davidp

I have a Sony RX10 IV. In looking up the best settings for taking an extended pictures of the sky at night trying to get the stars moving I get a little confused. If I want to have the lens open for 15 or more minutes what should the camera be set at? I did 5 minutes and the trails were small and at 35 minutes the picture was almost all white. Thanks ahead for any advice.
Dave

Anvil Loc: Loveland, CO

The approach that has worked for me has been to take many shots (a couple hundred), each one about 30 seconds, and then use a program like StarStax (https://www.markus-enzweiler.de/software/software.html) to stack them into one shot. StarStax is free.

Your camera's longest exposure, without going into bulb mode, is probably 30 seconds. That is one reason I recommend that shutter speed. You are going to need some kind of intervalometer to control the shutter. If you use a 30 second exposure time, you can just lock the intervalometer in the "ON" position for 30 minutes, an hour, whatever you like. The intervalometer is keeping the shutter button pressed, which is causing the camera to take shot after shot after shot.

Even with 30 second exposures, one after another, you'd see some, small gaps in the trail. StarStax will address that.

Using that approach, I was able to get this one. I really don't recall how long this was, but I think it was an hour's worth of shots.

(Download)

morkie1891

Steve Perry has a good video on YouTube that walks you thru the entire process.

rgrenaderphoto Loc: Hollywood, CA

Plus, you got photo bombed by an aircraft passing overhead, which can be difficult to remove. Since my star trail shooting time is 90 minutes, I can remove the offending frames and still get StarStax to create a pleasing image.

rgrenaderphoto Loc: Hollywood, CA

Here is what I use, I do not know if the RX10 has the controls that a fully featured DSLR does, but that being said, these settings work every time:

Set camera up pointing to North with a compass. If you use your Smartphone's compass app, take it out of the case. I've seen metal in cases effect compass readings. Do this before sunset, as it is a lot easier in daylight. It helps to have something in the foreground of the shot, to give sense of proportion.

Camera on sturdy tripod, leveled, fresh batteries.
Set camera up pointing to North with a compass. If you use your Smartphone's compass app, take it out of the case. I've seen metal in cases effect compass readings. Do this before sunset, as it is a lot easier in daylight.
Set camera into manual focus, focus to infinity. If the RX10's lens creeps, a bit of gaffer tape will hold it in place.
Set ISO to 400
Set shutter to Bulb and connect your intervalometer. I recommend the Vello ShutterBoss.
Set aperture to full open, you want to Hoover in as much light as possible.
Set Custom White Balance to: No Moon 4000k, Partial Moon 4500k, Full Moon 5200K.
Turn off an long exposure, High ISO processing, Image preview, back screen.
VR, if enabled, to OFF.
Once sky is dark, find Polaris (North Star) and center in viewfinder.
Once focus to infinity is set, cover viewfinder with gaffer tape or close shutter if available.
Minimum shooting time is 90 minutes, or until camera battery runs out.

Intervalometer settings, based on Velo ShutterBoss:

Delay 0.00.00
Long: 0.04.00 - 4 minute exposure
Interval: 0.00.01 - 1 second between shots
N: 0 = no finite limit.

I hang a glow stick from my tripod to be able to find it in the dark. No headlights after shoot starts, will bleed into image.

Do a test shot with the Intervalometer to make sure you get a 4 minute exposure.

Hit the button on the ShutterBoss (refer to manual) and let 'er rip.

I sit in a camp chair and stare at the stars for 90 minutes. You will have about 360 images in the can. After 90 minutes, turn off Intervalometer to stop process. I usually do 2 star trail sequences per night.

Steve Perry Loc: Sylvania, Ohio

Here's the video that was referenced above:
https://backcountrygallery.com/how-to-photograph-star-trails/

Takes you through it step by step