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Microstock Photography Forum - General => Photo Critique => Topic started by: Allen on February 04, 2009, 12:32

Title: Is this dust, or lighting problems?
Post by: Allen on February 04, 2009, 12:32

Hey guys/gals ;),

Please take a look at this photo and tell me what's up with the lightened spot on the shirt.  Is it dust, a reflection or what?  I haven't noticed it anywhere except in studio, but I may just not be observant.

Thanks for looking, and if it isn't dust, any idea how I can change my light setup so it doesn't do this?

Title: Re: Is this dust, or lighting problems?
Post by: Artmyth on February 04, 2009, 14:38

Are you referring to the grey streaks in the left corner?

edit - Oh the shirt - duhh pays to read doesnt it.

Id say theres a bit of luminance noise in there especially at the top of the shirt - along with a few flakes of dust
you could probably burn it out.



Ive seldom seen sensor dust in such a linear shape before - my guess is one of two things
1. did you dodge the background with the dodge tool? - possibly you just missed a spot
2 is there a wrinkle on your background causing a small shadow

It appears you may be lighting your background with separate lights is something obstructing one of them causing a shadow?

take a copy of the original image and in PS slowly adjust the levels so the image darkens sensor dust will begin to appear if you have any

alternative photograph a white background - or the sky - make sure the camera is focused place a square of paper to manually focus on remove the paper and take an image - then process it and adjust levels you can find you spots of sensor dust - which will always appear in the same place in the image

Title: Re: Is this dust, or lighting problems?
Post by: vikavalter on February 05, 2009, 05:35

it's a lens flare move you lights bit farther or to the sides so they don't peep into the lense and bounce around it, also remember reflectors, they can do that too

Title: Re: Is this dust, or lighting problems?
Post by: leaf on February 05, 2009, 05:43

The only way dust shows up is small black spots on the sensor that easiest seen when using a small aperature (but number... like 16 or higher).  The spots are very small, often you have to view the image at 100% to see them.  So no the light area is not dust.

Title: Re: Is this dust, or lighting problems?
Post by: icefront on February 08, 2009, 16:22

Quote from: vikavalter on February 05, 2009, 05:35

it's a lens flare move you lights bit farther or to the sides so they don't peep into the lense and bounce around it, also remember reflectors, they can do that too

I think too, it's a lens flare, I used to cover my side flashes with cardboard but I noticed that reflected light can cause lens flare too. This kind of lens flare. The solution may be lowering or raising the light sources so the bounced light on the background doesn't hit directly the lens. You may also try to use a longer and bigger lens hood, a matte (not shiny or semi-shiny) background.

Title: Re: Is this dust, or lighting problems?
Post by: e-person on February 10, 2009, 10:34

Lens flare. If you are using film lenses on a digital camera, it could even be sensor reflection against rear element, I think. In any case, it is still flare, though.