actually an Orlando address, though I live outside the official city limits.

My 200 has been a right bastard, too, but that was when it was adjusted completely wrong. I started trying to fix it last night when it was getting pretty dark for a 200mm lens at f/4, so I couldn't get it right 100%, but I could see an improvement. I'm hoping focus is a little easier now. I played with it a little in my bedroom this morning and it seemed that the distance scale was at least a little closer to correct. Where it would register something like 50 feet when I focused on the other side of the room before, it was now registering just over 20' (which was about right). Maybe I can get out when there's sufficient sunlight this weekend and tweak it a bit to get infinity correct.

Next step is a good split image focus screen. I'm looking at Katz Eye, but they're pretty pricey. I'm finding I almost prefer manual focus even with my auto focus lenses, so it might be a good investment.
10-22-2011, 09:48 AM   #10
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Thanks! (Pentax-f 70-210)

Thanks for all the posts. I was having the issue with the f 70-210 not focusing on infinity. Based on the posts, mine too was super easy to fix, as is was just three tiny screws on the outside of the barrel. I would have never though for a million years that these screws were even related to the focal scale if it were not for the posts here.
06-03-2012, 11:26 AM   #11
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Fixed the infinity focus on a S-M-C Takumar 200mm f4

QuoteOriginally posted by Jason 407 Quote
OK, so the Takumar ended up being ridiculously easy to adjust. Those three grub screws actually connect the focusing ring to the lens innards, allowing focus. Fixing it is a simple matter of focusing to infinity, backing out the screws, adjusting the ring back a bit, tightening a screw, and focusing back toward infinity. I don't even have to remove the front element and can make the adjustments while the lens is on the camera. Cool stuff. Thanks for the help!
As Jason 407 wrote, it's easy enough to do.

The Tak 200mm that I got recently did not quite focus at infinity.
It was obvious at f4, but, less so at f8.
The fix was :
1. adjust the focus to infinity
2. loosen the (3) three small screws on the large focusing ring (you need a set those tiny screwdrivers)
3. move the focus ring back, toward infinity, by 1 or 2 mm
4. re-tighten the screws a bit
5. take pictures of subjects at least 1-2 km away, at f/4 (and f/8 for reference)
6. compare images at 100% crop (on computer)
7. repeat, if necessary.

Ideally, it good to have another pics from another lens, to compare.

I was lucky the first time or so it seems, but today is foggy.
On a dry day, i will compare with a K mount SMC 200mm (K series).

-JF
10-20-2013, 11:11 AM   #12
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Jason, you say:

QuoteOriginally posted by Jason 407 Quote
Fixing it is a simple matter of focusing to infinity, backing out the screws, adjusting the ring back a bit, tightening a screw, and focusing back toward infinity.
Can you tell me how many mm of focus travel you need to fix it? I'm needing about 10-12 mm, do you guess I can get it?

Thanks
10-20-2013, 03:44 PM   #13
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QuoteOriginally posted by Jason 407 Quote
Next step is a good split image focus screen. I'm looking at Katz Eye, but they're pretty pricey.
Ummmm...you evaluated infinity focus using the stock focus screen and/or the AF confirm? Be prepared to re-calibrate when you get your Katz-eye.


Steve
07-30-2015, 05:20 AM   #14
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Hi there,

I have a SMC Takumar 200mm F4 that I would love to use on my Nikon body and I thought there would enough margin of error to achieve this but apparently I was mistaken...

Thank you guys for your contribution by the way. Since I read your posts I realized that adjusting infinity on this lens was much simpler than I initially thought.

So I bought the thinnest M42 to Nikon adapter I could find (no glass of course), I tried adjusting infinity but I think I may have reached the "end of the line". I can now focus further than before and I believe I'm very close to get there but not quite (at F4).

When I turn the focusing ring now, instead of reaching a hard stop at the infinity sign, I come to a somewhat different stop with a softer feel, around the 20m sign or so. This should be the end of the helicoidal, right?

Anybody attempted this and got a similar behaviour ?

I also submitted this comment in a thread at the mflenses forum.

Cheers!
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