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10-25-2009, 10:55 PM   #1
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K100D Stuck/bad pixels

I am sure it has been covered before, but weeding thru a few hundred threads does not seem fun.

Just bought a refurbed K100D and after taking a few hundred pictures and then viewing them, I have noticed about 4 stuck/bad pixels. I know it happens, but a few of them are dead center and are easily noticed.

They looked to be about 4x4 pixels in size. I see around 5-6 of these.

What are my options? Besides photo manipulation? Should I return and hope for a better sensor? Or is this that common? I have had it less then a month, so returning is an option imho.

Thanks.


Last edited by -Joe-; 10-25-2009 at 11:05 PM.
10-26-2009, 01:15 AM   #2
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A handful of bad pixels is well within the tolerances of a "normal" functioning sensor.
Usually, the defects are single isolated pixels. A bit unusual to have clusters of them together, and these have bigger effect on the output IQ.
Photoshop can handle it easily, by averaging between the surrounding pixels. Once you confirm the hot pixels the configuration can be used to correct all your shots from the camera.

The alternative is do the same mapping out in the camera. The K-7 and K20D allows the user to DIY to map out hot pixels. Other Pentax bodies will require Pentax service personnel to do that for you.
10-26-2009, 09:48 AM   #3
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I dont use Windows, so no photoshop for me. Linux is the way to go these days.

I take lots of pictures and doing single pictures one by one is not going to work.

I am sure gimp can do the same but would need a batch fix option.

I disagree about bad pixels being common.. I have 2 other cameras with zero stuck pixels.

Last edited by -Joe-; 10-26-2009 at 12:05 PM.
10-26-2009, 03:15 PM   #4
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Joe,

you might want to try this method:
Hot Pixels / Stuck Pixels (EOS 350D) - a cure?: Canon EOS 1000D / 500D - 300D Forum: Digital Photography Review

It's from a Canon user but in the past, I'd used it successfully with my K100D.
Some people are also successful, some get better than nothing and some said no improvement at all.
So the success rate varies.
I'm considered lucky since I've been using it for several times and it always works for me

Give it a try and let us know how it goes.

Hope this helps.

10-26-2009, 03:46 PM   #5
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"I disagree about bad pixels being common.. I have 2 other cameras with zero stuck pixels."

Just curious, what kinda DSLR`S are these?.
My K100D has some also, I consider it to be normal. Just PTA to deal with.

Cheers. Mike.
10-26-2009, 07:17 PM   #6
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QuoteOriginally posted by -Joe- Quote
I take lots of pictures and doing single pictures one by one is not going to work.

I am sure gimp can do the same but would need a batch fix option.

I disagree about bad pixels being common.. I have 2 other cameras with zero stuck pixels.
I'm not familiar with GIMP, but with Photoshop, once you have identified the bad pixels, you can store the data, and batch process all your subsequent files. Its not necessary to work it out with individual photos.

Most camera manuals that I've read - including Nikons and Canons have disclaimers that a very small percentage , typically 0.001% of the pixels may not function, and that is considered normal and not a faulty sensor. That's about 60 pixels in a 6MP sensor.
The most I have seen is just a handful, less than 10, even if you pixel peep.
10-27-2009, 02:48 AM   #7
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I have a k100d that has hot pixels in long exposures, but no stuck or dead pixels in normal use, so it sounds like a fault if it is that obvious. Are you shooting in RAW mode? Presuming that if you are in Linux you are using Rawtherapee or similar, which does not do the Photoshop autofixing/smearing effect to hide noise. It is quite an analytical rather than cosmetic approach to image editing. Have you tried Fottox? I am a Linux dabbler but it seems to be an interesting package and might control the problem better.
10-27-2009, 07:50 AM   #8
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Joe,

I am a Linux (Ubuntu) user. My *istD has a few hot pixels too. There is a free batch solution but you have to run it in WINE. Download this program Pixel Fixer | Hot pixel removal utliity . You will have to shoot in RAW then run the pixelfixer before using a raw converter like RawTherapee. Its not a big deal, I always shoot in RAW anyway. Pixels come out great - new life for older cameras that don't automatically map out bad pixels. Enjoy your K100D - its a good camera.

10-27-2009, 08:14 PM   #9
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I did find a script for gimp called hot dot, but it only fixes 1 pixel at a time. I have not researched it yet to make it do multiple.

I did have a *ist ds for a while then bought a k110d which I gave to the gf when I got the k100d. (She bought me a tamron 18-200mm so thought I would be nice as well)

Only complaining because I just got it. Oh well.

Last edited by -Joe-; 10-27-2009 at 08:21 PM.
10-28-2009, 02:10 PM   #10
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Pentax suggests sending it in for remapping.. So if I do so, then I guess I will be without for a few weeks. Wonder what kind of turn around time they have.
10-28-2009, 02:21 PM   #11
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Joe,

did you try the method I gave you on the link above?
If that works, you'll only be without camera for less than 30 seconds.
10-28-2009, 03:49 PM   #12
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QuoteOriginally posted by HermanLee Quote
Joe,

did you try the method I gave you on the link above?
If that works, you'll only be without camera for less than 30 seconds.
No i did not try it, because that just raises the mirror for cleaning. It does not do anything else.

The k100d does not do any type of self cleaning.

-edit-

to satisfy the masses, I tried.. Still have all the same stuck pixels as I figured would happen.
10-29-2009, 07:57 AM   #13
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As I mention in my recent related thread I've been struggling to grasp bad pixel issues with my K100D as well and a year or so ago I was noticing bright pixels in my jpgs loaded into Lightroom and after a bit of testing and research I had concluded they were stuck or dead pixels. As I recall there were 3 - 5 of these visible on many of my handheld normal shutter speed shots.

At that time I tried a utility called something like flameout as a trial but it was fairly inexpensive, and it "mapped" these bad pixels by running some dark frame test images through it so it could learn the problem locations. But you had to run all of your jpgs through the program to let it do it's thing which I found to be awkward and an extra step that I didn't want to do.

Since I was using Lightroom, which seemed to automatically do the "mapping out" if I shot RAW, as the files were converted, I just decided to always shoot RAW with the K100D. It was unfortunate though because I actually really like the out of camera jpegs from that camera, and you get more shots per memory card too.

After reading your thread, Joe, I dug out the camera again and started playing around a bit, and even though that sensor cleaning/reset method suggested didn't make any sense since as you say it only raises the mirror, I did it anyways thinking what the hey.

Well then I downloaded and ran that deadpixel test utility and it was showing 0 dead pixels, but when I got to 1 second shutter it shot up to 60 hot pixels.

I wasn't very scientific about it, and I have no idea if 60+ hot pixels is fairly normal for a 1 second exposure, but *maybe* that reset method worked for me?
10-29-2009, 08:22 AM   #14
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QuoteOriginally posted by -Joe- Quote


I disagree about bad pixels being common.. I have 2 other cameras with zero stuck pixels.
All digital cameras have hot or stuck pixels. What you probably have is 2 other cameras that mask the hot pixels during image processing.
Most raw converters now mask out hot or stuck pixels.
10-29-2009, 11:45 AM   #15
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QuoteOriginally posted by Wheatfield Quote
All digital cameras have hot or stuck pixels. What you probably have is 2 other cameras that mask the hot pixels during image processing.
Most raw converters now mask out hot or stuck pixels.
I really do not believe a Fuji S5200 has that ability.
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