Apply base lighttable settings to darkroom

Hi Guys,

Relatively new to darktable. I love it. My question is :

  • When I first preview my images in lighttable, sometimes the settings I see there applied to my picture are already close to perfect, without even having them opened in the darkroom. I believe this is the jpeg preview from my raw image itself (is that right?). In any case, when I open the image in the darkroom, the base settings I see (or the results of them) is quite different from the initial version in the lighttable, seems like I have to restart everything from scratch. Is there a way to apply the base settings (or result) that I see in the lighttable when opening the image in the darkroom? Because sometimes all I want to do is crop the image, I find the rest ok as it is. Or is there a way to crop straight from the lighttable?

Thanks.

This is not a developed version of your file…its your jpg taken from the embedded preview in your raw file so just crop your jpg for these images…DT gives a fairly neutral starting position that you can modify in almost any way but unlike other software it doesn’t add a profile to develop the image in the way it see’s fit or with an effort to match the jpg… those decisions are left to you… the second you open it in darkroom view then you see the true raw file and some basic steps that are necessary for that data to be displayed as an image… instead of that jpg preview that is present when images are first imported and viewed

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Ok I understand, but how do I crop that image preview in lighttable? I don’t see any controls to do that. Oh I guess I just have to export the image first and then crop it from there. Unless you see another way? Thanks.

Yeah, just tested that and it didn’t work, it exported its own version of what would have been if I opened it in the darkroom… :neutral_face:

I found another software (rawpreviewextractor) that simply extract the embedded jpeg from my nef file, works great. Unless I find a trick to do this directly in lighttable, I’ll use that.

Probably you should just save a jpeg in your camera, I think? If you don’t need the raw file…
Or save both, jpeg and raw. Then you can choose, which to use.

Yes it’s a good idea, I could do that next time, or if I run out of space, just shoot in raw and extract them later with rawpreviewextractor. Thanks.

Usually the extracted ones are fairly small low quality… If you find this need often you should really shoot raw and JPG or just jpg

My Panasonic LX7 embeds a low-res JPG preview, but the Nikon DSLR has full resolution previews (at high compression, though).

You could try the basecurve. If you are not really looking to do a detailed edit… You might find that the base curve and a couple of small tweaks will be good or good enough wrt you jpg…then you export won’t be the jpg of a jpg which could introduce some substantial degradation of the image…its just another thought… so use the basecurve in place of filmic or sigmoid and you might need to adjust the default exposure as it adds 0.7 ev that you might not need with the base curve…

I did a test by exporting the embedded jpeg from my nef raw file and was pleasantly surprised by the quality of the export. Certainly not worst (to my eyes at least) than a jpeg export darktable would have produced. I find this pretty cool because, the rare times I get pictures exposed exactly right, with the right composition etc, I don’t want to mess with them, perhaps just crop them out for a particular medium. Saves on processing time a lot, especially if you have hundreds or thousands of images to go through. Great addition to my workflow I find.

Thanks for all the great suggestions guys.

Erick

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Curious…what is the resolution of your preview jpg vs the jpg from the camera…

I don’t have the exact resolution off hand but it’s the full resolution that my D750 shoots at, about 6000 x 4000 px.

You definitely should shoot in RAW + Fine JPG from your Nikon. Storage space and memory cards are relatively cheap these days. If the JPG has already given you the look you want that is great because the job is done at high quality within the camera. This is what I want when I do a commercial job as I don’t want to spend hours editing images.

However, I often want to spend time editing my personal images and travel pictures. In this case I sometimes open the JPG in the darkroom view and take a snapshot. I then open the RAW file and use the snapshot to ensure I get a better edit than the RAW file. But I don’t always feel the need to compare my edit to the JPG out of the camera so I only sometimes do this described snapshot method.

I don’t own the camera but grabbing a couple of files from Imaging Resources for the D750 at least from that source had in camera JPG files of about 16MB…Raw was 32Mb and the extracted preview was 2.3MB so I suspect compression and quality of the preview as one might expect must be quite skewed to prefer size over quality of the output… but if it’s just for browsing on a screen then I suppose it could work … Then again the best quality image might help if the image is being cropped and then re-exported to a new jpg… esp if these are keeper shots that have been well taken.

There are also tools to perform lossless jpg crop (no decoding and recompression needed) that allow you to crop to the nearest 8th or 16th pixel. See How to crop a JPG without recompressing? - Graphic Design Stack Exchange, for example.

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