Question regarding older Pentax lenses on K1

CDW · 06-24-2016, 10:47 AM

I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks.

enoeske · 06-24-2016, 10:50 AM

Originally posted by CDW

I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks.

Its doesn't stop the aperture down until you take the photo.

Stone G. · 06-24-2016, 11:04 AM

And first of all: Make sure that you have set "Aperture Ring Permitted" in the Custom Menu Settings.

**paulh** · 06-24-2016, 11:06 AM

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html

pathdoc · 06-24-2016, 11:12 AM

Originally posted by paulh

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html

This should almost be a sticky at the top of the K-1 forum!

Adam · 06-24-2016, 11:22 AM

Originally posted by CDW

I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks.

For the A lens, just leave the aperture ring set to "A" and expose as you normally would.

For the M lens, you have to stop-down meter in M mode to get an exposure reading. Instructions can be found here:

https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html

In both cases, since K mount lens diaphragms are automatic, the aperture only stops down at the time of image capture (and when you press the green button).

CDW · 06-24-2016, 01:02 PM

Thanks everyone. I did remember from my K5 days to go into the menu and change the Aperture Ring Permitted setting to allow. So now, no problem with the 70-210. However, the 50 1.4 has no A setting on the A ring. When I mount the lens on the camera, in M mode, the aperture changes to wide open 1.4 and turning the aperture ring has no effect. When I press the shutter release there is no change in the aperture. I see F-- in the viewfinder. Sorry to be so dense about this, what have I missed?

enoeske · 06-24-2016, 01:04 PM

Originally posted by CDW

what have I missed?

this post

Originally posted by paulh

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html

grispie · 06-24-2016, 01:07 PM

Originally posted by CDW

Sorry to be so dense about this, what have I missed?

think you just have to push the green button (metering) and then fire away..

CDW · 06-24-2016, 01:29 PM

Thanks again, I was looking for the green button and stupidly ignored the green dot. All is well.

06-24-2016, 10:47 AM	#1
CDW Site Supporter Join Date: May 2011 Location: Big Island, Hawaii & Utah Posts: 457	Question regarding older Pentax lenses on K1 I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks.

06-24-2016, 11:22 AM	#6
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,594	Originally posted by CDW I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks. For the A lens, just leave the aperture ring set to "A" and expose as you normally would. For the M lens, you have to stop-down meter in M mode to get an exposure reading. Instructions can be found here: https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html In both cases, since K mount lens diaphragms are automatic, the aperture only stops down at the time of image capture (and when you press the green button). 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:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Regarding the new Pentax K1	benjikan	Pentax Full Frame	11	12-11-2015 03:42 PM
A question about older Pentax lenses on a DSLR.	Dewman	Troubleshooting and Beginner Help	9	05-16-2012 03:48 PM
Question regarding on Pentax K-7. =)	richard balonglong	Pentax DSLR Discussion	11	07-24-2011 05:24 PM
Question on older (manual focus) Pentax lenses	Duck Dodgers	Pentax SLR Lens Discussion	4	05-21-2009 11:05 AM
Metering Question On Older Lenses	metroeloise	Pentax SLR Lens Discussion	3	02-21-2009 08:34 PM

06-24-2016, 10:50 AM	#2
enoeske Veteran Member Join Date: Jul 2009 Location: Surprise, Az Photos: Gallery Posts: 2,136	Originally posted by CDW I received my K1 day before yesterday. I picked up a couple of older Pentax lenses, an M 1.4 50mm and A 70-210 F4 zoom. When I mount these on the K1 the aperture is wide open and rotating the aperture ring does not change the setting. I'm guessing I need some type of adapter to allow me to manually change the aperture when mounted. Can someone provide the answer or tell me what I may be doing wrong. Thanks. Its doesn't stop the aperture down until you take the photo.

06-24-2016, 11:04 AM	#3
Stone G. Pentaxian Join Date: Jun 2010 Location: North Zealand, Denmark Photos: Gallery \| Albums Posts: 1,516	And first of all: Make sure that you have set "Aperture Ring Permitted" in the Custom Menu Settings.

06-24-2016, 11:06 AM	#4
paulh Site Supporter Join Date: Sep 2010 Location: DFW Texas/Ventura County, CA Photos: Gallery \| Albums Posts: 33,262	https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html

06-24-2016, 11:12 AM	#5
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	Originally posted by paulh https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html This should almost be a sticky at the top of the K-1 forum!

06-24-2016, 01:02 PM	#7
CDW Site Supporter Join Date: May 2011 Location: Big Island, Hawaii & Utah Posts: 457 Original Poster	Thanks everyone. I did remember from my K5 days to go into the menu and change the Aperture Ring Permitted setting to allow. So now, no problem with the 70-210. However, the 50 1.4 has no A setting on the A ring. When I mount the lens on the camera, in M mode, the aperture changes to wide open 1.4 and turning the aperture ring has no effect. When I press the shutter release there is no change in the aperture. I see F-- in the viewfinder. Sorry to be so dense about this, what have I missed?

06-24-2016, 01:04 PM	#8
enoeske Veteran Member Join Date: Jul 2009 Location: Surprise, Az Photos: Gallery Posts: 2,136	Originally posted by CDW what have I missed? this post Originally posted by paulh https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html

06-24-2016, 01:07 PM	#9
grispie Veteran Member Join Date: Feb 2013 Posts: 1,199	Originally posted by CDW Sorry to be so dense about this, what have I missed? think you just have to push the green button (metering) and then fire away..

06-24-2016, 01:29 PM	#10
CDW Site Supporter Join Date: May 2011 Location: Big Island, Hawaii & Utah Posts: 457 Original Poster	Thanks again, I was looking for the green button and stupidly ignored the green dot. All is well.