How to recover an over-exposed black...?

[Dinarius]

I shot a room with charcoal black walls.

I mistakenly overexposed the walls to a dark grey.

Now, if I try darkening the image (to return the walls to their charcoal black) using either a minus Exposure adjustment, or a Levels shadow adjustment, the walls just fall to a muddy mess and not the black I was hoping for.

Failing a re-shoot, is there some other adjustment I should be trying?

Thanks.

D.

[Telecaster]

If your software gives you a curves tool, or something like a set of blacks/darks/lights/whites parameters to adjust, you should be able to crush the walls to a black as black as you want.

-Dave-

[Dinarius]

Thanks. I'm using Capture One.

D.

[E.J. Peiker]

Using the Levels tool, simply grab the small black arrow like, or home-plate like black slider right above the 0 and move it to the right until it meets the histogram.  In the attached example, I've dragged it from 0 to 15 to meet the bottom of the histogram.  Of course if you don't mind blocking things up to get more black, you can drag it into the histogram.  In the attached example I have remapped a value of 15 in the photo to 0 (see the diagonal line that says 15 on bottom and 0 on top)

[Dinarius]

Using the Levels tool, simply grab the small black arrow like, or home-plate like black slider right above the 0 and move it to the right until it meets the histogram.  In the attached example, I've dragged it from 0 to 15 to meet the bottom of the histogram.  Of course if you don't mind blocking things up to get more black, you can drag it into the histogram.  In the attached example I have remapped a value of 15 in the photo to 0 (see the diagonal line that says 15 on bottom and 0 on top)

Thanks for the reply.

As I wrote in my original post, a Levels adjustment isn't working.

I'm not in my office now, so can't try the Curves suggestion made above. But, will report back.

D.

[Peano]

It would help if you posted the image.

[Dinarius]

Ok.

Here is one of the works shot against white and looking as it should.https://drive.google.com/open?id=0BzGYFRmTYGTJUHkwRkVDd3ZwbXM

And here also is the overexposed one shot against black.https://drive.google.com/open?id=0BzGYFRmTYGTJWGx0c0J2UWlndTQ

Thanks.

D.

[Peano]

I used selective color adjustment layers to get this result. In the Blacks panel,  increased blacks. I'm seeing lots of blocky jpeg artifacts. Not sure whether that just because it's a low-quality image, or something else. Also, I'm not sure how black you want to make the blacks. If you go to far, the "subject" (whatever that thing is in the middle) won't be recognizable. Like a black cat at midnight. With a light subject, one fix would be to mask out the subject and darken the background independently, maybe even by painting it in.

[fdisilvestro]

Hi,

Those artifacts look like posterization to me. Did you shot raw? What profile/curve are you using? Also, remove any noise reduction, even add noise if you can.

Otherwise try this in photoshop:

Convert to 32 bit per channel - Adjust exposure (this is performed in floating point AFAIK) or
Convert to 16 bit - Add noise (1% gaussian) and the adjust exposure.

[Peano]

Hi,

Those artifacts look like posterization to me. Did you shot raw?

The posted jpeg is only 1050 px on the long side. You would have to start with the raw file to get anything acceptable out of this.

[Dinarius]

In the end I selected the work in the middle of the image in Photoshop using Quick Selection Tool and worked on that part of the image directly.

Worked very well.

I then tweaked the overall image.

I was happy with what I ended up with.

Thanks for the replies.

D.

[bjanes]

I shot a room with charcoal black walls.

I mistakenly overexposed the walls to a dark grey.

Now, if I try darkening the image (to return the walls to their charcoal black) using either a minus Exposure adjustment, or a Levels shadow adjustment, the walls just fall to a muddy mess and not the black I was hoping for.

Failing a re-shoot, is there some other adjustment I should be trying?

Thanks.

D.

If you are working with a raw file and did not clip any highlights, darkening the image with the exposure control should have the same effect as reshooting with less exposure. That is the basis for ETTR.

Bill

[Dinarius]

If you are working with a raw file and did not clip any highlights, darkening the image with the exposure control should have the same effect as reshooting with less exposure. That is the basis for ETTR.

Bill

Bill,

Thanks for the reply. That's what I would have thought, but it wasn't what happened.

However, there were no highlights blow in the image.

Maybe it's possible to overexpose blacks to a grey you can't recover from? I don't know.

Anyway, as I say, Quick Selection tool sorted it.

D.

[bjanes]

Bill,

Thanks for the reply. That's what I would have thought, but it wasn't what happened.

However, there were no highlights blow in the image.

Maybe it's possible to overexpose blacks to a grey you can't recover from? I don't know.

Anyway, as I say, Quick Selection tool sorted it.

D.

I am glad that you were able to resolve the problem, but have you considered that reshooting at a lower exposure might also not get the result that you want? That is what I would expect.

Bill