Uncover The Lightroom Demosaic Flaw And Say Goodbye To Halos With These Tips!

[@sebastianebbinghaus]

Thanks for showing us the issue!

[@AndyAstbury]

No problem!

[@mikedaines7843]

Happy New Year Andy. Another good LR/CR demosaicing vid and surely one day Adobe might come back to you with a response! As I said once before in all the years I have been watching KZbin vids on Adobe products, as good as they are, not one of the ‘big’ name contributors have ever mentioned this flaw even when they have referred to halos in their images! On an aside, being another old English ‘geezer’ I quite like listening to your waffle as it makes me smile and always amongst it are pearls of wisdom, please keep them coming.

[@AndyAstbury]

On the point of 'no one mentions this' Mike, see my cynical reply to @freetibet1000 comment!

[@markrigg6623]

Gidday Andy! Adobe just love to do their own thing, but its starting to catch up with them. So maybe they'll snap out of it ....? Seasons greetings, Ive been away from photography for a while, and now I have a huge backlog of your vids to binge on. 😊

[@jhmnieuwenhuis]

Thanks Andy, totally agree. Adobe should add a setting in the preferences for the demosaicing algorithm. I would also be prepared to pay a bit more.

[@AndyAstbury]

If I had my way Hans, I would walk in to Adobe, grab hold of Eric Chan and the senior Lr dev team, and demo what I've done in this video. It's the only way they'll ever become visually aware of the problem to the point where they feel the need to address the problem. They COULD invite me to Adobe Max; but somehow I expect they won't! Which is a shame, 'cos I could use the fee!

[@f-s-r]

Well, the difference between those programs is the difference between people who wants to make the best software they can with their available time, and people who prioritizes making money by making and selling software. Propietary software makers tend to pay attention to features that they think will give them better sales, and ignore bugs that don't seem to be detrimental to sales. They won't invest any resources unless that results in more money in their pockets.

[@-OzSteve]

Thanks Andy, and happy new year to you. Just wondering whether photoshop has the same issue ?

[@AndyAstbury]

Happy New Year to you too, thank you. To answer your question, Photoshop ACR shares the exact same demosaicing routine as Lightroom. In fact, Lightroom does not talk to Photoshop directly. It does so via an interpreter - called ACR!

[@Smillii]

That's really annoying that to fix the problem with Lightroom, you need another paid program for it. I generally don't print my photos so it's technically not a problem for me, but I still notice it.

[@dunnymonster]

As always Andy, thought provoking and informative 😊 Whilst I'm not a Fujifilm shooter ( other than the recent acquisition of an X100 VI ) I know many have bemoaned Lightroom's handling of their .RAF files, the " worms " effect being the biggest complaint. I assume that too is partly if not entirely due to LR de-mosaicing algorithm when met with a raw file from an X-Trans sensor. Be interesting to see how Rawtherapee and others handle such files not just in terms of artifacts but also if they can control pre sharpening halo's as you demonstrate here. Anyway, keep up the great work going into 2025! 👍

[@AndyAstbury]

I'll try! As far as I'm aware, the FOSS editors CAN do a better job with RAF files, but then I have no files to really check for myself. I have some Fuji files, but they are all from GFX's - and those have Bayer pattern sensors in them. So send me some!

[@Eigil_Skovgaard]

Well put Santa. One of the things Darktable should get from RawTherapee/Art is the pre-sharpening. It is very good, and it should be easy to transplant. Another problem with DT is the poor denoising, and when using DxO PureRAW 4 up front with denoising, the demosaicing becomes the one from DxO, and the AI-denoising further enhances high frequency details. In some cases the white edges ends up as bad as with Lightroom/ACR. The only way to compensate is with the two sliders Luminance and Force details. Maybe you could elaborate on the pixel peeping effects of DxO PureRAW 4's denoising - one day, Andy?

[@AndyAstbury]

Eigil - matey, how are you doing!!! Totally agree about the need to 'port' the capture sharpening into Darktable - but I would 'port' ART CS and not RT's, because of where it's located. You can't add capture sharpening in RT to a linear DNG from DXO etc because CS in RT is under the demosaic tab. In ART it's under the details tab. Denoising in DT/ART/RT is not the same technology as Ai Denoise in Lr/DXO PR4 or God forbid, Topaz. I doubt comparable tech will ever come to the three FOSS editors, simply because of the time and money obtaining the huge database of samples required. I could do that video Eigil, but honestly, it's already been done by Steve Perry,and my conclusions are exactly the same as his - here's a link to it matey kzbin.info/www/bejne/namQdqimfa5qfZYsi=_tp_RUuswaWPeg-q Stay well matey, and speak soon - all the best.

[@iainisbald]

Another issue with lightroom's demosaicing is it will produce 2x2 pixels squares on diagonal edges. You can see it on the beak of the first image.

[@Slave-Of-Christ]

I noticed that. Looks terrible.

[@AndyAstbury]

To both; that artifact is called 'mazing' and can be negated by the AMAZE demosaicing algorithm. But AMAZE (anti mazing and anti zippering) is not nice in areas of flat, low frequency detail such as sky. RCD (ratio corrected demosaicing) is a little gentler than AMAZE, and the best for low frequency detail areas is is VNG, or it's modern faster alternate called BILINEAR. The beauty of RT/ART and DT to a point, is that you can use combos of say RCD+Bilinear(my fave default) and you can vary the cross over between the two with a slider! And all that nice fancy stuff is bloody FREE!! Go figure...........

[@johndoe-nh9sh]

Interesting and thanks for bringing this up. I'll be taking a detailed look at this and although I'm not a LR user I do use ACR for my RAW conversion. Here's something to consider... Are you seeing this issue (to the same extent) with images shot against different backgrounds ie not blue sky?

[@AndyAstbury]

ACR/Lightroom/Lightroom Mobile and Lightroom Classic all use the same demosaicing algorithm, so you will see it if you look hard enough. The edge boundaries that show the fault worst of all are either: Smooth sharp edges and curves that delineate complimentary colours (yellow eagle beak against blue sky) or, high contrast edges between high frequency and low frequency detail - such as tree branches or cliff edges and a flat sky. So, the fault can show up in landscapes as well as birds in flight shots, and potentially any style of shot in between. But the edges have to smooth and sharp; you will not see them on edges of furry animals for instance. Couple of things I need to add. 1. you can mitigate them in part by selecting Enhance Details and unchecking the denoise element if you don't need it - but that doesn't remove them totally. 2. since switching to a 45Mp mirrorless Z9, I see a lot less of them. I don't know why this is, because I used to see them on D850 shots. Someone sent me a Z9 file a few weeks ago where there was one big long halo on the underside of a long-billed birds beak. In all fairness, the halos will not impinge on the average user, because their average output involves some sort of shrinkage. But full resolution jpegs with these faults will get rejected by QC at any stock agency such as Getty/iStock - and Adobe Stock; there's irony for you!

[@johndoe-nh9sh]

@@AndyAstbury Thanks Andy. I don't touch the detail tab in ACR (or do any additional sharpening after that in PS). Any noise reduction is done in PS (Topaz) on a duplicate layer. I've never had stock images rejected other than for keywords (using brand name). Camera wise I've shot mirrorless for the last 7 years (a9 then a1 when that came out). I have noticed it a little in some Red Kite images from a few years ago, pale blue sky, bird twisting and diving. I'll have to dig out some WTEs and have a look but I can probably count on one hand the number of trips where birds are against a blue sky from 14 years of photographing those birds on Mull 😂 I did check a nicely lit WTE with fish with hills background and that looked clear but more than anything it's something you've brought to my attention which I am very grateful for.

[@ianemmett2859]

Thanks Andy. Using PR4 with only CA adjustment, do you know why the returned DNG has zeroed the colour noise reduction?? Cheers and HNY

[@ianemmett2859]

Does PureRaw ignore LRs XMP or perhaps generate a completely new one ?

[@AndyAstbury]

Happy New Year to you too! If you make changes to a raw file in LrC, then right click on the image, choose Export>Process Instantly in DXO PR4, the PR4 output should come back into LrC and have the original raw edits applied to it automatically. If that's not happening, then something is awry. Are you following exactly what I do in the video?

[@ianemmett2859]

@@AndyAstbury The Colour Noise is also zeroed on your video... But the profile changes to Adobe Colour when I do exactly as you do. It looks like your profile does not change but I can see it on the video. Very odd... I sent some photos to your email.

[@AndyAstbury]

@@ianemmett2859 CNR is done by DXO at the time it does the demosaic. I turned off LUMINANCE noise reduction - different thing altogether. Go and watch the Steve Perry video if you havn't done that already. Lightroom Ai Denoise invents less false detail than DXO Ai Denoise. So if you have a halo problem, you can demosaic and remove colour noise in DXO, then use Lr Ai Denoise to remove the shot noise (luminance noise) - it does work very well IF and when you need it.

[@ianemmett2859]

@@AndyAstbury That is the process I have used in the past but right now the colour shift is huge even after resetting the profile to Camera Neutral. I sent some photos to your email if you have a chance to take a look.

[@luisfilipe9692]

Andy .. why dont you use Capture One 23 ? you save lot of Headache ;) Cheers ---

[@AndyAstbury]

Hi Luis, as I said in another reply, I've tried C1 many times over the years. I had to use it sometimes (back in the day when it was still in the hands of PhaseOne) because it was the only way of handling PhaseOne raw files. I must add that back then, I got it for free because I was using the gear. Today though, it's just another editor I'd have to learn inside out, and frankly there are not enough days in the week for me to that! The many faults in Lightroom, frankly, I can correct/remove on the rasterized image inside Photoshop, because that's where my longest experience is. So the Lr faults are a pain the butt, but easily corrected - FOR ME. But not everyone has that knowledge, and I'm just hoping that someone, somewhere, will send a link to this video to the Lr devs - but I'm not holding my breath! The other point I was trying to make is that you can avoid the problems by using FREE stuff. And C1 isn't free, and it's not good for me without Photoshop. So C1 + Photoshop would cost more.

[@Jon1a]

I almost never have this problem with ACR ( zoom level is "fit to screen" ) . When it happens , Photoshop can easily get rid of that.

[@bernym4047]

Thanks for this Andy. I only watched out of curiosity as I abandoned all Adobe software years ago. I would watch your videos more often but the amount of waffle and fluff I have to plough through before getting to the pith drives me insane. I usually turn up the playback speed to double until I think I've got to something interesting. I'm sure you could have condensed this by at least 30%. You are in competition with hundreds of similar channels and your viewers have a finite amount of time to spend watching you tubes.

[@AndyAstbury]

That's why I put the chapter time stamps in! I know I'm prone to waffle,, like most other 66 year old English geezer, and all I can do is apologise!

[@bernym4047]

@@AndyAstbury Fair enough :)

[@nyobunknown6983]

Can you see the problem at 100%? If not, then your whole video is a waste of time. I don't view my photos at 800-1600%

[@GerhardBothaWFF]

Maybe you should pay attention to what he says… he says as much. It matters when you need to go big etc… as he says.

[@AndyAstbury]

Thank you Gerhard; you put so more eloquently than I would! Cheers.