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12-22-2008, 11:24 PM   #1
Igilligan
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Have to map stuck pixels on your new K20?

I just received my new K20d. In putting it thru its initial test shots, I found that I have at least 15 'bright' stuck/dead pixels on the new camera. Five very close to the center of the frame. These are not long exposures.
One of the reason I got the K20 was the internal pixel mapping function, but I can not believe that a brand new camera would have been sent out with so many stuck/dead pixels.

How many K20d owners had to map dead pixels when you first got the camera?

I am trying not to be a negative ned here, and I know there are millions and millions of pixels.

Also can anyone tell me how to tell how find how many shutter actuations are on the camera? I have seen it mention here before but I cant find it in the search now.


Last edited by Igilligan; 12-23-2008 at 12:01 AM.
12-23-2008, 12:10 AM   #2
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QuoteOriginally posted by Igilligan Quote
I just received my new K20d. In putting it thru its initial test shots, I found that I have at least 15 'bright' stuck/dead pixels on the new camera. Five very close to the center of the frame. These are not long exposures.
One of the reason I got the K20 was the internal pixel mapping function, but I can not believe that a brand new camera would have been sent out with so many stuck/dead pixels.

How many K20d owners had to map dead pixels when you first got the camera?

I am trying not to be a negative ned here, and I know there are millions and millions of pixels.

Also can anyone tell me how to tell how find how many shutter actuations are on the camera? I have seen it mention here before but I cant find it in the search now.
If I am doing astrophotography with my K20D, I can bet on there being about 5 hot pixels showing up. If dark frame subtraction somehow misses them, I just clone them out in post-processing. I occasionally get about 3 hot pixels showing up in exposures up to 10 seconds but they are not consistent.

As for shutter actuation count, it is visible in programs such as Photo Me for the Windows platform or exiftool for linux. Not sure about Mac software.

Jack
12-23-2008, 12:35 AM   #3
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Hi gus,

I bought my K20 from the first shipment to the US, a couple of days after they started showing up in stores. It had two hot pixels starting off, but I just kept shooting with it, cloning them out in PP. I had previously had new cameras that exhibited hot pixels new, and they disappeared with time. I had hopes that this would also happen with my K20, and it did. They were not noticeable after about a week's use. Of course YMMV applies, so this might not happen with yours, but I'd try some patience first, then if they don't clear up, I'd just map them out. 5/14,000,000 is a pretty small number. . .

I tend to not obsess about this kind of stuff as you probably have guessed. . .

Scott
12-23-2008, 12:59 PM   #4
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Hi Gus,

I didn't have as many as you had, but I don't think I'd worry about it. Did you map them out yet? I did have a few to map out. In a sort of perverse way, I was glad there were a few to map out, as the pixel mapping feature was one of the features I wanted and it was nice to see it in action.

Only time I've noticed them lately is when using the extended dynamic range function, but I've pretty much given up on that as I don't like the noise it causes, even at low ISO.

12-23-2008, 02:19 PM   #5
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Hi Gus,
not when it was new, but when it came back from repairs to the power on/off issue I had, the sensor was mis aligned(so back it went). When it came back it had lots of hot pixels.

I ran the mapping function a couple of times and have not seen a hot pixel since.
12-23-2008, 02:35 PM   #6
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My K20 was an early one also, but I've not had any pixel problems at all.
12-23-2008, 03:00 PM   #7
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What's the easiest way to test for a hot pixel? Long exposure of a dark surface, I guess?
12-23-2008, 03:47 PM   #8
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QuoteOriginally posted by legacyb4 Quote
What's the easiest way to test for a hot pixel? Long exposure of a dark surface, I guess?
Best way to document them:
StarZen Technologies, Inc; DataFlex tools and books
See this thread for some more info:
https://www.pentaxforums.com/forums/pentax-dslr-discussion/44519-sensor-glitch-2.html

12-23-2008, 03:47 PM   #9
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QuoteOriginally posted by legacyb4 Quote
What's the easiest way to test for a hot pixel? Long exposure of a dark surface, I guess?

If you don't notice them, why look for them? Seriously, there's no need to look for a reason to be dissatisfied with your camera.

Okay, now that I got that off my chest, if you shoot longish exposures you may see them show up in dark areas of the frame. However, long exposure noise reduction will also mask them usually, and you can't turn that off.
12-23-2008, 03:55 PM   #10
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Oh fiddlesticks

Well I wish I could spend that kind of money on a camera and not look to see how it is doing.

These on my new camera are obvious. One of the main reasons to get the K20 was the ability to crop in and still have lots of detail... Even slight cropping and the Bright +'s are visable and the only reason I found all the others is that the AF is off with my sharpest lenses so I was looking close in to see how much the AF was off. Then I could see the +'s in lots of places.
If the AF would have been ok I probably would not have even seen most of them. But even my DA40 and Tammy 28-75 (my sharpest lenses) are softy's on the new cam.
12-23-2008, 04:35 PM   #11
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QuoteOriginally posted by Igilligan Quote
Well I wish I could spend that kind of money on a camera and not look to see how it is doing.

These on my new camera are obvious. One of the main reasons to get the K20 was the ability to crop in and still have lots of detail... Even slight cropping and the Bright +'s are visable and the only reason I found all the others is that the AF is off with my sharpest lenses so I was looking close in to see how much the AF was off. Then I could see the +'s in lots of places.
If the AF would have been ok I probably would not have even seen most of them. But even my DA40 and Tammy 28-75 (my sharpest lenses) are softy's on the new cam.
Sorry you're having trouble Gus - always a bummer with new stuff. I assume you can return it for a replacement?

Jer
12-23-2008, 05:11 PM   #12
Igilligan
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I was hoping to figure it all out

Thanks all

I want to try and get it right before breaking down and sending it back. I am afraid if it goes back, the K100d could be my last pentax. So I am fighting like the dickens to dial it in. It really should not be this tough though.

I forgot to ask, but is the K20 like the K10 in that they like to underexpose .5 to .7? I always would see you all talking about dialing in ev comp for some of the lenses but the K100 did not seem to need it much exept on a few of the old MF lenses.
12-23-2008, 05:46 PM   #13
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QuoteOriginally posted by Igilligan Quote
Thanks all

I want to try and get it right before breaking down and sending it back. I am afraid if it goes back, the K100d could be my last pentax. So I am fighting like the dickens to dial it in.
Man, life is too short - if it doesn't work to suit you, send it back and enjoy the holidays.

Jer
12-23-2008, 10:47 PM   #14
Igilligan
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You are so right...

I wasted too much time trying to decide which camera to get... back in the box it goes, a top of the line camera should not be this much work.

I will shoot the Christmas shots with the K100d and forget the k20d...

thanks for the perspective... sometimes it can be a "forest for the trees" kind of tunnel vision!
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