lens correction and denoise on by default

Thank you Pascal for this reminder,

Well, as master users, we’re the first to stop using these deprecated modules and even the “display-referred” workflow.
I’m taking advantage of this post on development to suggest that two modules should be active by default as soon as you enter the darkroom

  • lens correction, which has evolved to support metadata in addition to lensfun, broadening the range of lenses taken into account.
  • denoise (profiled) which does the job in 90% of cases.
    We rarely need to touch it up.

It could be two boxes to tick in preferences & settings in the processing tab.
Of course, it is possible to do this by preset, but it would be better to keep this solution for special cases.

A happy new year

1 Like

As a user, I disagree:

  • lens correction isn’t always needed, and in some cases the automatic choices are wrong (I see dt trying to use metadata for a camera with a thirtd-party lens, and those corrections don’t look right)
  • similar for noise reduction: I don’t need it for all images (esp. low ISO, depending on final use up to 400-800 ISO). Any noise reduction loses details, it’s inherent in the process. But this is also something that will be different for each user.

And the configuration dialog is already rather complex. I’d rather use presets (or just manually switch on lens correction and denoise when I need it) than have a config switch which anyway will be wrong part of the time.


@Pascal_Obry : If you feel this derails the discussion, I’ll delete the post.

3 Likes

+1

Your technical arguments are fully justified and acceptable.
Even for optical corrections, correcting a strong vignetting or a distortion inevitably leads to a chromatic aberration or a loss of sharpness.

Indeed, each user has different needs, but most do not have high-end optics and their exports will be limited to digital use without large format printing on paper. This relativizes the purely technical argument.

However, I agree that we should not reverse the problem and impose on those who do not want it to have to make a preset.

Hence my suggestion of preferences and parameters.

It remains to be seen what proportion of people would be in favor or not.

There is absolutely no way to prove this is true, and is an assumption.

We already have too many preferences. Make a style or a preset and auto apply it.

Darktable applies a minimum set of modules. You’re supposed to make it your own via styles, presets, and auto application. So do that.

9 Likes

I for one would not want lens correction applied blindly to all my images. I have seen many shots were lens correction causes more distortion than it corrects. However, what you propose is best handled not as a preference but rather as a picture style. I have a choice of picture styles which have various levels of sharpening applied using the diffuse or sharpen module and white balance as shot in camera in the CC module. All of them have denoise (profiled) included.

Count me as a not, but it is interesting hearing different viewpoints. What you propose could be implemented as a check box in preferences which I wouldn’t in principle have a problem with but I doubt the developers would want to clutter the preferences section with too many choices. Have a good 2024.

Hello paperdigits and happy new year 2024,

The reverse too

It wasn’t a personal request, I’ve had my own presets, exotic lens characterisations and even body noise profile for a long time now, which I supplied to darktable.org.
The current solution suits me fine.

It’s just a suggestion to make things easier for the less erudite

Yes, clearly. But you used it to write off another argument.

darktable is designed for users who want to have full control over the editing process. So just the necessary modules are activated by default.
It’s not like Lightroom or other commercial tools that needs to be attractive to a wide range of users because that increases revenue…

About the lens & noise modules applied as default to me it is not a good idea. As already said above because darktable is designed to to as little as possible and let user’s apply what they like. This is easy as auto-presets. It would be harder to force people to have auto-presets to disable modules.

7 Likes

There’s no doubt about it, I’m the first to direct new users there.

Not for me either, unless they are conditionally for very specific lenses. For noise above a certain ISO level. In these cases, a preset is sufficient. ( Je n’ai pas non plus dit, Pascal, qu’il fallait que ce soit activé par défaut en “dur” )

But they are not essential in the initial learning of dt. As with any learning process, it must be attractive to the novice, so that from the outset he can produce a pleasing result. I see too many giving up. It would be better if they concentrated on using the main modules: colour calibration, colour balance rgb, diffuse or sharpen, contrast equalizer, tone equalizer… the current core of dt.

My aim is simply to help newcomers get through the difficult early stages.
Thanks to the developers for rgb primaries, which is in this spirit.

The module supports 3 different corrections:

  • geometry
  • TCA
  • vignetting

You can enable any combination of those. For example, enabling TCA and vignetting won’t interfere with geometry:
image

And even if geometric corrections are applied, you get a choice of the projection. For example, stereographic has been quite useful to keep faces natural (at the cost of turning straight lines into curves).

Yikes.

The way I see it darktable is not a tool meant to automagically babysit your pictures.

Besides, those tools are useless CPU/GPU hogs and do not help a new user in any way.

  • They slow down processing on sub-optimal hardware
  • They hide functionality by uselessly overprocessing images
  • They have too many sub-settings in need of tuning based on personal taste

I know you mean well.


Edit: When you think two sentences at the same time and end up
making one of the worst germish grammar mistakes ever.
:see_no_evil: :woman_shrugging:

That’s right. To which we can add (for some) fine adjustment or even manual adjustment of vignetting.
My digital photo collections were taken using 12 lenses, including my current ones. I have almost as many presets as lenses, all of which are active at start-up… but only under certain conditions.

As long as distortion or vignetting are sufficiently discreet, nothing is done. Conversely, mainly with the Laowa 9 for vignetting and the XF 16-80 for distortion, it’s almost compulsory.

Manufacturers take advantage of a digital auto-correction either by the camera during the RAW-conversion into JPEG, including prime lens. This is a big problem for our RAW post-processing method.

I only use 3 lenses and a compact camera, but I find lens correction useful – therefore, I have created a preset:

  1. They hide functionality? What, exactly?
  2. I don’t denoise images all the time, but calling lens correction and denoising in general useless is quite surprising.

Split this from the other thread.

3 Likes

Thank you very much, makes me feel less bad for hopping onto a trainwreck of a derailed thread.

2 Likes

By hiding functionality I mean that the user gets an image presented and has no clue what is going on. As an over the top – and admittedly counterproductive – example you could turn on ALL tools by default, because, hey, that’s what darktable can do, right?

There is no one true way to image editing.

The less defaults you force onto the user the more freedom you give them.
Sure, you need some defaults but sticking to something almost everyone can agree with is better than forcing defaults of tools that have a very high level of personality and taste in them.

I really rarely turn on lens correction, because I consider it a useless pixel peeping enhancement. There are some use cases where the uncorrected lens distracts from the image, so then I turn it on.

Maybe useless was too harsh a word, let’s call denoise a nice bonus because it keeps the filesize of the JPGs down. Other than that it depends sooo much on the image, the usage, the overall mood that there will never be a single default that does it all. So it’s not helpful, let’s call it that.

Hi @kofa the context of my comment is that I would not blindly want it applied in the background. Yes there are shots were it does more harm than good. Thanks for reminding me that different corrections can be chosen. This strengthens my argument that I don’t want it applied blindly. Maybe only vignetting on some images, maybe only TCA, or maybe only distortion is all I wanted applied for a specific image. I will also explore the choice of projections that you have pointed out. Again I learn something new as usually I just click the module on or off and see if I get an improvement. Thanks

@ kofa
Me too, 75% of the time I go with my Laowa 9, XF 18 f/2 R, XF 27 f/2.8 R, I prefer fixed lenses.
My Σ 10-18 f/2.8 (Christmas present) will quickly replace my Laowa. Luckily it doesn’t vignette much and is very sharp in the centre at 18mm, inevitably a little less so in the corners. For the moment I’m not correcting it. I recommend it for APS-C

To be more specific.
With correction,

Without correction, oops !
Useful … as you say :hugs:


( author Jaco - license CC-BY-NC-SA )