Flicker Free ETTR Timelapse: - -Beginners Guide & Basic Post Processing --

Started by RenatoPhoto, May 26, 2013, 01:35:58 AM

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aleksi1

Hi everybody, and first: thanks to everyone who has contributed in this awesome tool!

Can somebody explain what is the logic between "highlight ignore" and "SNR limits"? I noticed that if I set a really low value to highlight ignoring (e.g. 0,1%) and a rather big value to shadow SNR limit (e.g. 4ev), the image gets too bright since I guess it's trying to meet the shadow value. So does auto ETTR ignore the highlight limit if the SNR limits require a longer exposure?

I'm asking because sometimes it's difficult to find out what is a good value for shadow and midtone snr limits, and requires a lot of test shots. Take a sunset scene as an example. The problem is that if I set too low shadow/midtone snr value it gets too dark in the pictures before ETTR starts to add to the exposure time. Likewise, if I accidentally set too big value, the images will be overexposed. I think it'd be easier if the "highlight ignore" value would override the SNR limits, so that I could set rather high SNR limits and then the "highlight ignore" would prevent the image from overexposing.

Am I understanding/doing something completely wrong here? I'm using 6d, and some of the recent nightly builds (don't remember exactly which one, but I can check if needed).

Thanks,
Aleksi

a1ex

Right, if SNR limits are reached (that is, the image becomes too noisy), more highlights are clipped.

However, for 6D, try one of the silent picture test builds (look here). This functionality is currently broken in nightly builds on this camera.

aleksi1

Thank you for the quick response! I guess I'll just have to keep experimenting with the values.. And check out that silent picture build :) Is it something that'll come to nightly biulds eventually, or is it always going to be a separate thing?

dchen99

Hi, I am new to ML and ETTR, first thank you very much all for contributing and supporting.
I installed the latest nightly build to my EOS-M and followed the instruction on page one. ETTR is working as I expected. However I am trying to make post deflicker working with xmp and don't seem to be able to have the camera generate xmp files. I have enabled both ettr and deflicker modules, set Global Draw, Zebras, Spotmeter, and Histogram on and started Intervolmeter. When I open the card in my computer I see only the .cr2 files.
Am I missing something?
Thanks,
Don

TheJuice

Hi,
Everytime I try to use the ETTR module for a timelapse, I get the same problem : the images are fine, until the ISO is changed when the module reaches the limit I set. And everytime it does that, I have a jump in exposure between one image and the next.
How am I supposed to correct that? In post? Or am I doing something wrong?
Thanks

dmilligan

Exposure jumps are to be expected. Read the first post for info on how to deflicker.

TheJuice

Ok thanks, if I understand it correctly I have to use the Post Deflicker algorithm and generate a correct exposure offset in the XMP files to have a good exposure ramp...
I'll have to do another timelapse because I threw away (supposedly) good ones thinking I had done something bad :-s

Thejungle

Hello, I would like to export files to some losless format like tiff or dng. How can I do it? I changed "jpeg" in bat to "tiff" but it didn't change anything.

endless_projects

Does anyone know how to solve this one?

I'm finding that if I'm shooting from total darkness to having the sun in frame and I try to add an ND between exposures, the program then starts to double up. I.e. it starts taking 2 shots back to back every 30 seconds. I guess it would make sense that it should do this once after it calculates that suddenly the image is 4 or 5 stops darker because I've stuck my variable ND on the front. But is it a bug that it continues to double up thereafter? Is my only option to stop the intervalometer, restart it with the ND in place, and deal with the missing frames gap in post?

Just to clarify, I'm adding the ND so that I can still have reasonably long exposures and wide apertures after the sun comes up. The only problem with it doubling up is that they are shot with exactly the same settings and not evenly spaced in time. It also means my duration between shots has to be at least double that of my shutter speed. (And obviously it means I have to stop to change cards more frequently).

dmilligan

You have neglected to provide a lot of important information (camera, ML version, settings used, etc.)

endless_projects

My apologies, the details of my set up were:
5dmkii
canon firmware 2.1.2
Nightly.2014Oct08.5D2212
ETTR always ON
Dual ISO on
Intervalometer Take a Pic

I have just tried to recreate the problem using these settings but shooting into overcast sky rather than into the sun and the problem has not occurred. I had been experimenting with ETTR auto snap at the time so that it would retake the shot after I applied the ND. This is now behaving favourably too, it retakes the shot and then goes back to taking one shot per interval. I'm afraid I don't know what I could have been doing differently in the field. Bracketing was off.

I have 8 x 16gb cards for ML so maybe it's one setting on a couple of cards. I will repost if this occurs again or I am able to solve it.

dmilligan

Quote from: endless_projects on February 26, 2015, 01:15:20 PM
I had been experimenting with ETTR auto snap at the time
There's the culprit. I would recommend not using auto snap for timelapse (a flickery scene could trigger extra shots at random times). Instead, quickly adjust exposure manually when adding the ND (this is what I did when I tried doing this sort of thing), or just throw out that one bad frame.

As I mentioned I have actually tried this ND filter thing, but I never could get satisfactory results b/c switching ND filters caused shifts in color that I couldn't really adjust for (which makes sense, a real ND filter cannot have a perfectly flat frequency response), and there would inevitably be noticeable jumps in color in the final sequence. I suppose a variable ND filter hooked up to some kind of stepper motor to slowly change would be a solution, but I don't feel like going to that much effort.

endless_projects

Ok. Could well have been too flickery a scene as I was shooting straight into the sun. Odd that it doubled up shots with the same settings but the guidelines do say to use 'always on' for timelapse so there is nothing to suggest 'auto snap' should work.

Thank you so much for your help!

ddim8

Hi, can someone explain how to choose or the reflexion to have for the right "highlight ignore" for the right setting of the ETTR.
or do I have to set  0.5% for each setting
Thank you

ddim8

it's all right I went to read the Topic: (Auto) ETTR (Exposure to the Right): -- History & Beginners Guide  to understand

RobFlanders

Hi all,

Ive been shooting some stuff in UFRAW mode with Dual ISO mode on.

UFRAW conveniently produces Jpegs, but doesn't sort out the Dual ISO mode, and CR2HDR.exe produces DNG files that can't be fed to UFRAW. Does anyone have a suitable workflow to sort them out?

a1ex

Have an example DNG that could not be processed in ufraw? What was the error message?

RobFlanders

Sorry I may have misunderstood - If I feed the dng's I get out of CR2HRD to UFRAW instead of the old CR2's, will that process the Dual ISO first with CR2 and the ETTR second with Ufraw?

(P.s. thanks for the speedy response - and the awesome feature-set!)

Edit: Seems I am supposed to do that - my google-fu seems to need some work. Thanks A1ex.

Edit2: Ufraw-batch is now looking for a CR2 - when obviously I have used CR2HRD to create a DNG. Obviously there isn't a converter to go back again - what's best here?

Nader

I'm having a frustrating problem with my 5D III ml 1.2.3. The intervalometer is not working constantly with CF Lexar 1066x 128g. Specially when used every 1, 2 or 3 seconds. ML is in a Sony SD class 10 16 gb.
¿Do anyone knows what is going on?

glubber

Quote from: RobFlanders on March 19, 2015, 02:22:50 PM

Edit2: Ufraw-batch is now looking for a CR2 - when obviously I have used CR2HRD to create a DNG. Obviously there isn't a converter to go back again - what's best here?

I got no original .ufr-file by hand, but my guess is that you would have to rename "CR2" to "DNG" inside the ufraw-sidecar.

For example:
<?xml version="1.0" encoding="utf-8"?>
<UFRaw Version='7'>
<InputFilename>E:\ufrawconvert\raw\IMG_2918.CR2</InputFilename>

to

<InputFilename>E:\ufrawconvert\raw\IMG_2918.DNG</InputFilename>

I never made a timelapse with Dual-ISO but to my knowledge a "flickerfree Dual-ISO Timelapse" can be achieved with the --same-level command.
It's simple deflicker in post-proccessing instead of doing it in Camera via sidecar.
http://www.magiclantern.fm/forum/index.php?topic=7139.msg114254#msg114254

EOS 550D // Sigma 18-200 // Sigma 18-70 // Canon 10-18 STM

keepersdungeon

I'm trying my 1st flicker free time-lapse. So module is on XML created, imported in light room, and saw the changes, and it worked perfectly!
But it was too exposed specially when got to night
I wanted to gradually edit the exposure a bit so I installed LRTimelapse and no matter what I do it always overrides the flicker fixed with ML.
Tried to export to dng then edit it and same thing didn't work.
Any help/recommendation would be great.
Thanks in advance.

keepersdungeon

Tried bridge and still didn't work they all override the values of ML and they don't do it well. Isn't there a way to use the xml generated by ML and just tweak the curves like in LRTimelaps?


toddex

Hi - I've managed to get this pretty much working correctly on a 5d m3 but am having some trouble with the color balance. I realize after the fact that I left the white balance setting as "auto" - is there any way to correct this after the fact? I have ufraw with applicable sidecar files, etc. Example video I'm working with (deflicker done with ufraw, merging done with virtualdub - I can provide all the camera and processing settings but I think the issue is specifically with the white balance...): https://vimeo.com/126751429. Issue is especially apparent in last three seconds of video.

Thanks in advance for any input!

Rgds,

-toddex


ansius

white balance is a post action for raw, so you just have to set all image color temperature the same, or as I do in bridge with script i ramp it for sunset time lapses.
Canon EOS 7D & 40D, EF-S 17-85mm IS USM, EF 28-300mm IS USM, Mir-20, Mir-1, Helios 44-5, Zenitar ME1, Industar 50-2, Industar 61L/Z-MC, Jupiter 37A, TAIR-3
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