Hi Qkano, > Just a reminder that PhotoSHop only uses 15 not 16 bits. > Generate a 16-bit TIFF, load it into PS, save it as a TIFF ... voila, image degredation ... It sounds very strange to me that Photoshop only uses 15 bit when you specify to use 16, at least that's what PS says in the menu. Although the 1 bit difference between 16 and 15 will represent a very high number of different colors, 15 bit will still show an incredible tonal response, but it seems very strange, can you give more information on that? > ... then again, since 8-bits can capture all meaningful levels of luminance information about the world I don't know why anyone would want more, let alone the floating point TIFFs > used by HDR shop (one of the best freeware games I have ever downloaded) As I said, I think same as you about "i don't know why anyone would want more than 8bit/channel". I think It's right, 8 bit/channel would be more than enough for final representation of the image, in any support. But I really think that more than 8bit tonal response is very important when you're severely working with digital manipulations, enhacements, corrections and so on. This is just the purpose of the HDR format you've suggested, they talk about incredible tonal responses due to the use of floating point numbers instead of natural numbers. In their webpage, under "introduction" section, they talk about the differences of working with 8bit/channel images and HDR images, and they show some examples. At the end, that's exactly what we're talking about: The advantages of the digital retouching using images formed with more of 256 values of tonal response per channel. > http://www.debevec.org/HDRShop/ Very interesting thing that HDR! I will check it! I've never heard of any digital image manipulation wich uses floating point values. Nice! -- Whatever you Wanadoo: http://www.wanadoo.co.uk/time/ This email has been checked for most known viruses - find out more at: http://www.wanadoo.co.uk/help/id/7098.htm
