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01-05-2008, 02:25 AM   #16
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QuoteOriginally posted by stewart_photo Quote
Are you certain the problem is actually a misaligned viewfinder
To be blunt, yes, and Pentax Japan agree, but they seem not to be able to fix it.

01-05-2008, 03:25 AM   #17
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The word "viewfinder" is rather vague (most are talking about the pentaprism when using this word), so (for my benefit) lets clarify the meaning, Rob. The viewfinder system consists of the mirror, focusing screen, condenser lens, pentaprism, eyepiece, and associated mounting hardware. Only a few of these could possibly cause the type of issue you describe. Do you know which part is causing the problem, or did Pentax Japan say?

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01-05-2008, 04:34 AM   #18
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QuoteOriginally posted by stewart_photo Quote
The word "viewfinder" is rather vague (most are talking about the pentaprism when using this word), so (for my benefit) lets clarify the meaning, Rob. The viewfinder system consists of the mirror, focusing screen, condenser lens, pentaprism, eyepiece, and associated mounting hardware. Only a few of these could possibly cause the type of issue you describe. Do you know which part is causing the problem, or did Pentax Japan say?
My apologies for not being specific, I think you'll find I've been far more specific in previous posts quoting specific angular offsets for both the prism and the screen. My issue however was primarily a rotated pentaprism as proven by my testing.

The service report from my local service centre when the camera was returned simply stated that the camera had been repaired in Japan. When the camera left me the sensor was very well aligned with the base of the camera but the finder showed rotation. However when I got it back it was quite apparent to see that the finder was quite well aligned optically with the sensor but the sensor was now no longer in alignment with the base of the camera. So what appears to have done was to apply an offset to the sensor positioning system in order to compensate for the rotated prism. This was not a satisfactory remedy and I indicated so.

The last correspondence that I received from my local service manager indicated that he had been sent a camera for replacement from Japan which had been checked and aligned by Japanese technicians. As such I sent my K10D to them a couple weeks before Christmas and I assume that when the promised replacement body arrives I'll be able to report that it's A OK, cross fingers.
01-05-2008, 04:57 AM   #19
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QuoteOriginally posted by Finn Quote
If you want 100% coverage, stick with a rangefinder. Then you can see everything outside the frame, too. A nice M8 setup is only, what, 10 grand?
A Leica M8 has a .68X viewfinder and they sell for around only $5K. You could buy a half dozen lenses and still be well under $10K.

To the best of my (limited) knowledge the only rangefinder-type camera with a 1:1 viewfinder is the Voigtlander Bessa R3A and R3M. The good news is that they cost significantly less than a Leica M8 and from what I have read, produce similar or better results. With the R3A you can look through the viewfinder and keep both eyes open while you shoot! I have tried it and it is true. If I wasn't so darn cheap I'd drop the $1,000 and buy one!

01-05-2008, 01:10 PM   #20
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QuoteOriginally posted by J.Scott Quote
A Leica M8 has a .68X viewfinder and they sell for around only $5K. You could buy a half dozen lenses and still be well under $10K.
I think you are mistaking VF magnification for coverage, the OP's question was regarding coverage, not an unreasonable question for a new SLR owner.

RF camera finders are have a fixed AOV and fixed magnification (excluding the Contax G1 and G2) with superimposed frames to indicate the AOV of the fitted lens. As such with longer lenses they can show many times the coverage of the fitted lens but with ultra-wides they are useless for framing and generally require the addition of an auxiliary finder.

Coverage of an SLR finder is limited by the design of the finder and is a fixed percentage of the frame regardless of the magnification. The angle of view presented by the finder of course is a direct function of the lens fitted.

01-05-2008, 01:45 PM   #21
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QuoteOriginally posted by Jasvox Quote
Here is an example...took this one yesterday...leveled with viewfinder lines but came out (typically) a little unlevel. The one is original, the other is as I leveled it on Picassa. What do you think?
About a half degree ccw (the original)... and not unusual for most brands......
As an example, Thom Hogan at one time stated:
"One final performance note: the viewfinder mask on my D50 is 0.6 degrees off from what it should be. Line something up with the bottom of the viewfinder frame and you'll be running Rotate Arbitrary in Photoshop a lot. I've yet to see a Nikon viewfinder that's perfect (curiously, they all seem to give you images that run downhill right), but my D50's is the worst of the bunch to date.
Nikon D50 Review by Thom Hogan
Sooo before we all run off and pretend that this is just a Pentax issue, it appears it's NOT....
Now there does seem to be a range of people's tolerance to this as well as the expected range of variation and Pentax, as far as I have heard will try to fix it for you BUT sometimes the fix causes more problems then the original. One poster here had the framelines adjusted but now the body is tilted. In other words a spirit level on the camera will not give a planer mage but using the viewfinder mask will........
01-05-2008, 11:29 PM   #22
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perhaps this is why "Live View" is attractive and not such a "gimmick" as some purists say...hey, if the image looks differently on screen or paper than whats in my view finder, I am not so happy, regardless of the 1-2 degrees of acceptance.

P.S. I think it's more than a half a degree...using the top of the monitor image and aligning with the roof line of the subject, looks more than that.
01-06-2008, 12:00 AM   #23
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QuoteOriginally posted by Jasvox Quote
P.S. I think it's more than a half a degree...using the top of the monitor image and aligning with the roof line of the subject, looks more than that.
Yes, measured it's about 0.67 degree, imagine what a constant 1 degree error looks like ;-(

01-06-2008, 12:46 AM   #24
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QuoteOriginally posted by distudio Quote
(snip) So what appears to have done was to apply an offset to the sensor positioning system in order to compensate for the rotated prism. This was not a satisfactory remedy and I indicated so.

Well, at least it does appear Pentax attempted to make adjustments. And adjusting one viewfinder part to balance against another would appear to be a reasonable approach since the individual parts do ultimately work together as a whole. In other words, I'd probably be satisfied with that solution if nothing else was adversely impacted. However, it's your camera (not mine), so the judgement in this case is obviously yours and yours alone.


QuoteQuote:
The last correspondence that I received from my local service manager indicated that he had been sent a camera for replacement from Japan which had been checked and aligned by Japanese technicians. (snip)

Sincerely hope you have better success with the new camera. However, surely not all are experiencing the same issue, so I'll continue to ask others the same questions about the focusing screen and frame since their solution might just be that simple.

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01-06-2008, 01:03 AM   #25
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QuoteOriginally posted by stewart_photo Quote
Well, at least it does appear Pentax attempted to make adjustments. And adjusting one viewfinder part to balance against another would appear to be a reasonable approach since the individual parts do ultimately work together as a whole. In other words, I'd probably be satisfied with that solution if nothing else was adversely impacted. However, it's your camera (not mine), so the judgement in this case is obviously yours and yours alone.
Given that I also shoot a lot of panos on a custom rig which relies upon the camera base plate being level with the sensor it certainly wasn't a desirable remedy. I've owned a lot of cameras and never have I owned one with such gross finder errors. I'm quite surprised that so many people appear to find it acceptable.
01-06-2008, 11:07 PM   #26
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Actually, since I'm one of those people, I'm not at all surprised, Rob. First, this most certainly isn't the only camera exhibiting this behavior. I first came across it some twenty years ago (see below), with a medium format camera costing several times more.

Second, perfect alignment just isn't a requirement in the vast majority of images taken by the vast majority. The environment/world around us is seldom perfectly flat, either optically or physically, so there's obviously little need for that in most images.

Finally, only minimal effort is required to make allowances for it when present. Again, I came across this issue while doing research for a panoramic requested by a client. A book on the subject devoted an entire chapter to the issue, describing it as a common problem. After renting a true panoramic tripod head with adjustments for this, it was simply a matter of offsetting the camera by an equal amount once the degree of error was determined by a series of test shots. The resulting panoramic was impressive (one of only three I've ever done).

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01-07-2008, 12:36 AM   #27
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QuoteOriginally posted by stewart_photo Quote
Actually, since I'm one of those people, I'm not at all surprised, Rob. First, this most certainly isn't the only camera exhibiting this behavior. I first came across it some twenty years ago (see below), with a medium format camera costing several times more.

Second, perfect alignment just isn't a requirement in the vast majority of images taken by the vast majority. The environment/world around us is seldom perfectly flat, either optically or physically, so there's obviously little need for that in most images.

Finally, only minimal effort is required to make allowances for it when present. Again, I came across this issue while doing research for a panoramic requested by a client. A book on the subject devoted an entire chapter to the issue, describing it as a common problem. After renting a true panoramic tripod head with adjustments for this, it was simply a matter of offsetting the camera by an equal amount once the degree of error was determined by a series of test shots. The resulting panoramic was impressive (one of only three I've ever done).

stewart
Interesting, all the MF cameras I owned twenty years ago (Pentax 67 and later 645 coincidentally) had well aligned finders and all the Nikon, Contax, Leica, Mamiya and Pentax gear I've owned subsequently has had too (I'm conscious of the fact as I have scanned a lot of the output from my film cameras). Given that there was no indication of common alignment problems in any of the prior Pentax bodies I'd be very surprised if all of a sudden people like me have become conscious of VF misalignment all in synchronism.

I can assure you that one degree misalignment is significant and apparent in any architectural or landscape image containing the horizon on water, granted anyone can rotate an image to "fix" the problem but it can introduce re-sampling/aliasing distortions but more significantly it forces the image to be cropped. As I've said before I agree that there are likely many photographers who are not particularly sensitive to the problem but that doesn't discount the fact that there are systemic errors in a significant number of K10D finders.

I don't know what kind of Pano rig you employed but I can't say that I've seen mention of the ability to compensate for angular camera offset on any current generic pano systems. As far as I'm aware they are all designed assuming that the base of the camera be level with the sensor/film. What was the rig that you used?

As it is I can work with an offset finder (not happy about it and the extra work it entails in post processing). However having the camera base changed from being effectively perfectly aligned with the sensor to an entire degree out of alignment meant a lot more work for me in assembling my panos and some loss of vertical AOV in the final images. I appreciate that it may not bother you, that's great (for you) but it does me (and apparently quite a number of other K10D/GX10 owners).

Cheers,
01-07-2008, 02:19 AM   #28
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QuoteOriginally posted by distudio Quote
(snip) What was the rig that you used? (snip)

I don't remember what it was, Rob. All this was some 22-23 years ago. It was something the book recommended. I called around to a few rental places and found one in another town. I used the head for three or four days and returned it without even a second thought till now. For the other two panoramics (also years ago, all three film based), the local lab insisted they could handle any misalignment while printing. Since these two weren't especially important, I let the lab do so. Don't know if there actually was any misalignment since the second two were done with another camera. By the way, the first camera was a Mamiya 645/1000s. I remember that only because it was the camera I had back then. I haven't noticed it with my Mamiya 645 Super, but can't honestly say I've been looking for it. A friend once mentioned, also years ago, a similar issue with his Bronica while doing some architecture work.

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01-07-2008, 08:48 AM   #29
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I´m sad to hear that you haven´t got your camera fixed yet, Rob. It´s strange tho, as my finder image was over 1 degree off from aligning with the camera base and sensor and it was returned fixed and sound.

Hope you´ll get it fixed!

// Mats
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