K3 Exposure Button

**stubyles** · 11-04-2014, 04:26 AM

Originally posted by stevebrot

you must enable the aperture ring in the menu settings.

This is the first thing I did to my K3

**Mikesul** · 11-04-2014, 05:57 AM

I have never understood why it is not on by default. You never know when you may need to use a lens with an aperture ring. I have never seen any disadvantage to turning the aperture ring option on. Just seems like a needless option.

**stubyles** · 11-04-2014, 06:00 AM

Originally posted by Mikesul

I have never understood why it is not on by default. You never know when you may need to use a lens with an aperture ring. I have never seen any disadvantage to turning the aperture ring option on. Just seems like a needless option.

Agreed, maybe pentax don't want people to think they can use manual lenses on DSLRs.

**Mikesul** · 11-04-2014, 06:02 AM

But retention of the Kmount is evidence that Pentax does want people to be able to use all older lenses. I wonder if there is some issue we do not detect with having the aperture ring enabled.

**stubyles** · 11-04-2014, 06:04 AM

Maybe, I can't imagine what it might be though?

---------- Post added 11-04-14 at 01:08 PM ----------

Originally posted by Tjompen1968

When in Av you descide the aperture and the camera the shutter speed. That´s it. What more do you want to do? The same goes for Tv, you descide the shutter speed and the camera sets the aperture...

Please explain your trail of thoughts.

The other strange thing is that when you look at the picture taken it says the shutter speed was 1/8000 but it's massively over exposed.
If I then set the same settings in manual the picture is massively under exposed as you'd expect at 1/8000.

stevebrot · 11-04-2014, 09:17 AM

Originally posted by stubyles

This is the first thing I did to my K3

Based on your comments, you apparently did not read the rest of my suggestion and/or are not familiar with the use of non-A contact lenses on your K-3. You can't use Av mode and expect the lens to stop down if you are controlling the aperture from the ring on the lens. Av mode is used when the aperture is being controlled by the body. Your K 50/1.2 does not support that feature and there is no work-around that will allow it to do so.

Use M mode with stop-down metering or external meter when using lenses that lack the "A" contacts.

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

Steve

Fogel70 · 11-04-2014, 10:01 AM

Originally posted by stubyles

Agreed, maybe pentax don't want people to think they can use manual lenses on DSLRs.

I believe it's done to avoid operating mirror & shutter without a lens mounted.

**stubyles** · 11-04-2014, 10:49 AM

Originally posted by stevebrot

Based on your comments, you apparently did not read the rest of my suggestion and/or are not familiar with the use of non-A contact lenses on your K-3. You can't use Av mode and expect the lens to stop down if you are controlling the aperture from the ring on the lens. Av mode is used when the aperture is being controlled by the body. Your K 50/1.2 does not support that feature and there is no work-around that will allow it to do so.

Use M mode with stop-down metering or external meter when using lenses that lack the "A" contacts.

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

Steve

I use AV mode on manual aperture lenses all the time and the camera sets the shutter speed perfectly.
Yes, it can't stop the lens down but it meters and sets the shutter speed accordingly.
it just won't do it with my K50 in the scenarios I describe.

Unregistered User · 11-04-2014, 11:32 AM

Originally posted by stubyles

I use AV mode on manual aperture lenses all the time and the camera sets the shutter speed perfectly.
Yes, it can't stop the lens down but it meters and sets the shutter speed accordingly.
it just won't do it with my K50 in the scenarios I describe.

When using my M42-lenses I can use Av for continous measuring but with my Chinon lens, K-mount, no A-setting, I need to use M-mode and stop down metering since I will not be able to get the aperture to close when in Av-mode.

I wonder if the behaviour in Av was different on my K-5 or earlier firmware on the K-3... No.

Remember that if you are using Live View the green button will not work in M-mode unless the contacts are shortened which is not always the case with older lenses. If so, use Av.

**stubyles** · 11-04-2014, 02:17 PM

Originally posted by Tjompen1968

When using my M42-lenses I can use Av for continous measuring but with my Chinon lens, K-mount, no A-setting, I need to use M-mode and stop down metering since I will not be able to get the aperture to close when in Av-mode.

I wonder if the behaviour in Av was different on my K-5 or earlier firmware on the K-3... No.

Remember that if you are using Live View the green button will not work in M-mode unless the contacts are shortened which is not always the case with older lenses. If so, use Av.

I'll have to have a good look at it, clean the base, etc. Maybe try it on my daughters K-x.
Thanks for the input.

11-04-2014, 11:32 AM	#24
Unregistered User Guest	Originally posted by stubyles I use AV mode on manual aperture lenses all the time and the camera sets the shutter speed perfectly. Yes, it can't stop the lens down but it meters and sets the shutter speed accordingly. it just won't do it with my K50 in the scenarios I describe. When using my M42-lenses I can use Av for continous measuring but with my Chinon lens, K-mount, no A-setting, I need to use M-mode and stop down metering since I will not be able to get the aperture to close when in Av-mode. I wonder if the behaviour in Av was different on my K-5 or earlier firmware on the K-3... No. Remember that if you are using Live View the green button will not work in M-mode unless the contacts are shortened which is not always the case with older lenses. If so, use Av. Last edited by Unregistered User; 11-04-2014 at 12:29 PM. Reason: Added

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11-04-2014, 04:26 AM	#16
stubyles Site Supporter Join Date: Oct 2013 Photos: Gallery Posts: 824	Originally posted by stevebrot you must enable the aperture ring in the menu settings. This is the first thing I did to my K3

11-04-2014, 05:57 AM	#17
Mikesul Loyal Site Supporter Join Date: Sep 2009 Location: Phoenix, AZ Posts: 7,594	I have never understood why it is not on by default. You never know when you may need to use a lens with an aperture ring. I have never seen any disadvantage to turning the aperture ring option on. Just seems like a needless option.

11-04-2014, 06:00 AM	#18
stubyles Site Supporter Join Date: Oct 2013 Photos: Gallery Posts: 824	Originally posted by Mikesul I have never understood why it is not on by default. You never know when you may need to use a lens with an aperture ring. I have never seen any disadvantage to turning the aperture ring option on. Just seems like a needless option. Agreed, maybe pentax don't want people to think they can use manual lenses on DSLRs.

11-04-2014, 06:02 AM	#19
Mikesul Loyal Site Supporter Join Date: Sep 2009 Location: Phoenix, AZ Posts: 7,594	But retention of the Kmount is evidence that Pentax does want people to be able to use all older lenses. I wonder if there is some issue we do not detect with having the aperture ring enabled.

11-04-2014, 06:04 AM	#20
stubyles Site Supporter Join Date: Oct 2013 Photos: Gallery Posts: 824	Maybe, I can't imagine what it might be though? ---------- Post added 11-04-14 at 01:08 PM ---------- Originally posted by Tjompen1968 When in Av you descide the aperture and the camera the shutter speed. That´s it. What more do you want to do? The same goes for Tv, you descide the shutter speed and the camera sets the aperture... Please explain your trail of thoughts. The other strange thing is that when you look at the picture taken it says the shutter speed was 1/8000 but it's massively over exposed. If I then set the same settings in manual the picture is massively under exposed as you'd expect at 1/8000.

11-04-2014, 09:17 AM	#21
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by stubyles This is the first thing I did to my K3 Based on your comments, you apparently did not read the rest of my suggestion and/or are not familiar with the use of non-A contact lenses on your K-3. You can't use Av mode and expect the lens to stop down if you are controlling the aperture from the ring on the lens. Av mode is used when the aperture is being controlled by the body. Your K 50/1.2 does not support that feature and there is no work-around that will allow it to do so. Use M mode with stop-down metering or external meter when using lenses that lack the "A" contacts. https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html Steve

11-04-2014, 10:01 AM	#22
Fogel70 Pentaxian Join Date: Sep 2009 Location: Stockholm, Sweden Photos: Albums Posts: 3,062	Originally posted by stubyles Agreed, maybe pentax don't want people to think they can use manual lenses on DSLRs. I believe it's done to avoid operating mirror & shutter without a lens mounted.

11-04-2014, 10:49 AM	#23
stubyles Site Supporter Join Date: Oct 2013 Photos: Gallery Posts: 824	Originally posted by stevebrot Based on your comments, you apparently did not read the rest of my suggestion and/or are not familiar with the use of non-A contact lenses on your K-3. You can't use Av mode and expect the lens to stop down if you are controlling the aperture from the ring on the lens. Av mode is used when the aperture is being controlled by the body. Your K 50/1.2 does not support that feature and there is no work-around that will allow it to do so. Use M mode with stop-down metering or external meter when using lenses that lack the "A" contacts. https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...k-x-k-7-a.html Steve I use AV mode on manual aperture lenses all the time and the camera sets the shutter speed perfectly. Yes, it can't stop the lens down but it meters and sets the shutter speed accordingly. it just won't do it with my K50 in the scenarios I describe.

11-04-2014, 02:17 PM	#25
stubyles Site Supporter Join Date: Oct 2013 Photos: Gallery Posts: 824	Originally posted by Tjompen1968 When using my M42-lenses I can use Av for continous measuring but with my Chinon lens, K-mount, no A-setting, I need to use M-mode and stop down metering since I will not be able to get the aperture to close when in Av-mode. I wonder if the behaviour in Av was different on my K-5 or earlier firmware on the K-3... No. Remember that if you are using Live View the green button will not work in M-mode unless the contacts are shortened which is not always the case with older lenses. If so, use Av. I'll have to have a good look at it, clean the base, etc. Maybe try it on my daughters K-x. Thanks for the input.