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04-05-2014, 02:38 PM   #1
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Should the 50mm Super Tak Macro F4 focus infinity?

Hello. I have a question about my new lens acquisition. I found a Super-Multi-Coated MACRO-TAKUMAR 1:4/50 bundled with another Takumar lens on ebay for a good price. I took the macro out with an m42 adapter on my K-50 the other day. Being a macro lens I mostly used it for macro type shots. At one point I decided to shoot cell tower a couple hundred yards away just for fun. I noticed however that I was unable to get the lens to focus far enough to get the tower in crisp focus (the lens is marked as infinity so I assumed even though it is a macro lens that it could focus this far). Is this normal for the lens to not be able to reach infinity focus? I tested the other m42 lenses I have and they are all able to reach infinity even with my cheap adapter. Any insight would be appreciated!

04-05-2014, 03:01 PM - 1 Like   #2
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Are you using the original Pentax Mount Adapter K, or are you using an adapter from a third party with a flange that sits against the lens mount? The flanged adapters will not allow infinity focus - they hold the lens a few mm further from the film plane than the correct adapter does.
04-05-2014, 03:05 PM   #3
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The adapter is flush with the mount on my camera. This is the adapter I have. Amazon.com: DSLRKIT Pentax M42 42mm to PK K Mount Adapter Infinity focus: Camera & Photo
04-05-2014, 03:05 PM - 1 Like   #4
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Yes this lens supposed to focus from infinity to macro distances. One problem might be your adapter - is it the one black with flange or one of those silver ones that allow focusing to infinity ? because that black adapters with wide flange will act as a thin macro extension tube at the same time reducing your max focusing distance.

AAnother possibility might be problem with your lens - as a matter of fact I once had a Macro Takumar 50mm version focusing down to 1:1 macro and it was not focusing to infinity. So I got exactly the same problem. Finally I took it apart and fix it but it was a bit of hassle. My problem was a screw fallen out of one place and stuck inside the focusing rails and so preventing the focusing from going across the full range.

hope these helps and hopefully your problem is just with the adapter because that is a minor issue. And good luck with this wonderful lens - I regret to this day parting with it !

--manntax

04-05-2014, 03:51 PM   #5
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Thank you both for the input. I now have taken a much closer look at the adapter with an m42 lens on my camera. I have noticed a very thin gap between the lens and my mount. About the width of a normal piece of paper. I have attached a picture of it on my dads K-X. (I attached a Tak 55/2 because I wanted to picture it with the macro tak, but forgot I don't have a second adapter... haha)

Would this very small gap have an effect on infinity focus?
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PENTAX K-50  Photo 

Last edited by Pizza; 04-05-2014 at 03:53 PM. Reason: Wrong way to attach a pic, and a spelling error lol
04-05-2014, 06:57 PM - 1 Like   #6
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When properly adapted, the face of the mount flange on your lens should snug up tightly against the mount flange of the camera body the same as if the body were native M42 mount. Two possible problems could result in this not happening:
  • The adapter is not fully threaded onto the lens
  • The bayonet "ears" are not properly machined to snug the lens up to the mount
I would suggest that you screw the adapter to the lens first and then mount the assembly to the body in the same manner as a regular K-mount lens.

Poor machining or poor mount compliance are two potential problems with third-party (non-Pentax) adapters. As a result, some don't fit properly. Some may also be difficult to remove, even with the supplied tool.


Steve
04-05-2014, 07:38 PM - 1 Like   #7
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QuoteOriginally posted by Pizza Quote
Thank you both for the input. I now have taken a much closer look at the adapter with an m42 lens on my camera. I have noticed a very thin gap between the lens and my mount. About the width of a normal piece of paper. I have attached a picture of it on my dads K-X. (I attached a Tak 55/2 because I wanted to picture it with the macro tak, but forgot I don't have a second adapter... haha)

Would this very small gap have an effect on infinity focus?
Yup, that gap could be the problem. Steve's advice is good- not all third-party adapters are reliable.

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04-06-2014, 01:37 PM - 1 Like   #8
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I noticed that the original Pentax OEM version sits a little loosely inside the lens mount and it is a little bit inset. When you screw on the M42 lens it will snug up against the body and gentle pull the adapter forward. It's like a self-locking nut system.

04-08-2014, 04:10 PM   #9
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Thank you for all of the feedback. I tested the lens on an old Spotmatic body and the lens appeared to focus to infinity (no film to test it on). Then I got the idea to hold the lens up against my K-50 with no adapter (I know I risk getting some dust inside my camera body, but this issue has been frustrating me so I took the chance) and sure enough it is able to focus to infinity simply held against my camera body. I attached a crop of me holding the lens vs mounting it with this adapter.

I have since been in contact with the company in China and they asked me a couple questions but have been unable to verify the problem. They offered a refund, but I am asking them if they can personally test an adapter themselves then to send me that one instead of a refund. I'll let everyone know my results. $6.79 + free shipping (it arrived in less than a week) is a fantastic deal if it will work properly.
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04-08-2014, 05:01 PM   #10
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QuoteOriginally posted by Pizza Quote
I have since been in contact with the company in China and they asked me a couple questions but have been unable to verify the problem. They offered a refund, but I am asking them if they can personally test an adapter themselves then to send me that one instead of a refund. I'll let everyone know my results. $6.79 + free shipping (it arrived in less than a week) is a fantastic deal if it will work properly.
Great job troubleshooting!

I know I sound like a parent, but do yourself a favor. Skip the risk of an incarcerated adapter and the other bad things that might happen and simply buy the real thing.* Adorama has them currently backordered at a decent price. They even pick up the shipping.

Pentax Adapter B - Adapts Pentax K Bodies to Screw Mount Lenses 30120

The difference between the brand-X and the genuine is obvious in use. It is worth waiting for.

Or if you don't want to wait, B&H has them in stock for $50 (shipping included)

http://www.bhphotovideo.com/c/product/673977-REG/Pentax_30120_Mount_Adapter_K.html


Steve

* Pentax part number 30120, sometimes called "Mount Adapter B" and sometimes "Mount Adapter K"

Last edited by stevebrot; 04-08-2014 at 05:12 PM.
04-08-2014, 08:46 PM   #11
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I paid $45 for mine several years ago. I sold one when I got my last screw mount changed out to K in the early 80's for $10. The guy got a good deal. I have no problems with the real adapter.
04-09-2014, 08:49 AM   #12
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If I wasn't so darn lazy I'd offer to mill the flange off of every top-hat adapter in the world and spot drill every M42 lens for the latch pin notch and end this topic for good -- with the proviso that the lens would no longer latch. Of course the latch issue would then become the new topic of the day, eh?

Every top-hat style adapter with a flange to accommodate the latch pin happens to also be a 0.7-0.75 mm extension tube!

I'd also note that the OEM-style adapter with the latch spring wasn't intended to be attached to lenses or easily removed; it was designed to be semi-permanently attached to *M42 (Spotmatic)* bodies so working photographers with expensive lens collections could transition to the the K-mount bodies without breaking their bank accounts. Thanks, Pentax!

* EDIT - correction: . . . attached to K-mount bodies. DUH!

Last edited by pacerr; 04-09-2014 at 05:56 PM.
04-09-2014, 01:30 PM   #13
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QuoteOriginally posted by pacerr Quote
Of course the latch issue would then become the new topic of the day, eh?
Of course! Then the post title would be:
My beloved 8-element ST 50/1.4 with Brand-X adapter just fell off my K-3!!
...and the first sentence would be:

"The focus was always a little stiff, but I never guessed the adapter might rotate out of the mount..."



Honestly though, the plate spring is only one of several known issues. Did you see the recent thread where the adapter did not fully seat down on the lens? Or where the ears were cut at the wrong ramp angle and did not allow the mount face to engage? (No infinity focus with either of those two.) How about the adapter that was poorly fitted with the result that metal filings were shaved off into the mirror box? How about over-rotation in the mount (kiss of death for non-crippled mounts in older cameras.) The quality is highly variable and there is no way to know up-front which are good and which aren't. Distributors such as Bower source from multiple suppliers.

I know these are horror stories, but once was enough for me. My first foray (Bower from Adorama) resulted in a stuck adapter and filings in the mirror box. I was given a refund, free return shipping, and a high respect for conventional wisdom in regards to third-party adapters.


Steve

---------- Post added 04-09-14 at 01:43 PM ----------

QuoteOriginally posted by pacerr Quote
I'd also note that the OEM-style adapter with the latch spring wasn't intended to be attached to lenses or easily removed; it was designed to be semi-permanently attached to M42 (Spotmatic) bodies so working photographers with expensive lens collections could transition to the the K-mount bodies without breaking their bank accounts. Thanks, Pentax!
I think it was the other way around, sort of. The adapter allowed owners to use their existing M42 screw mount lenses in their new K-mount cameras. It also allowed new Pentax K-mount camera owners to invest in the M42 lenses that were still in the Pentax line at the time the K-mount bodies debuted. The owner's manual for my KX indicates that the adapter should be screwed on to the lens and the assembly mounted to the camera. In other words, occasional use as needed. Unlike the Brand-X adapters, the genuine item is VERY easy to remove (sits loose in the opening) and requires no tool more sophisticated that a fingernail or the tip of a ball-point pen to disengage.
04-09-2014, 05:48 PM   #14
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QuoteOriginally posted by stevebrot Quote
I think it was the other way around, sort of.
Yeah, I said that bass-akwards, didn't I. Thanks for the catch, Steve.

And, yeah, there's been a big gap in the quality of ALL the knock-off adapters since the older M42's became popular via the web a few years ago.
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