How to favour exposure time over ISO?
So let’s start the ball rolling. This is a question that has been asked in many different guises on the TLV FaceBook page.
Supposing we know what the final exposure should be for a night exposure (good old 500 rule) and we want to keep the ISO as low as possible, how do we config that?
In my experience I often end up with an exposure time lower than my target and an ISO that is higher. The overall exposure is often correct.
As of right now (firmware v1.7), it’s not possible to set specific parameters for the night exposure. The VIEW tries to optimally select the best exposure possible given various constraints, the primary being the interval.
If you want a night shutter speed of 30s, for example, keep in mind that it’s actually 32s exposure time (powers of 2), plus 3-4 seconds for processing, so your night interval in this case should be 36 seconds (32 + 4).
Within the interval, the VIEW will try to keep the shutter as long as possible (unless you set a limit) and the ISO as low as possible.
Think the desire here is for the algo to adjust exp time favored over iso, so for example if the max interval is 36 the view would first reach an exposure of 30s @ 50-100iso then resort to iso as the last defense to maintain the exposure.
What I think would also be interesting would be a programmed interval increase over the course of the shot or perhaps even interval keyframes so the change in speed can be controlled or spread out through a shot making the interval transition a little less abrupt curve.
“powers of 2” could explain a great deal. Does that however imply only 2/4/8/16/32 etc? But I typically end up with 20 sec shutters.
So a desired shutter speed of 25s would also require a 36 sec interval? Would a 24s shutter speed only require 28 sec or would that also need a 36 interval?
I would be very happy with a shutter speed of 24s and an interval of 28s.
If that is true my problem is how to set 24s as my Nikons only allow 20, 25 and 30s shutter speeds.
it depends actually on what kinda timelapse you try to make. And the conditions you are making your timelapse , clouded or not , dusk , full sun,…. .
My preferrence i also exposure first than iso to be honest. Certainly when i try to make astro-timelapse where my exposures are going above the 30s. because i’m afraid my images get to blurry otherwise. i’m even go most of the time not higher than 800-1600. but this has more to do with the lightpollution where i live than thinking about the noise 🙂