Old Pentax lenses on Pentax DSLR bodies

Balisarda · 11-23-2010, 11:04 AM

Hello all,

I'd very much like to try some grand old Pentax K, M, and A lenses on a K20D, but before I spend any money I'd like to know if Pentax's DSLR bodies will support open-aperture metering with those old lenses.

(I already surmise I'll have to use Manual mode with most of those lenses, which is fine. I also surmise Aperture Priority mode will work the Pentax-A lenses, right?)

My sincere thanks,
Eric.

paperbag846 · 11-23-2010, 11:15 AM

yes. you got it.

PENTAX Tip: Using Older PENTAX Lenses on PENTAX DSLRs | Facebook

I would start with a 50 1.7 or 1.4. A version if you can swing it, because AV mode is a very nice thing to have while you are focusing manually.

**Lowell Goudge** · 11-23-2010, 11:41 AM

Originally posted by Balisarda

Hello all,

I'd very much like to try some grand old Pentax K, M, and A lenses on a K20D, but before I spend any money I'd like to know if Pentax's DSLR bodies will support open-aperture metering with those old lenses.

(I already surmise I'll have to use Manual mode with most of those lenses, which is fine. I also surmise Aperture Priority mode will work the Pentax-A lenses, right?)

My sincere thanks,
Eric.

the metering is not fully automatic with all lenses.

For A lenses there is no issue at all, you can shoot them in any mode on the camera and they will behave just like modern lenses (Less autofocus of course)

For K and M lenses, you need to meter using one of the manual metering methods. these are the green button, and using the DOF preview. the difference between the methods is as follows.
- The green button stops the lens down for about 1/2 to 1 second, at which time it meters, and then the lens opens up again. When it meters, it sets the shutter speed to match the light coming through the aperture. Using DOF preview stops the lens down, and activates the metering and you can
- read the over or under exposure in the viewfinder, but it does not change the camera settings.

as you can see, not true open aperture metering.

Additionally, you should be aware that there is an issue with the focusing screen in the K20 (also used in the K10) which leads to significant exposure errors at some apertures.

I have posted the attached chart before,

8540tomg · 11-23-2010, 12:00 PM

Eric,

First post I see. Welocme to the forum.

Wow Lowell you are quick.

Yes Eric - the K, M and A series are all supported to various degress on your K 20.

If you check in the lens review section you will find reviews of how most if not all performed.

You will find this thread useful on using old Pentax glass on DSLRs.

https://www.pentaxforums.com/forums/pentax-beginners-corner-q/110658-using-ma...x-dslrs-f.html

Have fun.

Cheers

Tom G

Balisarda · 11-23-2010, 12:30 PM

My thanks to everyone for their advice!

Happy Thanksgiving,
Eric.

Rick Clark · 11-24-2010, 03:56 PM

Well while I'm here I will tell you I used all my 30 year old Pentax glass on my new K5 today. It is a kick to use them in full manual like the good old days. I did post that my Ricoh flash worked with them.

8540tomg · 11-30-2010, 06:30 AM

Originally posted by Rick Clark

Well while I'm here I will tell you I used all my 30 year old Pentax glass on my new K5 today. It is a kick to use them in full manual like the good old days. I did post that my Ricoh flash worked with them.

Hi Rick,

How did the old glass perform on the K5? I have a K10 and a lot of older Pentax glass so I'm curious.

Tom G

11-23-2010, 11:04 AM	#1
Balisarda New Member Join Date: Nov 2010 Location: Belmont, MA Posts: 2	Old Pentax lenses on Pentax DSLR bodies Hello all, I'd very much like to try some grand old Pentax K, M, and A lenses on a K20D, but before I spend any money I'd like to know if Pentax's DSLR bodies will support open-aperture metering with those old lenses. (I already surmise I'll have to use Manual mode with most of those lenses, which is fine. I also surmise Aperture Priority mode will work the Pentax-A lenses, right?) My sincere thanks, Eric.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Question about New lenses on old Pentax bodies	tomaplaw	Pentax SLR Lens Discussion	3	03-20-2009 03:39 PM
Which Pentax K-mount Lenses Fit Which Bodies	Ole	Pentax Lens Articles	1	03-04-2009 03:29 AM
Slr lenses on Dslr bodies	nemocub	Pentax SLR Lens Discussion	3	04-28-2008 09:51 PM

11-23-2010, 11:15 AM	#2
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	yes. you got it. PENTAX Tip: Using Older PENTAX Lenses on PENTAX DSLRs \| Facebook I would start with a 50 1.7 or 1.4. A version if you can swing it, because AV mode is a very nice thing to have while you are focusing manually.

11-23-2010, 11:41 AM	#3
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by Balisarda Hello all, I'd very much like to try some grand old Pentax K, M, and A lenses on a K20D, but before I spend any money I'd like to know if Pentax's DSLR bodies will support open-aperture metering with those old lenses. (I already surmise I'll have to use Manual mode with most of those lenses, which is fine. I also surmise Aperture Priority mode will work the Pentax-A lenses, right?) My sincere thanks, Eric. the metering is not fully automatic with all lenses. For A lenses there is no issue at all, you can shoot them in any mode on the camera and they will behave just like modern lenses (Less autofocus of course) For K and M lenses, you need to meter using one of the manual metering methods. these are the green button, and using the DOF preview. the difference between the methods is as follows. - The green button stops the lens down for about 1/2 to 1 second, at which time it meters, and then the lens opens up again. When it meters, it sets the shutter speed to match the light coming through the aperture. Using DOF preview stops the lens down, and activates the metering and you can - read the over or under exposure in the viewfinder, but it does not change the camera settings. as you can see, not true open aperture metering. Additionally, you should be aware that there is an issue with the focusing screen in the K20 (also used in the K10) which leads to significant exposure errors at some apertures. I have posted the attached chart before,

11-23-2010, 12:00 PM	#4
8540tomg Veteran Member Join Date: Feb 2008 Location: Waterloo, Ontario Photos: Gallery Posts: 4,461	Eric, First post I see. Welocme to the forum. Wow Lowell you are quick. Yes Eric - the K, M and A series are all supported to various degress on your K 20. If you check in the lens review section you will find reviews of how most if not all performed. You will find this thread useful on using old Pentax glass on DSLRs. https://www.pentaxforums.com/forums/pentax-beginners-corner-q/110658-using-ma...x-dslrs-f.html Have fun. Cheers Tom G

11-23-2010, 12:30 PM	#5
Balisarda New Member Join Date: Nov 2010 Location: Belmont, MA Posts: 2 Original Poster	My thanks to everyone for their advice! Happy Thanksgiving, Eric.

11-24-2010, 03:56 PM	#6
Rick Clark Senior Member Join Date: Nov 2010 Location: Provo, Utah Posts: 128	Well while I'm here I will tell you I used all my 30 year old Pentax glass on my new K5 today. It is a kick to use them in full manual like the good old days. I did post that my Ricoh flash worked with them.

11-30-2010, 06:30 AM	#7
8540tomg Veteran Member Join Date: Feb 2008 Location: Waterloo, Ontario Photos: Gallery Posts: 4,461	Originally posted by Rick Clark Well while I'm here I will tell you I used all my 30 year old Pentax glass on my new K5 today. It is a kick to use them in full manual like the good old days. I did post that my Ricoh flash worked with them. Hi Rick, How did the old glass perform on the K5? I have a K10 and a lot of older Pentax glass so I'm curious. Tom G