I would suggest using either XCF

On Thu, Jan 9, 2014 at 9:50 PM, EGoldman wrote:

I had a point and shoot camera that only shot in Jpeg so after I did all my levels and curve and contrast changes, I would always export as Tiff file so I would have a negative/master file of my pic.

I have just bought a Canon DSLR which I can now shoot in the Raw, my question is after I make my color corrections, how should I export the file so I have a negative/master?

Any guidance would be so appreciated.

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On 01/09/2014 12:50 PM, EGoldman wrote:

I had a point and shoot camera that only shot in Jpeg so after I did all my levels and curve and contrast changes, I would always export as Tiff file so I would have a negative/master file of my pic.

I have just bought a Canon DSLR which I can now shoot in the Raw, my question is after I make my color corrections, how should I export the file so I have a negative/master?

Any guidance would be so appreciated.

The principal advantage of RAW images is the amount of data. Your jpeg files will have been compressed using lossy algorithms before the camera ever delivered them, and image data will have been lost. Exporting to PNG prevents that. TIFF may or may not lose image data, depending I think on the settings. Anyway, I usually export to PNG. I just did an experiment; I have a 5K by 6K portrait. The image exported to PNG is 10.3 MB, to TIFF it is 29.8 MB using packbits compression, uncompressed it is 117.4 MB. I think packbits is not lossy.

On Fri, Jan 10, 2014 at 2:57 AM, yvind Kols wrote:

On Thu, Jan 9, 2014 at 9:50 PM, EGoldman wrote:

I had a point and shoot camera that only shot in Jpeg so after I did all my levels and curve and contrast changes, I would always export as Tiff file so I would have a negative/master file of my pic.

I have just bought a Canon DSLR which I can now shoot in the Raw, my question is after I make my color corrections, how should I export the file so I have a negative/master?

Any guidance would be so appreciated.

Sorry, that email got sent off half way through the first sentence.

I would suggest using either XCF - if GIMP is your primary program for doing things. If you are using GIMP 2.9 though; I would suggest converting your images after load to 32 bit floating point linear, and storing the "negatives" as EXR files; which is a well defined high-fidelity format that more software packages than GIMP is able to load.

/pippin
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