Category Archives: darktable lens correction profiles

Darktable lens correction profiles

Dyxum website Dyxum home. New posts. Members Profile. Post Reply. Just a bit of a heads up for anybody that uses Linux and Gimp, Darktable, Digikam etc. It is not supported by Rawtherapee which however does support Adobe profiles. The list of supported lenses may be found here. Unfortunately the list of supported lenses is rather limited.

However here is the good bit - if you shoot a series of calibration images for any lens and send them off to Torsten Bronger, then a suitable calibration file will appear in your inbox after a couple of days. Even legacy lenses can be calibrated. Ensuring a flat field for the vignetting calibration may be the most difficult part, but I found the white ceiling with natural daylight in my living room to be very satisfactory. I've just got back calibration files for the DT 35mm f1.

I'll also do the DT and lenses soon. Any new calibration files go into the lensfun database to be generally available in the next release. Craig, thanks for posting this info. Beyond Gimp everything on Linux is new ground for me. So getting tips like this in Dyxum helps me, and other disillusioned Windows users who wish to take an alternate route for post processing.

I installed Darktable following a different Dyxum tip, I'll certainly be looking into some of these other suggestions you have given. Maybe it would be good to have a digital darkroom sub forum for Linux photo applications to help those who wish an open source route.

Anyone know how to get it going again??? My Flickr. Sony DT now added to the lensfun lens database with corrections for vignetting, CA and distortion. Sony DT will be added soon. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks. Sony DT now added to the lensfun lens database with corrections for distortion, CA and vignetting. This lens has considerable complex "moustache" type barrel distortion at 18mm that becomes a complex pin cushion distortion by 24mm and simple pin cushion distortion at longer focal lengths.

This is well corrected by lensfun. Hi guys, I'm kind of reviving this post with a question to anyone using LensFun on Linux.To keep the preview fast, RawTherapee uses the preview image of the current zoom level when applying these transformations. Because of this, the preview image can become soft. The former will be softer than the latter, though rotating the former will take less time than rotating the latter, which is why RawTherapee does that.

But don't worry, when saving the image RawTherapee uses the full resolution image, so it will be sharp. Do not confuse vignetting with a blurry lens hood being visible in the corners of your image.

Some cameras, typically small ones - compacts, bridge-type and even mirrorless - will capture parts of the lens hood or lens mechanism in the corners of the frame.

Typically the same cameras have lenses which suffer from strong distortion. The way these cameras deal with these two problems is by correcting the distortion, as a result of which the corners of the image get "pushed out" beyond the frame, thereby hiding the corners darkened by the lens or lens hood.

darktable 2.4.0

When you view a JPEG image from these cameras the distortion has already been corrected in-camera, so owners are often unaware that the problem existed in the first place and are surprised to find that the raw image shows these dark corners. Do as the camera does: correct the distortion, and the dark corners disappear. This option will upscale or downscale the photo to the extent that the whole image fits within the image boundaries with no black borders visible.

When correcting images that suffer from barrel distortion"Auto-fill" will perform downscaling to fit as much of the re-projected image as possible into the image boundaries, so that you don't unnecessarily lose any parts of the image.

darktable lens correction profiles

Conversely if the image suffers from pincushion distortion, "Auto-Fill" will upscale the corrected image to fill the frame without black borders around the periphery. When activated, it will not cause image interpolation, but instead will crop away the empty space left by the distortion correction or image rotation. Use the " Select Straight Line" button to set either a vertical or a horizontal image alignment.

Use the mouse to draw this line - click and hold mouse to start, move to draw a new vertical or horizontal axis and release to engage image rotation. As of RawTherapee 5. Both rely on a profile which contains the parameters for correcting lens distortion, vignetting and chromatic aberration. Lensfun is an open-source project. A database of lens parameters is maintained by the developers. You can find more information in the Lensfun FAQ. The options "Auto-matched correction parameters" and "Manual correction parameters" both use the Lensfun system.

Both the "Camera" and "Lens" comboboxes will contain long lists of cameras and lenses if they do not, your RawTherapee build is buggy - please report that.

A profile matching your camera and lens will be auto-detected if your photo contains metadata which matches an entry in the Lensfun database. In both cases you could try to find and run the executable lensfun-update-data to download the latest version of the Lensfun database.

You can find the camera and lens name and parameters contained in your photos by viewing the Exif quick info panel in RawTherapee, shortcut key "i" in the Editor tab.

If parameters for your camera and lens simply don't exist, view the Lensfun documentation to find out how to measure them and contribute them for everyone's benefit.

Should you need to use a Lensfun database in a custom location, you can point RawTherapee to it by editing the options file and setting the DBDirectory key's value to the absolute path of the custom Lensfun database file.

Adobe provides and offers tools to create and share what are called Lens Correction Profiles. These are text files which describe the distortion, vignetting and chromatic aberrations CA of a lens, so that simply loading this file in LCP-capable software such as RawTherapee will correct these issues. Select an Adobe LCP file read the guide on how to get LCP profiles to automatically correct geometric distortion, vignetting and lateral chromatic aberrations.

The Lens Correction Profile tool's distortion correction feature can be used together with the manual Distortion Correction tool, and the vignetting correction feature can be used together with the manual Vignetting Correction tool. This lets you use the manual controls in addition to the LCP profile for artistic reasons or if the LCP fails to sufficiently correct a parameter which happens on some extreme distortion occasions, like with some heavily distorting compact cameras.

Be careful that you don't overdo the distortion and vignetting correction by forgetting to turn the manual tools off if you use the LCP equivalents. The vignetting correction feature however is linked to the Flat Field tool, so that when you select a flat-field image then the LCP's vignetting correction will have no effect.The correction group contains the modules that will correct typical problems in an photo such as hotpixels, spot removal, noise, lens correction among others.

This group also includes the basic sharpening tools. This module works by enhancing the contrast around edges and thereby enhances the impression of sharpness of an image. In darktable this module is only applied to the L-channel in Lab color space. USM applies a gaussian blur to your image as part of its algorithm.

Rawtherapee VS Darktable How Do They Compare

This controls the blur radius which in turn defines the spatial extent of edge enhancement. Too high values will lead to ugly over-sharpening. Contrast differences below this threshold are excluded from sharpening. Use this to avoid amplification of noise. Each frequency band can be tweaked independently. Note that the edge parameter only affects the wavelet basis, not the image directly.

Adjusting the slider will upscale or downscale the splines on the y-axis. The slider was added as a convenience tool to help you modify the strength of the effect. It is not a module parameter in itself; when you leave darkroom mode all changes will be consolidated into the spline curves.

Have a look at the presets where there are a broad variety of examples that will provide a good starting point to gain an intuitive understanding of the controls. The darktable team, with the help of many users, has measured noise profiles for various cameras.

Differentiated by ISO settings we evaluated how the noise statistics develop with brightness for the three color channels. Our set of profiles covers well above popular camera models from all major manufacturers. The json format is quite straightforward and explained in depth in json. You can replace the default noise profiles by your own ones and specify that file on the command line when starting darktable.

If you generate your own noise profiles don't forget to share your results with the darktable team! Based on Exif data of your raw file, darktable will automatically determine the camera model and ISO setting. If found in its database, the corresponding noise profile will be used. If your image has an intermediate ISO value, the statistical properties will be interpolated between the two closest datasets in the database, and this interpolated setting will show up as the first line in the combo box.

You also have the option to manually overwrite this selection to suit your personal preferences better.

darktable lens correction profiles

The top-most entry in the combo box brings you back to the profile darktable deems most suited. This module can eliminate noise with two different core algorithms. Setting this to higher values can give more sharpness. Processing time will stay about the same. This parameter is here to fine-tune the strength of the denoise effect.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It only takes a minute to sign up. I took some raw CR2 photos and want to edit them in darktable.

The focal length is quite low and the distortion high. Usually I correct the distortion by using darktable's lens correction module which automatically chooses the right values based on the exif information.

It works for DSLRs but for this very camera the values are not known. Unfortunately, as of right now, darktable doesn't have a very good way of doing ad hoc distortion correction for a lens you don't have a lensfun profile for. The following is a dirty hack that may be useful in cases where the barrel distortion at the wide end of a zoom is so strong that even "incorrect" correction might be an improvement Now, when you change the value in the "mm" dropdown menu, you should get different degrees of generic "defishing"; start at the largest mm values and work down the list until you find something that looks closest to correct.

Clicking the circular arrow button to the right of the "scale" slider will auto-adjust the scale to the largest crop with no blank pixels. If you're trying to correct "pincushion" distortion at the long end of a zoom, change the mode to "correct" instead of "distort".

Missing lenses are probably added in the latest version of lensfun. The problem is that lensfun don't get updates via the packet manager. To update the database you need to run this command lensfun-update-data as root. Sign up to join this community. The best answers are voted up and rise to the top. Home Questions Tags Users Unanswered. Lens correction in darktable when my lens isn't known?

darktable lens correction profiles

Ask Question.With Affinity Photo 1. I did not recongnize any automatic correction when the RAW-File is opened in Affinity I opened the image with the default Finder Preview space key and saw no difference between the preview and the opened image in Affinity Photo. Here is the list of the supported Lenses, currently supported by Affinity Photo, which I'm sure will be added to over time.

It will only apply the corrections if needed, so sometimes you may not see any difference. Some improvements have been made to this and are in the latest beta build available here. I work with two Zeiss prime lens. Affinity Photo displays "Unknown 33 85mm" instead of the correct lens name. How can I tell whether my lens is recognised correctly by AP?

I can answer my own question: in AP 1. What confused me is that toggling the Lens Correction setting in the Develop Assistant does not dynamically modify the displayed image. But, upon opening two copies of the same image with Lens Correction on and off, respectively, the corrections become apparent. Here is the list of the supported Lenses Just want to point out a typo error on this list. Usually the lensfun database allows to make custom updates see for example hereat least when used in a system wide or shared manner.

But I somehow doubt that the Affinity APh software installs and re uses the lensfun database in such a general system-wide dynamic shared manner.

FWIW, in the Mac version some all? Many of them have names beginning with "liblib," which I think indicates they are specific to AP. One of them is "libliblf. Affinity Photo 1. The lens list is not on the forum afaik, and is the complete Lensfun database of around lenses.

Patrick Connor Serif Europe Ltd. Latest releases on each platform. In the list it is listed but no effect. Is the camera and the lens not available as a correction? I hope you can adjust that. Greats Dieter. I note that the TZ is in the current lensfun database but I am not seeing any lens corrections on my raw files.

Lens/Geometry

Have played around a bit with Darktable - it uses the Lensfun data too. I edited the appropriate Lensfun data file to replace TZ with TZ and thereafter the lens corrections occurred automatically with Darktable. Previously I have been using DxO Photolab for my RAW development but have to say I think I am getting better output using Affinity Photo so I just need to get the lens corrections right so data is a little more correct for my manual adjustments ['easy' when there are straight lines around, otherwise less so] and then I think Affinity Photo may be my main photo editing program.Darktable and RawTherapee developers are actually quite proactive in the way they support various flavours of raw files, reaching out to users to submit samples for an analysis.

I've had quite the opposite experience with a n expensive commercial package, where I was told by the support on a couple of occasions over the years that they'd add a support for a given camera if an unspecified number of people submitted a request for it -- simply put, some of their clients get the support without begging for it, whereas others have to stand in line as if they paid less for their product and were asking for a favour.

I'm not inclined to support such practice if I can help it. Be careful though as some settings can make darktable very slow to export files. Also a lot of localized edits can bog any system down, but that's just a fact of life for commercial software as well. A solution for that is baking the raw file into a working tiff file the moment the program gets slow. It breaks the non-destructive workflow but for some types of work it's unavoidable, e. Another option is making sure you use the computing power of your graphics card.

Some of the noise settings were way too aggressive but can be toned down. Increasing the patch size seems to help. The one thing that is currently bugging me a little is the color rendering, its nice for some colors but quite off for others. I'm hoping theres some way of adding some kind of color profile to get closer to original colors or more natural colors.

I think RT was better in this respect. I make my own camera profiles with a free command-line utility DCamProf. There's a commercial version of it called Lumariver Profile Designer. Those profiles made specifically for the use in C1 have to be processed in a special way in darktable -- you need to use the "unbreak input profile" module and probably change the first value linear to 0.

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With improved autofocus and a large touchscreen interface, we found ourselves really enjoying it. With a fast lens, GPS and useful tracking features, and Raw support, Olympus's flagship rugged compact continues to be the best waterproof camera on the market. While improvements like HyperSmooth 2. The Lume Cube 2. It's also pretty pricey among its competitors, but its feature set and quality of light may win you over. Find out more in our full review. Whether you've grown tired of what came with your DSLR, or want to start photographing different subjects, a new lens is probably in order.

We've selected our favorite lenses for Nikon DSLRs in several categories to make your decisions easier. We've selected our favorite lenses for Canon DSLRs in several categories to make your decisions easier. We've selected our favorite lenses for Sony mirrorlses cameras in several categories to make your decisions easier.

The fixed lens camera market may be a bit niche, but it's here that you'll find some of the best cameras you can buy. Sensors ranging from APS-C to full-frame are designed to match their lenses, which cover ranges from mm equivalent, so image quality is top-notch.

Profiling a camera with darktable-chart

Although a lot of people only upload images to Instagram from their smartphones, the app is much more than just a mobile photography platform. In this guide we've chosen a selection of cameras that make it easy to shoot compelling lifestyle images, ideal for sharing on social media. Submit a News Tip!Many image files contain metadata about how the image was created.

In case of digital camera images, a standard called Exif is used, this standard allows a camera to record many details about how an image was taken.

However Exif is not a singular well defined specification, there is a common part that is well defined, and there are the so-called MakerNotes. The MakerNotes are parts of Exif that each vendors gets to do with whatever they like. They are typically completely undocumented, and have to be reverse-engineered to be able to handle them in any way.

And without a reference lookup table such a number is quite useless. If you can find your lens in one of the above source files, it means even though your current version of Exiv2 might not recognize the lens, the developers are already aware of it, and a future release of Exiv2 will likely be able to recognize that lens. Presuming Exiv2 and thus darktable detects your lens properly, it passes the lens name off to the Lensfun library, which searches its own lens correction database for that particular name.

But for this to work the name Exiv2 supplies and the name in the Lensfun database need to be a fairly close match. Share this on: Twitter Facebook. CR2 grep -ai lens. To improve the situation with exiv2 I would propose: 1. Moving the lens information out of the cpp files into external files.

This would allow to add new lenses without to recompile exiv2.

darktable lens correction profiles

Move this files into extra packages, that can be released independent from from exiv2. With this changes it would be possible to create a website where everyone can upload an image.

The EXIV information is read and the user can enter the name of the lens. This information get saved into the lens information file and can be released in the next version of this file.

The user could even directly download the file and save it in the right folder and benefit immediately. It would be even possible to send this information e. With this implemented everyone would benefit: 1.

The exiv2 developers, because: a They don't need to change the code for new lenses. The users and all project using exiv2 because: a It will be easier to add new lenses. I think this sounds like a nice GSoC project or a crowd funding project.

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FC on Sat Feb 14 :. How can I check whether one is supported? How do I profile one? Do I need to profile it together with the lens, or somehow separately? Does it need profiling with every single lens I intend to use it, or is it enough to profile it with just one lens?

Mazhe on Sun Feb 15 :. Have you considered including an internal snapshot of exiv2 to fallback on when system version is not adequate? Since exiv2 is also cmake-based, this should be quite trivial Having lens recognition is a convenience feature, absolutely nothing critical depends on it.


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