About keeping the same f-stop
Posted 22 August 2011 - 01:41 PM
I worked in a short film where the DoP to maintain constant the f-stop in each scene, he varied the ISO (we did not have ND filter). Is it a right way to do it (without reaching extreme ISOs)?
Posted 22 August 2011 - 02:29 PM
If you want to maintain a constant depth of field, why not stack NDs (0.3ND) (0.6ND) (0.9ND) and try to set a standard exposure for your dimmest, least illuminated scene, and work from that to how much ND you need for your brightest scene?
In other words, I would SET your ISO for the dimmest lighting of the movie, then build up ND filters to your brightest scene (although past three stacked filters - still 9 full F/stops - you get noticeable softening) before I would change ISO or lens aperture.
EDIT: I see you have no ND filters - buy some! You will be rewarded with a consistent professional look. Only in a music video calling for bizarre changes in noise amounts would I do what you are suggesting. Compression noise is not aesthetically pleasing, just like extreme chunky, muddy film grain.
Edited by K Borowski, 22 August 2011 - 02:31 PM.
Posted 22 August 2011 - 02:40 PM
It would also be appropriate to change ISO when changing locations (For example, you're inside at say 400, and then outside @ 100.)
Posted 22 August 2011 - 03:58 PM