How to show histogram only for masked adjustment layer

[peterpanter]

Hi,

part of my workflow for black and white printing is making lots of level adjustment layers. I do this to ensure that I have control of the tonal range of all parts of the image. I'll give a simple example. In the images attached you can see that I made an adjustment layer with a mask so that only the area below the sky is affected by the levels adjustment. This works fine in Affinity Photo but what I'm missing here is a histogram which only shows data for the adjustment layer that I'm working on. Because only then do I have the information about the tonal range in the area I'm manipulating. 

So, how do I get the histogram in Affinity Photo to show me this? Is it even possible?

As you can see below in Photoshop CC this is no problem. The left histogram shows the entire image, the right histogram displays only the information for the layer so that the level adjustment triangles can be moved exactly.

The same picture in Affinity Photo. Both histograms are basically the same even though the adjustment layer is selected. I can do a levels adjustment but really only based on what I see on my monitor.

 

I tried to select the "Layer" box in the left histogram, hoping this would then make the histogram display only information for the selected layer. But, alas, everything just goes black. Selecting the "Marquee" box (whatever that stands for) didn't make any difference.

 

 

So, can anybody help me out? Any tip, hint, help or suggestion is greatly appreciated.

Thanks
Frank

[Dan C]

Hi peterpanter,

Welcome to the forums

My sincerest apologies for the delayed response, unfortunately Affinity doesn't have directly comparable Histogram options to PS currently, however there is one option that may be helpful to you.

The Marquee option in the Histogram Studio will change the active Histogram from the entire image to the area you have selected currently. This can be any 'marching ants' selection, so you can use any of the Marquee selection tools, the Freehand Selection Tool or the Selection brush for this. Alternatively, if you already have your masked adjustment layers in your document, you can hold CTRL(Win) or CMD(Mac) and left click on the Adjustments thumbnail, this will automatically create a pixel selection for the area the adjustment affects.

Now, with this pixel selection active, you can tick the Marquee option in the histogram and this will adjust the histogram to show only the area selected.

I appreciate this does not function in exactly the same way that it does in PS, however this is the current implementation in AP. I hope this helps!

[peterpanter]

Dan C,

thank you for your answer, I really appreciate it. Unfortunately, the marquee option is only a kinda-works-but-not-really workaround. I hope AP will gain this capability in the future. For me it's really the only reason I still pay for a PS subscription.

Anyway, thanks for pointing out the CMD-left click for selecting the unmasked adjustment layer area. This will come in handy in another context.

Thanks

[Lem3]

I have the same need:

1. Make a selection
2. Create an adjustment layer (usually Levels)
3. Adjust RGB sliders based on the histogram of the selected area showing in the Levels panel

A very quick and effective tool in PS.

[Beatriz Castillo]

+1

[Lem3]

On 10/29/2019 at 6:22 AM, Dan C said:

Alternatively, if you already have your masked adjustment layers in your document, you can hold CTRL(Win) or CMD(Mac) and left click on the Adjustments thumbnail, this will automatically create a pixel selection for the area the adjustment affects.

Now, with this pixel selection active, you can tick the Marquee option in the histogram and this will adjust the histogram to show only the area selected.

I appreciate this does not function in exactly the same way that it does in PS, however this is the current implementation in AP. I hope this helps!

This does not work in 1.9.2.1035.  The histogram in the Studio remains the same when I check Marquee.

[NotMyFault]

21 hours ago, Lem3 said:

This does not work in 1.9.2.1035.  The histogram in the Studio remains the same when I check Marquee.

It works well in my case, see video attached. 1.9.2.1035. Please ensure that you have the "hand" tool active. In some cases, the histogram stops getting updated, and i could not find out the exact cause. Switching to hand tool "activated" the histogram update in my case.

Can you provide a video of your workflow?

2021-04-06_18-15-46.mkv

[Dan C]

18 minutes ago, NotMyFault said:

In some cases, the histogram stops getting updated, and i could not find out the exact cause.

You may need to select the 'Generate Fine' option in the Histogram to update this, this is displayed as a yellow triangle on the Histogram and selecting this option should ensure the Histogram is fully updated for your current image/selection

@Lem3 This function is also still working for me as expected currently, please do let me know if you have any further issues here!

[NotMyFault]

6 minutes ago, Dan C said:

You may need to select the 'Generate Fine' option in the Histogram to update this, this is displayed as a yellow triangle on the Histogram and selecting this option should ensure the Histogram is fully updated for your current image/selection

@Lem3 This function is also still working for me as expected currently, please do let me know if you have any further issues here!

Hi @Dan C

I'm aware of the "generate Fine" symbol. Occasionally the histogram is totally frozen, including the yellow sign. Even hitting it with a hammer shows no effect at all besides potential damage to the monitor (or breaking the mouse button or even the table below the mouse)

[Lem3]

What works:

1. Make a selection
2. Create an adjustment layer, e.g., Levels
3. Clicking Marquee causes the histogram to change, reflecting the selection area.  True even with the yellow triangle showing and the selection brush tool selected.

What doesn't work:

1. Make a selection
2. Create an adjustment layer, e.g., Levels
3. Ctrl-D to unselect, do something else with the image
4. Crtl-click on the adjustment layer mask to re-select
5. Clicking Marquee has no effect on the histogram, with or without the triangle, hand tool selected or not.