PSD keeps saving image as 32 bit depth (not 24)

I may be using some incorrect terminology/calculations.

I have some third-party presentation software that requires all images be 8-bit. So I used Photoshop for all photo editing and made sure my PSDs were 8-bit before exporting stills (PNGs) for my presentation. 50+ PNGs were successfully created this way, but i'm having problems with a single file. When I open the correct files in Windwos Pic/Fax View, right click, show properties, go to Summery (advanaced), all the correct files have a bit depth listed as 24.

My problematic PSD says it's in 8-bit, but the PNGs that I create from it are consistently listed as having 32 bit depth in Windows Pic/Fax View. As a test I exported other images formats (TIFFs, JPEGs, etc...) and they all came out as 32 bit depth. How do I fix this? I tried opening the PSD, saving as different name, switching to 16-bit and then back to 8-bit, still didn't work.

Typically, 24 bit images will register as 32 bit when they have an alpha channel attached to them. That would make them 3 channels X 8 bit =24 + the 8 bit alpha channel making 32 bit. Do you have alpha channels saved in these files?

I don't think I have an alpha channel. The workflow to create this image is identical to all other images (none of them have alphas). Any way I can check whether an alpha inadvertently was included?

Thanks for also explaining the math behind 8 bit -> 24 bit lol.

Is it perhaps in CMYK mode?

Rob

The PSD is in RGB mode. The PNGs that are being created are also in RGB mode.

I have a workaround though :S. I export a JPG, that shows up properly as 24 bit depth. Then from there I export a PNG (just to use the same format as all my other images).

if its PNG 24 and it has transparency this could account for the alpha channel