Aperture Ring - Permitted/Prohibited? F--- Error?

krishna · 04-18-2010, 06:32 AM

I was experimenting my new Tamron 70-300 lens with my Pentax K-x. I observed "F---" when the "Aperture Ring" is not set to "A" position.

I read the manual and found the option in menu "Aperture Ring -Permitted/Prohibited". What for is this used? When I change to "Permitted" still I get the same error in viewfinder.

However, in Av Priority mode I can change the "Aperture" value using e-dial.

I am not clear on the Aperture Ring - Permitted/Prohibited. Could you please help me?

Thanks,
Krishna

emr · 04-18-2010, 06:36 AM

You need to set it to "permitted" to be able to use older, non-A lenses. When you set it correctly, you can manually choose the wanted aperture on the lens and then use the green button to measure correct exposure (time).

Zebooka · 04-18-2010, 06:56 AM

It will always show F-- for non A position of aperture on the lens.
This is because all Pentax DSLRs use "crippled" bayonet. That means - there is no aperture coupler for transmitting selected (on the lens) aperture value to camera.

**RuiC** · 04-18-2010, 07:05 AM

Originally posted by Zebooka

It will always show F-- for non A position of aperture on the lens.
This is because all Pentax DSLRs use "crippled" bayonet. That means - there is no aperture coupler for transmitting selected (on the lens) aperture value to camera.

So to get correct exposures in AV, with aperture on non-A position, you have to stop down, otherwise every shot will be be wide open, or you can switch to M and do correct measurement with the GreenButton (AElock?) (Here you also have to select custom function "Green button in TAv or M mode to TV shift)

Rui

JeffJS · 04-18-2010, 08:17 AM

Originally posted by krishna

I was experimenting my new Tamron 70-300 lens with my Pentax K-x. I observed "F---" when the "Aperture Ring" is not set to "A" position.

I read the manual and found the option in menu "Aperture Ring -Permitted/Prohibited". What for is this used? When I change to "Permitted" still I get the same error in viewfinder.

However, in Av Priority mode I can change the "Aperture" value using e-dial.

I am not clear on the Aperture Ring - Permitted/Prohibited. Could you please help me?

Thanks,
Krishna

I understand you are just experimenting but there really isn't a good reason to take an A type lens off of the A position. If you want to use a lens that does not have an A setting, then you need to set Using Aperture Ring to Permitted.

The way I do it on my K7 is that I set the camera to M mode, Set the aperture or shutter speed, pull the power switch to Preview (set it for DOF preview instead of Digital preview) which will show the meter, then set the other parameter (shutter speed or aperture) until I have the metering I want. There are other ways of doing it, I'm sure, but that one works for me.

Ira · 04-18-2010, 09:51 AM

Originally posted by RuiC

So to get correct exposures in AV, with aperture on non-A position, you have to stop down, otherwise every shot will be be wide open, or you can switch to M and do correct measurement with the GreenButton (AElock?) (Here you also have to select custom function "Green button in TAv or M mode to TV shift)

Rui

On the KX, in M mode, you don't have to set the Green to TV shift in M mode with a manual lens--the EV button (yes, the EV button) locks in the appropriate shutter speed.

I just learned this last week, and reconfigured my Green button to do something else.

**Canada_Rockies** · 04-18-2010, 10:03 AM

Originally posted by JeffJS

I understand you are just experimenting but there really isn't a good reason to take an A type lens off of the A position. If you want to use a lens that does not have an A setting, then you need to set Using Aperture Ring to Permitted.

The way I do it on my K7 is that I set the camera to M mode, Set the aperture or shutter speed, pull the power switch to Preview (set it for DOF preview instead of Digital preview) which will show the meter, then set the other parameter (shutter speed or aperture) until I have the metering I want. There are other ways of doing it, I'm sure, but that one works for me.

I use the same method on my K10d. It is very much like the original KX (film camera) where the blue needle showed the shutter speed set and the black needle showed where the meter thought it should be. In a strict emergency I will just press the green button and pray that the meter is using the correct exposure, but I much prefer to analyze my manual exposure settings.

With the K10/20 the meter is a line with the exposure showing above, sort of like this i..i..l..i..i but upside down, with bright blocks above showing the setting.

With the K200 and some others, the meter is +/- 0.0 values at the extreme right of the display. It's not quite as intuitive, but definitely usable.

JeffJS · 04-18-2010, 10:14 AM

Originally posted by Canada_Rockies

I use the same method on my K10d. It is very much like the original KX (film camera) where the blue needle showed the shutter speed set and the black needle showed where the meter thought it should be. In a strict emergency I will just press the green button and pray that the meter is using the correct exposure, but I much prefer to analyze my manual exposure settings.

With the K10/20 the meter is a line with the exposure showing above, sort of like this i..i..l..i..i but upside down, with bright blocks above showing the setting.

With the K200 and some others, the meter is +/- 0.0 values at the extreme right of the display. It's not quite as intuitive, but definitely usable.

The K7 works the same way as the 10/20 but I had to turn off the horizon level display to get the meter to show. I don't know that it was necessary for all modes, it is just one of the first things I did when I unpacked the camera and haven't given it a second thought.

bymy141 · 04-18-2010, 01:51 PM

Krishna,

I find it hard to believe that you have bought a new Tamron 70-300mm which is manual operated. If this lens is not second hand and old, something is wrong.

If it is second hand, perhaps you should then start to read this post: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/59272-shooting-...x-dslrs-f.html

- Bert

**Canada_Rockies** · 04-18-2010, 03:56 PM

Originally posted by bymy141

Krishna,

I find it hard to believe that you have bought a new Tamron 70-300mm which is manual operated. If this lens is not second hand and old, something is wrong.

If it is second hand, perhaps you should then start to read this post: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/59272-shooting-...x-dslrs-f.html

- Bert

The OP specified "when the aperture is not set to the A position" in his post. There really is no reason to take a lens aperture off the A position. The metering works better because of the missing trace on the modern mount and you can change the aperture without looking at the lens and see the results in the viewfinder.

bymy141 · 04-19-2010, 01:02 AM

Originally posted by Canada_Rockies

The OP specified "when the aperture is not set to the A position" in his post. There really is no reason to take a lens aperture off the A position. The metering works better because of the missing trace on the modern mount and you can change the aperture without looking at the lens and see the results in the viewfinder.

Thanks, missed that...

krishna · 04-20-2010, 10:34 AM

Thank you for your inputs. Now I could see it working. The "F---" continue to display in the monitor, the moment I change it from "A" position. Once I change it from "A" position, I immediately change Aperture Ring - Permitted.

I just want to experiment each and every aspect of K-x.

Once again, thanking you.

Marc Sabatella · 04-20-2010, 03:04 PM

There's no reason to the set the "Use Aperture Ring" to anything other than "Permitted" - there's no harm in leaving it set that way all the time. There's also no reason to ever move that aperture ring off "A" again, except maybe to practice how to use manual lenses.

Capslock118 · 04-23-2010, 08:06 PM

You folks seem fairly adamant about not moving the aperture ring to anything other than A and I have to ask why?

I noticed the camera loses it's ability to know what the aperture is set at to record into the EXIF data.

I'm coming into this discussion as a newbie, but:

I liken my lenses with aperture ring to my record player. There is something so fond in moving the ring versus pressing an electronic button where you don't feel or hear what is going on. I find that quite similar to grabbing a vinyl and listening to the warm sounds it produces.

speak of though, is there a case for the aperture blades breaking down faster over time used b hand versus letting the camera take over?

**Canada_Rockies** · 04-23-2010, 08:16 PM

Originally posted by Capslock118

You folks seem fairly adamant about not moving the aperture ring to anything other than A and I have to ask why?

I noticed the camera loses it's ability to know what the aperture is set at to record into the EXIF data.

I'm coming into this discussion as a newbie, but:

I liken my lenses with aperture ring to my record player. There is something so fond in moving the ring versus pressing an electronic button where you don't feel or hear what is going on. I find that quite similar to grabbing a vinyl and listening to the warm sounds it produces.

speak of though, is there a case for the aperture blades breaking down faster over time used b hand versus letting the camera take over?

The reason to use solely the "A" position is that it is the only position where the full automation of the camera will work. When you set the aperture manually using the aperture ring, only in M mode will the aperture stop down to the selected aperture. In any automatic mode, the aperture will not stop down, the camera will switch to Av mode and take the picture with the aperture wide open.

If you want to try out the functionality, first read the sticky about use of manual lenses at the top of this forum.

04-18-2010, 06:32 AM	#1
krishna Junior Member Join Date: Apr 2010 Location: CT Photos: Albums Posts: 41	Aperture Ring - Permitted/Prohibited? F--- Error? I was experimenting my new Tamron 70-300 lens with my Pentax K-x. I observed "F---" when the "Aperture Ring" is not set to "A" position. I read the manual and found the option in menu "Aperture Ring -Permitted/Prohibited". What for is this used? When I change to "Permitted" still I get the same error in viewfinder. However, in Av Priority mode I can change the "Aperture" value using e-dial. I am not clear on the Aperture Ring - Permitted/Prohibited. Could you please help me? Thanks, Krishna

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04-18-2010, 06:36 AM	#2
emr Guest	You need to set it to "permitted" to be able to use older, non-A lenses. When you set it correctly, you can manually choose the wanted aperture on the lens and then use the green button to measure correct exposure (time).

04-18-2010, 06:56 AM	#3
Zebooka Veteran Member Join Date: May 2008 Location: Russia, Siberia, Novosibirsk Posts: 323	It will always show F-- for non A position of aperture on the lens. This is because all Pentax DSLRs use "crippled" bayonet. That means - there is no aperture coupler for transmitting selected (on the lens) aperture value to camera.

04-18-2010, 07:05 AM	#4
RuiC Site Supporter Join Date: Jan 2009 Location: Lisboa - The best destination in Europe Posts: 633	Originally posted by Zebooka It will always show F-- for non A position of aperture on the lens. This is because all Pentax DSLRs use "crippled" bayonet. That means - there is no aperture coupler for transmitting selected (on the lens) aperture value to camera. So to get correct exposures in AV, with aperture on non-A position, you have to stop down, otherwise every shot will be be wide open, or you can switch to M and do correct measurement with the GreenButton (AElock?) (Here you also have to select custom function "Green button in TAv or M mode to TV shift) Rui

04-18-2010, 08:17 AM	#5
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by krishna I was experimenting my new Tamron 70-300 lens with my Pentax K-x. I observed "F---" when the "Aperture Ring" is not set to "A" position. I read the manual and found the option in menu "Aperture Ring -Permitted/Prohibited". What for is this used? When I change to "Permitted" still I get the same error in viewfinder. However, in Av Priority mode I can change the "Aperture" value using e-dial. I am not clear on the Aperture Ring - Permitted/Prohibited. Could you please help me? Thanks, Krishna I understand you are just experimenting but there really isn't a good reason to take an A type lens off of the A position. If you want to use a lens that does not have an A setting, then you need to set Using Aperture Ring to Permitted. The way I do it on my K7 is that I set the camera to M mode, Set the aperture or shutter speed, pull the power switch to Preview (set it for DOF preview instead of Digital preview) which will show the meter, then set the other parameter (shutter speed or aperture) until I have the metering I want. There are other ways of doing it, I'm sure, but that one works for me.

04-18-2010, 09:51 AM	#6
Ira Inactive Account Join Date: Mar 2009 Location: Coral Springs, FL Photos: Gallery \| Albums Posts: 5,216	Originally posted by RuiC So to get correct exposures in AV, with aperture on non-A position, you have to stop down, otherwise every shot will be be wide open, or you can switch to M and do correct measurement with the GreenButton (AElock?) (Here you also have to select custom function "Green button in TAv or M mode to TV shift) Rui On the KX, in M mode, you don't have to set the Green to TV shift in M mode with a manual lens--the EV button (yes, the EV button) locks in the appropriate shutter speed. I just learned this last week, and reconfigured my Green button to do something else.

04-18-2010, 10:03 AM	#7
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by JeffJS I understand you are just experimenting but there really isn't a good reason to take an A type lens off of the A position. If you want to use a lens that does not have an A setting, then you need to set Using Aperture Ring to Permitted. The way I do it on my K7 is that I set the camera to M mode, Set the aperture or shutter speed, pull the power switch to Preview (set it for DOF preview instead of Digital preview) which will show the meter, then set the other parameter (shutter speed or aperture) until I have the metering I want. There are other ways of doing it, I'm sure, but that one works for me. I use the same method on my K10d. It is very much like the original KX (film camera) where the blue needle showed the shutter speed set and the black needle showed where the meter thought it should be. In a strict emergency I will just press the green button and pray that the meter is using the correct exposure, but I much prefer to analyze my manual exposure settings. With the K10/20 the meter is a line with the exposure showing above, sort of like this i..i..l..i..i but upside down, with bright blocks above showing the setting. With the K200 and some others, the meter is +/- 0.0 values at the extreme right of the display. It's not quite as intuitive, but definitely usable.

04-18-2010, 10:14 AM	#8
JeffJS Inactive Account Join Date: Aug 2008 Location: Michigan, USA Photos: Gallery \| Albums Posts: 7,484	Originally posted by Canada_Rockies I use the same method on my K10d. It is very much like the original KX (film camera) where the blue needle showed the shutter speed set and the black needle showed where the meter thought it should be. In a strict emergency I will just press the green button and pray that the meter is using the correct exposure, but I much prefer to analyze my manual exposure settings. With the K10/20 the meter is a line with the exposure showing above, sort of like this i..i..l..i..i but upside down, with bright blocks above showing the setting. With the K200 and some others, the meter is +/- 0.0 values at the extreme right of the display. It's not quite as intuitive, but definitely usable. The K7 works the same way as the 10/20 but I had to turn off the horizon level display to get the meter to show. I don't know that it was necessary for all modes, it is just one of the first things I did when I unpacked the camera and haven't given it a second thought.

04-18-2010, 01:51 PM	#9
bymy141 Veteran Member Join Date: Aug 2007 Photos: Gallery Posts: 1,563	Krishna, I find it hard to believe that you have bought a new Tamron 70-300mm which is manual operated. If this lens is not second hand and old, something is wrong. If it is second hand, perhaps you should then start to read this post: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/59272-shooting-...x-dslrs-f.html - Bert

04-18-2010, 03:56 PM	#10
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by bymy141 Krishna, I find it hard to believe that you have bought a new Tamron 70-300mm which is manual operated. If this lens is not second hand and old, something is wrong. If it is second hand, perhaps you should then start to read this post: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/59272-shooting-...x-dslrs-f.html - Bert The OP specified "when the aperture is not set to the A position" in his post. There really is no reason to take a lens aperture off the A position. The metering works better because of the missing trace on the modern mount and you can change the aperture without looking at the lens and see the results in the viewfinder.

04-19-2010, 01:02 AM	#11
bymy141 Veteran Member Join Date: Aug 2007 Photos: Gallery Posts: 1,563	Originally posted by Canada_Rockies The OP specified "when the aperture is not set to the A position" in his post. There really is no reason to take a lens aperture off the A position. The metering works better because of the missing trace on the modern mount and you can change the aperture without looking at the lens and see the results in the viewfinder. Thanks, missed that...

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04-20-2010, 10:34 AM	#12
krishna Junior Member Join Date: Apr 2010 Location: CT Photos: Albums Posts: 41 Original Poster	Thank you for your inputs. Now I could see it working. The "F---" continue to display in the monitor, the moment I change it from "A" position. Once I change it from "A" position, I immediately change Aperture Ring - Permitted. I just want to experiment each and every aspect of K-x. Once again, thanking you.

04-20-2010, 03:04 PM	#13
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	There's no reason to the set the "Use Aperture Ring" to anything other than "Permitted" - there's no harm in leaving it set that way all the time. There's also no reason to ever move that aperture ring off "A" again, except maybe to practice how to use manual lenses.

04-23-2010, 08:06 PM	#14
Capslock118 Senior Member Join Date: Apr 2010 Location: New Haven, CT Photos: Gallery Posts: 173	You folks seem fairly adamant about not moving the aperture ring to anything other than A and I have to ask why? I noticed the camera loses it's ability to know what the aperture is set at to record into the EXIF data. I'm coming into this discussion as a newbie, but: I liken my lenses with aperture ring to my record player. There is something so fond in moving the ring versus pressing an electronic button where you don't feel or hear what is going on. I find that quite similar to grabbing a vinyl and listening to the warm sounds it produces. speak of though, is there a case for the aperture blades breaking down faster over time used b hand versus letting the camera take over?

04-23-2010, 08:16 PM	#15
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by Capslock118 You folks seem fairly adamant about not moving the aperture ring to anything other than A and I have to ask why? I noticed the camera loses it's ability to know what the aperture is set at to record into the EXIF data. I'm coming into this discussion as a newbie, but: I liken my lenses with aperture ring to my record player. There is something so fond in moving the ring versus pressing an electronic button where you don't feel or hear what is going on. I find that quite similar to grabbing a vinyl and listening to the warm sounds it produces. speak of though, is there a case for the aperture blades breaking down faster over time used b hand versus letting the camera take over? The reason to use solely the "A" position is that it is the only position where the full automation of the camera will work. When you set the aperture manually using the aperture ring, only in M mode will the aperture stop down to the selected aperture. In any automatic mode, the aperture will not stop down, the camera will switch to Av mode and take the picture with the aperture wide open. If you want to try out the functionality, first read the sticky about use of manual lenses at the top of this forum.