Using 16-bit TIFF instead of RAW as the archival master

Currently, I use CR2 RAW files as my archival format and Aftershot Pro as an all-in-one catalog/RAW developer/editor. I want to start automating my pipeline with F/OSS tools and possibly my own, beginning with importing from flash media and RAW development.
Questions:
• Native RAW file (CR2, NEF, etc...) vs. 16-bit TIFF?
• Do the file sizes differ markedly?
• Do tools commonly support XMP sidecars with TIFF files?

Thanks!

Whatever you do always keep the RAW file. A RAW file should be considerably smaller than a 16 Bit TIIFF file. RAW files only store luminance values, and even if the 12/14 bit values are each stored in 16 bits you only need one word per pixel in RAW compared to 3 words for an RGB file. Add to that that most RAW formats use a lossless compression system, as can be applied to TIFF so the TIFF won't gain much there.

As well as file size, only the RAW file will allow you full versatility if you later want to make major adjustments to exposure or colour.

Personally I just go with Adobe Lightroom (4.4 currently) as my combined DRM/RAW development workflow, sending images out to Photoshop (CS5) when I need any additional pixel level/layers editing (probably less than 10% of images). The edited .PSD files go back to the LR library along with the other 90% of files that stayed in LR for processing.

I also only generate "output" files as and when they are required. I do not store any JPEG files on the computer at all. It is just so simple to either use the Export function, or one of the other output modules, such as the print module, to produce the required output. If I have had to produce a JPEG file locally then once it has been used it is deleted. This ensures that the latest version of any image is always used.

Alan

To follow up on Alan's advice:

Example: Canon 5DII raw = 21 MB, 16bit TIFF = 126 MB (uncompressed).

Here is some more information that may be of assistance:

http://dpbestflow.org/​links/37

kirk

I save all the RAWs at a minimum, although I've lost about 4 the last 5 years from user oversight forgetting to back them up or accidentally deleting the wrong thing in Aperture.

If I had to really edit a file, heavily, such as exposure blending or other time consuming edits, I will save the 16Bit TIFF as well. Usually I save all my fine edit TIFFs anyhow, but sometimes if I later decide that it really wasn't all that great a photo, I'll delete the TIFF and just keep the RAW

I tend to keep both, the original RAW as transferred from camera and a fully processed 16 bit TIFF.
Or rather its 16 bit when my processing allows it, otherwise its just 8 bit!

From LR2, when I first went over to LR, to this day, each new version has decreased the percentage of occasions when I feel a need to export a tiff in order to do something that LR can't do (or does poorly). It still happens sometimes, but I try to keep it to a minimum, even if it means taking more time in LR to do something that could be done faster elsewhere.

Alone the fact that you only get the TIFF by demosaicing the RAW image is reason enough to keep the RAW file around, because changing the demosaicing method can yield quite different results and with TIFF you would be stuck with the one you used "back then". RAW is the closest data to what the sensor spit out, and I would use that as "archival master" no matter what. Everything else can be recreated from it, including TIFF, JPG or whatever else is needed. If you want to keep specific "developed" images, store maybe the final image but for sure store the metadata used to create that image.

Microcannon wrote in post #16110127
Alone the fact that you only get the TIFF by demosaicing the RAW image is reason enough to keep the RAW file around, because changing the demosaicing method can yield quite different results and with TIFF you would be stuck with the one you used "back then". RAW is the closest data to what the sensor spit out, and I would use that as "archival master" no matter what. Everything else can be recreated from it, including TIFF, JPG or whatever else is needed. If you want to keep specific "developed" images, store maybe the final image but for sure store the metadata used to create that image.

Quite right! And to demosaicing I would add the change from linear to tone curved data and the application of a particular camera profile that can influence not only color relationships, but highlight retention as well (assuming that the tiff was made with maximum highlight data conversion in mind, because what wasn't brought over to the tiff is gone forever if the Raw hasn't been saved.) Also, if the image contained highly saturated colors, rendering the tiff in any space narrower than ProPhoto RGB could result in losing those colors.