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05-01-2009, 01:17 PM   #31
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QuoteOriginally posted by cupic Quote
Is that a original one or a copy and roughly whats one worth?


cheers
It is a Pentax screen, and it cost a little over US$50 delivered to my door from Japan. If it works, it's worth every penny.

05-01-2009, 01:20 PM   #32
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So far, so good. + 16-50 is good, too!

I've run a set of tests from f/5.6 through f/45 with the new screen on the M 400, and all the exposures and histograms match.

I ran a second set of test with the AF 1.7X on the camera and the exposures were right on, a stop over, and then a stop under. Then I figured out that I had bracketing turned on, turned it off, and the metering is accurate all the way from f/5.6 through f/45 with the AF 1.7X as well. I'm loving it! Now to try out the DA* 16-50.

[EDIT] The DA* 16-50 exposed correctly all the way from f/2.8 through f/22. I'm in heaven! Thank you, thank you, all those who suggested the trouble was with the focusing screen. A simple $50 fix, and the camera meters 100% correctly.

Last edited by Canada_Rockies; 05-01-2009 at 01:26 PM. Reason: Added DA* 16-50 test
05-01-2009, 01:32 PM   #33
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But, the green button does not work correctly.

With the M 400/5.6 on my K10D with the LL-60 focusing screen, I get perfect metering as noted above.

BUT the green button starts to fail about half way up the aperture list, going more and more into underexposure. I suspect that the aperture on the 400 is too slow for the brief time the green button stops it down, causing the meter to see more light than when the aperture is all the way closed. e.g with the aperture at f/11, I get about a half stop over. It is as if the meter takes its reading at f/9.5 because the aperture has not completely stopped down.

Using the dof preview metering method, where the meter is on as long as one holds the power switch over, and setting the exposure to the centre of the scale, the histograms are exactly where they should be. Using the green button, the histogram moves gradually to the left. I can live with this, but thought I should note it for those of you who use the green button system to set the shutter speed. I normally use the dof sytem anyway, so it's no hassle for me, but be warned that it might happen to you as well.
05-01-2009, 02:33 PM   #34
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Thank you, Canada_Rockies for this very encouraging news. Now if only I could figure out this non-green-button method of metering...

...and if only my new K20D did not have this disappointing stripes issue...but that's no part of this thread...

05-01-2009, 02:40 PM   #35
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DOF preview metering in a nutshell

QuoteOriginally posted by Timarete Quote
Thank you, Canada_Rockies for this very encouraging news. Now if only I could figure out this non-green-button method of metering...

...<snip>...
Here is how it is done:
  1. Set the depth of field preview to [Optical] in the [Custom Settings] > [Preview Method]
  2. Mount your non-A type lens
  3. Turn the camera on
  4. Frame the subject
  5. Pull and hold the dof preview on the power switch - I use my index finger
  6. Adjust the shutter speed with the front e-dial - I use my longest finger, the not so polite one - or adjust the aperture with the ring.
  7. Balance the exposure where you want it on the scale.
05-01-2009, 03:00 PM   #36
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QuoteOriginally posted by Canada_Rockies Quote
Here is how it is done:
  1. Set the depth of field preview to [Optical] in the [Custom Settings] > [Preview Method]
  2. Mount your non-A type lens
  3. Turn the camera on
  4. Frame the subject
  5. Pull and hold the dof preview on the power switch - I use my index finger
  6. Adjust the shutter speed with the front e-dial - I use my longest finger, the not so polite one - or adjust the aperture with the ring.
  7. Balance the exposure where you want it on the scale.
As I wrote in the other thread, many thanks for your help!
05-01-2009, 04:16 PM   #37
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M 100/4 macro okay, green button, too.

Just ran the tests with the M 100/4 Macro, and the green button works correctly as well as dof preview metering. I suspect that the larger aperture in the 400 (twice the diameter) having both heavier aperture blades and further travel is too slow for the green button.

It is starting to look very much like the answer to metering troubles is as simple as switching focus screens. It's only taken me a year and a half to figure this out from all the posts. I'm slow.
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