Proper exposure for taking a sunset, stars, and moonrise timelapse

Question

I'm planning to take a sunset to nighttime to moonrise timelapse. On the day in question, the conditions are:

• Sunset at 7pm
• Nighttime at 8pm
• Milky Way visibility at 8:30pm
• Moonrise at 2:30am at 15% phase (visibility).

I have taken sunset timelapses before and I have done a little bit of astrophotography, but I haven't combined them or taken good stars + moon photos.

For sunset timelapses, I generally use the following exposure settings:

1. Set ISO 100.
2. Set mode to aperture priority.
3. Set F/4 @ 10mm
4. Set exposure compensation -1EV.
5. Take a picture every 15 seconds.

For astrophotography, I use the following exposure settings:

1. Set ISO 1600 (I think that's the highest noise I'm willing to endure).
2. Set F/4 @ 10mm
3. Set shutter speed to between 60s - 90s (confirm exposure and adjust).

My first question is what are common settings for photographing stars with a 15% moon.

My second question is how to properly shift from sunset to stars to moon settings properly without creating a jittery timelapse (I use LRTimelapse for editing, btw).

Thank you

Answer 1

After asking this question, I went out to do the shoot. I made several mistakes but also learned some valuable lessons (for me) and I wanted to share them. I was able to get a reasonable sunset to milky way timelapse (see here for results)

As I mentioned, I made several mistakes. Here are some:

1. I miscalculated and the moon rose out of frame.
2. I took too few pictures (1 every 2m, it should have been at least 1 every 30s or 15s, I think)
3. The lens fogged up (which you can see at the end of the sequence).

A quick note about my equipment. I used a Nikon D7500 with a Tokina 11-20mm F/2.8 and a Vello Shutterboss.

There are basically 3 periods in the sunset to stars sequence. The first is when the sun is visible. The second is twilight between the time the sun disappears and total darkness (this usually takes about an hour). Phase three is when the sky is completely dark.

Phase 1 While the sun is settings on the camera I used moved between 1/8000s F4 100 ISO down to 1/500s F4 500s. This kept the image at 0EV.

Phase 2 This is the transition phase. You want to keep it as smooth as possible between phase 1 exposure and phase 3 exposure, which I will talk about later. Here I tried moving from 0EV to -1EV so as to show the sun setting and the sky getting darker. I first continued to lower shutter speed until I got to about 10s, then adjusted to F2.8, then continued adjusting started raising ISO to about 1600, and then did finally adjusted for phase 3.

Phase 3 For starlight exposure, I did not want to get star trails. I checked PhotoPills and it told me not to go above ~20s exposure. So, my settings for this phase were 20s F/2.8 2000 ISO.

Hope this helps anyone else who might be trying the same thing.

Answer 2

The "Looney 11" rule of thumb for exposing the moon is f/11 with 1/ISO shutter speed, or equivalent exposure: https://en.wikipedia.org/wiki/Looney_11_rule

Answer 3

My second question is how to properly shift from sunset to stars to moon settings properly without creating a jittery timelapse (I use LRTimelapse for editing, btw).

For timelapse sequences at twilight, you will get best results by using a bramping intervalometer ("bramping" = bulb ramping). A bramping intervalometer not only controls the time between exposures, but it also controls the duration of each shutter actuation, to slowly ramp up or down the exposure time to account for anticipated changes in lighting conditions (such as increasing/decreasing sunlight at dawn or dusk).

However, even with a bramping intervalometer, there will be some unavoidable shot-to-shot variability or flicker, even if lighting is constant. The primary reason for this is because the aperture cycles between fully opened and closed (to the desired set point) for each shot. Before the camera takes a photo, its aperture is fully wide-open, regardless of the aperture you have set. This is to get as much light as possible through the lens, in order to help the autofocus and metering system. Once you actually take a shot, the aperture is closed to the desired size, and the shutter is then actuated.

For most modern camera brands, the aperture is electronically controlled. The glaring exception is Nikon F-mount cameras with non-E lenses. This includes pretty much all Nikon bodies older than 10 years, and all more recent Nikon DSLRs with most 3rd party lenses, and any Nikon non-E lens (which is still most of their lenses).

For instance, your Nikon D7500 is capable of controlling an electronic-aperture F-mount lens (Nikon's own electronic aperture lens have an "E" suffix, such as the AF-S Nikkor 28mm f/1.4E ED). But the aperture on your Tokina 11–20mm is actuated by a mechanical spring-loaded linkage to physically open the aperture. The opening-and-closing action of your lens's aperture has a lot more shot-to-shot variability than a EF-S mount version of that same lens mounted on a Canon body.

Not that any of this is fatal to your process; tools like LRTimelapse will do a good job of smoothing out the flicker. But it's good to know why th input sequence still might have some flicker, even when using a smooth bramping intervalometer.

See also:

• What is bulb ramping?
• What is the best practice to handle making time lapse in a changing lighting conditions in the morning?
• Where can I find a "bulb ramping" intervalometer which will work with a Canon T3i? (a little old, and asking about Canon, but some of the recommendations still apply)