ND For Timelapse. 2011 & 2012, what I learned...

[BobDiaz]

Back in 2011, I purchased some inexpensive ND filters for increasing the time of the exposure for timelapse to 1/2 a second. The problem was that the Tiffen ND filters were pure (insert expletive) and they messed up the color so bad there was nothing I could do to fix it in FCE (Final Cut Express). Here's a copy of the video:




Having learned my lesson, I purchased the B&W ND 1.8 and shot the same basic thing again this year. See video:



The cheap Tiffen ND Filters did show a major shift in the color and the better quality B&W Filter does not show this shift. There may be a very tiny shift, but I have to run additional tests to be sure because it's hard to tell.


Bob Diaz

[eiker_ir]

Were the Tiffen screw on or square filters with a Matte Box? Fader or regular NDs?

[BobDiaz]

The Tiffen filters were just cheap screw-in regular ND filters.


Bob Diaz

[BobDiaz]

I noticed the color was a tad off, so today I ran some additional tests to see if the B&W ND Filter does shift the colors. I'd say yes, BUT it appears that color balance does not work the same when the shutter speed is below the frame rate. Tomorrow I'll need to re-test by setting the color balance at 1/30 of a second and then setting the shutter speed to 1/2 a second.

The current tests show a slight, but correctable shift in the color with the B&W ND Filter, but this could be due to my error.

After 2 years, I'm still learning things about this camera....


Bob Diaz

[Felipe Henao]

Bob B&W seems not to affect color balance at all, at least if you use only one filter, either 0.6 or 0.9

[BobDiaz]

In testing the B&W Filter, I found that the B&W ND 1.8 does generate a slight color shift, but this can be corrected in post. I assume that the higher ND causes this shift, but the lower levels, like 0.6 and 0.9 do not have a noticeable shift. The video below shows the different tests I ran and the results:



Right now I have Final Cut Express and don't have a vector scope in the software to help adjust the color. So everything I do is just by eye.


Bob Diaz

[GrahamH]

I was told a while back that color shift with strong, cheap ND filtration occurs due to excessive infrared, which the camera's sensor remains somewhat sensitive to. The suggested solution (which I have not tried) was to use a "hot mirror" filter. I had never heard of these, but they are available: http://www.amazon.com/Tiffen-52mm-Ho...=I1F28KM3ZX0LT


Of course at that price, one could simply buy a better-quality ND filter.

[antcuc]

In testing the B&W Filter, I found that the B&W ND 1.8 does generate a slight color shift, but this can be corrected in post. I assume that the higher ND causes this shift, but the lower levels, like 0.6 and 0.9 do not have a noticeable shift. The video below shows the different tests I ran and the results:



Right now I have Final Cut Express and don't have a vector scope in the software to help adjust the color. So everything I do is just by eye.


Bob Diaz

You're correct the mistake you made in the beginning was not color balancing. But later in the video after you did balance the problem you're seeing with a light red/pink tint is normal. Any ND filter will not filter out infrared light and the more you increase the ND filter the more you will notice this tint.

Grahamh is correct, you need to use a hot mirror with your ND to filter IR. Or you could get an ND/IR combo:

http://www.bhphotovideo.com/c/produc...l_Density.html