Are all m42 to K adaptors created equal?

Northern Soul · 06-28-2011, 09:53 AM

Ok, so being on here has got me looking on that 'popular auction site' and now I'm watching a few m42 lenses. One of which I'm very excited about as it's - well, I don't want to give it any more publicity, but it's only got 7 hours to go and it's still very cheap indeed. Already has 2 bids though, which often doesn't bode well. We shall see.

Any road up, as they say around here, obviously I'm going to need an m42/k adaptor to use an m42 lens on my camera.

I know that, in their wisdom, pentax made the distance from the rear element to the film plane/sensor identical for the m42 and k mounts, so some adaptors won't let you get infinity focus, but apart from that is there anything specific to look out for with an adaptor? They seem to range in price quite a lot, but as far as I can tell they all do exactly the same thing, or am I missing something?

Thanks in advance for any help / tips.

**JoostW** · 06-28-2011, 09:55 AM

Just get the original, different alloys make it sometimes difficult to release the adapter again after use. The original does not have this problem and goes to infinity.

Northern Soul · 06-28-2011, 10:00 AM

I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again.

Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body?

Adam · 06-28-2011, 10:01 AM

See the first big paragraph here: https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...k-x-k-7-a.html

Adam
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Northern Soul · 06-28-2011, 10:09 AM

Thanks Adam - looks like you can put the adaptor on the lens and then mount it as a bayonet, but that you have to take the lens off separately from the adaptor. What a drag - was rather hoping just to glue it on. I'm lazy like that.

aleonx3 · 06-28-2011, 10:34 AM

Originally posted by Northern Soul

I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again.

Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body?

I bought a cheap one and remove the spring, it works just fine. And when I remove the lens, it comes out easier from the camera mount with the adapter still attached to the lens. So, this one stays on without any glue. I use the m42 lens as if it is a k-mount and use a proper rear lens cap. The only downside is that it is not as secure as it does not have a locking mechanism, but it is still good and secure enough.

glee46 · 06-28-2011, 10:45 AM

I wanted to go cheap. https://www.pentaxforums.com/forums/ask-b-h-photo/136668-bower-m42-adapter.html

It will give you enough info to decide that the original Pentax, from Pentax is the better all around choice.

excanonfd · 06-28-2011, 10:52 AM

Get the original if you are not going to get anymore m42 lens. Remove the spring and the retaining screw from the adapter (store where you can remember), screw the adapter on to the lens and using the PK lens cap, torque the adapter on tight. This should be sufficient to hold the adapter in place, this is what most m42 owners do. Just remember the lens will not lock onto your camera, you need to be mindful of that at all times - though sometimes I forget that I am using m42 lens.

If m42 LBA gets it's teeth into you, that's when you might want to get a few third party m42 adapters but quality varies wildly. Having an original to use as a benchmark you can make minor modifications to get those cheap adapters to work as they should.

Hope this helps,

bobva · 06-28-2011, 11:19 AM

I bought one of those cheap POS Off brand adaptors = Not happy

At first it was a (#%$%^#@*&) to remove for camera. Believe it or not that was a good thing.

The 3rd or 4th time I used it came off real EASY But this time I had my SMC 200/4 screwed in it.. well it hit the ground

Then I went to my local camera shop bought me the real McCoy.. Not a issue 1

But Im Still out One 200/4.

excanonfd · 06-28-2011, 11:39 AM

Originally posted by bobva

I bought one of those cheap POS Off brand adaptors = Not happy

At first it was a (#%$%^#@*&) to remove for camera. Believe it or not that was a good thing.

The 3rd or 4th time I used it came off real EASY But this time I had my SMC 200/4 screwed in it.. well it hit the ground

Then I went to my local camera shop bought me the real McCoy.. Not a issue 1

But Im Still out One 200/4.

Sorry to hear about your loss, the third party adapters should never be used with the spring attached - there are many nightmarish threads in the forums about doing just that. If the spring is removed, you have to be aware the lens is on the camera via friction and not locked. I've had a few near disasters happen to me because I forgot that I am using an m42 mount or using lenses with stiff focus rings. I was able to catch the lens before it hit the pavement or remember in time that the focus ring shouldn't turn so easily after being so stiff most of the way.

Thanks,

**LaurenOE** · 06-28-2011, 01:05 PM

The Pentax one works the best, but can be a bit tricky to get on and off. I have the old "Mount Adapter K - 30120" that I bought in the 80's and it works great. B&H still sell it and the number is the same - Pentax Mount Adapter K 30120 B&H Photo Video

Lloydy · 06-28-2011, 04:02 PM

SRB Griturn, a UK company make good quality adapters that work just fine, for a lot less than the genuine Pentax item. I've got a few, and one genuine, and I honestly can't tell the difference.

But, beware of some cheap adapters that are machined differently, with a curve instead of a right angle on one position that ensures that the adapter stops in the right position when engaging, the curve on the cheap adapters allow the adapter to over rotate in the body of the camera.

The SRB adapters are machined identically to the Pentax ones, I spent many years as a quality controller in a precision engineering environment so I would notice the difference.

M42 lenses on Pentax K

I know I keep pimping these on this forum, but I know they are good quality and a lot cheaper. ( And I have no connection with the company.)

Docrwm · 06-28-2011, 04:57 PM

Funny thing is that Adorama do not even list the part number as in their database and B&H is out of stock. The UK model mentioned is $2 less than the genuine Pentax (when you can find it) so its not bargain IMHO.

If you do buy one of the Bowen or other ones - TAKE THE CLIP OUT BY REMOVING THE SCREW. I sweated a bit when I first put one in and it got stuck. People here were VERY helpful but I learned that if you are going to use non-OEM parts you take your risks.

GerryL · 06-28-2011, 08:02 PM - **1 Like**

Originally posted by Northern Soul

I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again.

Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body?

This actually works since others have already done this.
You have to remove the locking clip out of these cheap adapters though since they tend to latch on or get stuck on the camera lens mount.
Without the locking clip, nothing would catch onto and get stuck on the mount.
Just use the rear cap of a K mount to tighten these adapters onto the M-42 lens. If tightened enough, it wont easily come off.
What you should be aware of though is, since most of these old lenses have a very dampened focus ring, you won't know when to stop twisting or when you have already reached the end of the focus throw or turn and you can accidentally unmount the lens off the body this way.
The trick to this, if you won't re-sell the lens, is to drill a hole on the back end of the lens to accept the camera lens mount lock pin. In that way, the lens would behave like a K mount lens.
Sorry, my drilling was done with a Dremel (a tad sloppy) since I didn't have a drill press then.

GibbyTheMole · 06-28-2011, 08:51 PM

Originally posted by aleonx3

I bought a cheap one and remove the spring, it works just fine. And when I remove the lens, it comes out easier from the camera mount with the adapter still attached to the lens. So, this one stays on without any glue. I use the m42 lens as if it is a k-mount and use a proper rear lens cap. The only downside is that it is not as secure as it does not have a locking mechanism, but it is still good and secure enough.

This is what I did as well. I just screw it down tight to the lens with the rear cap & it comes off with the lens every time. Works great.

Cheers,
Bobbo :-)

06-28-2011, 09:53 AM	#1
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494	Are all m42 to K adaptors created equal? Ok, so being on here has got me looking on that 'popular auction site' and now I'm watching a few m42 lenses. One of which I'm very excited about as it's - well, I don't want to give it any more publicity, but it's only got 7 hours to go and it's still very cheap indeed. Already has 2 bids though, which often doesn't bode well. We shall see. Any road up, as they say around here, obviously I'm going to need an m42/k adaptor to use an m42 lens on my camera. I know that, in their wisdom, pentax made the distance from the rear element to the film plane/sensor identical for the m42 and k mounts, so some adaptors won't let you get infinity focus, but apart from that is there anything specific to look out for with an adaptor? They seem to range in price quite a lot, but as far as I can tell they all do exactly the same thing, or am I missing something? Thanks in advance for any help / tips.

06-28-2011, 10:45 AM	#7
glee46 Veteran Member Join Date: Nov 2010 Location: North of San Francisco, California Photos: Gallery \| Albums Posts: 598	Here's the Cheap One I wanted to go cheap. https://www.pentaxforums.com/forums/ask-b-h-photo/136668-bower-m42-adapter.html It will give you enough info to decide that the original Pentax, from Pentax is the better all around choice.

06-28-2011, 08:02 PM - 1 Like	#14
GerryL Veteran Member Join Date: Jan 2009 Location: CA Posts: 2,731	Originally posted by Northern Soul I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again. Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body? This actually works since others have already done this. You have to remove the locking clip out of these cheap adapters though since they tend to latch on or get stuck on the camera lens mount. Without the locking clip, nothing would catch onto and get stuck on the mount. Just use the rear cap of a K mount to tighten these adapters onto the M-42 lens. If tightened enough, it wont easily come off. What you should be aware of though is, since most of these old lenses have a very dampened focus ring, you won't know when to stop twisting or when you have already reached the end of the focus throw or turn and you can accidentally unmount the lens off the body this way. The trick to this, if you won't re-sell the lens, is to drill a hole on the back end of the lens to accept the camera lens mount lock pin. In that way, the lens would behave like a K mount lens. Sorry, my drilling was done with a Dremel (a tad sloppy) since I didn't have a drill press then. Attached Images

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06-28-2011, 09:55 AM	#2
JoostW Site Supporter Join Date: Jun 2011 Posts: 22	Just get the original, different alloys make it sometimes difficult to release the adapter again after use. The original does not have this problem and goes to infinity.

06-28-2011, 10:00 AM	#3
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again. Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body?

06-28-2011, 10:01 AM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	See the first big paragraph here: https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...k-x-k-7-a.html Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

06-28-2011, 10:09 AM	#5
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494 Original Poster	Thanks Adam - looks like you can put the adaptor on the lens and then mount it as a bayonet, but that you have to take the lens off separately from the adaptor. What a drag - was rather hoping just to glue it on. I'm lazy like that.

06-28-2011, 10:34 AM	#6
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	Originally posted by Northern Soul I'm not so bothered about getting the adaptor off the lens as it will be my only m42. I was thinking if the cheap Chinese ones are any good I could just buy one with each lens and semi-permanently fix them on with super glue as I have no plans to start shooting film again. Is it possible to remove the lens and the adaptor in one, or do you remove the lens from the adaptor and then the adaptor from the body? I bought a cheap one and remove the spring, it works just fine. And when I remove the lens, it comes out easier from the camera mount with the adapter still attached to the lens. So, this one stays on without any glue. I use the m42 lens as if it is a k-mount and use a proper rear lens cap. The only downside is that it is not as secure as it does not have a locking mechanism, but it is still good and secure enough.

06-28-2011, 10:52 AM	#8
excanonfd Veteran Member Join Date: Jan 2010 Location: Vancouver, BC Posts: 1,421	Get the original if you are not going to get anymore m42 lens. Remove the spring and the retaining screw from the adapter (store where you can remember), screw the adapter on to the lens and using the PK lens cap, torque the adapter on tight. This should be sufficient to hold the adapter in place, this is what most m42 owners do. Just remember the lens will not lock onto your camera, you need to be mindful of that at all times - though sometimes I forget that I am using m42 lens. If m42 LBA gets it's teeth into you, that's when you might want to get a few third party m42 adapters but quality varies wildly. Having an original to use as a benchmark you can make minor modifications to get those cheap adapters to work as they should. Hope this helps,

06-28-2011, 11:19 AM	#9
bobva Forum Member Join Date: May 2011 Location: Tacoma Everett Posts: 53	I bought one of those cheap POS Off brand adaptors = Not happy At first it was a (#%$%^#@*&) to remove for camera. Believe it or not that was a good thing. The 3rd or 4th time I used it came off real EASY But this time I had my SMC 200/4 screwed in it.. well it hit the ground Then I went to my local camera shop bought me the real McCoy.. Not a issue 1 But Im Still out One 200/4.

06-28-2011, 11:39 AM	#10
excanonfd Veteran Member Join Date: Jan 2010 Location: Vancouver, BC Posts: 1,421	Originally posted by bobva I bought one of those cheap POS Off brand adaptors = Not happy At first it was a (#%$%^#@*&) to remove for camera. Believe it or not that was a good thing. The 3rd or 4th time I used it came off real EASY But this time I had my SMC 200/4 screwed in it.. well it hit the ground Then I went to my local camera shop bought me the real McCoy.. Not a issue 1 But Im Still out One 200/4. Sorry to hear about your loss, the third party adapters should never be used with the spring attached - there are many nightmarish threads in the forums about doing just that. If the spring is removed, you have to be aware the lens is on the camera via friction and not locked. I've had a few near disasters happen to me because I forgot that I am using an m42 mount or using lenses with stiff focus rings. I was able to catch the lens before it hit the pavement or remember in time that the focus ring shouldn't turn so easily after being so stiff most of the way. Thanks,

06-28-2011, 01:05 PM	#11
LaurenOE Site Supporter Join Date: Sep 2009 Location: Back in Florida, but worldwide gigs! Photos: Albums Posts: 3,690	The Pentax one works the best, but can be a bit tricky to get on and off. I have the old "Mount Adapter K - 30120" that I bought in the 80's and it works great. B&H still sell it and the number is the same - Pentax Mount Adapter K 30120 B&H Photo Video

06-28-2011, 04:02 PM	#12
Lloydy Veteran Member Join Date: Aug 2007 Location: Shropshire, UK Posts: 1,114	SRB Griturn, a UK company make good quality adapters that work just fine, for a lot less than the genuine Pentax item. I've got a few, and one genuine, and I honestly can't tell the difference. But, beware of some cheap adapters that are machined differently, with a curve instead of a right angle on one position that ensures that the adapter stops in the right position when engaging, the curve on the cheap adapters allow the adapter to over rotate in the body of the camera. The SRB adapters are machined identically to the Pentax ones, I spent many years as a quality controller in a precision engineering environment so I would notice the difference. M42 lenses on Pentax K I know I keep pimping these on this forum, but I know they are good quality and a lot cheaper. ( And I have no connection with the company.)

06-28-2011, 04:57 PM	#13
Docrwm Veteran Member Join Date: Sep 2010 Location: Somewhere in the Southern US Photos: Gallery \| Albums Posts: 12,285	Funny thing is that Adorama do not even list the part number as in their database and B&H is out of stock. The UK model mentioned is $2 less than the genuine Pentax (when you can find it) so its not bargain IMHO. If you do buy one of the Bowen or other ones - TAKE THE CLIP OUT BY REMOVING THE SCREW. I sweated a bit when I first put one in and it got stuck. People here were VERY helpful but I learned that if you are going to use non-OEM parts you take your risks.

06-28-2011, 08:51 PM	#15
GibbyTheMole Veteran Member Join Date: Nov 2009 Location: Iowa Photos: Albums Posts: 2,275	Originally posted by aleonx3 I bought a cheap one and remove the spring, it works just fine. And when I remove the lens, it comes out easier from the camera mount with the adapter still attached to the lens. So, this one stays on without any glue. I use the m42 lens as if it is a k-mount and use a proper rear lens cap. The only downside is that it is not as secure as it does not have a locking mechanism, but it is still good and secure enough. This is what I did as well. I just screw it down tight to the lens with the rear cap & it comes off with the lens every time. Works great. Cheers, Bobbo :-)