M42 Help Pls!

Not a Number · 08-05-2013, 06:09 AM

Originally posted by altopiet

Now I'm more than confused myself. I had a look at my Tak 55/1.8, and the pin that is talked about is the same as the Tak you have, and of the image I found on the web.

Looking at the position of the pin, it does not seem possible that the pin could be stuck in the adapter, reinforcing my original opinion that you should be able to unscrew the lens from the adapter.
EDIT:If it was mine, I'd have gone with a little WD40, taking care to ensure none enters the camera body in any way, and some elbow grease, and unscrew it.

http://www.retrocamera.net/review-of-asahi-super-takumar-135mm35-m42-lens.html

The pin in question is the auto/manual lock/release pin. It is not visible in the photo you show.

Here is my Super-Multi-Coated Takumar 50mm Macro f/4. Not the greatest photos but I was too lazy to set up the white box and just used a flash in the shoe. The red arrow indicates the auto diaphragm stop-don pin, yellow indicates the auto/manual lock/release pin and green indicates where the focus diamond would be.

side view

side view with OEM m42 adapter installed, loosened about 1/3 of a turn

On most 3rd party adapters the slot is cut too deeply allowing the pin to pop out. The OEM adapter leaves enough material to cover about 1/2 the pin keeping it from catching in the slot. See the also the photos in the thread I linked above:
https://www.pentaxforums.com/forums/general-technical-troubleshooting/222627-...ml#post2362237

All the cross slotted screws on the body should be JIS. While you can use Philips drivers they are designed to "cam" out when the screw is "locked" this leads to stripping the head on JIS screws. Coming in at an angle increases the likelihood the driver with slip out. JIS drivers are compatible with Philips head screws.

Last edited by Not a Number; 08-05-2013 at 06:15 AM.

GBNeil · 08-05-2013, 08:26 AM

Originally posted by Not a Number

The pin in question is the auto/manual lock/release pin. It is not visible in the photo you show.

Here is my Super-Multi-Coated Takumar 50mm Macro f/4. Not the greatest photos but I was too lazy to set up the white box and just used a flash in the shoe. The red arrow indicates the auto diaphragm stop-don pin, yellow indicates the auto/manual lock/release pin and green indicates where the focus diamond would be.

On most 3rd party adapters the slot is cut too deeply allowing the pin to pop out. The OEM adapter leaves enough material to cover about 1/2 the pin keeping it from catching in the slot. See the also the photos in the thread I linked above:
https://www.pentaxforums.com/forums/general-technical-troubleshooting/222627-...ml#post2362237

All the cross slotted screws on the body should be JIS. While you can use Philips drivers they are designed to "cam" out when the screw is "locked" this leads to stripping the head on JIS screws. Coming in at an angle increases the likelihood the driver with slip out. JIS drivers are compatible with Philips head screws.

This is really useful information, thanks! It also explains why I had no problem with my Helios 58 44-M-4 initially - it has no auto/manual lock!

GBNeil · 08-07-2013, 03:50 AM

The feeler gauges arrived today: Tried for about 45 mins but have to stop now:

The offending location seems somewhere around the red dot on the Mount, but exactly where is not clear.

Does it matter if I try to turn the lens clockwise or anti?

Does it matter if the lens release is depressed or not?

This will work

Not a Number · 08-07-2013, 10:13 AM

The ultimate goal is to remove the lens so you would want to turn it anti-clockwise with the lens facing you. However you may need to turn it in either direction the get the gauge under the pin. The gauge might catch on the k-mount locking stud, if it does just depress the lens release button. Otherwise it shouldn't matter as it plays no role in locking either the adapter or the screwmount lens.

Best of luck!

PS: I'm thinking that one could bevel the edges of the slot so the pin would be able to be depressed as it passes over the bevel. Something to play with later on.

GBNeil · 08-28-2013, 01:28 AM

Just a quick update to say I've had no success so far. I haven't given up but I bought a used K-x and yesterday a Pentax Adapter. I'm actively trying to sell the combo but will not give it away. I'm going to try and repair a Super Tak 55mm F2 and based on that perhaps try & remove the lens from the combo.

Thanks again for all our help!

Btw Is there anything I need to watch out for with the genuine Pentax Adapter?

Not a Number · 08-28-2013, 11:19 AM

Sorry to hear that you haven't been able to solve this problem yet. Maybe if you put it on the back burner and just fiddle about with it now and then you'll get lucky and something will click in or out of place.

I think the only thing with the OEM adapters is that some of the Russian lens won't fit snugly and a shim is needed. There is another thread where someone had the screw strip out and the clip came out while it was mounted. First time I've heard of that but I suppose it has happened before.

**Lowell Goudge** · 08-28-2013, 12:02 PM

Originally posted by GBNeil

The feeler gauges arrived today: Tried for about 45 mins but have to stop now:

The offending location seems somewhere around the red dot on the Mount, but exactly where is not clear.

Does it matter if I try to turn the lens clockwise or anti?

Does it matter if the lens release is depressed or not?

This will work

Lens release if it is depressed also withdraws the screw drive , this can help a lot if a pin is caught in the screw drive, or if the tip if the screw drive is hitting a screw head on the munt

08-05-2013, 08:26 AM	#62
GBNeil Forum Member Join Date: May 2013 Location: Colchester, UK Posts: 76 Original Poster	Originally posted by Not a Number The pin in question is the auto/manual lock/release pin. It is not visible in the photo you show. Here is my Super-Multi-Coated Takumar 50mm Macro f/4. Not the greatest photos but I was too lazy to set up the white box and just used a flash in the shoe. The red arrow indicates the auto diaphragm stop-don pin, yellow indicates the auto/manual lock/release pin and green indicates where the focus diamond would be. On most 3rd party adapters the slot is cut too deeply allowing the pin to pop out. The OEM adapter leaves enough material to cover about 1/2 the pin keeping it from catching in the slot. See the also the photos in the thread I linked above: https://www.pentaxforums.com/forums/general-technical-troubleshooting/222627-...ml#post2362237 All the cross slotted screws on the body should be JIS. While you can use Philips drivers they are designed to "cam" out when the screw is "locked" this leads to stripping the head on JIS screws. Coming in at an angle increases the likelihood the driver with slip out. JIS drivers are compatible with Philips head screws. This is really useful information, thanks! It also explains why I had no problem with my Helios 58 44-M-4 initially - it has no auto/manual lock! Last edited by GBNeil; 08-07-2013 at 03:42 AM.

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08-05-2013, 06:09 AM	#61
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Originally posted by altopiet Now I'm more than confused myself. I had a look at my Tak 55/1.8, and the pin that is talked about is the same as the Tak you have, and of the image I found on the web. Looking at the position of the pin, it does not seem possible that the pin could be stuck in the adapter, reinforcing my original opinion that you should be able to unscrew the lens from the adapter. EDIT:If it was mine, I'd have gone with a little WD40, taking care to ensure none enters the camera body in any way, and some elbow grease, and unscrew it. http://www.retrocamera.net/review-of-asahi-super-takumar-135mm35-m42-lens.html The pin in question is the auto/manual lock/release pin. It is not visible in the photo you show. Here is my Super-Multi-Coated Takumar 50mm Macro f/4. Not the greatest photos but I was too lazy to set up the white box and just used a flash in the shoe. The red arrow indicates the auto diaphragm stop-don pin, yellow indicates the auto/manual lock/release pin and green indicates where the focus diamond would be. side view side view with OEM m42 adapter installed, loosened about 1/3 of a turn On most 3rd party adapters the slot is cut too deeply allowing the pin to pop out. The OEM adapter leaves enough material to cover about 1/2 the pin keeping it from catching in the slot. See the also the photos in the thread I linked above: https://www.pentaxforums.com/forums/general-technical-troubleshooting/222627-...ml#post2362237 All the cross slotted screws on the body should be JIS. While you can use Philips drivers they are designed to "cam" out when the screw is "locked" this leads to stripping the head on JIS screws. Coming in at an angle increases the likelihood the driver with slip out. JIS drivers are compatible with Philips head screws. Last edited by Not a Number; 08-05-2013 at 06:15 AM.

08-07-2013, 03:50 AM	#63
GBNeil Forum Member Join Date: May 2013 Location: Colchester, UK Posts: 76 Original Poster	The feeler gauges arrived today: Tried for about 45 mins but have to stop now: The offending location seems somewhere around the red dot on the Mount, but exactly where is not clear. Does it matter if I try to turn the lens clockwise or anti? Does it matter if the lens release is depressed or not? This will work

08-07-2013, 10:13 AM	#64
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	The ultimate goal is to remove the lens so you would want to turn it anti-clockwise with the lens facing you. However you may need to turn it in either direction the get the gauge under the pin. The gauge might catch on the k-mount locking stud, if it does just depress the lens release button. Otherwise it shouldn't matter as it plays no role in locking either the adapter or the screwmount lens. Best of luck! PS: I'm thinking that one could bevel the edges of the slot so the pin would be able to be depressed as it passes over the bevel. Something to play with later on.

08-28-2013, 01:28 AM	#65
GBNeil Forum Member Join Date: May 2013 Location: Colchester, UK Posts: 76 Original Poster	Just a quick update to say I've had no success so far. I haven't given up but I bought a used K-x and yesterday a Pentax Adapter. I'm actively trying to sell the combo but will not give it away. I'm going to try and repair a Super Tak 55mm F2 and based on that perhaps try & remove the lens from the combo. Thanks again for all our help! Btw Is there anything I need to watch out for with the genuine Pentax Adapter?

08-28-2013, 11:19 AM	#66
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Sorry to hear that you haven't been able to solve this problem yet. Maybe if you put it on the back burner and just fiddle about with it now and then you'll get lucky and something will click in or out of place. I think the only thing with the OEM adapters is that some of the Russian lens won't fit snugly and a shim is needed. There is another thread where someone had the screw strip out and the clip came out while it was mounted. First time I've heard of that but I suppose it has happened before.

08-28-2013, 12:02 PM	#67
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,892	Originally posted by GBNeil The feeler gauges arrived today: Tried for about 45 mins but have to stop now: The offending location seems somewhere around the red dot on the Mount, but exactly where is not clear. Does it matter if I try to turn the lens clockwise or anti? Does it matter if the lens release is depressed or not? This will work Lens release if it is depressed also withdraws the screw drive , this can help a lot if a pin is caught in the screw drive, or if the tip if the screw drive is hitting a screw head on the munt