Not understanding HSL

[clonkel]

Hi,

I have two hearts in the image. Both are red and I have applied a HSL adjustment to one of them. If I choose the red option in the HSL and then the picker and take the Hue all the way to red the heart turns light blue. On the outer wheel of the colour picker it shows the light blue. I do not understand why it does not show red?

 

thank you

 

[thomaso]

I am not sure what exactly you don't understand. Consider that inner & outer wheel colours represent the colours before & after adjustment. I would rather say the colours displayed in the Hue slider can be misleading since they might imply to be related to colours of the source or the result, as the two wheel areas do.

[clonkel]

@thomaso Thank you. That was my misunderstanding. So the Hue slider has no relationship with the outside wheel?

thank you

[walt.farrell]

I cannot explain the colors shown on that slider.

But note that the slider is labeled Hue Shift and the box is in degrees. In your screenshot, you are operating on Reds, and you have applied a hue shift of 180 degrees. So if you go around the inner wheel (which you are operating on) 180 degrees, you get the transformed color, which you then see in the outer wheel.

[clonkel]

@walt.farrellthank you. I believe you are correct. If I take the centre point of the 4 dots and look at 180 on the inside wheel it will show cyan. If instead I look at -90 I get green.  

Not sure what the colours are on the hue shift slider. Instead I now drag the slider and look at the outer wheel on the colour wheel as that makes more sense to me.

 

thank you

[thomaso]

17 minutes ago, clonkel said:

That was my misunderstanding. So the Hue slider has no relationship with the outside wheel?

Initially you wrote about the "outer wheel", not the slider. Yes, the colours in the slider have no relationship with either your image or the adjusted result. Just imagine, to be more meaningful here these colours would need to be able to change + occur different depending on either the input source or the adjustment setting, what they obviously don't.

Here the slider colours are rather an unnecessary left over from the general colour wheel as colour chooser, which describes colors in a circle, with red at the 0 degree position. So, for instance if you adjust yellow (90º) by 145º you end up at blue (235 º) etc. – Historically there were many different ways to show and define colours in certain models, wheel and sliders are not the only ones.

[clonkel]

@thomaso Thank you. Being able to drag the outer wheel instead of the slider would make it better for me. Thank you

[R C-R]

2 hours ago, clonkel said:

Being able to drag the outer wheel instead of the slider would make it better for me.

I must admit I have never gotten very comfortable with using the channel nodes in the HSL adjustment, but as I understand it, according to the help topic, there is just one color wheel, not separate inner & outer ones. However, to move all 4 adjustment nodes around it at the same time, as the the help topic says, you can drag the center black line connecting the two inner nodes.

It is not obvious to me why it is set up this way but it does offer a lot of ways to change the adjustment values.

[clonkel]

@R C-RI don't find the slider/wheel/4 points intuitive at all and found an issue when switching to HSV where the work becomes pixelated and requires a reset. 

[R C-R]

6 minutes ago, clonkel said:

@R C-RI don't find the slider/wheel/4 points intuitive at all and found an issue when switching to HSV where the work becomes pixelated and requires a reset. 

I don't think it is particularly intuitive either.

However, I am not (as far as I can tell) seeing any pixelation issues when I toggle on or off HSV mode. Can you provide an example of that or a 'recipe' to recreate it?

[carl123]

More confusion:

 

[clonkel]

@R C-R I can recreate every time. Create a shape with a gradient and rasterise. Apply a HSL adjustment but only the Hue Shift. Check the HSV box and change the Saturation slider. This is not the only way as it also happens on images (not gradient) as well which is where I first saw it and then recreated it more simply.

 

 

[Old Bruce]

5 hours ago, clonkel said:

@R C-R I can recreate every time. Create a shape with a gradient and rasterise. ....

Very important that the gradient go from a neutral grey to some colour.

[clonkel]

Not sure if it is a bug or not. Either way it does not look great and happens on images as well