what is the purpose of using 32 bit color mode

[Guest]

When trying to print an image made in 32 bit color mode Photoshop CC will not allow printing. The button is greyed out. When I convert the file to 16 bit the colors turn wonky and an HDR window pops up. Exactly what is the purpose of 32 bit mode. I am a photographer, not a graphic artist. TIA

[khatwani]

Hi

Greetings!!!

Here it is explained better : http://www.instructables.com/id/RAW-8-bit-16-bit-and-32-bit-explained/

Regards

Jitendra

[Per Berntsen · Accepted solution]

The article you linked to is, as far as I can tell, inaccurate and misleading.

chuckcars - I suggest that you look here instead: Photoshop Help | Image essentials

I have no experience with 32-bit, but it's used for HDR images in PS.Don't think it is intended for general use. (and file sizes are enormous)

Are you working with an HDR image, or did you convert an 8-bit or 16-bit image to 32-bit?

[Guest]

Thanks for the answer. 32 bit is HDR usage. Printing is greyed out, therefore unavailable. Will dig deeper for that.

[Test Screen Name]

PostScript printers support a maximum of 12 bits per channel. PDF supports a maximum of 16. I mention these limits because maybe Photoshop refuses to do anything which would automatically cut the colour depth to succeed.

[Herbert2001]

Test Screen Name wrote:

PostScript printers support a maximum of 12 bits per channel. PDF supports a maximum of 16. I mention these limits because maybe Photoshop refuses to do anything which would automatically cut the colour depth to succeed.

As I have just explained, that is not entirely true: when opening a true full range 16bpc image in Photoshop, Photoshop's 15bpc mode will throw away part of the data without informing the user about this.

[Terri_Stevens]

Basically it is a computers way of emulating the continuous tones you see in a photograph. With an 8 bit image Photoshop sets aside in memory and on disk sufficient space to hold  two to the power of eight shades of red, green and blue respectively or 256 shades for each channel if you prefer going from complete black to brightest red, green and blue. With 16 bit Photoshop does the same thing but assigns two to the power of 16 shades per color channel or 65,536 and with 32 bit images it assigns two to the power of 32 or about 4 billion shades. Visually the result is color blends more seamlessly together without banding patterns being visible as the number of bits used increases. The downside is file sizes increases with increasing bit depth. They say the human eye cannot distinguish between 65,000 and 4 billion shades so many people never use 32 bit mode. There are quite a few things in Photoshop that are not supported with that much color detail

Terri

[Herbert2001]

A note on the side: Photoshop's 16bpc mode is actually a 15bpc one. It generally does not matter for photography, because cameras typically record at 12bpc or 14bpc (and due to noise and other factors, there is little use in shooting at 14bpc anyway).

If, however, images are rendered in a 3d application at full 16bpc with extreme highlights and shadows (for example), or a 16bpc depth map is created, or several texture maps are saved in a 16bpc file for game development, then Photoshop will remove part of that data. And that may become problematic.

It seems this is a legacy "feature" from the time when a 16bpc mode was first introduced - possibly to counter performance problems? Not certain. Anyway, it is a little surprising Photoshop still does not support a "full" 16bpc mode. Other image editors such as Photoline and Affinity Photo do.