Interval Recording- Changing NDs and Iris?

[groveChuck]

I did my first interval recording on the HPX170 of a sunset- from the bright ball of the sun to near dark (about 45 minutes). 1 frame per 5 seconds.

I've shot many sunsets, and always have the manual iris stopped down for the sun itself, but in doing timelapses with manual iris, I could always see the small changes in iris.

So I said, "I'll shoot this one in auto iris (which I never use) and set Auto Iris Level for -7.
But then as the sun gets lower, I have to reduce the ND, from 1/64 to 1/16.
"No problem" I say, I'll do it during the 4 seconds the camera's not grabbing a frame.

Except that it changes the picture (the optics, I guess) you can see it change the lens flare and colors around :02.
And then as I change to 1/4ND, then no ND, there's a change in image each time.

Also as I change the Auto Iris Level from -7, to -5, -3, -2, -1, to 0.

So, what's the beat way to shoot a sunset timelapse, where the sun's not blown out, you can see colors in the clouds, and keep recording after the sun goes down, with smooth changes???

 

[videoatlanta]

I think you have to strike a happy medium. I have always left the exposer alone. Dial it in for the sun and leave it. This will yield the smoothest final results.

 

[Al MacLeod]

What about a variable nd filter? Change the value over the length of your session. It would leave the iris and shutter alone.

 

[stuckfootage]

I think you have to strike a happy medium. I have always left the exposer alone. Dial it in for the sun and leave it. This will yield the smoothest final results.

I agree. Set it and forget it. Unless you can afford two cameras and do an HDR composite.

By the way, check out the top video (bars+tone) on my website for an example of this.