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Author Topic: LR photomerge when combining multiple HDR dng images--results overexposed  (Read 3222 times)

Paul2660

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Recently I have found what I consider a major issue with LR and the photomerge feature.  When LR first came out with the HDR and Pano features, I was very impressed as now it was possible with single row stitching to keep the work all in LR and LR's ability to keep the output in a DNG format was a plus to me. 

I have worked up hundreds of image combinations, but recently have started to notice an issue when merging multiple HDR files within LR. 

I have attached a lot of screen shots, but they will be all at the bottom of the post as I don't have the editing skill to place them where I want. 

Example, I have a 5 segment series of a sunset.  The series was taken with a Nikon D810 and 14-24 lens, with the lens @ 24mm.  I was set as close to the nodal point as I could determine and was level.  I took the series in 5 vertical shots, each segment was at least 3 bracketed exposures, except the shot which contained the sun, where I took a total of 5 shots to keep from totally blowing out the highlights. 

Workflow:

1.  Create a HDR within LR of each of the 5 segments
2.  Take the 5 HDR dng files and then create a pano. 

Sounds simple, but in reality, LR fails terribly here.  LR is grossly overexposing the process, such that there is no recovery for the are around the sun.  As I am sure most know, the HDR output from LR is very neutral, and has the highlights and shadows sliders, maxed out, Highlights all the way down and shadows all the way up.  This tends to create a very flat looking file, but there is plenty of image left to work on.  However when you take a HDR and then try to create a pano, it's like LR totally redoes the process over and thus blows out the end result.  You can see this in my screen shots below. 

You can of course export the individual HDR dngs and tif and run them in Ptgui, CC or Kolor and you get a fine result.  But that is not what I am wanting to do. 

HOWEVER IF YOU EXPORT THE HDR DNGS AS TIFF AND THEN IMPORT THEM INTO LR TO CREATE A PANO, LR FAILS AND GIVES THE ERROR MESSAGE "UNABLE TO MERGE THE PHOTOS" even though LR just processed out the same darn files as HDR dng's within LR, albeit grossly overexposed.

I also took the 5 HDR's and exported them directly to CC from the LR dialog box and CC runs them fine.  No gross overexposure. 

The other problem I see almost every time, even if the exposure works, is the message "This image appears to be damaged", however you can still work on the file and export it with no problems.  Not sure why the message comes up at all.

To the people closer to Adobe, I pose this question, was LR never designed to take a series of HDR dngs created in LR and then create a pano?

To me this is a gross oversight by Adobe and hopefully can be fixed in a later version, but I hold small hope for that as LR doesn't ever seem to change or modify a process once it's in place.  The movement of the dehaze from a main adjustment to also being available in a local adjustment is an exception.

LR/Adobe has done a lot of positive work on the both HDR and panorama stitching, but this issue to me a pretty much a limiting factor to allow full production for creation of HDR, to pano.

I have had the same issue with Fuji raw, Canon Raw and Nikon raw files.

Paul C

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Paul Caldwell
Little Rock, Arkansas U.S.
www.photosofarkansas.com

BAB

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #1 on: February 11, 2016, 12:12:49 am »

There are few times PS either w/ HRD or Pano works as well as Photomatic for HRD or PTGui for pano, I just used affinity photo for pano it's great. LR has very little control for HRD compared to photo matrices Pro. Adobe could save time and money buying one of theses thrive party companies or partnering up with them(which I'm sure has happened in the past).
On another topic do you use a VR drive and if so do you prefer the Dr. Clauss RODEON piXpert or the Seitz VR drive?
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Slobodan Blagojevic

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #2 on: February 11, 2016, 02:14:14 am »

Paul, that #2 has a +1.05 exposure adjustment. Isn't that the cause of the overexposure?

Paul2660

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #3 on: February 11, 2016, 07:27:49 am »

Paul, that #2 has a +1.05 exposure adjustment. Isn't that the cause of the overexposure?

Hello Slobodan,

Actually I don't think so.  Take at a look at the images I have listed out below.

Image No 5, show the LR pano preview box, and you can see here that the image has been grossly overexposed as if in an attempt at exposure blending?  You can also see the HDR dng in the background.  It's not over exposed at all.  But it also has the same exposure adjustment, as part of the creation of the HDR dng.

Image No 6 Just shows that single image in detail.

Image No 7 Shows the LR pano results, just like the preview, totally blown.  Note the exposure settings are identical to the HDR dng single.  Note also the same message "This image appears to be damaged" I am getting this pretty much with any HDR pano combination

Image No 9 Shows what the LR Pano, after I pulled the exposure down, as you can see the area around the sun is ruined. 

Compare that back to the Adobe CC run, which is basically fine. 

I am not sure if LR developers ever intended to allow HDR pano's just one or the other, if so that is a huge disappointment to me.  The HDR pano will work, however not if you have such an extreme amount of work done on one file, in this case the sun shot.   Not sure if LR folks even know about the problem.  Or if they see it as a problem.  I just find it very interesting that Adobe CC can take those same HDR dng's as exports from LR and it runs the exposure blend fine.  This is shown in the image from my first post.

Paul C

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Paul Caldwell
Little Rock, Arkansas U.S.
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kirkt

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #4 on: February 11, 2016, 08:43:45 am »

I cannot fully appreciate what you are doing to your HDR DNGs prior to trying to merge them into a panoramic composite.  Try creating each HDR and then simply merging those HDR DNGs without changing any of the settings on any of the DNGs. 

If these are truly HDR data, then you should not have to do anything to the DNGs prior to stitching the pano.  Once they are stitched, you can adjust the full HDR pano and apply local adjustments to the areas that may need them.  It appears that your attempt at tone mapping one of the HDR images in the pano is affecting the exposure of the entire pano composite.  Reset all of the DNGs to 0 settings and stitch again and see if the outcome is any different.

In a 32 bit pano workflow, you typically make no tonal (exposure) adjustments to any of the input images for the exact reason you seem to be having.  While LR/ACR has come up with a nice DNG-based HDR workflow, I find it fails pretty regularly and do not use it much.

kirk

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Paul2660

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #5 on: February 11, 2016, 08:58:12 am »

Hello Kirk:

That is exactly what I did, I took the straight HDR's dng files and then went to pano merge.  I did not change anything in the HDR's.  LR is blowing out the conversion during the pano merge for some reason.  And now I am noticing that LR always gives the message "this image appears to be damaged" whenever I create a pano from HDR files. 

Remember, that the HDR dng from LR will have the sliders maxed out for shadow and highlight and sometimes a bit of exposure is added although not all the time. 

I even re-imported the files from a separate location, created the HDR and took those again straight to LR pano.  The results are the same.  Totally over blown highlights. 

Paul C

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Paul Caldwell
Little Rock, Arkansas U.S.
www.photosofarkansas.com

Paul2660

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Re: LR photomerge when combining multiple HDR dng images--results overexposed
« Reply #6 on: February 11, 2016, 09:55:33 am »

One last example.

Same files, re done as HDR then without anything being done to the HDR's, LR pano merge is run.

Note 3 part looks OK, running from Right to left, but there is still a blown highlight ring around the sun, could be fixed in post, but shouldn't be needed.

Note 4 part, same issue, by the time you add the slightly lighter 4 segment, LR now totally blows out the whole series at least in the sky. 

The HDR's were not altered in any way, however LR in the process of creating them used slightly different amounts of exposure.  I did not alter this. 

Also both pano's created, the 3 and 4 part received the same message, "this image appears to be damaged"

As long as there is not an extreme highlight i.e. sunset with sun in the shot, LR seems to pano merge multiple HDR images OK, but even those still get the same error message.

Paul C

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Paul Caldwell
Little Rock, Arkansas U.S.
www.photosofarkansas.com
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