M42 lens on Pentax DSLR

lotech · 04-01-2015, 01:37 AM

Hi there,

I am using various type of manual lens on the K3 via adapter, recently I purchased a Zenitar M 50/1.7, I was looking for a Helios instead but I came cross the Zenitar and I heard good comment about it, it is a very rare lens very little info I can find on the net, including how to fix the non functioning 'auto' aperture switch... I tested the lens and it blown me off, it is even sharper than my Pentacon 50/1.8 (a CZJ copy ??), but there is some problem in my copy, or this is common issue I don't know, the contrast reduced considerably when stopping down, and the focus seems to shifted, I expected to get a clearer sharper image but I can't even get sharp focus after stop down to f8 and beyond, but physically the lens is in near mint condition the glasses are clear and clean, any comment ?

I am also looking for the best way to adapt the m42 lens to the K mount, as far as I know there are only 2 types of adapter, one 'sink' into the camera body and locked, need a special key to remove it, the other is keyless but thicker prevent infinity focusing, I want an adapt that can fit into the body securely and can be removed easily without the key, also allows infinity focusing, any suggestion ?

Adam · 04-01-2015, 01:41 AM

Originally posted by lotech

I am also looking for the best way to adapt the m42 lens to the K mount, as far as I know there are only 2 types of adapter, one 'sink' into the camera body and locked, need a special key to remove it, the other is keyless but thicker prevent infinity focusing, I want an adapt that can fit into the body securely and can be removed easily without the key, also allows infinity focusing, any suggestion ?

The genuine Pentax adapter- or any adapter without a flange- is the way to go.

lotech · 04-01-2015, 02:10 AM

Still need the key, if I remove the spring 'leaf' the lens will not fit tight in the body.

---------- Post added 04-01-15 at 05:27 PM ----------

There are some Russian lens came in K mount such as the Helios 44K, it would be prefect if we can replace the mount completely instead of using add on adapter, I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story.

**jatrax** · 04-01-2015, 02:32 AM

Originally posted by lotech

Still need the key, if I remove the spring 'leaf' the lens will not fit tight in the body.

No you do not. The genuine adapter fits flush and can be removed with just your fingernail. The cheaper knock offs look the same but they are not. The machining is often poor which allows them to get stuck unless you remove the spring.

lotech · 04-01-2015, 02:43 AM

I will look for it thanks !

redcat · 04-01-2015, 03:58 AM

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html <= the perfect guid for M42 on Pentax dslr ^^
I use the Kipon adapter (as recommend in the guide) and it works perfectly

Na Horuk · 04-01-2015, 04:23 AM

The genuine m42 adapter works best and has high quality machining. I think its worth the extra cost. Made by Pentax, for Pentax.
On the other hand, some users report success with cheaper knock-off adapters. These usually need a tool to be removed (unlike the Pentax adapter, where a fingernail is enough). The real problem is if you get one that is poorly machined. There were cases where people had problems removing it from the camera.
Also, if you buy third party adapter, some have a flange or collar. This can be problematic as it prevents many lenses from reaching infinity focus. Unless you know what you are doing and want the collar/flange, stay away from these

Originally posted by lotech

the contrast reduced considerably when stopping down, and the focus seems to shifted, I expected to get a clearer sharper image but I can't even get sharp focus after stop down to f8 and beyond, but physically the lens is in near mint condition the glasses are clear and clean, any comment ?

This is not normal behaviour. Most lenses are best stopped down one or two stops. Around f8 they have the widest DoF before diffraction starts to make the image fuzzy. If you make the photo with f16, it will not be very sharp due to diffraction, but that shouldn't affect contrast much.
Its difficult to say why you are experiencing your problem without a methodological test, with well-labelled test photos and controlled variables. I suspect the problem might be shiny aperture blades. Some older lenses are known to have metal aperture blades, sometimes with oil on them, so light reflects off of the back the lens and sensor, back to the aperture blades, and back onto the sensor. This can cause some odd flares and overall loss of contrast. Not much you can do about this other than adding a polarizing filter and a tight lens hood to minimize incoming light. A tight lens hood is a good idea for older lenses anyway, because they have (compared to modern lenses) poor lens coatings, so they cannot resist flare, ghosting as well.

Originally posted by lotech

I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story.

Wow, sounds good!

Last edited by Na Horuk; 04-01-2015 at 04:31 AM.

**boriscleto** · 04-01-2015, 04:28 AM

There are two problems with the cheap knock-off adapters. The first is the poor machining that can lead to problems such as getting stuck in the camera or a lens mounting upside down. The second is that the screw that holds the spring clip is often too long. This can then engage the threads on the lens and make the lens impossible to remove without damage.

redcat · 04-01-2015, 04:57 AM

Originally posted by lotech

I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story.

Do tell that story

did you take photos of the process ? It'd be super interesting !

npc · 04-01-2015, 08:55 AM

Originally posted by redcat

Do tell that story

did you take photos of the process ? It'd be super interesting !

Leica & Pentax & Nikon | Leitax ?

**Lowell Goudge** · 04-01-2015, 09:37 AM

What every one has missed is the fact that many non pentax M42 lenses do. Not have an auto manual switch. For Auto aperture only M42 lenses there is an adaptor that presses the aperture pin to allow control, but there are some pitfalls to watch out for with respect to the spring clip and screw.

The other option is a mount mod, whre you put a small spacer around the pin just behind the mount inside the lens to block the aperture in the position set on the ring.

lytrytyr · 04-01-2015, 09:48 AM

Originally posted by lotech

I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story.

Summicron R?

04-01-2015, 01:37 AM	#1
lotech Pentaxian Join Date: Apr 2012 Posts: 1,312	M42 lens on Pentax DSLR Hi there, I am using various type of manual lens on the K3 via adapter, recently I purchased a Zenitar M 50/1.7, I was looking for a Helios instead but I came cross the Zenitar and I heard good comment about it, it is a very rare lens very little info I can find on the net, including how to fix the non functioning 'auto' aperture switch... I tested the lens and it blown me off, it is even sharper than my Pentacon 50/1.8 (a CZJ copy ??), but there is some problem in my copy, or this is common issue I don't know, the contrast reduced considerably when stopping down, and the focus seems to shifted, I expected to get a clearer sharper image but I can't even get sharp focus after stop down to f8 and beyond, but physically the lens is in near mint condition the glasses are clear and clean, any comment ? I am also looking for the best way to adapt the m42 lens to the K mount, as far as I know there are only 2 types of adapter, one 'sink' into the camera body and locked, need a special key to remove it, the other is keyless but thicker prevent infinity focusing, I want an adapt that can fit into the body securely and can be removed easily without the key, also allows infinity focusing, any suggestion ?

04-01-2015, 01:41 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	Originally posted by lotech I am also looking for the best way to adapt the m42 lens to the K mount, as far as I know there are only 2 types of adapter, one 'sink' into the camera body and locked, need a special key to remove it, the other is keyless but thicker prevent infinity focusing, I want an adapt that can fit into the body securely and can be removed easily without the key, also allows infinity focusing, any suggestion ? The genuine Pentax adapter- or any adapter without a flange- is the way to go. 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:

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04-01-2015, 02:10 AM	#3
lotech Pentaxian Join Date: Apr 2012 Posts: 1,312 Original Poster	Still need the key, if I remove the spring 'leaf' the lens will not fit tight in the body. ---------- Post added 04-01-15 at 05:27 PM ---------- There are some Russian lens came in K mount such as the Helios 44K, it would be prefect if we can replace the mount completely instead of using add on adapter, I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story.

04-01-2015, 02:32 AM	#4
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by lotech Still need the key, if I remove the spring 'leaf' the lens will not fit tight in the body. No you do not. The genuine adapter fits flush and can be removed with just your fingernail. The cheaper knock offs look the same but they are not. The machining is often poor which allows them to get stuck unless you remove the spring.

04-01-2015, 02:43 AM	#5
lotech Pentaxian Join Date: Apr 2012 Posts: 1,312 Original Poster	I will look for it thanks !

04-01-2015, 03:58 AM	#6
redcat Veteran Member Join Date: Jul 2014 Location: Paris Photos: Gallery Posts: 1,939	https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html <= the perfect guid for M42 on Pentax dslr ^^ I use the Kipon adapter (as recommend in the guide) and it works perfectly

04-01-2015, 04:23 AM	#7
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	The genuine m42 adapter works best and has high quality machining. I think its worth the extra cost. Made by Pentax, for Pentax. On the other hand, some users report success with cheaper knock-off adapters. These usually need a tool to be removed (unlike the Pentax adapter, where a fingernail is enough). The real problem is if you get one that is poorly machined. There were cases where people had problems removing it from the camera. Also, if you buy third party adapter, some have a flange or collar. This can be problematic as it prevents many lenses from reaching infinity focus. Unless you know what you are doing and want the collar/flange, stay away from these Originally posted by lotech the contrast reduced considerably when stopping down, and the focus seems to shifted, I expected to get a clearer sharper image but I can't even get sharp focus after stop down to f8 and beyond, but physically the lens is in near mint condition the glasses are clear and clean, any comment ? This is not normal behaviour. Most lenses are best stopped down one or two stops. Around f8 they have the widest DoF before diffraction starts to make the image fuzzy. If you make the photo with f16, it will not be very sharp due to diffraction, but that shouldn't affect contrast much. Its difficult to say why you are experiencing your problem without a methodological test, with well-labelled test photos and controlled variables. I suspect the problem might be shiny aperture blades. Some older lenses are known to have metal aperture blades, sometimes with oil on them, so light reflects off of the back the lens and sensor, back to the aperture blades, and back onto the sensor. This can cause some odd flares and overall loss of contrast. Not much you can do about this other than adding a polarizing filter and a tight lens hood to minimize incoming light. A tight lens hood is a good idea for older lenses anyway, because they have (compared to modern lenses) poor lens coatings, so they cannot resist flare, ghosting as well. Originally posted by lotech I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story. Wow, sounds good! Last edited by Na Horuk; 04-01-2015 at 04:31 AM.

04-01-2015, 04:28 AM	#8
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	There are two problems with the cheap knock-off adapters. The first is the poor machining that can lead to problems such as getting stuck in the camera or a lens mounting upside down. The second is that the screw that holds the spring clip is often too long. This can then engage the threads on the lens and make the lens impossible to remove without damage.

04-01-2015, 04:57 AM	#9
redcat Veteran Member Join Date: Jul 2014 Location: Paris Photos: Gallery Posts: 1,939	Originally posted by lotech I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story. Do tell that story did you take photos of the process ? It'd be super interesting !

04-01-2015, 08:55 AM	#10
npc Veteran Member Join Date: Apr 2013 Posts: 313	Originally posted by redcat Do tell that story did you take photos of the process ? It'd be super interesting ! Leica & Pentax & Nikon \| Leitax ?

04-01-2015, 09:37 AM	#11
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,891	What every one has missed is the fact that many non pentax M42 lenses do. Not have an auto manual switch. For Auto aperture only M42 lenses there is an adaptor that presses the aperture pin to allow control, but there are some pitfalls to watch out for with respect to the spring clip and screw. The other option is a mount mod, whre you put a small spacer around the pin just behind the mount inside the lens to block the aperture in the position set on the ring.

04-01-2015, 09:48 AM	#12
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by lotech I have successfully converted a Leica Summicron into K mount with infinity focusing but that's another story. Summicron R?