1st Attempts at Astrophotography

[H18 ENF]

Looking for tips and feedback please folks.

I know my way around film cameras but it's frustrated me for years that I'm a real novice when it comes to stills!

So, being a self proclaimed space nerd I thought I'd try pointing at the stars.

These are the results of the best 2 photographs I could manage. Can anyone advise how to improve as they are bloomin' grainy and I have no idea whether this is an issue with something I'm doing in camera or something I should be doing better in Lightroom?

All suggestions welcome!

Thanks

[eltawater]

What are your settings?

[H18 ENF]

eltawater said:

What are your settings?

Bugger, sorry I thought I'd posted those!

Canon 7D ISO 3200, 25 secs @ f/3.5

[anonymous-user]

ISO 3200 is going to be grainy, maybe try lower ISO and longer exposure.

[H18 ENF]

Okay, I'll do that next, thanks!

[eltawater]

Careful on the longer exposures, you might end up with star trails.

[steveatesh]

I have had one night at this, my shots were useless primarily because I didn’t have the focus right.

On the plus side there’s loads of help and advice online for setting, plus the rule to use for shutter speed, it’s something to do with 500 being divided by your focal length to give you the maximum shutter opening to avoid trails.

I used a 24mm lens so I made sure all my shots were less than 20 seconds shutter speed to avoid star trails.

The next moonless night is 7th September I understand, so I’ll be out giving it another go, just got to improve that manual focus technique!

[DIW35]

To get round the problem of grain if using high ISO or star trails if using lower ISO and longer shutter speeds, you can do multiple exposures and stack them using free software. I can't remember the name of it, but a Google search should bring it up.

[Sparkov]

You're going to struggle slightly if f/3.5 is your widest aperture, but it's worth looking at the ISO you're using. Lower ISO settings often don't result in lower noise in low light situations due to some cameras being 'ISO invarient'. You might actually get less noise using a higher ISO such as 6400 or even 12800 (assuming shutter speed and aperture remain constant):

How to Find the Best ISO for Astrophotography: Dynamic Range and Noise

It may also be worth looking into taking multiple images and 'stacking' them in post processing to average out the noise:

Stacking: How To Reduce Noise In Photoshop For Astrophotography Like a Pro

[H18 ENF]

DIW35 said:

To get round the problem of grain if using high ISO or star trails if using lower ISO and longer shutter speeds, you can do multiple exposures and stack them using free software. I can't remember the name of it, but a Google search should bring it up.

That's interesting! Thanks

[Gad-Westy]

H18 ENF said:

DIW35 said:

To get round the problem of grain if using high ISO or star trails if using lower ISO and longer shutter speeds, you can do multiple exposures and stack them using free software. I can't remember the name of it, but a Google search should bring it up.

That's interesting! Thanks

Starstax, among others.

[richelli]

Be aware if you camera is a crop sensor then you have to factor in the crop factor with the lens focal length. So a 20mm lens on a 1.6 crop factor becomes a 32 mm lens. So when you work out your maximum shutter opening time you need to use 32mm not 20mm.