5D II Dual ISO & Hot pixels

Started by stefanoviola, September 04, 2014, 01:27:12 PM

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stefanoviola

Hi there, my first post in ML forum!  ;)
I've got a very quick question: I'm doing some tests with DUAL ISO on my 5D Mark II and it is working very good except for the fact that for exposures longer than 5 sec I got too much hot pixels (100+ among green, blue, even black). Is it normal? Is there something I can do for that?
I will post pictures as soon as possible.

stefanoviola


a1ex

You could try cr2hdr --really-bad-pix. If that doesn't solve the issue, upload some CR2 files.

mothaibaphoto

Faced with this issue on 1 sec exposure images shot with FRSP. My findings:
1. It depend on base ISO. Can't get hot pixels on +3EV(100 - 800) and easy reproduce a lot on -3EV(800-100).
2. Probably depend on sensor temp - I have ISO 800 image with much more hot pixels than ISO 1000.
3. Hot pixels from different shots in one day generally overlaps. But not any black frame i shot now (2 month later) trying to make black frame subtraction.
4. --really-bad-pix completely ruines image.
5. Photoshop Dust&Scratches filter even worse.
Side notes:
1. cr2hdr-20bit keeps metadata just with CR2 on input. DNG output from mlv_dump it overwrites just before it tries to copy metadata from the same file.
2. cr2hdr-20bit constantly reports about MK III files, while works with MK II files.

This problem was discussed in this thread too:
http://www.magiclantern.fm/forum/index.php?topic=14127

Some files:
https://www.dropbox.com/s/fsr1roft93w136l/000000_ISO1000.DNG?dl=0
https://www.dropbox.com/s/ugcuh44xsan4nxf/000000_ISO800.DNG?dl=0
https://www.dropbox.com/s/nwtb0npwh61nv5b/BlackFrame.DNG?dl=0

a1ex

Can you also upload the original CR2 files?

mothaibaphoto

I can upload mlv_dump output DNG files. Ok, bit later.

a1ex

Right, forgot the original is also a DNG.

Metadata handling is indeed an issue on Windows (where the filesystem is not case-sensitive). I keep forgetting about this one, because on Linux the input files are lower-case .dng, and output files are upper-case .DNG, so there are no problems about overwriting files...