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Title: Red grains in photo when not using Flash Post by: Crazy zou on April 10, 2011, 03:51:18 AM Hi, I am still not that good when it comes to indoor lighting, and sometimes I just don't want to use the flash. I usually shoot out doors so I don't have this problem :))
So, why do red grains appear in the dark areas of the photo ? I also believe most probably it would be in the area that is out of focus. How can I fix this problem? Title: Re: Red grains in photo when not using Flash Post by: Johnf on April 10, 2011, 04:32:29 AM Is it just digital noise. If you are shooting indoor without a flash, are you drivig your ISO very high? This will generate more noise.
John F Title: Re: Red grains in photo when not using Flash Post by: Bob Atkins on April 10, 2011, 01:43:50 PM It's most lilkely chroma noise which shows up at high ISO settings. It could also be hot ot stuck pixels if you are using long exposures (several seconds).
Most EOS cameras have a high ISO noise reduction setting in the custom functions menu which can bE set to "strong" to minimize noise (at the expense of a slight reduction in sharpness) You can also shoot RAW and adjust the noise reduction setting in the software. Title: Re: Red grains in photo when not using Flash Post by: Crazy zou on April 17, 2011, 11:41:45 AM I'm using Rebel Xti and i don't think am using high ISO...well sometimes ...or most of the time the subject is in focus and sharp however if the surrounding area was a dark one..like the hair for example....or shadow...or whatever...there are a lot of red grains....but I guess I'll try RAW and see the difference....Thank you.
Title: Re: Red grains in photo when not using Flash Post by: KeithB on April 18, 2011, 07:46:27 AM I'm using Rebel Xti and i don't think am using high ISO...well sometimes ...or most of the time the subject is in focus and sharp however if the surrounding area was a dark one..like the hair for example....or shadow...or whatever...there are a lot of red grains....but I guess I'll try RAW and see the difference....Thank you. Look at the ISO data on the shots with a lot of "red grains" and those without and tell us the ISO. You can also do an experiment, get a stuffed animal, or other willing subject 8^), and put the camera on a tripod in "Ap" (Aperture Priority) mode. (I assume you are not using flash). Set an Aperture of f/8 - or whatever your favorite Aperture is, and take at series of shots at various ISO's and evaluate the images. |