I shoot some timelapse sequences during dusk hours using the method recommended by gwegner, adjusting shutter speed, and ISO manually during the shoot time.

This work pretty well, but I like to keep my shutter speed very slow in the beginning stage (during day light), so I able to get very smooth sequence with motion blur of people or vehicles. I have 3 stops, 6 stops, 10 stops ND filter and a circular polariser filter, but it is not possible to change filters within 10- 12 seconds interval.

So I purchase a variable ND filter, and think this will be a solution, able to change the exposure during the shooting.
Yesterday evening I shot a timelapse sequence of city skyline using this variable ND filter, but when I try to post process this timelapse sequence with LRtimelapse, I realize this method is not workable.

As variable ND filter is basically a polariser filter, so if I rotate the filter during the sequence, it not only change the amount of light enter the lens, it also polarise the light in the sky, or changing the reflection on glass, and any reflective surface like water, tiles etc. So LRtimelapse won't able to even out the exposure of all these changes.

The only way to use variable ND filter for changing the exposure during timelapse sequence is to rotate slowly through out the whole sequence.

Sharing this just to let everyone know, so you won't make a same mistake like me.

Thank you for your report.
I don't recommend using Vario-ND filters for that at all because of the points you described. Additionally the Vario-NDs will introduce wierd diagonal, uneven shadings that change position and size when you change the filters density. Impossible to correct. Furthermore Exif-Data will not reflect the changes so that Key-Frames Wizard and Holy Grail Wizard won't detect them as well.

Yes, I aware that I can't use the maximum strength of the Vario-ND filters.
The Holy Grail Wizard not able to detect some of the changes, so the not able to even out he exposure changes, the deflicker workflow also not able to even it out.

Now I know this method won't work.

It will be good if there is a way I can start sequence with the shutter speed at half a second instead of 1/250 or higher.
anyway, I have tried to correct my timelapse sequence manually, it has the smooth motion effect I want, except those sudden changes of reflections on buildings and some part of sky.

You caould use a lens with manual aperture ring and start shooting stopped down.

Yes, currently I'm using a Tilt shift lens, which is manual aperture ring lens, will try shoot start from f16 and open up to f5.6 to see the results.
Thanks for the suggestion. :-)

I shoot some timelapse sequences during dusk hours using the method recommended by gwegner, adjusting shutter speed, and ISO manually during the shoot time.

This work pretty well, but I like to keep my shutter speed very slow in the beginning stage (during day light), so I able to get very smooth sequence with motion blur of people or vehicles. I have 3 stops, 6 stops, 10 stops ND filter and a circular polariser filter, but it is not possible to change filters within 10- 12 seconds interval.

So I purchase a variable ND filter, and think this will be a solution, able to change the exposure during the shooting.
Yesterday evening I shot a timelapse sequence of city skyline using this variable ND filter, but when I try to post process this timelapse sequence with LRtimelapse, I realize this method is not workable.

As variable ND filter is basically a polariser filter, so if I rotate the filter during the sequence, it not only change the amount of light enter the lens, it also polarise the light in the sky, or changing the reflection on glass, and any reflective surface like water, tiles etc. So LRtimelapse won't able to even out the exposure of all these changes.

The only way to use variable ND filter for changing the exposure during timelapse sequence is to rotate slowly through out the whole sequence.

Sharing this just to let everyone know, so you won't make a same mistake like me.

Thanks so much for this enlightenment

Yes, currently I'm using a Tilt shift lens, which is manual aperture ring lens, will try shoot start from f16 and open up to f5.6 to see the results.
Thanks for the suggestion. :-)

Did this work out as I have a very important dusk time lapse project and I was wondering what to do to increaase the exposure while using a (fixed nd filter to  avoid the problems you mentioned prior)?

This post was last modified: 2017-06-17, 09:52 by Gunther.

What exactly is the question? With the holy grail method, you can just adjust exposure, iso and aperture when you need it. LRTimelapse will smooth everything then.

Don't use a variable ND filter!

This post was last modified: 2017-06-17, 18:25 by ElFalal.

What exactly is the question? With the holy grail method, you can just adjust exposure, iso and aperture when you need it. LRTimelapse will smooth everything then.

Don't use a variable ND filter!

The question is " If  I use a Fixed 6 stop Nd filter in  a dusk timelapse will  LRTimelapse smooth everything ?"

Sure.

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