image different after frequency separation (darker or lighter)

[Jennyyy]

Hey!

A lot of times when i do frenquency seperation, the image is different before i even start editing, when it should look the same, shouldnt it?

I am using a 16 bit tiff, when i use the action for 16 bit it gets darker, when i use the 8bit action it gets a little lighter. 

Does anyone know the reason for that? 

Thanks

[davescm]

Without seeing the exact steps you have taken in your action it is impossible to say what is wrong, but no I do not see that here.

Make sure you, or your action, follow these steps exactly.

1. Make 2 duplicates of your image layer

    Name the lower - "Low frequency"

    Name the Higher - "High Frequency"

2. Select the Low frequency layer and use Filter Gaussian Blur (around 6.0)

3. Select the High frequency layer
    Go to menu Image > Apply Image
    Set the source layer to Low Frequency
    Set the blending mode to Subtract
   Set Scale to 2      *
   Set offset to 128  *
   Click OK

4. Change the blending mode of the high frequency layer to Linear Light

5. Now you can clone out blemishes on the high frequency layer and lighten or darken areas on the low frequency layer

*  Note - the above steps are for 8 bit/channel images. For 16 bit/channel step 3 changes slightly

3. Select the High frequency layer
    Go to menu Image > Apply Image
    Set the source layer to Low Frequency
   Check "Invert" next to channel

   Set the blending mode to Add
   Set Scale to 2
   Set Offset to 0
   Click OK

Now carry on with step 4 above

If that does not work for you - please post a screen shot showing the Apply image settings and the layers panel

Dave

[Jennyyy]

I redid it with the exact steps and its still the same.

The screenshots are german, but i hope its still understandable

[davescm · Accepted solution]

I don't see anything wrong with the settings in your screenshot. Just in case there is an issue with Linear Light blending on your GPU , can you go to Preferences > Performance and check "Legacy Compositing" and see if it makes a difference.

Oh and make sure you are comparing before and after at 100% zoom

Dave

[Jennyyy]

If i zoom in at 100% its the same! does that mean i can ignore it?

i cant find the legacy composition setting in the performance window but thats maybe because i've still got photoshop cc17

[davescm]

Yes

If you view at less than 66.7% then the composite image on screen is blended using 8 bit previews (even on 16 bit images). This is done for speed and most of the time does not show a difference, but on some images with for example fine noise or fine textures, the difference becomes visible.

It is the 100% zoom version that is accurate and will match the version in the final saved file.

With CC2017 you will not see the legacy compositing checkbox. Any reason you are using such an old version ? 🙂

Dave

[Jennyyy]

Thank you a lot for explaning! 

A lot of my co students had problems with updating to 2018 back then, so i waited at first and since then i kinda forgot about it but i guess i should take care of that sometime soon now haha

[c.pfaffenbichler]

Please provide a meaningful description of what you are actually doing. 

»when i use the action«

Which exact steps does the the Action comprise of? 

Please provide the atn-file or at least a fully ecpanded screenshot of all its steps. 

[Jennyyy]

I did it manually and also with a downloaded action and its always the same.

I tried the action from PiXimperfect for example https://drive.google.com/file/d/1hgR_1mWShxYesDBkA_WveXdmwmnbkZ3r/view

[Jennyyy]

I just saved the image as a tiff with the Frequency seperation on and one with the FS of and it seems to look the same. So i guess it's actually a display problem in photoshop ?

[Jennyyy]

edit