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Using Magic Lantern => General Help Q&A => Topic started by: stefanoviola on September 04, 2014, 01:27:12 PM

Title: 5D II Dual ISO & Hot pixels
Post by: stefanoviola on September 04, 2014, 01:27:12 PM
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.
Title: Re: 5D II Dual ISO & Hot pixels
Post by: stefanoviola on September 04, 2014, 01:43:17 PM
A couple of crops:


(https://www.magiclantern.fm/forum/proxy.php?request=http%3A%2F%2Fwww.stefanoviola.net%2Fvarie2%2Fpixels1.jpg&hash=afb98851d1122265ba399a6fa2e12760)

(https://www.magiclantern.fm/forum/proxy.php?request=http%3A%2F%2Fwww.stefanoviola.net%2Fvarie2%2Fpixels2.jpg&hash=314763ab483bd2a887b4b5c23d1c8146)
Title: Re: 5D II Dual ISO & Hot pixels
Post by: a1ex on September 04, 2014, 02:12:35 PM
You could try cr2hdr --really-bad-pix. If that doesn't solve the issue, upload some CR2 files.
Title: Re: 5D II Dual ISO & Hot pixels
Post by: mothaibaphoto on February 17, 2015, 11:41:39 AM
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
Title: Re: 5D II Dual ISO & Hot pixels
Post by: a1ex on February 17, 2015, 11:49:47 AM
Can you also upload the original CR2 files?
Title: Re: 5D II Dual ISO & Hot pixels
Post by: mothaibaphoto on February 17, 2015, 12:05:10 PM
I can upload mlv_dump output DNG files. Ok, bit later.
Title: Re: 5D II Dual ISO & Hot pixels
Post by: a1ex on February 17, 2015, 12:22:16 PM
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...
Title: Re: 5D II Dual ISO & Hot pixels
Post by: mothaibaphoto on February 17, 2015, 05:15:24 PM
1. Unprocessed first frames from two sequences, mentioned before:
https://www.dropbox.com/s/6cpacazk7krtfe0/000000_ISO800_Orig.dng?dl=0
https://www.dropbox.com/s/fpbhqloeys49dxb/000000_ISO1000_Orig.dng?dl=0

2. Some files from these sequences cr2hdr-20bit keep unchanged with message "Interlacing method not supported". This one:

https://www.dropbox.com/s/9bzpfd14g2e1nae/000026_cr2hdr-20bit_dont_process.dng?dl=0
3. And most interesting thing: from some point both sequences after some W/B or brightness fluctuation contains just clear frames without hot pixels. Here are transformation points:
https://www.dropbox.com/s/jcdgbuubv1gc0bi/000039_Last_With_Hot_Pix.dng?dl=0
https://www.dropbox.com/s/9d537w580sjyl1v/000040%20_No_More_Hot_Pix.dng?dl=0
https://www.dropbox.com/s/f02dy6irvolbw6g/000069_Last_With_Hot_Pix.dng?dl=0
https://www.dropbox.com/s/pdnu8b5a9tqcvwt/000070_No_More_Hot_Pix.dng?dl=0