Saving as tiff compressed vs. uncompressed with CNX2

[vivid light photography]

<p>I've been experimenting with saving a NEF file as a tiff file with different bit sizes and compression and noticed something that does not make sense. If I save it as an 8bit uncompressed the file size is almost double as as a compressed save image. This I expected, but if I save a 16bit uncompressed the file size is just a little less than a compressed file save; the opposite of the 8bit save. Does anyone know why this would be. I would expect both an 8bit compressed or 16 bit compressed file to be less than an uncompressed file. I tried several times just to make sure I didn't miss lable them either.<br>

Thanks.</p>

[rainer_t]

<p>I'm just guessing ...<br>

the 16 bit files will certainly contain more noise information in the least signifficant bits. This makes a file much harder to compress (and can even lead to a the effect, that the "compressed" file is slightly larger than the original).<br>

The 8-bit file ... this might depend on the compression algorithm you use ... tif knows several different algorithms ... zip, lzw, jpg and more ... while most of them are lossless, jpg is certainly not ... and obviously jpg can only be applied on 8bit data ... may be, your algorithm was jpg, which usually has a quite signifficant compression compared to the original.<br>

With that, the behaviour you observed could eventually be explained.</p>

<p>My personal experience is, that it is better not to use compressed tif ... because not all programs that can handle tif-files generally do handle all variants of the compression well. In order to have maximum compatibility, you might want to work with uncompressed tifs.</p>