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+--- Thread: Concern with a DSLR modded (/thread-8650.html)
Concern with a DSLR modded - djoubert - 2017-01-30
Hi,
First I would remind how I enjoy to use LRtimelapse, And I realised a lot of timelapse with it, enjoying to use it.
This post is about one concern I met time to time,
I am wondering what I miss in such a case
or wondering if this is linked to the fact it is a Canon 6D modded ?( infrared filter replace for astronomy use )
My concern:
After following the full process, I get special flickering that I am not able to remove.
I made many tests including some test without any Lightroom treatment.
for instance a case at sunset with holygrail process applied regarding the parameters changes. the modded Canon 6D / Samyang 85mm opened at 1.4 / shutter speed 1/15esc
The bad effect is between 2 pictures each time the ISO changes.
This pictures are saturated ( is it the root cause ? ) and the original white balance is the one provided for daylight use.
I guess Gunther will have a look to this post. I could provide the CR2 files ( 30 to 50 for illustration ? )
I am expecting to know what I missed or to explain if it's linked to the modded DSLR ?, and the way to avoid this concern?
On the other hand I succeeded to have quite good sequences with this modded DSLR.
Thank you very much for any help
Dominique
RE: Concern with a DSLR modded - Gunther - 2017-01-30
Hi Dominique, with very saturated and perheaps a bit over exposed images it's important to set a reference area for the deflicker (draw it into the preview panel with the mouse and make sure that it's on a part, that's not clipped (oversaturated).
Then do some deflicker / refine steps to get the purple curve smooth.
For such sequences, sometimes one deflicker step is not enough.
For refining, after applying deflicker, just wait until the visual previews have been created again. Then apply deflicker again, with the refine option.
RE: Concern with a DSLR modded - djoubert - 2017-01-30
Hi,
Thank you for your ansswer,
Actually when I said I was not able to remove the flickering, it was already applying the way you propose ( drawing a subpart in the preview panel) and applying Deflicker + many refines.
I will try agin, choosing a part which is not clipped... this is not easy because the flickering appears only on saturated part...
I will try and be back to give the results
Thank you for your help
Dominique
RE: Concern with a DSLR modded - djoubert - 2017-01-31
Hi Gunther,
I did many try, and I am not able to get a correct result.
( I know the very good results whe can have, using deflicker process very often )
in this case, and time to time some sequences I am not able to succeed...
So I would appreciate if you could have a look.
I uploaded the Raw sequence, if you agree, you can download here : https://we.tl/xKWSSbyJAZ
Actually the concern is 2 times for consecutives frames linked to the ISO changes.
Possibly linked to fact that it's a modded DSLR ?
Thank you very much if you can have a look
Dominique
RE: Concern with a DSLR modded - Gunther - 2017-01-31
I've looked at your sequence. Those images have massively clipped highlights. They are just overexposed. I'm sorry, but it's not possible to correct that. When you combine clipped highlights with the holy grail, you get that typical "pumping" because at the adjustments the one image will be "more blown" as the other and then you'll see the effect.
I'm sorry, but LRTimelapse cannot fix this since the image information in the highlights is not there.
This has nothing to do with you astro modified camera, it would happen with any other camera too.
My recommendation is to closely watch the histogram when setting up an shooting. As soon as one of the RGB channels starts to blow, make your adjustment. Maybe with the camera that is more sensitive to red, you will have to be even more careful.
RE: Concern with a DSLR modded - djoubert - 2017-01-31
Thank you very much
I saw that these frames was overexposed...
... and now I understand the effect that could lead when it is with an Holygrail sequence.
Thank you to have took time on my pictures, and for your explanations.
it's quite clear now, I have to take care when shooting....
Best regards
Dominique
RE: Concern with a DSLR modded - djoubert - 2017-02-04
HI Gunther,
One more time, thank you for previous explanations, I involved my comprehension.
Nevertheless, I am back to this post with some questions.
I would appreciate if you could provide me with more information.
-1- When the "HG lum levelling" data are calculating, are initial "White balance" parameter taken into account ?
-2- I guess that the initial preview, without any treatment is based on the initial "White balance" parameter, Am I correct ?
I ask these 2 questions because analyzing more holy grail sequences where I have the typical "pumping" you explained, are done with my moded 6D ( I have one modded, and another one not modded ), and the specific personalized "white balance" leads in some cases clipped histogram either on lowlights or hightlights ( I am often shooting sequences starting or ending with the night...
So if the answer is yes at the question -1-, is there any possibility to reset the "HG lum levelling" data based on the new "White balance" from Lightroom treatment ? ( when it's clipped, the "white balance" change could allows to avoid clipped histogramme. )
Thank you very much.
Dominique
Not Urgent, the answer can wait until monday or tuesday
RE: Concern with a DSLR modded - Gunther - 2017-02-04
The Lum Leveling has nothing to do with Whitebalance. LRTimelapse always works on RAW file, the whitebalance is only applied to the previews, and doesn't have any effect on the final output.
The initial previews shows the camera previews with white balance applied, but again: no influence on the final output.
When you edit the keyframes in Lightroom, you'll manually set the WB. This is what matters, together with the exposure used here.
In your examples, the RAW files are clipped. That's what makes the final video pump.
You are right, that there might be cases, where the previews are clipped but the raw files not - but in those cases, LRTimelapse will produce perfect results, since the original previews will be displayed, but never used for the final clip.
RE: Concern with a DSLR modded - djoubert - 2017-02-06
Hi,
Thank you very much,
I was dreaming about one way to recover such a bad shooting...
I apologize to have insisted with additionnal questions.
Your information are quite clear.
I involved my knowledge !
Thank you
best regards
Dominique