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08-14-2009, 05:31 AM   #16
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Per the other thread, I'm betting on user error or lens problems. Too many good reviews by too many good photographers' using the K7!

08-14-2009, 06:51 AM   #17
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Puzzling

I have a K100D and I tested focus with my FA50 wide open.

When I aim centered on the "Focus Here" line with the center focus point selected, sitting on that line, focus is spot on.

Part A. When I stay centered on the "Focus Here" line and select a focus point a half inch above or below that line, that spot a half inch above or below the line is in focus (not the line) as it should be. Fine up to this point.

Part B. However, when I select one of those off center focus point in the viewfinder, and REPOSITION the camera to point that off center focus point onto the "Focus Here" line, I get front focus of 10 to 14 mm, roughly the same distance the off center focus point is from the center of my viewing screen.

I'm not understanding why this test shows "Perfect" for Part A, above, but seems way off for Part B.
08-14-2009, 07:32 AM   #18
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If you are shooting wide open it won't be sharp anyways. When you use the off-center point, the light has to pass through more glass at an off angle thus making the appearance of front focus. Because you are shooting wide open this increases the effect. f/1.4 is a super shallow depth of field.

I hope i understood what you were saying and answered your question. The center focus point is the most accurate point.

Could also be a lens issue.
08-14-2009, 08:00 AM   #19
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QuoteOriginally posted by fulcrumx29 Quote
Hi All,

I just cannot get as sharp image from K-7 as those from D90....
Tony
If you're going to pixel peep, the lens and aperture used can make a huge difference. Also, shoot RAW, that's the only way to know what the camera can really do. Pentax JPEG sharpening is less agressive than Nikon's I believe (simply look at any Nikon lens test chart, this is quite evident as no lens, not even Zeiss, are as good accross the field and aperture than Nikon test charts would make you believe, which shows that Nikon does in camera sharpening quite agressively, and rather effectively one might argue), and if you're comparing the FA50mm at f1.4 against lets say a Nikon zoom at f2.8 or less, then you're comparing apples to oranges. Not to say that there isn't something wrong with the camera/lens combo, but the FA50mm is known to be razor sharp closed down. Nikon's noise reduction at all ISOs is also more agressive (and also arguably more effective) than Pentax's; that's a known fact. This being said, I doubt that you'll see the noise that you're seeing pixel peeping on a 11 x14 print, and arguably there's more texture in the Pentax images than Nikon's.

08-14-2009, 08:35 AM   #20
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Oh no! Another horrible result at 100 percent crop. Out of focus, noisy and not sharp. Or not.

Last edited by tarsus; 12-23-2009 at 06:14 AM.
08-14-2009, 08:45 AM   #21
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QuoteOriginally posted by davebris33 Quote
Pixel peeping is killing photography
No, people just want the best from their high priced gear. No different than looking at slides on a light box.
08-14-2009, 08:51 AM   #22
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QuoteOriginally posted by K-9 Quote
No, people just want the best from their high priced gear. No different than looking at slides on a light box.
I don't remember shooting focus charts or brick walls with slide film.

But maybe we were just weird.
08-14-2009, 10:16 AM   #23
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QuoteOriginally posted by nostatic Quote
I don't remember shooting focus charts or brick walls with slide film.

But maybe we were just weird.
I recall the color chart tests, but that was mostly for testing film. I meant people compared quality of lenses by comparing slide sharpness back in the film days. The bodies really didn't have an affect on sharpness (unless they had metering issues), so it was always lens vs. lens only.

08-14-2009, 11:23 AM   #24
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QuoteOriginally posted by K-9 Quote
No, people just want the best from their high priced gear. No different than looking at slides on a light box.
Yes, it is different. Looking at slides on a light box with an 8x loupe is like looking at an 8x10 print from a negative. (same degree of magnification of the individual elements) My monitor is 12" high/1050 pixels. If I display and image so that it is 8" high, that would be 693 pixels. The original image is 3136 pixels high. If I now look at it at "actual Pixels" size, rather than "fit Screen", I have essentially enlarged the image approximately 4.5 times (3136/693). Pixel peeping is like looking at the 8x10 print through a 4.5x loupe and complaining that it looks soft and grainy.

Last edited by Parallax; 08-14-2009 at 11:37 AM.
08-14-2009, 12:17 PM   #25
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Aside from the FA50/1.4 being very soft overall, I don't see any sort of focus problem in any of these shots, FWIW - the center of the center line looks to be well within the zone of acceptable focus in all cases, Is there a particular aspect of one of the shots where the problem is more apparent when pixel peepeing at 100% or something?

As for "soft jpg with noisy dots", you'd have to post an example to demonstrate what you mean regarding that too - along with the exact same image (same scene, same exposure, and both on sturdy tripods) from the D90.

Last edited by Marc Sabatella; 08-14-2009 at 04:22 PM.
08-14-2009, 03:52 PM   #26
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QuoteOriginally posted by Parallax Quote
Yes, it is different. Looking at slides on a light box with an 8x loupe is like looking at an 8x10 print from a negative. (same degree of magnification of the individual elements) My monitor is 12" high/1050 pixels. If I display and image so that it is 8" high, that would be 693 pixels. The original image is 3136 pixels high. If I now look at it at "actual Pixels" size, rather than "fit Screen", I have essentially enlarged the image approximately 4.5 times (3136/693). Pixel peeping is like looking at the 8x10 print through a 4.5x loupe and complaining that it looks soft and grainy.
Looking at slides with a loupe on a lightbox is not like looking at a print!

Slides are much crisper and sharper and you'd have to look at the negative with a loupe for a comparison, as you'd be reviewing first generations from the camera and not second (the print).
08-14-2009, 04:30 PM   #27
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Just realized you said the posted shots are with adjustment turned on. Perhaps that explains why I didn't see a problem. How about posting the results *without* adjustment?
08-14-2009, 04:40 PM   #28
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QuoteOriginally posted by K-9 Quote
Looking at slides with a loupe on a lightbox is not like looking at a print!

Slides are much crisper and sharper and you'd have to look at the negative with a loupe for a comparison, as you'd be reviewing first generations from the camera and not second (the print).
True, but the magnification in my example is still the same for the two. I think I could have made a better case against pixel peeping by saying that it is like comparing an 8X10 print to a 36X45 print from the same negative.
08-14-2009, 05:19 PM   #29
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QuoteOriginally posted by Parallax Quote
True, but the magnification in my example is still the same for the two. I think I could have made a better case against pixel peeping by saying that it is like comparing an 8X10 print to a 36X45 print from the same negative.
True. It's all in what size you're happy with printing in the end, and if the quality is at the level you intended. If you're not happy with the K-7, you gotta go full frame from there!
08-14-2009, 05:58 PM   #30
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QuoteOriginally posted by lurchlarson Quote
When you use the off-center point, the light has to pass through more glass at an off angle thus making the appearance of front focus.
That doesn't make sense to me.
Perhaps gfmucci should post an image. Perhaps it is something simple like the camera focusing on the ruler rather than on the focus target. I don't like that focus chart, BTW, because the focus target is unecessarily wide.

QuoteOriginally posted by tarsus Quote
Oh no! Another horrible result at 100 percent crop.
Nice shot, Ansel! Err, tarsus.
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