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old4570 · 02-22-2013, 11:50 PM

I have a 500mm F8 Mirror lens ..

Pentax K5 , I need to set ISO and F stop , but how do I do that ? ( M mode )

User manual ? I cant find it .( info )

RollsUp · 02-23-2013, 12:22 AM

I don't own a mirror lens but AFAIK they have fixed apertures, f8 for your lens. To change the ISO on my K5 I press the ISO button and turn the rear dial.

old4570 · 02-23-2013, 12:51 AM

Fixed it ...

Go into the menu :
Custom settings in manual mode ( M )
Go to C3 - I set my AFS setting to 2 , release priority
C4 - I set Using aperture ring to 2 , permitted ..

And now I can run manual lenses ...

I still dont know how to set the F to F8 to match the lens ... Picture shortly

demp10 · 02-23-2013, 12:54 AM - **1 Like**

You cannot set the aperture on a mirror lens. It is fixed at F8.

Being a manual lens (with no contacts) you can used it either in manual mode (M) where you set the shutter speed and the ISO, or in Av mode where the camera sets the shutter speed for the selected ISO. All automated modes will default to Av for manual lenses.

The easiest way to use it is to set the camera to Av, set the ISO to Auto (in the menu) for a range that you can tolerate the noise (e.g. 80-1600) and let the camera set the shutter speed.

A tripod is almost essential for acceptable images at that focal length except in very bright conditions.

old4570 · 02-23-2013, 01:11 AM

So I cant set the F to F8 on the camera ... ( OK ) Thank you

demp10 · 02-23-2013, 01:48 AM - **1 Like**

All manual lenses without contacts and an "A" in the aperture ring will show "F--" and you will not be able to set aperture from the camera.

You can use these lenses wide open in Av mode or if they have an aperture ring, you can set the aperture there, set the mode to "M" and use the green button to measure the exposure. That will set the proper shutter speed.

old4570 · 02-23-2013, 02:40 AM

Originally posted by demp10

All manual lenses without contacts and an "A" in the aperture ring will show "F--" and you will not be able to set aperture from the camera.

You can use these lenses wide open in Av mode or if they have an aperture ring, you can set the aperture there, set the mode to "M" and use the green button to measure the exposure. That will set the proper shutter speed.

Thats what Im doing .. Thank you ..

Adam · 02-23-2013, 04:52 AM

Here's a complete write-up on the manual exposure process if you want to learn all of the ins and outs:

https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...x-k-7-a-3.html

**mattt** · 02-23-2013, 05:44 AM

The F stop does not show because the K mount is crippled - the camera does not know where the aperture arm is - and you do not input the Aperture value. If you want Aperture values recorded in EXIF data, you will need to edit the EXIF.

stevebrot · 02-23-2013, 08:33 AM

Originally posted by mattt

If you want Aperture values recorded in EXIF data, you will need to edit the EXIF.

There are a number of tools (free and otherwise) that allow you to do this. I use ExifTool (free) and can recommend it, though it works easiest if you also download the graphical user interface (GUI) so that you don't have to memorize the command-line options.

Steve

old4570 · 02-23-2013, 04:01 PM

Thanks guys , I got the camera yesterday ( 23-Feb-2013 ) so was only using it for the very first time ..

Thank you for the help .

ChrisJ_K5 · 04-24-2017, 07:58 PM

Originally posted by old4570

Fixed it ...

Go into the menu :
Custom settings in manual mode ( M )
Go to C3 - I set my AFS setting to 2 , release priority
C4 - I set Using aperture ring to 2 , permitted ..

And now I can run manual lenses ...

I still dont know how to set the F to F8 to match the lens ... Picture shortly

I just bought a K5 and I have an old mirror lens which I can now use thanks to you.

02-22-2013, 11:50 PM	#1
old4570 Veteran Member Join Date: Feb 2013 Location: Melbourne Photos: Albums Posts: 2,551	K5 Question regarding F stop on manual lens I have a 500mm F8 Mirror lens .. Pentax K5 , I need to set ISO and F stop , but how do I do that ? ( M mode ) User manual ? I cant find it .( info )

02-23-2013, 12:51 AM	#3
old4570 Veteran Member Join Date: Feb 2013 Location: Melbourne Photos: Albums Posts: 2,551 Original Poster	Fixed it ... Go into the menu : Custom settings in manual mode ( M ) Go to C3 - I set my AFS setting to 2 , release priority C4 - I set Using aperture ring to 2 , permitted .. And now I can run manual lenses ... I still dont know how to set the F to F8 to match the lens ... Picture shortly Last edited by old4570; 02-23-2013 at 01:02 AM.

02-23-2013, 02:40 AM	#7
old4570 Veteran Member Join Date: Feb 2013 Location: Melbourne Photos: Albums Posts: 2,551 Original Poster	Yeah Originally posted by demp10 All manual lenses without contacts and an "A" in the aperture ring will show "F--" and you will not be able to set aperture from the camera. You can use these lenses wide open in Av mode or if they have an aperture ring, you can set the aperture there, set the mode to "M" and use the green button to measure the exposure. That will set the proper shutter speed. Thats what Im doing .. Thank you ..

02-23-2013, 04:52 AM	#8
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,609	Here's a complete write-up on the manual exposure process if you want to learn all of the ins and outs: https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...x-k-7-a-3.html 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:

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02-23-2013, 12:22 AM	#2
RollsUp Veteran Member Join Date: Apr 2008 Location: AK USA Photos: Gallery Posts: 1,766	I don't own a mirror lens but AFAIK they have fixed apertures, f8 for your lens. To change the ISO on my K5 I press the ISO button and turn the rear dial.

02-23-2013, 12:54 AM - 1 Like	#4
demp10 Veteran Member Join Date: Jun 2011 Location: Atlanta Photos: Albums Posts: 602	You cannot set the aperture on a mirror lens. It is fixed at F8. Being a manual lens (with no contacts) you can used it either in manual mode (M) where you set the shutter speed and the ISO, or in Av mode where the camera sets the shutter speed for the selected ISO. All automated modes will default to Av for manual lenses. The easiest way to use it is to set the camera to Av, set the ISO to Auto (in the menu) for a range that you can tolerate the noise (e.g. 80-1600) and let the camera set the shutter speed. A tripod is almost essential for acceptable images at that focal length except in very bright conditions.

02-23-2013, 01:11 AM	#5
old4570 Veteran Member Join Date: Feb 2013 Location: Melbourne Photos: Albums Posts: 2,551 Original Poster	So I cant set the F to F8 on the camera ... ( OK ) Thank you

02-23-2013, 01:48 AM - 1 Like	#6
demp10 Veteran Member Join Date: Jun 2011 Location: Atlanta Photos: Albums Posts: 602	All manual lenses without contacts and an "A" in the aperture ring will show "F--" and you will not be able to set aperture from the camera. You can use these lenses wide open in Av mode or if they have an aperture ring, you can set the aperture there, set the mode to "M" and use the green button to measure the exposure. That will set the proper shutter speed.

02-23-2013, 05:44 AM	#9
mattt Site Supporter Join Date: Feb 2011 Location: Niagara Photos: Gallery \| Albums Posts: 3,907	The F stop does not show because the K mount is crippled - the camera does not know where the aperture arm is - and you do not input the Aperture value. If you want Aperture values recorded in EXIF data, you will need to edit the EXIF.

02-23-2013, 08:33 AM	#10
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by mattt If you want Aperture values recorded in EXIF data, you will need to edit the EXIF. There are a number of tools (free and otherwise) that allow you to do this. I use ExifTool (free) and can recommend it, though it works easiest if you also download the graphical user interface (GUI) so that you don't have to memorize the command-line options. Steve

02-23-2013, 04:01 PM	#11
old4570 Veteran Member Join Date: Feb 2013 Location: Melbourne Photos: Albums Posts: 2,551 Original Poster	Thanks guys , I got the camera yesterday ( 23-Feb-2013 ) so was only using it for the very first time .. Thank you for the help .

04-24-2017, 07:58 PM	#12
ChrisJ_K5 New Member Join Date: Apr 2017 Posts: 1	Originally posted by old4570 Fixed it ... Go into the menu : Custom settings in manual mode ( M ) Go to C3 - I set my AFS setting to 2 , release priority C4 - I set Using aperture ring to 2 , permitted .. And now I can run manual lenses ... I still dont know how to set the F to F8 to match the lens ... Picture shortly I just bought a K5 and I have an old mirror lens which I can now use thanks to you.

K5 Question regarding F stop on manual lens

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