K10D with M & K lenses

ptx-elf · 04-26-2007, 05:47 AM

Hi all,
I think I discovered a useful method for getting correct exposure with P K & M lenses. In the custom menu set up, change the preview method to digital preview, set your camera on AV mode, set your lens aperture to your choice and turn the preview lever to right. Shutter releases and you can see image and histogram (if enabled). If it looks ok, just press the shutter release and you're in business. If exposure needs adjusting add or subtract appropriate amount with exp. comp. setting and try again. I only have a few K lenses but really enjoy my 135 f2.5 for portraits and semi macro with tubes. The set up with my istD was simpler - set to manual, press green button. Hope some of you find this a help.

RBellavance · 04-26-2007, 06:37 AM

M & K lenses will not be stopped down in any mode but M on the K10D. Put another way, they can only be used wide-open with the method you describe.

The M mode + green button works fine on the K10D. You just need to make sure you have enabled "use aperture ring" and the menu, and set "green button in M & TAv" to "Tv shift".

Jonas B · 04-26-2007, 07:16 AM

What do you mean with works fine? Most other people report the exposure to be way off when stopping down the lens. You don't get this?

RBellavance · 04-26-2007, 07:29 AM

Originally posted by Jonas B

What do you mean with works fine? Most other people report the exposure to be way off when stopping down the lens. You don't get this?

I mean it sets an exposure value when one presses the green button

I have not done extensive enough testing to see if I get the exposure problem, but I reckon I would. FWIW, I have not seen blatant problems with my M50/1.7 used between f/1.7 and f/5.6.

I'm sorry, I should have mentioned it. I simply meant to say the M + green button could be used on the K10D too.

Jonas B · 04-26-2007, 07:39 AM

Ok. It was the expression "works fine" that made me wonder.

For me the exposure is totally whacky with the Zenitar, M50/1.7 and Takumar 50/1.4 when reading the light stopped down (=using the green button).

ptx-elf · 04-26-2007, 08:32 AM

To use my method do NOT use the green button. Instead push, turn the on/off switch to the right, towards the picture of the iris. The lens aperture does close down.
this is using Aperture priority (AV) I am currently am using version 1.0. The reason -- this is my 4th K10D. I have two weeks to check everything out on this camera.
#1 had bad focus problems. returned next day; #2 worked fine but succumbed to a waterfall -5 minutes under 1' deep water. Only function after drying - showed a battery present. Insurance, thank goodness. #3 insurance paid for replacement. Would not focus my 300 FA 4.5 properly. Using debug mode I could either have normal range of lenses focus OK or my 300. Returned to dealer. #4 works fine at all focal lengths. My original post was FWIW. Try it please.
Cheers,
Eric

Gimbal · 04-26-2007, 09:22 AM

Originally posted by Jonas B

Ok. It was the expression "works fine" that made me wonder.

For me the exposure is totally whacky with the Zenitar, M50/1.7 and Takumar 50/1.4 when reading the light stopped down (=using the green button).

I bought a Tokina 100-300mm at a flea market a while ago, and stop down metering works pretty well. Only small corrections up/down depending on the scene is needed. No complains there.

Jonas B · 04-26-2007, 09:41 AM

Hmm, lucky you. I wonder if it is because it is a tele lens? The longest manual lens I have is the Takumar SMC 50/1.4. Here is what a grey card reads when using the green button and dofferent apertures:

1.4 - 164
2.0 - 142
2.8 - 114
4.0 - 099
5.6 - 134
8.0 - 139
11. - 164
16. - 166

The above is with the original viewfinder screen. If I change it to a screen for the *ist DS I get this:

1.4 - 155
2.0 - 132
2.8 - 105
4.0 - 092
5.6 - 106
8.0 - 111
11. - 110
16. - 114

All measurments done with center weighted metering and in daylight (sun right on to the grey card. So, now I use the DS screen and underexposures a biut using the lens wide open (seldom) and just do some exposure brackeiting sometimes.

Do you use the original K10D screen, and have you tried any other screw mount or K or M lenses?

Gimbal · 04-26-2007, 10:03 AM

Original K10D with firmware 1.11, I tested it again with both spot and multi segment metering shooting out through the window. Acceptable exposures at 100mm f32, f16, f5.6, same result at 300mm, no corrections where needed.

It’s unfortunately the only manual lens I have, so far, I might add.

roscot · 04-26-2007, 10:04 AM

I haven't tried any K or M lenses yet ( I've only 2 left), but from what I've read here and at DPR, it is the fast (f1.4 - f2.8) lenses that have the exposure problem when stopped down on the K10. A slower tele zoom like the Tokina probably does OK.

Jonas B · 04-26-2007, 10:21 AM

Thank you.

Jonas B · 04-26-2007, 10:22 AM

Nah, I have an f/4 lens (should be considered slow I guess) and it also shows errors. I'm more thinking of the screen and what angle the light is coming from, probably in combination.

carpents · 04-26-2007, 10:28 AM

I'll do the same later today and post here on my results. The only semi-controlled tests I did were with an f/4 lens that did in fact increase exposure moderately on the K10 beyond f/8 but not noticeably on the DS.

At the f/22 end of the range (not that I'd ever use it) the K10 needed -1 exposure compensation. Since some (normally calm) members can get heated about this issue, I suspect that not all cameras/focus screens behave identically. I'll try to repeat your test with a similar lens that you used.

Gimbal · 04-26-2007, 10:39 AM

Jonas, did you cover the viewfinder (with an eye for instance) when testing your lenses? Just guessing, but sun at the grey card, camera at the grey card, sun at the viewfinder…. On the other hand, your obviously not alone.

jeffkrol · 04-26-2007, 10:45 AM

Originally posted by Jonas B

Hmm, lucky you. I wonder if it is because it is a tele lens? The longest manual lens I have is the Takumar SMC 50/1.4. Here is what a grey card reads when using the green button and dofferent apertures:

1.4 - 164
2.0 - 142
2.8 - 114
4.0 - 099
5.6 - 134
8.0 - 139
11. - 164
16. - 166

The above is with the original viewfinder screen. If I change it to a screen for the *ist DS I get this:

1.4 - 155
2.0 - 132
2.8 - 105
4.0 - 092
5.6 - 106
8.0 - 111
11. - 110
16. - 114

All measurments done with center weighted metering and in daylight (sun right on to the grey card. So, now I use the DS screen and underexposures a biut using the lens wide open (seldom) and just do some exposure brackeiting sometimes.

Do you use the original K10D screen, and have you tried any other screw mount or K or M lenses?

Another DS success story (pretty good f2.8 and on (slight glitch at f4, but not really significant. Wide open and f16 seems to fit the general pattern of Pentax cameras...)
Thanks, wasn't sure you tried "the trick"

Any side effects to report?

04-26-2007, 08:32 AM	#6
ptx-elf Inactive Account Join Date: Apr 2007 Location: Holtsville, NY Posts: 2 Original Poster	Clarification K10D & K, M lenses To use my method do NOT use the green button. Instead push, turn the on/off switch to the right, towards the picture of the iris. The lens aperture does close down. this is using Aperture priority (AV) I am currently am using version 1.0. The reason -- this is my 4th K10D. I have two weeks to check everything out on this camera. #1 had bad focus problems. returned next day; #2 worked fine but succumbed to a waterfall -5 minutes under 1' deep water. Only function after drying - showed a battery present. Insurance, thank goodness. #3 insurance paid for replacement. Would not focus my 300 FA 4.5 properly. Using debug mode I could either have normal range of lenses focus OK or my 300. Returned to dealer. #4 works fine at all focal lengths. My original post was FWIW. Try it please. Cheers, Eric Last edited by ptx-elf; 04-26-2007 at 12:47 PM.

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04-26-2007, 05:47 AM	#1
ptx-elf Inactive Account Join Date: Apr 2007 Location: Holtsville, NY Posts: 2	K10D with M & K lenses Hi all, I think I discovered a useful method for getting correct exposure with P K & M lenses. In the custom menu set up, change the preview method to digital preview, set your camera on AV mode, set your lens aperture to your choice and turn the preview lever to right. Shutter releases and you can see image and histogram (if enabled). If it looks ok, just press the shutter release and you're in business. If exposure needs adjusting add or subtract appropriate amount with exp. comp. setting and try again. I only have a few K lenses but really enjoy my 135 f2.5 for portraits and semi macro with tubes. The set up with my istD was simpler - set to manual, press green button. Hope some of you find this a help.

04-26-2007, 06:37 AM	#2
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	M & K lenses will not be stopped down in any mode but M on the K10D. Put another way, they can only be used wide-open with the method you describe. The M mode + green button works fine on the K10D. You just need to make sure you have enabled "use aperture ring" and the menu, and set "green button in M & TAv" to "Tv shift".

04-26-2007, 07:16 AM	#3
Jonas B Inactive Account Join Date: Sep 2006 Location: Göteborg, Sweden Posts: 810	What do you mean with works fine? Most other people report the exposure to be way off when stopping down the lens. You don't get this?

04-26-2007, 07:29 AM	#4
RBellavance Veteran Member Join Date: Nov 2006 Location: Near Montréal, Canada Photos: Gallery Posts: 1,716	Originally posted by Jonas B What do you mean with works fine? Most other people report the exposure to be way off when stopping down the lens. You don't get this? I mean it sets an exposure value when one presses the green button I have not done extensive enough testing to see if I get the exposure problem, but I reckon I would. FWIW, I have not seen blatant problems with my M50/1.7 used between f/1.7 and f/5.6. I'm sorry, I should have mentioned it. I simply meant to say the M + green button could be used on the K10D too.

04-26-2007, 07:39 AM	#5
Jonas B Inactive Account Join Date: Sep 2006 Location: Göteborg, Sweden Posts: 810	Ok. It was the expression "works fine" that made me wonder. For me the exposure is totally whacky with the Zenitar, M50/1.7 and Takumar 50/1.4 when reading the light stopped down (=using the green button).

04-26-2007, 09:22 AM	#7
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	Originally posted by Jonas B Ok. It was the expression "works fine" that made me wonder. For me the exposure is totally whacky with the Zenitar, M50/1.7 and Takumar 50/1.4 when reading the light stopped down (=using the green button). I bought a Tokina 100-300mm at a flea market a while ago, and stop down metering works pretty well. Only small corrections up/down depending on the scene is needed. No complains there.

04-26-2007, 09:41 AM	#8
Jonas B Inactive Account Join Date: Sep 2006 Location: Göteborg, Sweden Posts: 810	Hmm, lucky you. I wonder if it is because it is a tele lens? The longest manual lens I have is the Takumar SMC 50/1.4. Here is what a grey card reads when using the green button and dofferent apertures: 1.4 - 164 2.0 - 142 2.8 - 114 4.0 - 099 5.6 - 134 8.0 - 139 11. - 164 16. - 166 The above is with the original viewfinder screen. If I change it to a screen for the *ist DS I get this: 1.4 - 155 2.0 - 132 2.8 - 105 4.0 - 092 5.6 - 106 8.0 - 111 11. - 110 16. - 114 All measurments done with center weighted metering and in daylight (sun right on to the grey card. So, now I use the DS screen and underexposures a biut using the lens wide open (seldom) and just do some exposure brackeiting sometimes. Do you use the original K10D screen, and have you tried any other screw mount or K or M lenses?

04-26-2007, 10:03 AM	#9
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	Original K10D with firmware 1.11, I tested it again with both spot and multi segment metering shooting out through the window. Acceptable exposures at 100mm f32, f16, f5.6, same result at 300mm, no corrections where needed. It’s unfortunately the only manual lens I have, so far, I might add.

04-26-2007, 10:04 AM	#10
roscot Veteran Member Join Date: Sep 2006 Location: Virginia Beach VA USA Photos: Gallery Posts: 1,363	I haven't tried any K or M lenses yet ( I've only 2 left), but from what I've read here and at DPR, it is the fast (f1.4 - f2.8) lenses that have the exposure problem when stopped down on the K10. A slower tele zoom like the Tokina probably does OK.

04-26-2007, 10:21 AM	#11
Jonas B Inactive Account Join Date: Sep 2006 Location: Göteborg, Sweden Posts: 810	Thank you.

04-26-2007, 10:22 AM	#12
Jonas B Inactive Account Join Date: Sep 2006 Location: Göteborg, Sweden Posts: 810	Nah, I have an f/4 lens (should be considered slow I guess) and it also shows errors. I'm more thinking of the screen and what angle the light is coming from, probably in combination.

04-26-2007, 10:28 AM	#13
carpents Veteran Member Join Date: Sep 2006 Location: West Chester, PA Photos: Gallery \| Albums Posts: 1,420	I'll do the same later today and post here on my results. The only semi-controlled tests I did were with an f/4 lens that did in fact increase exposure moderately on the K10 beyond f/8 but not noticeably on the DS. At the f/22 end of the range (not that I'd ever use it) the K10 needed -1 exposure compensation. Since some (normally calm) members can get heated about this issue, I suspect that not all cameras/focus screens behave identically. I'll try to repeat your test with a similar lens that you used.

04-26-2007, 10:39 AM	#14
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	Jonas, did you cover the viewfinder (with an eye for instance) when testing your lenses? Just guessing, but sun at the grey card, camera at the grey card, sun at the viewfinder…. On the other hand, your obviously not alone.

04-26-2007, 10:45 AM	#15
jeffkrol Veteran Member Join Date: Sep 2006 Location: Wisconsin USA Photos: Gallery Posts: 8,434	Originally posted by Jonas B Hmm, lucky you. I wonder if it is because it is a tele lens? The longest manual lens I have is the Takumar SMC 50/1.4. Here is what a grey card reads when using the green button and dofferent apertures: 1.4 - 164 2.0 - 142 2.8 - 114 4.0 - 099 5.6 - 134 8.0 - 139 11. - 164 16. - 166 The above is with the original viewfinder screen. If I change it to a screen for the *ist DS I get this: 1.4 - 155 2.0 - 132 2.8 - 105 4.0 - 092 5.6 - 106 8.0 - 111 11. - 110 16. - 114 All measurments done with center weighted metering and in daylight (sun right on to the grey card. So, now I use the DS screen and underexposures a biut using the lens wide open (seldom) and just do some exposure brackeiting sometimes. Do you use the original K10D screen, and have you tried any other screw mount or K or M lenses? Another DS success story (pretty good f2.8 and on (slight glitch at f4, but not really significant. Wide open and f16 seems to fit the general pattern of Pentax cameras...) Thanks, wasn't sure you tried "the trick" Any side effects to report?