Curves adjustment by numbers

[mrenters 0]

I'm trying to use Affinity Photo to make a curves adjustment layer for digital negatives that will be used in a traditional darkroom process. I need to be able to compensate for the response curves of the medium (e.g. photographic paper, cyanotype) I will be contact printing the negative to. I can calculate the curve but I can't find a way of telling Affinity Photo to make an adjustment curve where input value 5 maps to output value 20, input value 16 maps to output 32, etc. as is possible in Photoshop. I'd be happy to have a way to create a preset in the text file or something if that is possible as the curve would be the same for all images made into negatives and darkroom printed to the same medium.

 

Any ideas?

 

Martin

[firstdefence 2,790]

It looks like what you want is not possible, but, I'd put in a feature request for future releases, because curves are an important tool in photography so the addition of input/output as an accurate node control would be a good addition to the curve tool.

I can remember there was a plugin called curvemeister that was like curves on steroids but it isn't sold any more as far as I know. There is also an extension for photoshop called Floating Adjustments Plugin but its actually an extension and brings back the floating adjustment layers from CS3, I think it was because the windows were scalable so you could fine tune the curves better but either way it's a no-go with regards to affinity. 

 

I'm not doing very well here am I lol! 

 

I think a proper curves plugin certainly would be something people would consider as long as it was done well. shame I can't programme, unless you can programme with a hammer then I'm good to go lol!

[v_kyr 2,217]

Well you can only customize mixing options here that way. See the bottom right settings gear icon there, when clicking on that another panel pops up, on which you can insert nodes, select them and then setup the needed input/ouput values in percentage.

To make custom curve presets you would use the top left Add Preset button, this adds the current adjustment settings as a preset by applying a name for it (for later reuse) under the studio adjustments panel curves presets (menu View ▸ Studio ▸ Adjustment) with that name.

For PS/PSE always likes SmartCurves for saving/loading custom curves.

[firstdefence 2,790]

@v_kyr Shame its windows only  I've emailed the author anyway to see if he would add the input output feature in, you never know.

[v_kyr 2,217]

Don't know if the author of SmartCurves still maintains that plugin at all, since it's origin is already a bit older now and I used that first time some years ago. Though it also still works nowadays as before.

[mrenters 0]

Thanks for all the responses. It would be great if Affinity Photo added this feature. In the meantime, I've found that GIMP is able to do this, so I'll just use that for the time being.

 

Martin

 

[furtonb 38]

Yes, numerical input for curves should be implemented in my opinion too.

[Subclavius 28]

Hello,

I would also like to see this feature implemented for precisely the reasons that mrenters described in the initial post.  In the Blend Options panel of a layer it's possible to put in a large number of points and specify the input/output values for each one.  It doesn't seem, on the face of it, to be be very difficult to implement this idea for the curves adjustment as well.  Please, someone in the know at Serif, would you consider implementing this or putting on the roadmap?

Nigel

[v_kyr 2,217]

Personally I would like it to offer all what the above referenced SmartCurves does here (...save/load, b/g/w pipettes etc.).

[Subclavius 28]

I was thinking earlier of just the absolute basics but of course a fully featured SmartCurves would be fantastic.  This is partially referenced in thread 76455:

where the ability to save and load presets is requested.  That would be so handy for alternative processes ...

[AT.HA 26]

I´ve been waiting for this feature to be able to produce Digital Negatives for Platinum Palladium prints as it is done with Photoshop.

Anyone suggests an alternative; while we wait... ?

Thanks.

[Subclavius 28]

I have posted an article on how to set up curves manually in the Tutorials forum:

 

It uses a LUT and requires some manual editing to set up but it isn't rocket science.

Nigel