Levels adjustment not working on my layer

[lottebrockbank]

Hello,

I'm having an issue trying to adjust the levels on this layer in affinity photo. The layer is a scan of a charcoal drawing that I have removed the background from using the 'select sample colour' tool to make the white areas transparent and copy and pasting the remaining dark areas into their own layer. Now that I have this layer however, I can't adjust it's levels. I can open the levels box but nothing happens when I move the dials. 

I also cannot paint onto it in black using protect alpha, only white. I can paint on top of it without protect alpha in any colour, but not with protect alpha on. 

I have rasterised the layer.

Can you help?

[carl123]

Can you upload that document to the forum?

[NotMyFault]

The issue is caused by making the background transparent, and having black as color for the opaque pixels.

so all color values within the canvas are pure black, and only alpha differs per pixel.

levels adjustment does not impact alpha (when using master).

Use the channels panel to see the difference.

Only if you add a rectangle (or fill layer) in white as bottom layer, colors of pixel will start to differ.

you may use „transparent canvas“. Otherwise Affinity tricks you: the background is shown white, but the color values (info panel or channels panel) are actually all zero (unless you export to a bitmap format and flatten / matte the transparency).

 

 

[NotMyFault]

3 hours ago, lottebrockbank said:

I also cannot paint onto it in black using protect alpha, only white.

As you use protect alpha, you cannot paint on background pixels. Those are already black, but you can make them white (and black again, unless you changed the brush blend mode from normal).

[NotMyFault]

Hi @lottebrockbank

This is your third post covering more or less the same issue.

We know you have recently switched from PS and Affinity is new and unfamiliar for you. But you never explained to us what you actually try to achieve. Please provide the full picture, otherwise we might give bad advise using the small information crumbles from you.

you have charcoal drawings, scanned, and try to change colors. Do you want to change the color globally, making e.g. all black pixel red or green? Or use multiple colors for different parts?

or do you want to color the inside between the black lines?

I

[lottebrockbank]

Hi @NotMyFault, thank you for your help.

Putting a white background pixel layer has helped so thank you for that. I think I don't understand why that is - your post suggests that when I make the background transparent, does that then make whatever opaque part of that image become the background? And that would be why black doesn't work in alpha protect mode? This is the part I don't understand: what happens when I make the background transparent. I'm not sure what you mean about colour values either, it's not a term I'm familiar with but I'd like to learn. 

In answer to your last question about what I want to achieve, I'm an illustrator and a lot of the time I want to digitally colour a scanned drawing. When it's a pencil drawing I find that simply changing the levels and using the selection tool is enough to get me a layer of only drawn line to colour beneath, sometimes I then use alpha protect to change the colour of that line using paint.

What I'm trying to do at the moment is retain the texture of charcoal and still colour beneath it, which I can't do by simply changing levels and deleting white areas using the selection tool as it's too clunky and I end up with big patches of grey. This current method of the colour selection tool was much more subtle and gave the desired effect of keeping all the smudges and grainy areas. A friend has also recommended I use a mixture of channels and masks, but as they use photoshop they couldn't help me work it out. I'd love to hear a good method if you have one. 

Thanks again for your help

Lotte

[lottebrockbank]

Hi again, I'm afraid it hasn't actually meant I can change levels, once I merge the changes are gone! How can I darken the charcoal layer now?

[NotMyFault]

Can you share one of your older works, so we can see the original scan, and the result after all your edits?
so please upload those 2 files. If possible use PNG or TIFF format. When using jpg, Please place both files into a .afphoto file and upload this file.

[NotMyFault]

1 hour ago, lottebrockbank said:

What I'm trying to do at the moment is retain the texture of charcoal and still colour beneath it

So you want to use the color as background?
Simply add a pixel layer below the charcoal, and paint on that layer.

[lottebrockbank]

4 minutes ago, NotMyFault said:

So you want to use the color as background?
Simply add a pixel layer below the charcoal, and paint on that layer.

Yes that's what Ive been doing- as you'll see in the file. The problem now is that I can't darken the original scan, or paint on it using protect alpha. I want to be able to continue to edit the scan layer as well as paint underneath it.

[lottebrockbank]

[thomaso]

1 hour ago, lottebrockbank said:

How can I darken the charcoal layer now?

• To visually hide the paper white of the scan layer it may be sufficient to adjust its Blend Range Curve accordingly (without the need to delete white in the scan). Then the Level adjustment can darken the grays in the scan.

• If you don't want to paint directly on the scanned layer, you may work instead to set its blend mode to "Multiply" to hide the white on colours painted below.

• For painting behind the scan you can alt-/ or cmd-click (win/mac) on empty areas of the scan, then switch to a layer below for painting.

For colourizing the charcoal strokes of the scan there are several methods. One would create a pixel selection from the black by alt-/cmd-Click (win/mac) on its layer thumbnail to achieve a pixel selection of the black, and then, with the selection active, paint on a layer above for instance.

18 minutes ago, lottebrockbank said:

paint on it using protect alpha. I want to be able to continue to edit the scan layer as well as paint underneath it.

Unfortunately, when painting on the scan layer directly, you can only use "Protect Alpha" if its paper white has been actually removed/deleted and thus alpha created for the scan. Otherwise, this brush option has no impact:

[lottebrockbank]

Hi Tomaso, thanks so much for your very detailed help! 

The problem I have with colouring under blend mode is that it has a slightly patchy effect - as you can see in the screenshots I've attached here. 

What I want to achieve is retaining all the subtle texture of the charcoal without any patchiness, like when I use the colour selection tool for white and deleting that selection, but then be able to also darken sections of the charcoal in the drawing, without compromising the texture.

Is this possible?

 

 

[lottebrockbank]

(the top image is in blend mode, the bottom is colour selection tool)

[thomaso]

1 hour ago, lottebrockbank said:

(the top image is in blend mode, the bottom is colour selection tool)

Which layer is set to which blend mode? And what does "image … is colour selection tool" mean?

I am afraid I don't understand your description. If the scan layer is set to blend mode "Multiply" its white pixels won't be visible on any colour ≠ white and its gray + black pixels will get multiplied with any colour below.

It is also unclear to me whether you

a.) want to paint directly on the charcoal stroke, to make it appear with a colour other than gray/black and/or to draw new strokes on this layer?
or if you
b.) want to paint colour only behind the charcoal scan?

Depending on the goals a./b. different workflows may be required.

If you make screenshots it may be helpful to increase the Layers panel height to show all layers (e.g. close the Colours Panel). If you refer to a specific layer it may help to mention its name or to have it selected with the Move Tool for the screenshot and thus make it highlighted in the Layers panel and display its bounding/selection box.

[lottebrockbank]

2 hours ago, thomaso said:

Which layer is set to which blend mode? And what does "image … is colour selection tool" mean?

This is when the charcoal scan is set to the blend mode you suggested, and blend mode is multiply: 

But when I colour behind this, it seems to pick up some unwanted texture and lighten the colour I choose, like this:

When what I would like it to look like is this:

This is the version where I used the colour selection tool to remove white, and painted underneath

However, using this tool then means I cannot edit the charcoal layer, as changing levels doesn't work with it's transparent background. 

2 hours ago, thomaso said:

It is also unclear to me whether you

a.) want to paint directly on the charcoal stroke, to make it appear with a colour other than gray/black and/or to draw new strokes on this layer?
or if you
b.) want to paint colour only behind the charcoal scan?

Depending on the goals a./b. different workflows may be required.

 

I want to be able to paint behind the charcoal scan without it being patchy, and be able to darken the charcoal layer (as I would using levels). It would be useful to be able to paint directly onto it as well, though I don't need to do that for this particular image at the moment.

As you can see here, her head and feet are now lighter than the rest of the image, so I want to be able to select parts to darken.

[lottebrockbank]

Apologies- I made a mistake, the blend mode wasn't in Multiply - that has made a difference

[thomaso]

1 hour ago, lottebrockbank said:

I want to be able to paint behind the charcoal scan without it being patchy, and be able to darken the charcoal layer (as I would using levels). It would be useful to be able to paint directly onto it as well, though I don't need to do that for this particular image at the moment.

You can paint directly on the charcoal layer but not with the brush option "Protect Alpha". Instead, use alt-/cmd-Click (win/mac) on this layer's thumbnail to create a selection of the non-transparent pixels of this layer, luckily its Blend Range Curve gets considered + paper white gets excluded from the selection. For more control while painting hide the 'running ants' via the View menu options.

1 hour ago, lottebrockbank said:

As you can see here, her head and feet are now lighter than the rest of the image, so I want to be able to select parts to darken.

An Affinity adjustment contains a mask: Select the Level Adjustment layer + a black brush + paint where you want to mask / don't want the adjustment affect the charcoal. Below such a mask is currently selected and shows its bounding/selection box.