which of the Pentax bayonet mount lenses fit the K 50?

Not a Number · 08-13-2015, 12:54 PM

Also if the lens mount has a non-conducting coating you may have to scrape it off exposing bare metal over the data pin. The green button does not work on some bodies if no electrical connection is present.

LSAGuy · 08-13-2015, 03:09 PM

Thanks for all your help everyone. We just got back from errands and the answer was waiting for me. Enabling the custom aperture setting did the trick. After dinner I get to take the Vivitar out for a drive. Woohooo!

Rick

jmclaugh · 09-14-2015, 06:49 AM

Hi,

I found this forum when looking into the use of old K bayonet lenses on new Pentax DSLRs so I joined. Anyway I still have an old Pentax MX and the following lenses; SMC 50mm 1.7, Vivitar 28mm 2.8, 35mm 2.5 135mm 2.5 all late 1970s vintage that started out life on a K1000. As I need a new camera I thought I'd look into just getting a new Pentax DSLR body and use the lenses. I've seen the info on here which all seems pretty straightforward other than the bit about conductive. https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html
and I also came across this video which indicates you also need to specify the focal length.

You Tube

Firstly I'm hoping someone could clarify if the Vivitar lenses will work? I've examined the mounts and they look identical to the Pentax SMC mount so I'm hoping there isn't a conductive issue.

Secondly can anyone confirm if the focal length must be entered as per that video as that sounds a real pain each time you switch lenses? (It doesn't make sense why the camera needs to know that and I don't see how that works with a zoom lens so I'm thinking there must be some other reason like shake reduction?)

As for the camera I'm thinking of a K500 or K50.

jmclaugh · 09-14-2015, 07:04 AM

P.S. Can't seem to edit that post well not yet anyway and I forgot to ask ano question. So while I remember when using an old K bayonet mount lens can you manually set the shutter speed and the aperture and the camera light metering system tells if it is ok or not as per full manual operation or do you have to set the aperture and leave shutter speed selection to the camera?

mholford · 09-14-2015, 08:20 AM

Originally posted by jmclaugh

P.S. Can't seem to edit that post well not yet anyway and I forgot to ask ano question. So while I remember when using an old K bayonet mount lens can you manually set the shutter speed and the aperture and the camera light metering system tells if it is ok or not as per full manual operation or do you have to set the aperture and leave shutter speed selection to the camera?

i'll try to answer (although I'm no expert)
With regards to focal length - this is for the shake reduction system - the camera body compensates for shake, but needs to know the focal length of the lens to do it effectively. so yes, any time you mount an old lens on the digital body it will bring up a screen asking for focal length - you just use the buttons to move back and forth and select the appropriate focal length (doesn't take much - I cycle between 50mm and 200mm on my old pentax k lenses). You can turn off shake reduction. It wouldn't ask for focal length then (I believe). if you ignore the screen or just hit okay it will use whatever the last entered focal length was - which might not help, but means if you leave your 28mm on the camera, the next time you turn on the camera the focal length will be set to 28, and you just hit okay to get past the screen.
And yes, there is an "M" setting on the mode dial where you essentially set everything by hand (shutter, iso, aperture). You can also use the green button and it will check the exposure and change the shutter speed for you to what it thinks you need. You don't have to use the green button but it does help to quickly get close to a well exposed image. So no, you don't have to the the camera chose. But you can. And you can over-ride it after and change the shutter speed before firing if you disagree with it's choice.
I just spent a month shooting with nothing but an old Pentax K lens, and the process of taking a picture became quite instinctive once I got used to what had to be done.
btw. I ended up with a pentax DSLR for the exact same reason you are proposing - I had an old pentax SLR, and several old lenses and thought it would make the initial jump to DSLR less expensive. The initial jump was indeed much less expensive, and I've been able to snag some nice lenses since then as budget allows - now I have an interesting mix of old and new glass which my camera body takes great photo's with either way.
oh... only trick with vivitar - some of the mounts have a bigger aperture level shield than standard pentax K - those need physical modification... (just check to see if the guard is much longer than the equivalent pentax lens. although if it's not an "A" lens then this may be a moot point as there wouldn't be a level to protect...

vonBaloney · 09-14-2015, 08:39 AM

Originally posted by mholford

(just check to see if the guard is much longer than the equivalent pentax lens. although if it's not an "A" lens then this may be a moot point as there wouldn't be a level to protect...

The aperture lever is there of course with any K mount lens, doesn't matter if it is an 'A' or not. Most Vivitar lenses have no trouble, but there are definitely some that have the "too long" aperture guard. (And I think it is ONLY vivitar lenses that have this problem.)

As far as setting focal length on old manual zooms, yes that is a pain, so you can set it to some lowish value (setting it under rather than over the true value is preferred) or just turn it off, or if you are not really zooming much that day (using your zoom as a prime) just set it to the value you are actually using. Then again, the list of old manual zooms that are acceptable performers on digital cameras is not long so it doesn't come up much as not many people are using them. However, there are at least a handful of very nice old zooms that are still good performers.

The other thing to watch out for with third-party K-mount lenses is the dreaded "ricoh pin" which can cause the lens to get stuck on your camera if it is of a certain style. (search for "ricoh pin" and you'll find a ton of stuff on that)

jmclaugh · 09-14-2015, 10:05 AM

Many thanks mholford and vonBolony for the kind replies. So it is the apeture guard depth that is the issue, I've just checked my SMC 55mm lens to the Vivitar ones and the latter do seem to have a guard which is a tad longer. Sounds like the best course of action is to try one out so maybe a visit to a camera shop is the best idea to see if they fit a DSLR properly.

I googled "ricoh pin" and it seems such lenses are marked "KR" and all my Vivitar lenses are marked PK and have no such pin so I don't think I will have that problem. There is some stuff here if anyone is interested about it and how to fix it if you have that problem.

theatre of noise: Ricoh Lenses On Pentax Cameras -- The Ricoh Pin Fix

As for a K50 or K500 body it seems the latter is unavailable in the UK and I can only find it with an 18-55mm lens which I don't really need. Perhaps it has discontinued. It seems the only difference between them is the K50 is weather resistant and displays what area of the picture the autofocus has used which is obviously irrelevant for a manual focus lens. Any thoughts on the two much appreciated.

**pepperberry farm** · 09-14-2015, 10:17 AM

I was under the impression that the K-500 had been discontinued...

mholford · 09-14-2015, 12:43 PM

Originally posted by jmclaugh

Many thanks mholford and vonBolony for the kind replies. So it is the apeture guard depth that is the issue, I've just checked my SMC 55mm lens to the Vivitar ones and the latter do seem to have a guard which is a tad longer. Sounds like the best course of action is to try one out so maybe a visit to a camera shop is the best idea to see if they fit a DSLR properly.

I googled "ricoh pin" and it seems such lenses are marked "KR" and all my Vivitar lenses are marked PK and have no such pin so I don't think I will have that problem. There is some stuff here if anyone is interested about it and how to fix it if you have that problem.

theatre of noise: Ricoh Lenses On Pentax Cameras -- The Ricoh Pin Fix

As for a K50 or K500 body it seems the latter is unavailable in the UK and I can only find it with an 18-55mm lens which I don't really need. Perhaps it has discontinued. It seems the only difference between them is the K50 is weather resistant and displays what area of the picture the autofocus has used which is obviously irrelevant for a manual focus lens. Any thoughts on the two much appreciated.

there is a picture here https://www.pentaxforums.com/forums/attachments/10-pentax-slr-lens-discussion...0-imgp2139.jpg that illustrates the longer vs. shorter aperture guard...
not a big deal reducing the size of the guard (I shortened it on my old vivitar zoom lens) there are several discussion threads outlining different ways of doing it.

jmclaugh · 09-16-2015, 02:48 AM

Originally posted by mholford

there is a picture here https://www.pentaxforums.com/forums/attachments/10-pentax-slr-lens-discussion...0-imgp2139.jpg that illustrates the longer vs. shorter aperture guard...
not a big deal reducing the size of the guard (I shortened it on my old vivitar zoom lens) there are several discussion threads outlining different ways of doing it.

Thanks for that. I'm going to take one of the VIvitar lenses to a camera shop and hopefully they'll let me try it on say a K50 body. If they don't fit I'll probably opt to remove the guard.

One thing I hadn't realised is using these lenses on a non-full frame DSLR is like having 1.5x teleconverter on it. In a nutshell that means I do need something like an 18-55mm lens for wide angle use or some prime lenses but the latter would get pretty expensive and defeats the idea of using my existing lenses. Still I guess the SMC 50mm 1.7 will become a very nice portrait lens and the 135mm 2.5 will become a fast 200mm telephoto lens,

vonBaloney · 09-16-2015, 07:52 AM

Originally posted by jmclaugh

Thanks for that. I'm going to take one of the VIvitar lenses to a camera shop and hopefully they'll let me try it on say a K50 body. If they don't fit I'll probably opt to remove the guard.

Well the guard will scrape into the protrusion with the SDM pins inside the mount, so what you are actually asking is "Can I see if this lens will scratch up the interior of the mount on your body?" So do so slowly and carefully. What lenses exactly are we talking about? We can probably just tell you if there is a problem....

jmclaugh · 09-16-2015, 09:14 AM

Originally posted by vonBaloney

Well the guard will scrape into the protrusion with the SDM pins inside the mount, so what you are actually asking is "Can I see if this lens will scratch up the interior of the mount on your body?" So do so slowly and carefully. What lenses exactly are we talking about? We can probably just tell you if there is a problem....

No wish to damage a mount and if the guy in camera shop says no or yes it will damage it so he won't try that's fine.

The 3 lenses are Vivitar PK mount late 1970s glass and metal construction; 135mm 2.5 Auto Telephoto, 28mm 2.8 Auto Wide-Angle, 35mm 2.5 Auto Wide-Angle. The mounts look exactly like the mount on a Pentax SMC-M 50mm 1.7 lens except the base lens element is in a casing that sits higher that the base of mount so while the guard looks higher on the Vivitar mount I suspect it is actually the same size but I'm not sure. A couple of quickly taken pics are attached, the first is the SMC mount, the second is the Vivitar.

jmclaugh · 09-18-2015, 09:46 AM

Just to finish the story a nice bloke at a camera shop was happy to try the lens for me, it fitted and worked fine. So now I know the Vivitars work ok I'll be going with a Pentax DSLR. Options look to be a new K500 + 18-55 at £289, new K50 + 18-55 at £350 though the shop have a used K30 +18-55 in good nick at £200.

ZombieArmy · 09-18-2015, 09:56 AM

Originally posted by jmclaugh

Just to finish the story a nice bloke at a camera shop was happy to try the lens for me, it fitted and worked fine. So now I know the Vivitars work ok I'll be going with a Pentax DSLR. Options look to be a new K500 + 18-55 at £289, new K50 + 18-55 at £350 though the shop have a used K30 +18-55 in good nick at £200.

Get the k-50, you'll regret not getting the weather resistance and other neat little features that come with it.*

*k-30 is also basically a k-50, but if you go with the used k-30 make sure the 18-55 that comes with it is WR.

09-14-2015, 08:20 AM	#20
mholford Senior Member Join Date: Dec 2012 Location: Vancouver Island, BC Photos: Albums Posts: 238	Originally posted by jmclaugh P.S. Can't seem to edit that post well not yet anyway and I forgot to ask ano question. So while I remember when using an old K bayonet mount lens can you manually set the shutter speed and the aperture and the camera light metering system tells if it is ok or not as per full manual operation or do you have to set the aperture and leave shutter speed selection to the camera? i'll try to answer (although I'm no expert) With regards to focal length - this is for the shake reduction system - the camera body compensates for shake, but needs to know the focal length of the lens to do it effectively. so yes, any time you mount an old lens on the digital body it will bring up a screen asking for focal length - you just use the buttons to move back and forth and select the appropriate focal length (doesn't take much - I cycle between 50mm and 200mm on my old pentax k lenses). You can turn off shake reduction. It wouldn't ask for focal length then (I believe). if you ignore the screen or just hit okay it will use whatever the last entered focal length was - which might not help, but means if you leave your 28mm on the camera, the next time you turn on the camera the focal length will be set to 28, and you just hit okay to get past the screen. And yes, there is an "M" setting on the mode dial where you essentially set everything by hand (shutter, iso, aperture). You can also use the green button and it will check the exposure and change the shutter speed for you to what it thinks you need. You don't have to use the green button but it does help to quickly get close to a well exposed image. So no, you don't have to the the camera chose. But you can. And you can over-ride it after and change the shutter speed before firing if you disagree with it's choice. I just spent a month shooting with nothing but an old Pentax K lens, and the process of taking a picture became quite instinctive once I got used to what had to be done. btw. I ended up with a pentax DSLR for the exact same reason you are proposing - I had an old pentax SLR, and several old lenses and thought it would make the initial jump to DSLR less expensive. The initial jump was indeed much less expensive, and I've been able to snag some nice lenses since then as budget allows - now I have an interesting mix of old and new glass which my camera body takes great photo's with either way. oh... only trick with vivitar - some of the mounts have a bigger aperture level shield than standard pentax K - those need physical modification... (just check to see if the guard is much longer than the equivalent pentax lens. although if it's not an "A" lens then this may be a moot point as there wouldn't be a level to protect... Last edited by mholford; 09-14-2015 at 08:22 AM. Reason: added note about vivitar

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08-13-2015, 12:54 PM	#16
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	Also if the lens mount has a non-conducting coating you may have to scrape it off exposing bare metal over the data pin. The green button does not work on some bodies if no electrical connection is present.

08-13-2015, 03:09 PM	#17
LSAGuy New Member Join Date: Jul 2015 Posts: 16 Original Poster	Thanks for all your help everyone. We just got back from errands and the answer was waiting for me. Enabling the custom aperture setting did the trick. After dinner I get to take the Vivitar out for a drive. Woohooo! Rick

09-14-2015, 07:04 AM	#19
jmclaugh Inactive Account Join Date: Sep 2015 Location: Devon Posts: 12	P.S. Can't seem to edit that post well not yet anyway and I forgot to ask ano question. So while I remember when using an old K bayonet mount lens can you manually set the shutter speed and the aperture and the camera light metering system tells if it is ok or not as per full manual operation or do you have to set the aperture and leave shutter speed selection to the camera?

09-14-2015, 08:39 AM	#21
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by mholford (just check to see if the guard is much longer than the equivalent pentax lens. although if it's not an "A" lens then this may be a moot point as there wouldn't be a level to protect... The aperture lever is there of course with any K mount lens, doesn't matter if it is an 'A' or not. Most Vivitar lenses have no trouble, but there are definitely some that have the "too long" aperture guard. (And I think it is ONLY vivitar lenses that have this problem.) As far as setting focal length on old manual zooms, yes that is a pain, so you can set it to some lowish value (setting it under rather than over the true value is preferred) or just turn it off, or if you are not really zooming much that day (using your zoom as a prime) just set it to the value you are actually using. Then again, the list of old manual zooms that are acceptable performers on digital cameras is not long so it doesn't come up much as not many people are using them. However, there are at least a handful of very nice old zooms that are still good performers. The other thing to watch out for with third-party K-mount lenses is the dreaded "ricoh pin" which can cause the lens to get stuck on your camera if it is of a certain style. (search for "ricoh pin" and you'll find a ton of stuff on that)

09-14-2015, 10:05 AM	#22
jmclaugh Inactive Account Join Date: Sep 2015 Location: Devon Posts: 12	Many thanks mholford and vonBolony for the kind replies. So it is the apeture guard depth that is the issue, I've just checked my SMC 55mm lens to the Vivitar ones and the latter do seem to have a guard which is a tad longer. Sounds like the best course of action is to try one out so maybe a visit to a camera shop is the best idea to see if they fit a DSLR properly. I googled "ricoh pin" and it seems such lenses are marked "KR" and all my Vivitar lenses are marked PK and have no such pin so I don't think I will have that problem. There is some stuff here if anyone is interested about it and how to fix it if you have that problem. theatre of noise: Ricoh Lenses On Pentax Cameras -- The Ricoh Pin Fix As for a K50 or K500 body it seems the latter is unavailable in the UK and I can only find it with an 18-55mm lens which I don't really need. Perhaps it has discontinued. It seems the only difference between them is the K50 is weather resistant and displays what area of the picture the autofocus has used which is obviously irrelevant for a manual focus lens. Any thoughts on the two much appreciated.

09-14-2015, 10:17 AM	#23
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,766	I was under the impression that the K-500 had been discontinued...

09-14-2015, 12:43 PM	#24
mholford Senior Member Join Date: Dec 2012 Location: Vancouver Island, BC Photos: Albums Posts: 238	Originally posted by jmclaugh Many thanks mholford and vonBolony for the kind replies. So it is the apeture guard depth that is the issue, I've just checked my SMC 55mm lens to the Vivitar ones and the latter do seem to have a guard which is a tad longer. Sounds like the best course of action is to try one out so maybe a visit to a camera shop is the best idea to see if they fit a DSLR properly. I googled "ricoh pin" and it seems such lenses are marked "KR" and all my Vivitar lenses are marked PK and have no such pin so I don't think I will have that problem. There is some stuff here if anyone is interested about it and how to fix it if you have that problem. theatre of noise: Ricoh Lenses On Pentax Cameras -- The Ricoh Pin Fix As for a K50 or K500 body it seems the latter is unavailable in the UK and I can only find it with an 18-55mm lens which I don't really need. Perhaps it has discontinued. It seems the only difference between them is the K50 is weather resistant and displays what area of the picture the autofocus has used which is obviously irrelevant for a manual focus lens. Any thoughts on the two much appreciated. there is a picture here https://www.pentaxforums.com/forums/attachments/10-pentax-slr-lens-discussion...0-imgp2139.jpg that illustrates the longer vs. shorter aperture guard... not a big deal reducing the size of the guard (I shortened it on my old vivitar zoom lens) there are several discussion threads outlining different ways of doing it.

09-16-2015, 02:48 AM	#25
jmclaugh Inactive Account Join Date: Sep 2015 Location: Devon Posts: 12	Originally posted by mholford there is a picture here https://www.pentaxforums.com/forums/attachments/10-pentax-slr-lens-discussion...0-imgp2139.jpg that illustrates the longer vs. shorter aperture guard... not a big deal reducing the size of the guard (I shortened it on my old vivitar zoom lens) there are several discussion threads outlining different ways of doing it. Thanks for that. I'm going to take one of the VIvitar lenses to a camera shop and hopefully they'll let me try it on say a K50 body. If they don't fit I'll probably opt to remove the guard. One thing I hadn't realised is using these lenses on a non-full frame DSLR is like having 1.5x teleconverter on it. In a nutshell that means I do need something like an 18-55mm lens for wide angle use or some prime lenses but the latter would get pretty expensive and defeats the idea of using my existing lenses. Still I guess the SMC 50mm 1.7 will become a very nice portrait lens and the 135mm 2.5 will become a fast 200mm telephoto lens,

09-16-2015, 07:52 AM	#26
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by jmclaugh Thanks for that. I'm going to take one of the VIvitar lenses to a camera shop and hopefully they'll let me try it on say a K50 body. If they don't fit I'll probably opt to remove the guard. Well the guard will scrape into the protrusion with the SDM pins inside the mount, so what you are actually asking is "Can I see if this lens will scratch up the interior of the mount on your body?" So do so slowly and carefully. What lenses exactly are we talking about? We can probably just tell you if there is a problem....

09-18-2015, 09:46 AM	#28
jmclaugh Inactive Account Join Date: Sep 2015 Location: Devon Posts: 12	Just to finish the story a nice bloke at a camera shop was happy to try the lens for me, it fitted and worked fine. So now I know the Vivitars work ok I'll be going with a Pentax DSLR. Options look to be a new K500 + 18-55 at £289, new K50 + 18-55 at £350 though the shop have a used K30 +18-55 in good nick at £200.

09-18-2015, 09:56 AM	#29
ZombieArmy Pentaxian Join Date: Jun 2014 Location: Florida Posts: 3,210	Originally posted by jmclaugh Just to finish the story a nice bloke at a camera shop was happy to try the lens for me, it fitted and worked fine. So now I know the Vivitars work ok I'll be going with a Pentax DSLR. Options look to be a new K500 + 18-55 at £289, new K50 + 18-55 at £350 though the shop have a used K30 +18-55 in good nick at £200. Get the k-50, you'll regret not getting the weather resistance and other neat little features that come with it.* *k-30 is also basically a k-50, but if you go with the used k-30 make sure the 18-55 that comes with it is WR.