Advice for the meteor showers tonight.

Panasonic LUMIX DMC-LX100

08/12/2009 05:12:06 AM · #1

//news.bbc.co.uk/1/hi/sci/tech/8197303.stm

I did a test shot last night and even tripod mounted with a remote shutter cable, there was motion blur in the stars. My 1st guess would be the planet revolving just enough during the 30 second exposure to blur them slightly ? For those of you chuckling away please educate me ;) I need all the help I can get here !!
I've seen some amazing starry night photo's on here ( green and dark skies alike ) and wondering if you could share your thoughts, wisdom and settings in case we're lucky enough to get a clear sky here tonight !
Many thanks in advance and happy snapping those of you who are lucky enough to see it too !
- David.

spiritualspatula

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

08/12/2009 05:27:51 AM · #2

Yeah, 30 seconds is enough to invoke blur from movement of celestial bodies.
Check out this tutorial for some basic info.
An Astrophotography Primer

Canon EF 17-40mm f/4L USM

08/12/2009 05:32:56 AM · #3

Many thanks for such a quick reply - I will look at it right now !

LoudDog

Canon EOS-350D Rebel XT

08/12/2009 06:51:42 AM · #4

I found with night shots you either want to go at least 15 minutes (more is better) to get full up star trails or just a couple seconds to avoid blur and tiny star trails.

A nice long 30 minute shutter with star trails and several meteors may be an interesting shot?

08/12/2009 08:02:00 AM · #5

Thanks LoudDog,
I'm wondering even at the highest F number and lowest ISO setting could you get a 15minute bulb mode exposure without it whiting out ?
I tried that once for a lightning storm and it didnt go at all well, just kept whiting out after a couple of minutes. Would love to hear where I've been going wrong !
Is it a combination of exposures ?
Big thanks once again to spiritualspatula for the link - it was very informative and some gorgeous photo's there which I will try to learn from.
Clear skies here so far, fingers crossed they will be tonight !

kirbic

Canon EOS R5

Canon RF 24-70 f2.8 L IS

08/12/2009 10:47:30 AM · #6

Assuming that you are using ISO 100 and a relatively large aperture (f/2.8 or f/4), you can expect that:
- Under dark skies, 3- to 5-minute exposures are easily done
- Under urban/suburban skies, even 1 minute will give very bright sky background
With regard to star motion, 30 seconds is about the maximum when using very wide angle lenses, e.g. 16mm on a FF camera (or a 15mm fisheye). the longer your focal length, the shorter the exposure possible without objectionable trailing.
To get effectively longer exposures without a mount that can "track" to cancel the Earth's rotation, try this:
1.) Take successive short exposures and "stack" them. You'll need to align them since the frame will rotate and translate from exposure to expossure
2.) Raise the ISO in order to capture fainter detail. This will raise noise, but averaging multiple stacked frames will reduce random noise
3.) Shoot "dark frames" and subtract from the individual image "subexposures" to reduce effects of fixed-pattern noise

There is a whole body of knowledge on best practices for using DSLRs for long-exposure astrophotography. One can literally spend years learning technique. It's a very rich area of study.