Photoshop Raw file format

[Helga232257797935]

Please can someone explain to me what is the use of the Photoshop Raw file format for saving images?

I don't seem to be able to get "the image back" when I have saved it as PS Raw and then try to re-open it - all I get is this grey image with only one Channel and my Alpha Channel is gone (image 3).

Is there a specific way to do the save settings (image 1)?

Is there a specific way when opening the image (image 2), and what is the "Guess" button for?

[Semaphoric · Accepted solution]

It's a relic (note "IBM PC" rather than Windows). I think it was for editing technical and scientific images from proprietary sensors. I've never heard of anyone actually using it.

[Helga232257797935]

Thank you!