Author Topic: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --  (Read 368058 times)

garry23

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@audionut

Thanks for the assistance short of actual help ;-o)

I will keep my mouth shut.

Audionut

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I will keep my mouth shut.

No need for that.  Just try doing a little leg work first.  :)

Audionut

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I've polished the OP a little.  Hopefully it is a little easier to understand. 

I hope to do some more work later, and add some silent pic specific stuff.

dmilligan

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I've polished the OP a little.  Hopefully it is a little easier to understand. 
You linked the wrong script of mine, that one can't deflicker ;)

should be this one: http://www.magiclantern.fm/forum/index.php?topic=8850.0

Audionut

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Fixed, thanks.

smier

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Has anyone experienced ETTR blowing out the highlights on night to day timelapses? Unfortunately I do not have the debug DNGs, but as the sun rose the ISO and shutter speed did not change for probably 25 shots which caused massive overblown highlights (like 75% overblown). There was plenty of time between shots for ETTR to evaluate, and I only had a highlight ignore of 0.5%. Even after it adjusted, it was still a bit overblown but not as bad. This was not in direct sunlight either.


Also just to help me understand, what exposure target does is knocks the histogram back to the left (darker) based on the setting? an exposure target of -0.5 will take the original ETTC calculation and move it 0.5 stops to the left and -1 will move it 1 stop to the left, etc?

What about the in the deflicker module, deflicker target level, how does that work? The wiki states "Desired exposure level for processed pics", and is recommended to leave at -4. I guess this means that my photos will be lowered 4 stops on the histogram with the XMP files.

dmilligan

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What about the in the deflicker module, deflicker target level, how does that work? The wiki states "Desired exposure level for processed pics", and is recommended to leave at -4. I guess this means that my photos will be lowered 4 stops on the histogram with the XMP files.
No, it moves the median (or whatever other percentile level you select, median is just 50th percentile) of the histogram to 4ev from the right. So it doesn't necessarily move it by -4ev, it may actually move it up some if the median is at less than -4ev.

Basically it tries to make the center of all the histograms at the same location.

Audionut

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At highlight ignore = 1%, the image is metered at 99th percentile: that brightness value is adjusted to match the target level. That means, 99% of pixels will be darker than target, the other 1% will be brighter.  See http://en.wikipedia.org/wiki/Percentile

For deflicker purposes, you would meter at 50th percentile (median), so exactly half pixels will be darker than the exposure target, and the other half will be brighter.

You may say why not compute the average brightness (simple or weighted) and use that for metering? Answer: median and percentiles are statistically robust (they ignore outliers => less flicker). Average (mean) is not.

smier

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Thanks for the answers. If I wanted to see the difference between a deflicker target level of -4 and -2, could I shoot at -4 and then use dmilligan's bridge script to additively add 2ev/stops of exposure? Would the results be the same if I were to begin with the deflicker target level of -2?

Audionut

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Should be close enough I think.  Take 2 shots, try it and let us know.   :)

dreamwalker

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Could anyone tell me why I cannot see ETTR menu in my camera (EOS 600D) firmware1.0.2 ml v2.3?
This feature is not supported or something else is the problem?

Thanks for answer, Tom.

Walter Schulz

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You haven't told which version you are using.
Go to module tab and activate ETTR.MO

dreamwalker

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I don't have a module tab either. I use v2.3 or what do you mean?

Walter Schulz

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If you want to use ETTR and other stuff lately developed you have to run a nightly build.

dreamwalker

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..ohh that.. :) now I understand.... Thank You!

dreamwalker

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OK, now works :)

CreativeEndeavor

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So I screwed up tonight and wrote out UFRAW instead of XMP for the sidecar files for a timelapse.  Is there a way to convert the .UFR files to XMP to use the Bridge Ramp Multiple and Deflicker Scripts?

If not, what is the workflow for adjusting the images (preferably in Adobe Camera Raw) prior to exporting them to JPEG via UFRAW?  Any help greatly appreciated.


dmilligan

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Is there a way to convert the .UFR files to XMP to use the Bridge Ramp Multiple and Deflicker Scripts?
You don't need to, the Bridge script will deflicker for you, even without XMPs from the camera.

isaacgolding

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I hate to say it, but Ive read over the whole thread a couple times and to be honest I'm still confused about the work flow.

I've been trying the XMP workflow with Bridge CC2014 on the Mac  (bridge 6.1.blah) and I'm missing a step or adding a step because I end up with a lot more flickr.

I'd love to see an updated workflow for the XMP/Bridge method of deflicker

isaacgolding

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So I'm still struggling to really nail down ETTR timelapse with post deflicker using XMP ACR via Bridge in Mac.

I went to a very nice vista and pointed my camera into the sun over a scene and followed the ETTR tutorial with setup for XMP.  I processed via the directions for XMP Bridge and ACR and then assembled the pictures using GoPro's video software (which does a great job of converting jpg timelapse into video)

Here is the end result.

I'd love some suggestions and I can make a zip with the original 300 some pics available if somebody wants to look at those settings.

CreativeEndeavor

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Re: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --
« Reply #296 on: August 08, 2014, 08:37:05 AM »
Found a bug:  When I checked the resolutions of the past couple timelapses I've shot, I noticed some of the images being cropped from RAW 5760 X 3840 to 5760 X 3240.  I am not sure what is going on because this is a new problem for me after shooting with ETTR before.  I have the aspect ratio set to 16:9 for HD.  What information do you need from me to figure out why this is happening?

I will crop the errant images by hand in Photoshop unless there is a better solution.

Thank-you for your time.

a1ex

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Re: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --
« Reply #297 on: August 08, 2014, 09:02:59 AM »
Code: [Select]
In [622]: 5760./3240
Out[622]: 1.7777777777777777

In [623]: 16./9
Out[623]: 1.7777777777777777

=> bug invalid.

JasonMillard

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Re: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --
« Reply #298 on: August 08, 2014, 07:58:54 PM »
Tried a time-lapse last night but was completely off.  I am very new to this and read through the posts.  When setting everything up i get stuck on this step:

Take two or three pictures until the RAW histogram ETTR hint is less than 0.2j

How does one exactly perform this?  Any videos showing a step-by-step process of setting everything up?  I am also not sure what is meant to be doing throughout.  If i set it up properly do I just click the shutter to engage the intervalometer and sit back for 2 hours or do I have to manually make changes as the day turns into night.  If so how?

The settings I have for a sunset tonight in NY (start at 7-9):

1. 5d Mark iii - 50mm 1.8 lens on MF
2. WB: 2700
3. ISO 100
4. Shutter 1/50
5. Ap f 16
6. Auto ETTR : slowest shutter (32") highlight ignore (.5%) 5ev/3ev
7. Global Draw: On, all modes
8. zebras: raw RGB
9. Spotmeter: raw, afbox
10. histogram: raw histobar
11. Intervalometer: ON, 15s, stop after 480 shots
12. Post deflickr: Adobe XMP/50%/-4EV


Sorry.  I understand the overwhelming knowledge and the experience of this community far outstrips my very new-to-the-game disposition.  But I appreciate any help and advice!

I'd love to get great shots of the sunset in Queens tonight and make sure the set up and process is accurate before I overwhelm myself with my Mac and the post-process!

Cheers.

barepixels

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Re: Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --
« Reply #299 on: August 08, 2014, 09:54:48 PM »
I see a conflict here

slowest shutter (32")
Intervalometer: ON, 15s
5D2 + nightly ML