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LRT and the VIEW XMP

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#1 Joe_Belanger
If I pull my VIEW XMP files into my image directory and load them into LRT (shooting Nikon NEF), the idea is that I'd get smooth transitions. But as soon as I go into Lightroom am I able to make exposure adjustments without losing the XMP smooth transition I'm supposed to get? Or is it moot as soon as I make corrections? I put a day to night through LRT and it does not output flicker free time lapse. But I did that without using XMP files from the VIEW. I'm getting frustrated with LRT as most of my time lapses processed through there have plenty of flicker even with using the holy grail tool. I've followed Gunther's training video and I'm not doing anything different than that. I have smooth pink lines that are nearly exact to the deflicker curve, so the transitions should be spot on.  Looking for a different way than relying on LRT to develop the transitions for me.

Thanks in advance for the help.

Joe
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#2 Gunther
Hi Joe, if you use XMPs from the View, you should see those corrections appear in the "Ext Lum Default" column. LRTimlepase will then transfer them to "HG-Lum Leveling", this allows you to keyframe the exposure in Lightroom. Don't use the Holy Grail wizard, if you want to preserve the corrections from the view.

You'll get a very similar result, if you use the "Holy Grail" Wizard. It will do its own corrections, instead of using the externally provided ones from the View. It's up to you.

In any case, you should apply Visual Deflicker, to smooth everything out.
If after deflickering, you get a smooth pink line, normally the playback should be smooth too.
If it's not, like you are reporting, your sequences has "contrast flicker", that means changing contrasts that cannot be easily removed.
There are 2 reasons for contrast flicker:
  1. Overexposed images - if the image before or after the camera adjustment has blown highlights and the adjacent image not, then of course you will see this. It's not flicker, but it does not look nice. Blown highlights cannot be recovered. Next time try to expose less.
  2. Too much editing on the keyframes. If you use certain "non-linear" tools in Lightroom to a high extent, like Dehaze, Clarity, Whites, Blacks - Lightroom might introduce contrast flicker. Try a more neutral editing on the keyframes in order to get smooth results.
Again - if the pink curve is smooth - then the overall luminance of the visual previews matches closely. Any remaining visual effects are not LRTimelapses fault.

Maybe you could post a link to your result here, that would make it much easier to evaluate what's going on.
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#3 Joe_Belanger
Thank you, Gunther.  To be honest, it could be my editing. One of the things I do (and maybe I shouldn't) is to drag the highlights slider all the way to the left and the shadows slider all the way to the right then use the whites and blacks with the "OPTION KEY" held down to find my white and black points. The image looks very good but I am unsure of how that might affect lighter or darker images that appear after that particular keyframe.  I took a class with Ron Risman and another guy names Casey Kiernan both of whom explained the non linear application of those variables you mentioned, so I don't use them for holy grail unless I am using a mask across the Milky Way.

Anyway, it is my SINCERE hope that this flicker experience is me. I really want LRT to be my go-to solution and avoid having to load in XMP files.  I will post a link and some screen shots and maybe this can be a learning thing for people newer to LRT and Holy Grail.  Most of my TL editing prior to this was through Photoshop and Final Cut Pro.  Once I bought my slider and started doing hoy grail I found LRT (about a year ago). Works fine for daytime. I just haven't dialed in the right "mojo" yet for holy grail. 

Regards,

Joe
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#4 Gunther
You can easily test this by exporting a holy grail sequence that you edited with the Holy Grail Wizard (or View XMPs) and keyframing only exposure. Nothing else. Then you'll most likely get a perfect result.
You approach with Highlights and Shadows all the way and Whites Blacks, is most likely the reason for the problems.
After confirming this (by doing the test I just suggested), you can try adding a bit of editing. Try using the parametric tone curve instead for contrast enhancements, it behaves more linear.
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#5 Joe_Belanger
If I use the VIEW XMP files will they be overwritten when I do some Lightroom exposure tweaks, save metadata to file then go back into LRT and output?
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#6 Gunther
Again: LRTimlepase will migrate the View's Exposure adjustments to a background layer, so that you can easily keyframe Exposure additionally. It will happen on two different layers. You can individually change exposure on the keyframes without messing with the Views Exposure-compensations. That's a huge advantage when working with LRTimelapse.
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#7 Joe_Belanger
Thanks, Gunther. I was (and am a little) getting confused because over in the VIEW Facebook group Jay is suggesting that I CANNOT tinker with exposure at ALL. Here is his comments.

" When applying these changes to all of the images in the folder (and thus changing the XMP data), you should 'UNCHECK' the exposure setting to all of the frames so that you are not applying the current frames exposure setting to all of the frames."

So a couple of things that don't make sense.

1. I don't copy metadata manually like that so I can unclick the exposure box in LR.  I use your sync feature.  

2. You say I CAN play with exposure he says I can't.  Now, I did do an output with the VIEW XMP's and changed exposure and there was still 'some'flicker but that was correctable with your deflicker tool.  Much better output than I was griping about earlier.  

So I think I could use your wisdom. If I'm hearing you correctly....

1. Drag in the VIEW XMP files (this smoothed everything out). No need to use Holy Grail if I use VIEW XMP.
2. Go to LR and edit any linear slider I want (including exposure), but try to keep those adjustments subtle and not over do it
3. Bring back into LRT.  Reload, transition, save
4. Visual preview (this saves a crap load of time than rendering only to find out you need more tweaks)
5. If needed, add some deflicker, save.
6. Preview - approve or add more deflicker if needed
7. Off to LR, read meta from file, export

So the real misinformation in my mind is can I use exposure adjustments with VIEW XMP's. You say yes, Jay says no.

Here's the link to the discussion if you want to chime in.

https://www.facebook.com/groups/395686464095972/


The thread starts out like this:

"If I pull my VIEW XMP files into my image directory and load them into LRT, the idea is that I'd get smooth transitions. " 

You can see near the bottom where Jay is giving me some tips.  Perhaps we can get some misinformation realigned.  I think it "USED" to be that an exposure adjustment would invalidate the XMP's but you addressed that in LRT at some point.

Thanks. This has been a great learning experience.

Joe
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#8 Gunther
Jay obviously doesn't know the LRT workflow very well.

Here is an faq on how to use LRTimelapse with sequences from the view: https://forum.lrtimelapse.com/Thread-usi...rtimelapse
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