Problem with low light shooting

AntonioG · Feb 1, 2012

Hi! This is my first post in these forums. I've asked this question to a couple of photographers I know, some of them say it's just normal posterization but one of them told me it could be a problem called "banding", and that I should get my camera back to the shop to get a new one, because it might be a sensor problem. Take a look at these pics and decide yourselves; images are too large, so I give you the links.

http://img641.imageshack.us/img641/1935/dsc0103wf.jpg
http://img577.imageshack.us/img577/1500/dsc0102ik.jpg
http://img254.imageshack.us/img254/4974/dsc0101aq.jpg

is this normal? I tried to shoot in RAW (.NEF to be clear), but it's still the same. It would be nice if you could help me. Thanks!

MrSleepin · Feb 1, 2012

i think it might just be the texture of your wall.

hard to tell.

got any more examples?

AntonioG · Feb 1, 2012

Thanks for the reply! My wall doesn't have any texture, it's just plain white. I will upload more examples tomorrow!

Forkie · Feb 1, 2012

I genuinely see nothing wrong with these images. The only thing I can think of that you are talking about could be the mottling in the area where it changes from light to dark. But as MrSleepin said, it just looks like the texture of the wall.

Although your wall is painted plain white, the wall is not perfectly flat. It has human-rendered plaster underneath which has imperfections, pock-marks and uneven areas in it. This will cause the light from the bulb to have variations in coverage as it spreads away from the bulb, resulting in what appears to be an uneven gradient from light to dark.

I really see nothing wrong in these photos at all.

cnutco · Feb 1, 2012

Forkie said:
I genuinely see nothing wrong with these images. The only thing I can think of that you are talking about could be the mottling in the area where it changes from light to dark. But as MrSleepin said, it just looks like the texture of the wall.

Although your wall is painted plain white, the wall is not perfectly flat. It has human-rendered plaster underneath which has imperfections, pock-marks and uneven areas in it. This will cause the light from the bulb to have variations in coverage as it spreads away from the bulb, resulting in what appears to be an uneven gradient from light to dark.

I really see nothing wrong in these photos at all.

That sounded pretty dang good to me! Nice comment.

I donot really see anything wrong with them either. Do you have any other "regular" pictures that have these problems you speak of?

MReid · Feb 1, 2012

I can't see the photos...but sometimes you will get dark bands if you underexpose, expecially if there is some noise.

Joey_Ricard · Feb 1, 2012

That is not bad at all, even large.

KmH · Feb 1, 2012

Posterization and banding are the same thing. Both are seen in gradients when the bit depth of an image is reduced, which is what happens to a JPEG.

JPEG is an 8-bit depth only file type made from 12-bit depth or 14-bit depth capture files (Raw). 8-bits can only render 256 gradations of tone per color channel, Posterization and banding result becuae 256 gradations of tone cannot render all the tones in the gradient.

Your friend is likely repeating something read somewhere, but not understood.