[madmacgames]

I've been looking around a little, and it seems you can indeed make a PNG8 format image with alpha transparency. However, for the life of me I cannot figure out how to get Photoshop/Imageready (CS) to do it. It seems to only do alpha transparency with PNG24 format, which is no good for web pages, as the file size is way too big for such a small dimension image.

So my question is, is Photoshop capable of doing PNG8 w/ alpha transparency, and if so, how?

[graphicpush]

I don't believe it is possible. PNG8 is the same as GIF -- limited to 256 colors with 1-bit transparency, meaning the color is on or off. PNG24 is the only way I know to get full transparency in webpages, but IE doesn't support it without some small hacking.

[Ardfry Imaging]

This thread is a bit dated, but I wanted to post a correct answer.

The PNG spec allows for an indexed color image with an 8 bit alpha channel through the use of the tRNS chunk.

Sample images in this format are here: http://www.libpng.org/pub/png/pngs-img.html

However, Photoshop can neither read nor write files in this format without the use of a third party plugin.