Problem with saving selections

[Harald]

Hi! I have a large document in .psb-format and want to make 72 simple square selections and save them each in a separate channel. Until selection 53 this worked ok. But when I made the 54th selection and wanted to save it, Photoshop does not show the current document name as target to save the selection but only the option "save in a new document". Does anyone know what's wrong here? Thanks!

[S_Gans]

Hi. Per this page, Photoshop maxes out at 56 channels. 
https://helpx.adobe.com/photoshop/using/channel-basics.html#:~:text=An%20image%20can%20have%20up,inf....
I'm surprised it only let you get to 53, although you'd still have been stuck for the rest. 
Perhaps if you clarify why you want so many channels, we can make a suggestion on how to accomplish your end result with duplicates of your image?

[Harald]

That's interesting, thanks. The reason I need so many selections is, that I'd like to make a photocollage showing 96 pictures in a tableau and adressing them all separately...

[Jeff Arola]

In an RGB file, for example, you already have 3 channels: Red, Green and Blue which in addition to the 53 gives you the 56.

[JJMack]

You could make a Mockup template for your 96 Image Photo Collage.   My Photo Collage template design uses Alpha Channels  to map Collage image location size and shape.  Therefore, there is limit to 53 Images  I did not know there was a small limit when I was developing  my Collage toolkit. It was my first attempt at Photoshop scripting. I found the limit  after I coded the toolkit scripts.  I had the change the scripts to deals the limit collage after I hit the limit I limited Collage templates to 53 images.  So  my collage scripts can only populate up to 53 images and can add  layer styles and file name stamps to the Populated Collages images.  My Mockup templates design use smarts object layers  for image replacement.  There is no 53 Image limit.  However, my batch mockup populating scripts do not have option to add Layer style and file name stamp to populated smart object.   Mock up Templates can add rotation and distortion to the populated smart object replacement because smart object layer are used in the templates. Collage Templates do not support rotation and distortion like  perspective.  Mockup Template do.. 

[Stephen Marsh · Accepted solution]

If the selections are simple, you could save them as paths rather than channels.

[JJMack]

Yes Photoshop Alpha channels are limited to 53.  That is why my Photoshop Photo Collage template have a 53 Image limit. I discovered that limit years ago when I developed my collage toolkit package.  However, you can save many more selection then 53.  For Layer Mask are like Alpha channels.  All you do to save a selection is to add a layer name it like you  would like to name an Alpha channel saved selection.  Fill the layer with a color and add a layer mask with the current active selection.   Layer limit is 8,000. To load the saved selection you loads the layer transparency as a selection. 

[Harald]

That's an idea, thanks!

[Harald]

JJMack: In this case would I need a separate layer with layer mask for each selection?

[JJMack · Accepted solution]

Yes instead of alpha channels you have Layers they can be any color  so you can just add solid fill layers  that you a selection you want to save as a layer mask.  These save selection  layers can be in a layer group and the group visibility can be turn off.  Your save selection  are in the layers palette not the Channel palette.  However, when you target one of the layers its layer mask will also be in the channels palette for Layer mask are like alpha channels. You only need to use this method when you need to have more than 53 saved selections in a document.  That is a lot of saved selection. I would think a document that need that many save selection would contain many layer and be complex to edit to need so many saved selections.

In a complex document you would also be able  to group layers into Smart Object layers instead of layer groups. You can the edit the layer's Smart object grouped layers in  photoshop the smart object can have 53 alpha channels save selections. Each smart object can be opened for edit and each can have up to 53 Alpha channels.  Layer are versatile and where Photoshop powers lies.

[Harald]

JJMack, thanks for describing this. I'll give it a try as soon as there is more time.

[Stephen Marsh · Accepted solution]

Your welcome, as you mentioned PSB and that the selections were simple squares, then paths will have the least amount of overhead compared to channels and layers.

You could even use the shape tool for a square vector shape layer and store them all inside a layer set/group and turn off the visibility of the group or set the group's opacity to 0% and load selections as required.

[Harald]

Stepen, thanks very much for this alternative approach! Much appreciated!