chunhua_wang Posted January 24, 2007 Share Posted January 24, 2007 I found out three dead pexils when i tested as ISO1000 35mins and F8. is it serious? i bought canon 30d for over 3months. is this serious to photography? it's commen or special case? need your advice, thanks a lot! Link to comment Share on other sites More sharing options...
ronaldo_r Posted January 24, 2007 Share Posted January 24, 2007 A big non-issue. How often do you keep your shutter open for 35 minutes at ISO 1000? Seriously? Link to comment Share on other sites More sharing options...
alex j loveridge Posted January 24, 2007 Share Posted January 24, 2007 Its normal, I have 3 on mine as well, Usually don't even notice them, and when i do, takes a few secods in photoshop to fix Link to comment Share on other sites More sharing options...
jo7hs2 Posted January 24, 2007 Share Posted January 24, 2007 It is very common. Considering how many pixels there actually are, 3 dead ones work out to such a low percentage that it is probably impossible to build every sensor perfect. There are quite a few zeroes behind that decimal. Something like 0.000000375%, but I don't pretend to be good at math. My 350d has two "hot pixels" that only show up on very long exposures, one red, one blue. They behave normally below about 10 seconds, but beyond that, they start shifting color darker and darker. They're not totally dead, they just misbehave. Link to comment Share on other sites More sharing options...
ci_p Posted January 24, 2007 Share Posted January 24, 2007 How can I keep my shutter open for 35 minutes? I will be doing this less than 41 times a day, for sure. Link to comment Share on other sites More sharing options...
frank_kimble Posted January 24, 2007 Share Posted January 24, 2007 I never had any dead, dying or hot pixels with my film camera. Link to comment Share on other sites More sharing options...
alec_myers Posted January 24, 2007 Share Posted January 24, 2007 >>I never had any dead, dying or hot pixels with my film camera. How do you know? Have you actually checked? :-) Link to comment Share on other sites More sharing options...
phule Posted January 24, 2007 Share Posted January 24, 2007 No Frank, but how many thumb-prints have you had on your slides or negs? Link to comment Share on other sites More sharing options...
chunhua_wang Posted January 24, 2007 Author Share Posted January 24, 2007 Sorry, not 35mins just 35seconds. yesterday i used one test soft and found 0 dead pexil but over 20 hot pexils as the result. but i felt the hot pexils are too obviously. Link to comment Share on other sites More sharing options...
carnagex_carnagex Posted January 24, 2007 Share Posted January 24, 2007 Dumb question do you have the auto noise reduction ON (not on AUTO, but ON). It is in your custom functions # 2, select 2 from the settings ( 0=off 1=Auto 2=ON). Use the ON setting when you know you will be using long exposures. (personally I keep auto on my 5D, which helps with dark scenes over 1 sec. exposures). Give it a shot and tell me if you notice a differance. As you can see in the picture what the differance between Noise Reduction OFF and ON looks like. (photo from dprevew.com) Link to comment Share on other sites More sharing options...
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