Beginner Advice on workflow: RawTherapee and Gimp

Tom Pinchenzo · 7 Dec 2018

Hi All,

Looking for a bit of advice on using the above programmes. In the past I have used RawTherapee almost exclusively but I've started exporting to Gimp for more local adjustments. The problem is once in Gimp I'm editing a JPEG, which isn't ideal. I know lightroom allows you to make local adjustments to the RAW file. Is there an obvious way of being able to make local adjustments (mostly using the dodge/burn brush) to a raw file (without paying for lightroom). I know most people here are LR/PS so probably don't have this problem.

Any advice would be great!

Cheers,
Tom

droj · 7 Dec 2018

Can you not export a 16-bit tif from RT, to work on in Gimp?

If you can, you'll have more to work with, & it'll degrade less.

john.margetts · 7 Dec 2018

Gimp certainly will use Tiff files (and Adobe's PSD files). It is a couple of years since I used Gimp but I understand that Gimp does now process 16 bit files

Tom Pinchenzo · 7 Dec 2018

I assumed there would be a straightforward solution. Tiff files weren't even on my radar! Do Tiffs contain as much as Raw? Or just more than JPEGs?

Cheers guys

Tom

droj · 7 Dec 2018

Gimp 2.9 or later is my belief for 16-bit file handling. Check that.

Jpg's degrade more as they are processed & then re-saved, moreover the format is limited to 8-bit. Having 16-bit, as you can in a tif, allows the file to contain more colour and tonal info. Thus you have more headroom.

A tif still degrades as it's worked on, though, just less than a jpg.

It's all about workable compromises.

The first thing is to output the maximum bit-depth raw from the camera (see it's menus).

Nothing contains as much as a raw.

Tom Pinchenzo · 7 Dec 2018

I’ve been exporting 8 bit JPEGs so 16 bit TIFFs should be an improvement!

droj · 7 Dec 2018

Tom Pinchenzo said:
16 bit TIFFs should be an improvement!

They should be! Tif's (16-bit) were all I had to work with for years (from film scans) and I made decent 10 x 15" prints from them.

Your camera, I believe, will export 12-bit raws. I'm hoping / assuming that RawTherapee can in turn export 16-bit tif's & that Gimp (v2.9 +) can work with those.

If Gimp also has 'adjustment layers' (if it hasn't yet, I'm sure that they're on its shopping list), then that'll be another help.

john.margetts · 9 Dec 2018

droj said:
Jpg's degrade more as they are processed & then re-saved, moreover the format is limited to 8-bit. Having 16-bit, as you can in a tif, allows the file to contain more colour and tonal info. Thus you have more headroom.

This can be completely avoided by doing all your processing in one sitting - thus removing the re-saving part. Also, once in Gimp (or your editor of choice) you can save as Tif, PSD, or your motor's native format thus avoiding Jpegs altogether apart from the initial save - one save as a Jpeg will not produce noticeable degradation.

Tom Pinchenzo · 9 Dec 2018

john.margetts said:
This can be completely avoided by doing all your processing in one sitting - thus removing the re-saving part. Also, once in Gimp (or your editor of choice) you can save as Tif, PSD, or your motor's native format thus avoiding Jpegs altogether apart from the initial save - one save as a Jpeg will not produce noticeable degradation.

But you have to export the file from your raw file editing software into gimp or photoshop as they can’t work with Raw files. Is there software that allows you to do all your editing including local adjustments to the raw file?

ianp5a · 3 Jan 2019

Tom Pinchenzo said:
But you have to export the file from your raw file editing software into gimp or photoshop as they can’t work with Raw files. Is there software that allows you to do all your editing including local adjustments to the raw file?

The raw file doesn't ever get edited. It's like your master file, where you work on a converted copy.
The easy way to do this is open the raw in RT and click on the 'Open in External editor' button at the bottom. This will make a converted copy of the image information on the fly, and open it in Gimp directly. This does not make a jpeg file or lose any quality with compression.

This video shows it in action. I'd recommend you use Gimp 2.10 as it has very many improvements over previous versions.