I need to make a transparent image with a png 24 format, NOT 32. Photoshop saves any image with transparency only as 32png. How do i get around this?
24 bit PNGs do not have the alpha channel. There are only the normal R,G and B channels - total three bytes per pixel.
One can sacrifice one color for transparency. This can be useful if the storage space is limited and it's OK to have opaque colored pixels, fully transparent pixels and no partially transparent pixels. For watching the images he needs a special program that knows which RGB combination should be rendered as transparent
It can be also possible that someone says "I want PNG24 images" to be sure he gets 16 million possible colors, not only 256 colors as with PNG8. In addition he wants the full alpha transparency (=partial transparency possible in every pixel and color), so actually he wants PNG32.