[Trigger Happy]

Turns out my K-30 is behaving exactly the same as Kozlok's. It will not meter at all in M mode with an M42 (or no lens) attached. The green button changes shutter speed to approx. 1/ISO no matter how much light there is. Manual ISO, aperture ring enabled, green button set to Tv Shift or P line for M mode - no difference.

It meters fine in Av mode or live view. It has the same wacky behaviour described by Kozlok in post #8 where it uses the "last known" metering from Live View if you change the ISO, still ignoring the amount of ambient light.

It's easiest to reproduce with no lens on the camera. The body will not meter in M mode, period. It doesn't show the light meter bar graph in the viewfinder either so it's impossible to use M mode except by trial and error (take a photo, look at histogram, adjust).

[Not a Number]

On the later bodies the aperture control lever will not actuate unless there is a lens attached. It may be that this is a feature of all firmware released after a certain date. The only way the body has of detecting whether or not a lens is attached is through the electrical contacts. With no lens attached, no electrical contact. With most M42 lenses the mount is anodized/coated/painted - no electrical contact. I'm willing to bet that without a lens attached (or electrical contact) the meter doesn't activate in certain modes such as Manual.

This is easy enough to test by just covering the pins with a bit of thin foil or attaching a 3rd party flanged M42 adapter without a lens (should short the contacts)..

[Trigger Happy]

I will try with the foil later. But it seems more like a firmware bug, as it can meter fine in Av mode or in live view with no lens.

[Kozlok]

I finally successfully got Pentax to actually pay attention to my problem, instead of telling me to enable aperture ring in the menu, and their response is quoted below:

Dear Keith, Thank you for contacting RICOH. I sent your email to our technical support specialist in the corporate office and he tested the K-30 there and got the same results that you reported. It appears there is not a specific problem in your K-30. We do not have any information from Japan about what, if any firmware updates they have planned for the camera. If you are in need of further assistance, please respond to this email or call our technical support center at 800-877-0155. Sincerely, Randall S. RICOH IMAGING AMERICAS CORPORATION

[ssokolich]

My K-50 has the same issue with metering using M42 Super Tak lenses. Metering works in Live view but not through the viewfinder. It wouldn't surprise me if Japan's software engineers simply made the choice to implement metering only in live view. I work for a japanese company here in the U.S. I could tell you horror stories about how Japan engineers implement "features." In some cases, their choices are not intuitive.

[Ole]

I've been shooting with my Super Takumar 55/2 as my single in July. First time using an M42 on my K-30, but used them quite a bit on my KX (The Tak and a Helios).

When I place my K-30 in M, the green button metering seems to default to whatever the sunny 16 shutter speed would be. The button is set on Tv Shift, and it does change the shutter speed, but no matter where I set my aperture on the lens, and no matter what the light, the shutter speed chosen is the inverse of the ISO setting (i.e. the correct shutter speed for sunny 16). If I go to Live View, the green button meters correctly and chooses the correct shutter speed. If I put an M lens on, it likewise meters correctly. If I switch to Av mode, it constantly meters (correctly).

I'm pretty sure I used the green button to meter on my KX with success, and I recall that it was a more reliable way to control my metering process, since I could use it to lock exposure on a specific point. It's possible, and perhaps more likely, that I'm crazy and it never worked that way, but man, I really think it did.

Is there a menu setting I missed somewhere?

The solution is to use Av mode on the K-30 (and K-50), lens must be in Manual aperture mode. Shoot away, no need to use Green button.

Pentax must have changed how M mode and Green button metering works somewhere along the line. But Av mode is more convenient anyway, so it is a minor loss.

[ssokolich]

On my K-50 with Av mode instead of M mode, Aperture ring enabled, with M mode set to TvShift, and a fixed ISO, I can get my super taks (m42) to meter. But Ricoh needs to fix the M mode so it will meter when not using Live view.

[marcusBMG]

Turns out my K-30 is behaving exactly the same as Kozlok's. It will not meter at all in M mode with an M42 (or no lens) attached. The green button changes shutter speed to approx. 1/ISO no matter how much light there is. Manual ISO, aperture ring enabled, green button set to Tv Shift or P line for M mode - no difference.

It meters fine in Av mode or live view. It has the same wacky behaviour described by Kozlok in post #8 where it uses the "last known" metering from Live View if you change the ISO, still ignoring the amount of ambient light.

It's easiest to reproduce with no lens on the camera. The body will not meter in M mode, period. It doesn't show the light meter bar graph in the viewfinder either so it's impossible to use M mode except by trial and error (take a photo, look at histogram, adjust).

Very interested to read your account of the behaviour of the K30. I shall include this in my web page :

How to use KM mount, KA mount lenses on Pentax (and Samsung) DSLR's: metering and other issues, hacks and tricks

which I am putting tpgether because I have had similar issues/confusions on my K-r, and felt that s/o ought to write up st...
On my page I say that pressing the +/- button produces a meter value: have you tried that? Also does the K30 have a stop-down preview mode like the mode on the K-r?
Do try the foil trick (usual procedure is to short out the data contact thats the one at the half past position).
I would be interested to know:
whats the metering like in Av mode with M42 lenses (the big bug with the K-r is silly amounts of exp compensation are necessary 2-3 stops typically)?
does the metering change with foil shorting the contact (roughly corrects the silly exp comp on the K-r BUT introduces mirror flopping)?

[Fluke]

Very disappointed to find that my new K50 has this issue.
I've used my late uncle's collection of Takumar telephoto lenses on an *ist DL2 and a K200d with great success. If Pentax/Ricoh are downgrading compatibility with legacy lenses, they will lose me as a customer. The information on their website specifically states that the K30 at least will meter correctly in Manual mode with M42 lenses.
I shall try this:
https://www.pentaxforums.com/forums/122-lens-clubs/31601-takumar-club-125.html#post548307
as it seems the most elegant DIY solution, but I'm not happy.

[rp_dxn]

Had the same issue with my k30.
The only easy/simple solution for now is the foil method. really works...

[reeftool]

I have always used M42 lenses in Av going back to my K10D and manual K mount lenses in M and using the green button. To do a quick check in my rather dark room, I just took a couple of shots with my Tak 28/3.5 wide open and got the same shutter speed. As I stopped down, there was a difference in shutter speed settings between the Av and M settings but only about 1 stop. The shots would all have been usable. The Av tended to underexpose a little but easily correctable in PP. The histogram in M was pretty much in the center of the scale. My K mount lenses tend to overexpose with green button metering so I think this was about normal. I have had pretty much the same results with my K5. Since my K10D has a Katz Eye screen, It's my manual lens camera.

There has always been some accuracy issues in metering with older glass and results will vary from lens to lens. In my experience, the green button is good for a starting point and I usually need to adjust exposure a little up or down depending on the lens. I don't consider this a problem. I take a shot, look at the histogram, and then adjust my shutter speed up or down and won't need to change it unless I change aperture of the light changes a lot. I'm thankful that I can use my old glass even if I have to fiddle with the settings a bit. Canikon owners use their old manual glass for paperweights and doorstops. The new Nikon DF has made big news because it's the first digital camera Nikon has made that will allow older manual lenses to be used.

[Fluke]

I have always used M42 lenses in Av going back to my K10D and manual K mount lenses in M and using the green button. To do a quick check in my rather dark room, I just took a couple of shots with my Tak 28/3.5 wide open and got the same shutter speed. As I stopped down, there was a difference in shutter speed settings between the Av and M settings but only about 1 stop. The shots would all have been usable. The Av tended to underexpose a little but easily correctable in PP. The histogram in M was pretty much in the center of the scale. My K mount lenses tend to overexpose with green button metering so I think this was about normal. I have had pretty much the same results with my K5. Since my K10D has a Katz Eye screen, It's my manual lens camera.

There has always been some accuracy issues in metering with older glass and results will vary from lens to lens. In my experience, the green button is good for a starting point and I usually need to adjust exposure a little up or down depending on the lens. I don't consider this a problem. I take a shot, look at the histogram, and then adjust my shutter speed up or down and won't need to change it unless I change aperture of the light changes a lot. I'm thankful that I can use my old glass even if I have to fiddle with the settings a bit. Canikon owners use their old manual glass for paperweights and doorstops. The new Nikon DF has made big news because it's the first digital camera Nikon has made that will allow older manual lenses to be used.

I appreciate your input but we are not talking about inaccuracy here.
With any of my M2 lenses on my K50, while Av results are OK, Manual mode metering makes no sense at all. It is way off the mark and does not change, no matter what the lens aperture or the amount of light entering the camera.

[stevebrot]

I appreciate your input but we are not talking about inaccuracy here.

Yes...This is an emerging issue with several models (K-30 and K-50 for example). Lenses without conductive bases (most M42 and some K-mount) have been reported as not metering in M mode. I have a friend who recently purchased a K-50 and may be able to spend some time in the near future characterizing the issue on that camera so that I can be more helpful.


Steve

[ofer4]

Kozlok... Any more word on this issue?

I do have one (completely speculative) theory here. My K-r went through the infamous "mirror flop" fiasco. It since has had a complete replacement of the aperture assembly by CRIS...it's like new. But the mirror flop first started when I used my first m42 lens. My theory at the time was that some sort of voltage regulator was problematic in the K-r, and the lack of drain from the contacts was sufficient to cause problems. It would also, for example, happen with no lens attached. I'm now wondering if their "fix" to this issue was just to prevent the aperture lever from firing at all if no contacts are detected. This issue would explain the change in K-30 onward via firmware.

On a brighter note, my lengthy repair at CRIS (4 months and two trips) led me to get a K-30.

[Fluke]

Thanks for your input.


You would think that Pentax/Ricoh would tell us 'Yeh. That's the way it is now.' But from my communications with them, their customer service people don't have the equipment to test the issue themselves and my persistent questioning has been 'escalated' several time but with no answer. Just repeated advice to use Manual ISO, Aperture Ring = Permitted and customize the Green Button to TV-Shift or Program-Shift.