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04-27-2012, 12:18 PM   #121
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QuoteOriginally posted by abacus07 Quote
It will take a picture in other modes (at least Av) but the result will be the common overexposed photo that so many talk about at first.
That's what it says under the *


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04-27-2012, 05:00 PM   #122
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QuoteOriginally posted by Adam Quote
That's what it says under the *
This is not what I'm talking about.
QuoteQuote:
Screwmount lenses may also be used in Av mode since they are always stopped down to the aperture you will be shooting at (unlike M&K lenses, which are stopped down only when the shutter is released or when you meter as described above).
05-23-2012, 10:22 AM   #123
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I've just skipped to the last page so I don't know if this has already been mentioned, but is there a reason why there's no metering bar in the viewfinder with a non A lens? I guess it's because the camera doesn't know what aperture the lens is set to, but it'd be so much handier if there was a bar to help you get to your exposure without having to press the green button every time.

EDIT: I've just found out that if you hold the optical preview lever on, you get a meter reading! That changes everything! Woo!

Last edited by Mareket; 05-23-2012 at 10:28 AM.
12-06-2012, 07:02 PM   #124
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QuoteOriginally posted by Adam Quote
Manual/Takumar/M42 Screwmount lenses on Pentax DSLRs

I've written two articles on how to use Manual K-mount M & K series / Takumar / M42 Screwmount lenses on Pentax DSLRs, as well as how to meter.

How to use Screwmount/Takumar lenses on Pentax DSLRs (K-7, K-x, etc.)

Manual Metering on Pentax DSLRs with Manual and Automatic Lenses


In a nutshell:

First, if your camera won't fire, set "Allow aperture setting other than A" to 2 (allowed) in the custom function menu. Then:

  1. Set your camera to M mode using the mode dial (your camera won't fire in other modes*)
  2. Compose and focus your image.
  3. Using the aperture ring (the ring at the very back of your lens; it will have numbers such as 2.8, 4, 5.6, 8 written on it), select your desired aperture setting. Note that the smaller the aperture number is, the more light passes through the lens, and the blurrier the out of focus areas of your photograph will be.
  4. [Screwmount lenses only] Switch the diaphragm clutch on your lens to "Manual" (you can leave it on Auto when composing and focusing).
  5. Measure the light by either pressing the "Green Button", or pushing your power button to DOF preview mode (only available on select bodies). Your camera will automatically set the shutter speed for you.
All that's left now is for you to press the shutter release button to take your photo. Congratulations- you've now learned how to use M42 and M & K manual lenses with Pentax DSLRs!

*Screwmount lenses may also be used in Av mode since they are always stopped down to the aperture you will be shooting at (unlike M&K lenses, which are stopped down only when the shutter is released or when you meter as described above).





You may also find our older discussion thread on this topic very helpful: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/59272-shooting-...x-dslrs-f.html
An occasional issue with late Takumar lenses: Why is the Auto/Man diaphragm clutch stuck on my S-M-C Takumar lens?

If your manual focus lens has an "A" setting on the aperture ring, leave it in "A" and instead use the e-dials on your camera to control the shutter speed and aperture. Don't follow the steps above.
Adam: In using older lenses, the screen message calls for selecting the lens focal length so the shake control feature will work on the camera body. Should the user set the stated focal length of the lens, as for the old film cameras for which the lens was designed. . . or should you set the digital equivalent focal length, i.e., 75 mm for an older full-frame 50 mm lens? I have always used the full-frame lens stated focal length, i.e., 50mm, but have never seen this point discussed. Thanks, ivan

12-06-2012, 08:00 PM   #125
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QuoteOriginally posted by ivanvernon Quote
Adam: In using older lenses, the screen message calls for selecting the lens focal length so the shake control feature will work on the camera body. Should the user set the stated focal length of the lens, as for the old film cameras for which the lens was designed. . . or should you set the digital equivalent focal length, i.e., 75 mm for an older full-frame 50 mm lens? I have always used the full-frame lens stated focal length, i.e., 50mm, but have never seen this point discussed. Thanks, ivan
Use the real focal length, 50mm is 50mm, regardless of format.
12-09-2012, 10:44 AM   #126
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I'm trying to climb the learning curve as a new K-5 owner, the slope made a bit steeper in that the only lenses I presently have are manual.

Question - when the mode dial is set to manual does the focus mode lever need to be set to 'M' also? Page 115 in Bourque's book states 'To focus manually with a non-Autofocus lens, set the camera focus mode to MF.'

In experimenting with it I've found that the focus mode indicator appears whether the lever is in 'M' or 'AFS' mode, so I don't see any advantage one way or another unless I'm missing something?
12-09-2012, 10:57 AM   #127
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Arcturus, you're right, there isn't a massive difference. You don't need to be in M focus mode to manual focus, that'd just be weird. Setting the focus to AF-S does. however, allow you to make use of Catch in Focus. Maybe AF-C does as well, I'm not sure. That's the only reason I can think of to set it in either mode with an MF lens.

Then again I've never had any luck with CiF, so perhaps I'm doing something wrong.
12-10-2012, 07:07 AM   #128
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I have noticed one weird thing with my K-x and M42 lenses.

With my Sicor-XL 28mm on M works fine but Av mode underexposes by about 2 EV. However, if I short the contacts with some aluminium foil it meters correctly in Av mode as well. Anyone have the same behaviour with M42?
When I have the Helios-44M-4 58mm on both Av and M modes work like a charm. I'm guessing it has enough bare metal at the base to short the contacts on its own.

It's not a big deal, M works and I have the workaround for Av, but if anyone has an explanation to why metering is affected I would be happy to hear it.

12-11-2012, 05:50 PM   #129
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No stop down on K-30 unless ...

I have tried in vain to get the k-mount Takumar 55mm 1.8 lens I have to work in anything other than fully open aperture. This is not an A lens. Even after following all the instructions(set the dial to M, set focus to MF, make the two adjustments to the advance program settings that allow the camera to recognize the lens, input the focal length) that others as well as you have posted, I find that there is no way to stop down the lens when it has been fully mounted. However, I have a work around, that I don't really like, but which works. If I don't fully mount the lens, but position it at about 50% of the turn to fully locked down, then the manual aperture ring will adjust the aperture the full range from 1.8 to 22. Does anyone have any input on this, and any way to get the K-30 to fully work manually in a locked down position? I would prefer that since my work around leaves the lens in a potential state of being able to come off since it is not in the locked position.
12-11-2012, 09:00 PM   #130
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QuoteOriginally posted by rad291 Quote
I have tried in vain to get the k-mount Takumar 55mm 1.8 lens I have to work in anything other than fully open aperture. This is not an A lens. Even after following all the instructions(set the dial to M, set focus to MF, make the two adjustments to the advance program settings that allow the camera to recognize the lens, input the focal length) that others as well as you have posted, I find that there is no way to stop down the lens when it has been fully mounted. However, I have a work around, that I don't really like, but which works. If I don't fully mount the lens, but position it at about 50% of the turn to fully locked down, then the manual aperture ring will adjust the aperture the full range from 1.8 to 22. Does anyone have any input on this, and any way to get the K-30 to fully work manually in a locked down position? I would prefer that since my work around leaves the lens in a potential state of being able to come off since it is not in the locked position.
Hi there and welcome

It has been brought up earlier in this thread, K mount lenses actually don't stop down until you either press the button to preview/meter or press shutter release to take the shot. The rest of the time it stays fully open. Just mount it fully and try that first.
12-11-2012, 10:12 PM   #131
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rad291, is AutoISO turned on? If it is, even though the dial is set to M mode, 'Av' will show in the upper left corner of the LCD, and it is actually in "TAv" mode (Sensitivity-Aperture priority). This is a feature of the K-30 and K-01. If you turn off AutoISO, the LCD should show "M", the Green Button will cause the lens to stop down for metering, and the lens will stop down when you press the shutter.
12-12-2012, 02:43 AM   #132
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rad291...
Have you overlooked the auto/manual switch at the rear of the lens barrel? In 'Auto' the diaphragm remains wide open. In 'Manual' it opens/closes as you turn the aperture ring. You can switch between the two provided the lens is screwed home fully and the tiny pin at the rear is depressed against the flange of the camera body or adapter. Off-camera the switch locks in the Auto position and you can't stop down except via the much fatter diaphragm pin (but there is no actuator/pusher plate within digital bodies so you must forget that). You can test the tiny pin by depressing it with a fingernail to release the switch. Assuming this mechanism is OK, screw the lens into the body firmly and move the Auto/Manual switch to manual and you should be able to stop down using the aperture ring.

I find the 5-to-12 position of the switch awkward given the overhanging top plate of digital SLRs. Much better if it was 20-to-12 so you could flick it with your thumb from wide open (Auto) to your preset aperture (Manual) just before you shoot. For this reason I tend to leave it on Manual and open up to focus and compose, then turn the ring a few clicks - four clicks to f4, six clicks to f5.6 - no need to take your eye from the viewfinder - and take the picture. Leave the mode dial on Av and it meters automatically. Of course, there'll be situations where you need to meter manually and use the 'green button', or AEL button, in which case set the dial to M. I can't speak for what happens on a K30 - I use an istDS and a K-7.
12-12-2012, 04:36 AM   #133
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unfocused:
What you are saying would be true for an M42 lens but since his is K mount it doesn't work the same way.
12-12-2012, 05:01 AM   #134
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QuoteOriginally posted by enemix Quote
I have noticed one weird thing with my K-x and M42 lenses.

With my Sicor-XL 28mm on M works fine but Av mode underexposes by about 2 EV. However, if I short the contacts with some aluminium foil it meters correctly in Av mode as well. Anyone have the same behaviour with M42?
When I have the Helios-44M-4 58mm on both Av and M modes work like a charm. I'm guessing it has enough bare metal at the base to short the contacts on its own.

It's not a big deal, M works and I have the workaround for Av, but if anyone has an explanation to why metering is affected I would be happy to hear it.
This goes back to the *istD, Av mode and M mode meter differently for M42 lenses. I think it has to do with the fact that most M42 lenses have black , I.e. insulating bases, in M Mose the camera is programmed to interpret this different ly than Av mode
12-12-2012, 07:13 AM   #135
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QuoteOriginally posted by Lowell Goudge Quote
This goes back to the *istD, Av mode and M mode meter differently for M42 lenses. I think it has to do with the fact that most M42 lenses have black , I.e. insulating bases, in M Mose the camera is programmed to interpret this different ly than Av mode
Yup, seems that way. The Helios seems to be the only one of my M42 lenses with enough bare metal to get accurate metering in Av mode. Will have to fix the Sicor-XL and ZM-5SA so I won't have to fiddle with foil, would you recommend filing off some paint with sandpaper? Or maybe I'll just get a some aluminium duct tape and do a less permanent fix? XD

I still think it's silly, why would the lack of electric contact make it underexpose by almost exactly 2 EV stops in Av mode but not in M mode? The amount of light that comes in through the lens is still the same. Doesn't make any sense to me. (I don't really expect anyone outside of Pentax to know the answer to that, it's more of a rhetorical question)
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