Night photography (layers of black)

Hi people,


I have recently been shooting more night photograps of a local bridge. Thus far I have some pretty good images I would like to print. HOWEVER, is there a way to get rid of "layers" that occur when editing the image? I could provide an image here but compressing it will only make it look horrific. I'm not talking about adding layers in photoshop I'm talking about the layers of black to grey whenever brightening the image.

Here is a crappy web image of it but you can see the layers I'm talking about.

Maybe this one is better?

Try to describe the problem in different terms as layers of black isnt a technical term nor does it describe a problem. Be as descriptive as possible.

I think tristan is referring to posterization. The lack of a smooth gradient from gray to black.

If that is the case, tristan, it may be your monitor that is causing it. I only have a tablet to view your image now, but it looks fine to me.

I can't see it very well in what you posted but I assume it is what we normally call "banding" or "posterization".

This can have several causes:

First, it can happen on your monitor. Most monitors only have 256 tonal values in a B&W image from black to white. That's not many when you are viewing a smooth gradient on a large monitor. Monitor quality and how well it has been calibrated and profiled can also impact visibility of monitor banding. The good news is if it's monitor banding, the actual image may be just fine. Others may see it OK and if you print, it may not be visible at all.

Second, this can happen in the actual image if you are pulling up the brightness of shadows. In the raw file, there are much fewer tonal levels recorded for dark tones than for light ones. You can read a little about that here:
http://www.luminous-landscape.com/tutorial​s/expose-right.shtml

ETTR won't help you here, since you are already clipping highlights, but here are some things you can try to do to reduce the banding if it is occurring in the actual image:

- Make sure you are working in 16-bits until the last possible moment. Saving a final 8-bit Jpeg is fine but you want to be in 16-bits up until then.

- You can try to add a very little bit of fine, monochromatic noise to the image. As counter-intuitive as that sounds it often works since it "breaks up" the solid bands and makes them harder to notice. Some people try to blur the bands but this usually makes them worse.

Hope that helps.

I don't know the technical term hence the poor description... When lightening the photo you see layers stacked on top of one another going from lighter shade to lighter shade. Here is an attached photo of an exaggerated example. Thanks.

Did you process this in 8-bits at any point ? That's normally what leads to this problem. Regardless, if the posterization is in the image and can't be rectified by altering your process (particularly if you're messing with curves), adding a bit of noise can help.

Like others have said, try adding noise. Also, I believe files react better to adjusting exposure in color and then converting to B&W, rather than starting with B&W and then boosting shadows. Maybe try doing things this way around.

Can you describe your workflow to produce these images?

kirk