In-camera noise reduction or not?

[the lemming]

I'm on holiday at the moment, somewhere top-secret and dark. I wish 🙂

I've got a holiday let in Wiltshire which has an adjoining field and so little light polution that I can just about see Andromida by eye and definitely by binoculars. But it's a steep learning curve and I only have a couple of nights left of clear skys before home time.

I have a 7.5mm f2 lens, camera (GH5) and tripod.

With trial and error I think that I have worked out that I can use a 15 second or possibly 20 second maximum exposure with ISO 2000 to get pin-sharp stars.

For Star Trails I have the shutter speed of 3 seconds at ISO 800. Is this about right or can I push things further?

Is it better to use in-camera noise reduction or use my computer's processing power to do this for me?

I'm experimenting with Starstax, Sequator and lightroom to reduce noise.

[Nik271]

If you record raw files you can replicate any noise reduction in the camera later in software. So my advice is leave it off and deal with it in lightroom.

If you are stacking that automatically takes care of the noise. A general practice is to shoot several dark frames at the same time at the same settings with the lens cap on. These basically record the read and thermal  noise of your camera. Very useful if you do loooong exposures, like minutes. For 30 seconds with a modern camera I have found that dark frames are not essential. But definitely shoot raw and NR off. The stacking works best if it has as close to raw data as possible.  

 

Nikolay

Edited September 17, 2020 by Nik271

[Adam1234]

2 minutes ago, the lemming said:

 

Is it better to use in-camera noise reduction or use my computer's processing power to do this for me?

 

You could take advantage of the high ISO and long exposure noise reduction built into the camera, but this then doubles the time taken to take each exposure, so in a given amount of time you get less light frames. As you've only got a limited time on your holiday I'd personally make the most out of your time and concentrate on getting your light frames, as these are the most important.

 When you are back home or whatever take a load of bias frames (shortest exposure possible) to calibrate your lights with and do some noise reduction in post processing 

[Uranium235]

Leave it switched off and create calibration frames at another time (but taking care to re-create the ambient temperature conditions if poss), as you dont really want the camera processor messing too much with your data. Advantage of this method is that you now have a library of calibration files (at different settings) you can use over and over again.

[Alien 13]

I sometimes use the in camera long exp noise reduction if I am shooting single frames on a static tripod with foreground, the extra 6-20 seconds or so is a small price to pay for a perfectly matched dark.

Alan

[the lemming]

Thank you everybody for your help.

🙂