When I export a photo to CS5 or Nik plugins for further editing I use 16 bit Tiffs. Is this what you recommend? Or should I save space and use 8 bit?
When I export a photo to CS5 or Nik plugins for further editing I use 16 bit Tiffs. Is this what you recommend? Or should I save space and use 8 bit?
Edward,
It really depends on what you’re doing. The advantage of 16-bit is that you have essentially all of the data from the RAW file (most high-end dSLRs are shooting 12- or 14-bit), and other than the RAW conversion, it’s essentially the same as working in RAW.
However if you get your exposure balanced and corrected in the RAW file, and then go to 8-bit, the space you’re throwing away should be empty. So it shouldn’t matter.
This is all theoretical. I haven’t done any side-by-side tests, nor researched it, which I probably should do. Whenever I go to any external editor, it’s nearly always at the very end of my workflow, so I’ve always just left it at 8-bit. To be honest I haven’t even compared the file size.
OK let me do that now… let’s see.
Whoah, yeah that’s a big difference… [screenshot]
CR2 (RAW) = 27.2 MB
8-bit TIF = 63.1 MB
16-bit TIF = 126.2 MB
So, yeah, unless you really need it… I’d stick with 8-bit ;-)
-Joseph @ApertureExpert
@PhotoJoseph
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Edward, I’m glad you brought this up. I export to Topaz programs a lot and have always assumed that Topaz needed the 16-bit Tiff to effectively do it’s best. Sounds like what Joseph is saying is that once I get exposure, contrast, etc. set; it really doesn’t matter if I send the 16-bit Tiff to Topaz or not. I have my camera set to record at 14-bit depth.
I went to a seminar and a Nikon expert recommended always using “uncompressed” RAW recording. Does anyone know if it matters which compression option you pick?
James,
Saying “uncompressed RAW” is like saying “wet water”. Actually, “uncompressed RAW” is a bit of an oxymoron. RAW is neither compressed nor uncompressed; it’s simply raw data. JPGs are compressed, TIF is uncompressed, but RAW is just data that has to be decoded by software and turned into an image.
I’d guess the Nikon guy was saying that to help attendees understand what RAW meant.
I encourage you to do a test in your plug-ins. Set your preferences to make a 16-bit TIF or PSD and open in your plug-in of choice. Dial in the settings you want and save them as a preset (or use a preset, or write the settings down—the point is to be able to get back EXACTLY the same settings next). Apply the settings to the 16-bit photo. Now, change your Aperture preferences to 8-bit, open another version of the same original photo into the same plug-in and apply the exact same settings.
Then compare the two files (the 8-bit and 16-bit) in Photoshop. Layer them and apply the Difference blend mode; this will show you the difference (if any) between the two files.
If you don’t have Photoshop, feel free to drop the two files in the Dropbox (see the More menu at the top of this page), or get them to me however you like, and I’ll put them through Photoshop and post the results.
-Joseph @ApertureExpert
@PhotoJoseph
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