Fill and Blacks in ACR

[cinnamate7]

I have watched the ACR tutorial twice now, and I'm still getting lot's of "a-ha!" moments. One thing in particular really intrigues me. In one example Jeff mentions pushing the Fill values and then pushing the Blacks. He talks about the sensitivity of the Blacks slider being dependent on the Fill level (?!) This resulted in an apparent increase in shadow detail and to my eyes, an increase in color saturation in the shadows. I have begun using this technique as part of my basic workflow, but it has become quickly obvious through my fumbling and some fairly erratic results that I still don't really understand what I'm doing.  

 My rudimentary understanding is that the Fill slider controls the luminance values of pixels of low tonality, and Blacks sets the black clip point. Can someone give me a more in depth explanation of what these controls really do, and the "proper" way to integrate them into a RAW workflow?

Thanks,

Robert

[Ben Rubinstein]

I have watched the ACR tutorial twice now, and I'm still getting lot's of "a-ha!" moments. One thing in particular really intrigues me. In one example Jeff mentions pushing the Fill values and then pushing the Blacks. He talks about the sensitivity of the Blacks slider being dependent on the Fill level (?!) This resulted in an apparent increase in shadow detail and to my eyes, an increase in color saturation in the shadows. I have begun using this technique as part of my basic workflow, but it has become quickly obvious through my fumbling and some fairly erratic results that I still don't really understand what I'm doing.  

 My rudimentary understanding is that the Fill slider controls the luminance values of pixels of low tonality, and Blacks sets the black clip point. Can someone give me a more in depth explanation of what these controls really do, and the "proper" way to integrate them into a RAW workflow?

Thanks,

Robert

I don't know anything about the technical side but from experience fill brightens the darks and blacks controls the shadows (using the terms from the parametric curve tool). That's what I see, no idea if that is what is meant to happen.

[cinnamate7]

I don't know anything about the technical side but from experience fill brightens the darks and blacks controls the shadows (using the terms from the parametric curve tool). That's what I see, no idea if that is what is meant to happen.

 I'm wondering if this is essentially a fine curves adjustment, or something that operates on different principles altogether.

[NikoJorj]

My rudimentary understanding is that the Fill slider controls the luminance values of pixels of low tonality, and Blacks sets the black clip point. Can someone give me a more in depth explanation of what these controls really do, and the "proper" way to integrate them into a RAW workflow?

I'd say (guesstimation inside) :
- the Fill light sets a mask on the darker parts of the image, and then lightens what's inside this mask,
- the Blacks steepens the very bottom of the tone curve, allowing to set the black level without moving the midtones. As in Photoshop, that steeper curve boosts saturation as well, and that suits me generally well in this case (after a Fill light boost).

The first operation offsets the black level to a higher value, making the darkest parts of the image ("shadows") appear weak, and decreases a bit the contrast in the "darks" - that's what the subsequent Blacks boost is made for.

[cinnamate7]

I'd say (guesstimation inside) :
- the Fill light sets a mask on the darker parts of the image, and then lightens what's inside this mask,
- the Blacks steepens the very bottom of the tone curve, allowing to set the black level without moving the midtones. As in Photoshop, that steeper curve boosts saturation as well, and that suits me generally well in this case (after a Fill light boost).

The first operation offsets the black level to a higher value, making the darkest parts of the image ("shadows") appear weak, and decreases a bit the contrast in the "darks" - that's what the subsequent Blacks boost is made for.

OK, this explanation is beginning to shed some light for me. If I understand tonal curves correctly, the only way to steepen the bottom of the curve without flattening midtones (inverted-S), would be to shift the left-hand corner point to the right, which resets the black point. The masking concept for the fill slider is interesting, and I have to wonder if it would be useful to include user control over masking parameters (or is that already possible, and I don't realize it?).

[NikoJorj]

If I understand tonal curves correctly, the only way to steepen the bottom of the curve without flattening midtones (inverted-S), would be to shift the left-hand corner point to the right, which resets the black point.

That's also what I understand - it steepens "a certain amount" of the shadows/darks.

The masking concept for the fill slider is interesting, and I have to wonder if it would be useful to include user control over masking parameters (or is that already possible, and I don't realize it?).

I don't know of any - I don't know either if that would be tremendously useful, that said.
The main problem with Fill Light is halos that appear in a few cases - the kind of things that calls for for a hand retouch of the mask, I'd say.