order of operations for holy grail milky way timelapse

Let's help each other to become better photographers and videographers. Tips and tricks for better photos, videos, timelapse etc. are welcome.
Post Reply
Posts: 41
Joined: November 19th, 2023, 2:42 am

March 2nd, 2024, 6:25 pm

This might be a newbie question, but then I am a newbie.
When choosing the ramping order for a holy grail milky way time lapses I was thinking of:
0. Focus at infinity during daylight.
1. begin with a landscape-appropriate aperture, e.g. F8 or F5.6.
2. Set the limit aperture to that I would choose for a single astro exposure, eg F2.2 on my Sony 14mm GM.
3. Set the max shutter speed to 10 seconds with an interval of 30 seconds (would 15 second be better).
4. Set the max ISO to 6400, as i would typically not use a higher ISO for single exposures.

Does this sound reasonable?

Should the ramping order be Shutter Speed, Aperture then ISO. or Shutter Speed, ISO, then Aperture?
Posts: 29
Joined: October 31st, 2023, 4:04 pm

March 2nd, 2024, 8:04 pm

The answers to your questions depend on a lot of parameters:
0. Focus to the most remote object which should be sharp. E.g., when i take pictuters of the night. sky, I use the live view of my camera with highest magnification for focusing manually to get a sharp picture of a star. Setting just to infinity might be a bad idea.
1. I usually use a fix aperture, because changing the aperture during the sequence might produce weird results because of the change in DoF.
2. see 1.
3. The intervall is a result of the longest exposure time + the darktime. The darktime is the time the camera needs to write to the SD/CF card and to get ready for the next picture. So you have also to take into account of how long UNLEASHED needs to calculate the values for the next picture. Do not underestimate this!
4. The max ISO depends on the noise your camera produces. For night skies I usually have not more than 3200 ISO. But you can test this easily by making some test shots.
Posts: 1127
Joined: October 9th, 2018, 4:17 pm

March 4th, 2024, 10:29 am

The default ramping order for a sunset is Shutterspeed->Aperture->ISO.
Please note that you always specify the ramping order for a sunset. For a sunrise it will actually use the reverse order!

Your procedure sounds about right, with a few notes:
First of all, as a developer, I like that you start your list with a 0 not a 1 ;-)
0) You'll want the stars in focus, which is not very easy to achieve, as most lenses can focus beyond infinity, so the focus you want will be just before the infinity stop on your lens. Having to set focus during the day is therefore not ideal, but the best you can do is focus on the most distant object, for example clouds, or a feature on the horizon. Or better yet, focus on a bright star the night before (Hint: Bahtinov Masks can really help), and put some tape over your focus ring so it won't change until your shoot on the next day.

1/2) By default we set the day and night limits to the current aperture - ie even if it's in the ramping order, it won't actually get ramped. Some people suggest that changing the aperture will also introduce more flickering, as apertures other than fully open are never perfectly the same from shot to shot, though this will probably get smoothed out in post. However, changing the aperture has the most obvious effect on the look of the image, changing depth of field, and vignetting, the latter being quite obvious in the sky - almost always a very important part of holy grail timelapses. And lastly, with shutterspeed and ISO (especially if you're fine with ISO 6400 or higher), you already have an incredible dynamic range, so you seldomly need the additional 3-4 stops you might be able to get from also ramping Aperture.
I personally usually shoot wide open for two additional reasons: A) when shooting through a glass window, you're less likely to see dirt particles/raindrops on the window, B) when my camera (Nikon Z 7II) is set to silent shooting, the only noise it makes is changing the aperture to anything other than wide open.
i.e wide open it's 100% silent, so I can shoot timelapses while sleeping in a hotel-room with a great view.

3) Typically, you will want to use an interval as close as possible to the longest shutterspeed you're planning to use. ie if you set your shutterspeed night limit to 15 seconds for Milky Way shots, add 2 seconds for the Unleashed's processing time, and set the interval to 18 seconds. The avid reader might have noticed that my arithmetic seems off, but it's actually the camera manufacturers time measurement that's off: setting shutterspeed to 15s will actually make the camera trigger for 16seconds, and 16+2=18. Same for 30s actually resulting in a 32s exposure. However you might also want to try to get a cinematic look, by choosing settings close to a 180º shutter angle, ie the exposure being exactly half of the interval. This is of course difficult for bright days, and even more difficult for holy-grail timelapses, but can be achieved with ND filters in some cases.

4) yep, generally this sounds good! However, if you're planning to end on milky way shots, you can do some test shots the night before, and set your limits to the perfect Milky Way exposure settings, which might actually be lower than you think! That way, even if the Algorithm might want to try to further brighten your exposure, the night limits will make sure it won't. I found that 8s, f/2.8, ISO3200-6400 is actually great for Milky Way shots!

I hope this helps!
Founder & CEO of Foolography, Hardware & Firmware developer.
Post Reply