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01-19-2009, 06:41 AM   #1
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hot pixels

Hello

I have bought a new camera pentax k20d. A this is my first digital camera, I need your help to assess the quality issue (I have no experience with DSLR, so I need your help).
I made some pictures with the lense closed (black background) to check hot pixels and was shocked to see two very bright ones with exposure of 3 seconds. Please see these files to assess how bad the matrix is:

3 sec
Dump.Ru - 3sec.jpg

1/3 sec
Dump.Ru - 0.3sec.jpg

When I use Levels in Photoshop to increase the contrast on these images drastically, I cann see many more colour spots.

So, should I go to the retailer to get a new camera, or do I risk to get an even worse sample of the camera?

Please respond with advice.

01-19-2009, 06:55 AM   #2
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Nothing to worry about.
What happens if you use the in-camera pixel mapping (available in the menu)?
01-19-2009, 08:24 AM   #3
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cobra: run the "pixel mapping" item from the maintenance menu.
Mine came out of the box with even more hot pixels than that (at least 10) and they had weird halos around them. The pixel mapping fixed them all. I was pretty surprised it did and had expected to return the camera for an exchange.
Why Pentax shipped it w/ all those hotpixels unmapped, I have no clue :-P
01-20-2009, 05:01 AM   #4
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Normal

What you have seen are all normal. The K20D is probably the most "hot" DSLR ever made on Earth. Do a search on web and you will find all those user reports and findings.

QuoteOriginally posted by cobra333 Quote
Hello

I have bought a new camera pentax k20d. A this is my first digital camera, I need your help to assess the quality issue (I have no experience with DSLR, so I need your help).
I made some pictures with the lense closed (black background) to check hot pixels and was shocked to see two very bright ones with exposure of 3 seconds. Please see these files to assess how bad the matrix is:

3 sec
Dump.Ru - 3sec.jpg

1/3 sec
Dump.Ru - 0.3sec.jpg

When I use Levels in Photoshop to increase the contrast on these images drastically, I cann see many more colour spots.

So, should I go to the retailer to get a new camera, or do I risk to get an even worse sample of the camera?

Please respond with advice.


01-20-2009, 07:21 AM   #5
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QuoteOriginally posted by RiceHigh Quote
What you have seen are all normal. The K20D is probably the most "hot" DSLR ever made on Earth.
I used to agree with you based on DPR's findings that the firmware fix didn't get rid of all the hotpixels because they move around unlike other sensors.

However, after running the "map pixel" thing, I haven't seen any, and I tested it quite a bit. If you want to know how OCD I am about testing this stuff, look at the Tamron 28-75 tests I did looking for a good copy of it

I tested the K20D on a tripod at ISO100-1600, did handheld tests, underexposed, overexposed, did 30sec exposure tests, and then pixel peeped the images. Before running the map pixel thing, I saw the hotpixels move around, change shape, get worse w/ higher ISO, etc. so I knew what I was looking for.
Hope that makes it into your blog...
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