Just FYI: I have found that V8a in 32-bit float mode can import 16-bit PNG files and the video properties dialog identifies them as 64 bit per pixel images.
However, when importing 16-bit TIFF files, Vegas identifies them as 24-bit images (eg. only 8 bits per channel). I have found that most applications that support any high bit depths are more likely to support TIFF than anything else, but Vegas seems to do the reverse.
If you want to experiment, I put sample 16-bit PNG and TIFF images at the bottom of this page: http://www.bealecorner.org/red/test-patterns/
My image was constructed with a combination of Imagej ("ramp") and ImageMagick (16-bit version). Although Photoshop CS2 has 16 and 32 bit per channel modes, some operations seem to silently truncate your image to 8 bits even when in 16-bit mode. I confirmed true 16-bit values by exporting to uncompressed PNM (ASCII mode) and viewing in a text editor.
See also:
http://rsb.info.nih.gov/ij/ (ImageJ utility)
http://www.imagemagick.org/script/index.php (ImageMagick, 8 & 16-bit versions)
However, when importing 16-bit TIFF files, Vegas identifies them as 24-bit images (eg. only 8 bits per channel). I have found that most applications that support any high bit depths are more likely to support TIFF than anything else, but Vegas seems to do the reverse.
If you want to experiment, I put sample 16-bit PNG and TIFF images at the bottom of this page: http://www.bealecorner.org/red/test-patterns/
My image was constructed with a combination of Imagej ("ramp") and ImageMagick (16-bit version). Although Photoshop CS2 has 16 and 32 bit per channel modes, some operations seem to silently truncate your image to 8 bits even when in 16-bit mode. I confirmed true 16-bit values by exporting to uncompressed PNM (ASCII mode) and viewing in a text editor.
See also:
http://rsb.info.nih.gov/ij/ (ImageJ utility)
http://www.imagemagick.org/script/index.php (ImageMagick, 8 & 16-bit versions)