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10-20-2010, 09:52 PM   #31
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Thanks, everyone, for your input. I will continue to closely monitor this, and post any images that just don't seem right.

10-20-2010, 09:52 PM   #32
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I guess my eyes are not what they used to be.

Can someone point out where the blurriness is? I can't seem to see it. The images (assuming it a 1:1 crop) seem fine to me.
10-20-2010, 10:05 PM   #33
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QuoteOriginally posted by Christine Tham Quote
I guess my eyes are not what they used to be.

Can someone point out where the blurriness is? I can't seem to see it. The images (assuming it a 1:1 crop) seem fine to me.
Take a look at this and it becomes quite evident.

https://www.pentaxforums.com/forums/members/slowdive101-albums-k-7-blur-pictu...836-detail.jpg

I never considered myself to be a person that nitpicks down to the last pixel (I do a lot of hand-held HDR, which lends itself to some softness), but I've just never felt quite right about the K-7 in medium- to low-light. This image is a classic example.
10-21-2010, 01:26 AM   #34
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QuoteOriginally posted by slowdive101 Quote
I will continue to closely monitor this, and post any images that just don't seem right.
Your issues are very easily testable using simple flat test charts, rather than complex pictures like the one you posted, where issues of DOF, focus, CA, variable illumination etc complicate seeing any problems.

I suggest you download and print this PDF (200k) which is the ISO 12233 Resolution test chart.


Then mount your camera on a solid tripod, disable SR, and take a series of photos of the chart at various shutter shutter speeds, apertures, and focal lengths, with even constant light, making sure to have the camera and the test chart aligned correctly - ie nice and perpendicular to each other.

Then see if any issues crop up.

10-21-2010, 06:48 AM   #35
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One think I don't know if has been mentioned in this thread, but it is very likely that his camera will have a small range of shutter speeds where things can go a little sideways. It isn't uncommon at all in lighter weight camera.
I haven't noticed this with my K7 yet, but I haven't gone looking either.
I recall my old Super Program film camera needed a 15 pound tripod to tame it's shutter bounce at 18 and 1/15 second.

It would be a good idea for him to tripod mount his camera and run a shutter speed test to see if there is a range of speeds that causes some blurriness.
10-21-2010, 06:57 AM   #36
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QuoteOriginally posted by Eric Seavey Quote
in combination of the use of hotshoe flash and shutter speeds from 1/125 to 1/180 seconds (used flash as fill flash).
More than likely, your problem is caused by a phantom exposure before and/or after the flash exposure. This is a common occurence when using a flash as fill in with rather bright surrondings and a moving subject.

Using a more powerful flash will allow you to use a smaller lens opening, which would held reducing the ghost images.
10-21-2010, 07:02 AM   #37
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I have to agree that an older DSLR with smaller sensor is more forgiving of older lenses than a newer DSLR is.

This is why with my K200D I use it with my screw mount macro lenses than my K20D. (Other than DFR with long exposure shots).
10-21-2010, 08:06 AM   #38
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I think there's a somewhat noticeable haze around the copula in this shot: https://www.pentaxforums.com/forums/members/slowdive101-albums-k-7-blur-pictu...836-detail.jpg


However, what it looks like to me is someone discovering they can pixel peep just THAT much closer in their new higher resolution pixels, and discovering the calamity that pixel peeping can bring.

The fact that it's shot at 1/60, and in a HDR sequence says two things to me:

1) You shot it too slow, and there's some motion blur from the bang bang bang of the shutter
2) You only KNOW it's got a tiny tiny bit of motion blur, because you're looking at it ridiculously close.

*Edit*

Incidentally, I'd like to the see the bracketed shots, because to me there remains the possibility that it's front focused slightly (resulting in a depth of field that mostly looks like it takes up the space BETWEEN the chapel and the branches)

10-21-2010, 06:09 PM   #39
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QuoteOriginally posted by flyer Quote
More than likely, your problem is caused by a phantom exposure before and/or after the flash exposure. This is a common occurence when using a flash as fill in with rather bright surrondings and a moving subject.
can you elaborate on this? I can replicate this with my K7 just about any day of the week...

I don't care what people say their camera does or doesn't do, mine does this, and I can't say I think it's a feature!

I've come to the conclusion that it's the combination of SR, flash, high contrast details and maybe a shutter in the suspect 1/60-1/125 range. I could show you a lot more examples but haven't uploaded them. Maybe the flash aspect just highlights what's going on anyway in regard to Falk & Co's research into the bouncing shutter.

I've posted these in another thread, but here goes again...

full scene (resized)


100% crop


This shows two distinct images, not a blurred effect camera shake would exhibit.
This was a case of significant ambient light (which is why I used the flash to light the canteen lady) but I've seen it in shots lit by just the flash.

Recently after updating the firmware to the latest incarnation of the latest version, I ran the around the house to test it, hoping is might have been fixed but within the 1st few shots, had replicated it. Over the next few nights I tried again and in about 75 shots couldn't get a 'dud'. The camera had about 3 days left before the warranty ran out and I had a heap of school yearbook pics to take (I still have a K10D I could have used but it has trouble focusing accurately at the best of times) so decided not to take it in. Couple of days later, got a 'dud' when shooting one of the yearbook pics, luckily I zoomed in enough on the LCD to notice it and could reshoot (remembering to turn SR off this time, which returned the desire result).

Guess what I'm saying is, people can suggest to put it on a tripod, turn SR off, focus with live view, stop the world rotating, etc... to prove the camera can take a correct shot (and all that is a useful exercise in itself), but that's not how we always use our cameras, and I can say I've got no confidence in my K7 once I bolt that AF540FGZ on!

Cheers, Nige
10-21-2010, 07:16 PM   #40
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Sorry that you are having this problem. My K-7 is incredibly sharp with all of my lenses. Of course, I took the time to do proper lens calibrations. If you have not done so, I suggest that you do it, and then test your camera again. FWIW, focusing on my first K-7 was so far off that I could barely correct it using the focusing adjustment function. I returned it for a second body that was easy to adjust.

Rob
10-21-2010, 07:35 PM   #41
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QuoteOriginally posted by slowdive101 Quote
Definitely not shot from a moving car. I've been shooting for over 20 years, and like to think I know my way around a camera. A clear shot at 1/125s has never been a problem before the K-7. I'm not seeing a pattern at all, though, as a 1/30s shot could come out crystal clear.

Having said all that, problem does seem to diminish when shooting with a tripod. I know that would lead one to suspect that the problem is with me (ie; shaky hands), but I just don't think it is...I really don't.

Take some more pictures and post them, even with a tripod. It could very well just be your lens.
10-21-2010, 07:48 PM   #42
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QuoteOriginally posted by HGMonaro Quote
This shows two distinct images, not a blurred effect camera shake would exhibit.
Actually, that is exactly what camera shake looks like. Put your camera on a tripod and try again. If you still get that result you have a problem. I've found out myself I need to shoot at least 2 * the focal length to be guaranteed sharp results. At first I had a bunch of shots that looked like yours and I blamed the camera, I've since found out my camera is fine and it's my hands that are faulty.
10-21-2010, 08:27 PM   #43
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QuoteOriginally posted by twitch Quote
Actually, that is exactly what camera shake looks like. Put your camera on a tripod and try again. If you still get that result you have a problem. I've found out myself I need to shoot at least 2 * the focal length to be guaranteed sharp results. At first I had a bunch of shots that looked like yours and I blamed the camera, I've since found out my camera is fine and it's my hands that are faulty.
I don't think so as there's no smearing of the edges of the lettering don't bleed into each other (that image is not the best to show it due to the 'starburst' graphics on the box confusing the problem). I haven't tried the tripod/flash combo... but, do I have SR on whilst on the tripod (since I believe that's part of the problem)? I'll upload a better (clearer) example tonight.
10-21-2010, 08:42 PM   #44
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QuoteOriginally posted by robgo2 Quote
Sorry that you are having this problem. My K-7 is incredibly sharp with all of my lenses. Of course, I took the time to do proper lens calibrations. If you have not done so, I suggest that you do it, and then test your camera again. FWIW, focusing on my first K-7 was so far off that I could barely correct it using the focusing adjustment function. I returned it for a second body that was easy to adjust.

Rob
What HGMonaro has shown has got nothing to do with the sharpness of your lenses or lens calibration. What his K-7 images show is a known issue with the K-7 when used with flash that was first discovered by some users in China. When flash is used, there is a slight double image recorded. This issue appears in varying degree, on some K-7s it is more obvious, less so on others. The latest firmware fix does does help reduce the severity of the double image but it does not fully go away. This only happen when flash is used so if you're shooting normally without flash, all is good. This is one of the niggling issues that made me dump my K-7 for the K-5. Thankfully I haven't encountered any issue like this on the new K-5.
10-21-2010, 08:57 PM   #45
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QuoteOriginally posted by creampuff Quote
What HGMonaro has shown has got nothing to do with the sharpness of your lenses or lens calibration. What his K-7 images show is a known issue with the K-7 when used with flash that was first discovered by some users in China. When flash is used, there is a slight double image recorded. This issue appears in varying degree, on some K-7s it is more obvious, less so on others. The latest firmware fix does does help reduce the severity of the double image but it does not fully go away. This only happen when flash is used so if you're shooting normally without flash, all is good. This is one of the niggling issues that made me dump my K-7 for the K-5. Thankfully I haven't encountered any issue like this on the new K-5.


Does pentax recognize this as a defect? Would they do a free fix for it?
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