darktable ep 029 - Local Contrast module

[@CTRL_SMarcos]

This is the most informative Darktable series of the entire platform. Thank you so much for your videos.

[@audio2u]

No dramas!

[@CTRL_SMarcos]

@@audio2u Well, I don't understand the comment. I said the most informative which is demostrable by doing a search, but okay.

[@audio2u]

Sorry... It's an Aussie saying! It can be used in a multitude of contexts. In this case, what I was getting at is "glad you're enjoying the videos and getting something from them!". Sorry, I need to remember that not all Australian sayings are known worldwide! 😃

[@CTRL_SMarcos]

@@audio2u Haha, no problem 😃

[@RicoResolves]

Always great to see your videos Bruce! I love your in depth explanations!

[@audio2u]

Thanks!

[@lassefischer6974]

I just started using Darktable and it seemed a daunting task to begin with. Your videos really help me a lot. Thank you.

[@audio2u]

No worries, Lasse! Thanks.

Great video as always! Loved the explanations of the sliders!

[@audio2u]

Thanks!

[@mariners_platter]

Thank you Darth(table) Vadar! another great episode!

[@audio2u]

Bwahaha!

[@weekendwarrior-es]

Hi Bruce, great videos. I'm a newbie in this photography world, can you explain the difference between the local contrast module and the contrast brightness and saturation module in order to add contrast to an image? What they do, what they are intended for? when you would use the one or the other?

[@audio2u]

I'd only be taking a guess, but sure, here goes. The local contrast module only adds contrast to the mid tones, where I suspect the contrast part of the CBS module would be a slightly wider contrast curve. I don't use the CBS module at all. When I want contrast, I'll use a tone curve module. If I want saturation, I'll use the output saturation of the color balance module. And although I use a tone curve for contrast, I find that there are very few images which don't benefit from just turning the local contrast module on, even if you don't tweak the sliders.

[@weekendwarrior-es]

Thank you for the answer, I'll give it a try

[@leona_devon]

another informative and well demonstrated video, I have found and subscribed to your podcast too, will keep my entertained and educated on my commute too and from work. I really am surprised your videos don't get more views and likes, it's such great content, please keep it up.

[@audio2u]

Thanks for the vote of confidence, Leona. Maybe I suck at self-promotion! :) I create a short 20-30 sec promo for each episode, which I upload to my instagram account (although I'm questioning the utility of that, as I can see from my youtube dashboard that I'm getting almost no traffic coming in from instagram). I promote it on the darktable unofficial group in FB, and I post it to my photography website. I probably need to find other photography groups to share on, but I don't want to be too spammy.

[@leona_devon]

@@audio2u thank you for naming the last podcast after me, was a lovely touch. Hashtags are all the rage now, try putting the posts you make on intragram onto twitter, see if you can get a slot on the master photography or the northrops's, sadly you have to put yourself out there to get noticed, I understand about not wanting to be pushy, but I think it's about connecting with the right people and having them mention or promote you, I have learnt a lot from these videos, it seems a Shame to have them hidden away, keep up the good work.

[@zephyrxcyrus]

Amazing as always. Nice to see you back. :)

[@audio2u]

Thanks!

Thanks, I've been looking for the clarity modul and now I've got it.

[@audio2u]

Woohoo! My work here is done! :)

[@AlgoFodder]

Hi, and thanks for your informative darktable series - this has been my go-to resource as I've started learning the software - very useful indeed! In this episode, though, I thiink you may have it a bit wrong on the "coarseness" slider for the bilataral mode. I've previously been working on the basis this slider is the spatial *scale* of the details you want to affect, akin to the spatial frequency scale in the equalizer, rather than a tonal range. Though the manual itself just has "Make the details you want to adjust finer or coarser," if you hover over the slider itself, you get: "feature size of local details (spatial sigma of bilateral filter)" which is a bit less ambiguous. What you describe here seems more like the midtone range in the laplacian filter (and is a good description of that.) Anyway, you might like to have a further play with the slider - perhaps on an image with a greater initial tonal range - and see if the above makes sense; apologies if I have it wrong, just wanting to offer something back.. Thanks again for the great series!

[@audio2u]

Thanks for the input! I'll certainly go back and have a look at that.

[@jommnn]

Thanks for uploading! I actually thought the coarseness slider decides if coarse or fine structures are affected?

[@beerstein7137]

Thanks for your videos. Much appreciated. Way back when I still had access to a dark room we would use a technique to change the local exposure in a picture while exposing the photo sensitive paper under the enlarger. We would use either a sheet of paper with a hole in to increase the exposure in an area or a piece of paper on a stick to locally mask (reduce) the exposure. The amount by which the exposure changed was determined by the time and one would move the paper in small circular movements to prevent any sharp edges. It was a bit of a hit and miss technique because one would only know how successful it was after the photo paper was in the developer. I am looking for something like this in darktable to reduce the "flare" effect of a light leak onto a B&W negative. Masking does not provide good results because the amount required to increase the exposure by is not homogeneous over the affected area. Any ideas?

[@audio2u]

I'd persevere with the masking tools. Remember that using your shift key and the mouse wheel, you can desaturate the intensity of the mask, which means you can build up the effect with multiple passes, much like you did with your piece of paper on a stick.

[@beerstein7137]

@@audio2u Thanks I will give it a go

[@lert2161]

Great work as always Bruce :)

[@audio2u]

Thanks Graham!

[@stevebarnesmedia]

Astro: Pentax K-1 has Astro-tracing, which tracks movement of stars.

[@bernym4047]

Not a module I'm likely to use much but thanks for the review.

[@audio2u]

Don't feel unique! I've done lots of videos on modules I'll never use either! 😃

[@chhil]

The equalizer has a default clarity preset, are they comparable or is one preferred over the other and when?

[@audio2u]

Good question! I'll have to investigate that!

[@audio2u]

Just been having a play with both. Personally, I think the Local Contrast does a nicer (less heavy-handed?) job of it. Like everything, I guess it's a matter of personal taste... and what suits the image at hand.

[@bigb2602]

Thank you verry much. You speak verry slow and clear and so I can understud as a german all ;-)

[@audio2u]

Hahaha! No worries, Bernd! Glad you are finding them helpful!

[@hirambaasch6388]

Uncanny! Minutes after cancelling my Adobe subscription (feeling largely at home in darktable now) I open this video and it starts with...

[@audio2u]

Bwahaha! Classic. 😃

[@bubulubugoth]

Can you do a white balance episode? explainin like if the image is greennish you need to lower this and up that, when to use tint or temperature...

[@audio2u]

Sure!

[@bubulubugoth]

@@audio2u great!!! :) Love the channel a lot :)

[@fotografie-joerglang]

Thanks for this video. Great :-)

[@richardbarge8077]

Thanks for uploading these videos. I'm loving Darktable more and more with each one I watch. I'd be grateful if you could cover something that is really bugging me. When I process photos in Darktable, they look good on my computer and also when I print them out. When I export them to upload them to Instagram, the colours are all wrong and look unnatural. I make sure I'm saving them as an 8-bit JPEG, 76% quality and set the profile as sRGB(web-safe). I must be doing something wrong but I'm stumped!

[@audio2u]

Thanks Richard. When you say images look right when you export them as jpeg, but look wrong on Instagram, are you viewing on the same device?

[@richardbarge8077]

@@audio2u Hi, the problem is when I try to upload them to Instagram.

[@audio2u]

But are you viewing instagram on the same device, or a different device?

[@richardbarge8077]

Yes, the same device. I've watched this KZbin video, but still have the same problem. kzbin.info/www/bejne/oJW4i5ttf9p6i5o

[@JulesMoyaert_photo]

👍🙏

[@audio2u]

Cheers.