Hi, (Photoshop CS5 newbie)
I have been putting together a birthday cadr for someone and adding layer after layer with many his res images etc., I have saved the beast in the default PSD format and it weighs in at a massive 388,963 KB. Photoshop doesn't let me save in any other format, ie JPG or PNG, even after flattening the layers and reducing the image size.
Q. Is there an threshold in terms of size that limits the output file type?
Q. Please suggest a way forward so I can save as a JPG or PNG ?
"Attempting"??? What do you mean "attempting"? Just do it. Well make a copy if you don't understand what you're doing, and convert the copy.
The dialog box is telling you what you should already know. Namely that "reducing the bit depth" (i.e. going from 32 bits to 8 bits) will affect the colors of layered images. That's OK, because the PNG format does not support either layers nor 32 bits, so there's no other way of doing it.
Yes, Merge the layers, and Convert to 8 bit. Then Save as PNG or JPEG.
Thanks again for a very quick and helpful response.
Re. 32-bit, still learning Photoshop, don't fully understand the implications and differences between switching the Mode between 8, 16 or 32 bit, other than I presume image size.
Basically: the less bit the worse Adjustment (Layer)s will affect the image.
But the difference between 8-/16- and 32bit is a more basic one, the latter one using floating point units for the pixel values instead of discreet units – so some features are available only in 8-/16- or 32-bit but not both.
Check out the chapters in the Help on HDR-images.