Dehaze Slider in Lightroom CC and ACR CC

[Mike Buckley]

Maybe the best option is to take one shot with a neutral card in hazy conditions so that you have at least an initial reference point for WB.

That would be effective if the quality of light is the same where the neutral card is placed and where the haze exists.

[Mike Buckley]

Randy,

Thanks for the link to Julianne's explanation. Her blog also contains a link to a video she produced, though the video presents no information that is not in the text of the blog and vice versa.

Thanks also for the before-and-after images demonstrating your use of the Dehaze capability.

I'm not sure if I am understanding your 'order of adjustments.' Is that a comparison, to see which works, doing the temp and then the dehaze or the other way around?

It's based on Julianne's recommendation to adjust the white balance before using the Dehaze slider. (I would always try to get the white balance correct as my first edit step regardless of the likely edit steps to be used later.) In some situations though, you won't be able to properly adjust the white balance or at least the color balance until the haze is eliminated. That would likely be true in the example of Manfred's treatment of my image shown earlier in the thread. Indeed, in my own version of that image, I wasn't able to properly adjust the color balance in certain areas of the image until the 8th edit step and that was because I had to first apply all of the adjustments affecting the haze. In those cases, it might be better to remove the Dehaze function after adjusting the white balance and color balance and then reapply the Dehaze function once we are satisfied with our white balance and color balance.

[Brownbear]

Thank you to all for sharing. When I saw this thread I was especially excited to think that there might be some hope for some of my hazy mountain images, but alas from my first try today, I think Mike's method works better because one can apply his adjustments selectively.

Perhaps not fair to say from a first try but while the dehaze slider seems to do a great job of dehazing mountains it also darkens the entire image and results in unnatural dark colours/white balance.

[Mike Buckley]

I think Mike's method works better because one can apply his adjustments selectively.

From Julianne's blog: "Dehaze can be added locally by applying ACR as a Smart Filter in Photoshop."

while the dehaze slider seems to do a great job of dehazing mountains it also darkens the entire image and results in unnatural dark colours/white balance.

I would say that it is the haze that makes the image unattractively bright. So, once it is removed, it's to be expected that the image would become darker. Indeed, one part of my method of removing haze is to darken the affected area. As for the white balance being affected, I would expect the color balance if not also the white balance to be off after using the Dehaze capability. Hopefully you've seen the discussion earlier in the thread about that.

[Brownbear]

Hi Mike,

Thank you for advising.

1. I will learn how to use Smart Filters...

2. I recall your lesson in haze removal which involved darkening the shadows and warming up the WB (to the best of my recollection)... I will revisit the posts. I tried it very quickly on a bunch of images and the colours seem to change in an odd way with increasing application of the de-haze function. Even when I tried adjusting the WB, before and after, as was suggested.

Thank you, as always.

From Julianne's blog: "Dehaze can be added locally by applying ACR as a Smart Filter in Photoshop."



I would say that it is the haze that makes the image unattractively bright. So, once it is removed, it's to be expected that the image would become darker. Indeed, one part of my method of removing haze is to darken the affected area. As for the white balance being affected, I would expect the color balance if not also the white balance to be off after using the Dehaze capability. Hopefully you've seen the discussion earlier in the thread about that.

[TonyW]

After reading this thread, I have just tried the haze remover in ACR and found that it worked well but also created a blue cast as in Manfred's example. At this stage, I would adjust the white balance and then see if the haze remover needed tweaking again and probably repeat a couple of times. I don't see how you could get the white balance right before using the haze remover.

[dje]

Here's my demo, I thought it was quite impressive. The image ended up with some purple fringing in parts of the sky which I had to fiddle around with to remove. I also had to back the saturation off.

View in Lightbox to get the best comparison.

Dave

[rachel]

I'd be interested in de-hazing. I took lots of pictures of the Andes when I was living in Santiago and they were almost all affected by haze.

I just noticed an offer in Digital Camera magazine for a free full version of Perfect Effects which apparently includes a dehazer. It's only available for PC and Mac and not Linux, but it might be of interest to some of you.

[Manfred M]

After reading this thread, I have just tried the haze remover in ACR and found that it worked well but also created a blue cast as in Manfred's example. At this stage, I would adjust the white balance and then see if the haze remover needed tweaking again and probably repeat a couple of times. I don't see how you could get the white balance right before using the haze remover.

I found that this blue overtone came out when the filter was pushed to the extreme. In the example I was using, this was really the hazy background and sky. While I didn't post the corrected image, the fix was quite easy; make a selection the offending super blue areas, apply an appropriately large feather and desaturate the area and the image came out looking "correct".

[TonyW]

I found that this blue overtone came out when the filter was pushed to the extreme. In the example I was using, this was really the hazy background and sky. While I didn't post the corrected image, the fix was quite easy; make a selection the offending super blue areas, apply an appropriately large feather and desaturate the area and the image came out looking "correct".

Yes. I didn't find it hard to correct the white balance although in my case i did it slightly differently.

[Mike Buckley]

Another demonstration of the Dehaze slider that is so effective that it reveals a monster dirt spot on the sensor (and the photographer doesn't even mention it!)

[davidedric]

I have just had a play with the (free) Prolost Dehaze preset for Lightroom. If you have CC it just positions the slider to the same value as specified in the Preset (there are nine positive and nine negative values). If you don't have CC, my understanding is that it uses Lightroom's Dehaze in the same way, even though you can't move the slider yourself.

Dave

[Mike Buckley]

This article explains the effect of using the Dehaze slider to eliminate light pollution in a photograph of the sky captured at night. Very impressive!

[dennybeall]

Don't know why you'd want to but it will also add haze if there is non there. Perhaps for a Dawn of the Dead series???

[proseak]

There is a way to do this, but it's a bit fiddly - here's a link from DPR;

http://www.dpreview.com/forums/post/56001178

[davidedric]

Just thought I'd try out dehaze on some of my Africa pictures. There's no mist, surprisingly, but especially towards the end of the dry season there is a lot of dust, almost everywhere. It works very well. No need to go mad, but it improves things in a way which would be beyond my pp abilities.

Dave

[Mike Buckley]

Thanks for reporting your impressions, Dave. Very helpful!

[Manfred M]

I've started using this new tool almost as a matter of course for most of my outdoor images. During the months where the air temperature is above the freezing point, there is almost always a touch of haze in the air, and it is certainly quite prevalent in hot and humid summer conditions.

I find settings between 5 and 15 almost always improve the image sharpness with no discernible negative impact (unless you like a slightly softer image).

[Dave Humphries]

Earlier in the thread there was discussion suggesting applying Dehaze first, to help identify the correct WB required (which I can see may be helpful), then removing Dehaze, applying the (now known) 'correct' WB adustment and then re-applying Dehaze.

It is also my understanding that adjustments in ACR and LR are 'parametric', therefore, I see no advantage to the final few steps - surely it makes sense just to process however suits your workflow; either WB first then Dehaze, or Dehaze, then WB - "job done".

This simpler process obviously would not hold true if adjusting WB outside of ACR/LR though.

Please note that the above thoughts are offered on a theoretical basis, I have not tried it yet to see if it makes a difference which order you apply the 'final' adjustments of WB and Dehaze.
If my theory is correct, all other things being equal; if the same numeric values of Dehaze and WB (with Tint) are applied in either workflow order, the result should be identical.

I may 'give it a whirl' later and post the results.
EDIT:
I guess it may depend how much 'intelligence' there is in the algorithm that determines the precise breakdown of channel adjustments and these could be altered by a different starting point (caused by the WB setting) - I'll definitely give this a try

I think it is will be a 'personal preference' which order people do these two adjustments in and even then, some subjects may require one to reverse that order for certain images.

I suspect that both adjustments should be done fairly early in the image's work flow though, so given that other adjustments will almost inevitably be carried out (a few seconds) later, it really doesn't matter if the results immediately after setting the Dehaze are the correct WB or not.

Cheers, Dave

[Mike Buckley]

Earlier in the thread there was discussion suggesting applying Dehaze first, to help identify the correct WB required (which I can see may be helpful), then removing Dehaze, applying the (now known) 'correct' WB adustment and then re-applying Dehaze.

It is also my understanding that adjustments in ACR and LR are 'parametric', therefore, I see no advantage to the final few steps - surely it makes sense just to process however suits your workflow; either WB first then Dehaze, or Dehaze, then WB - "job done".

I made those suggestions not being a user of ACR or LR for these purposes and I still haven't tried using the Dehaze slider. Your comments make sense to me.