Astro photogtaphy question

Rudlin

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Hello,

Just as I'm about to depart to Snowdonia to capture astro photography snaps I cannot come to a decision which camera and lens would suit me best.

I have a 6D with f4 brightest aperture lens and i also got sony a57 with 1.8 f number prime lens. Obviously Canon wins hands down against Sony in iso test. But the lens seem to equalise or maybe even lean towards Sony's advantage.

Any coments on this greatly appreciated.
 
Have you considered the focal length of the lenses,if the Canon F4 lens is a wide angle it may be more suitable than the Sony F1.8 lens. :confused:
 
Hm yes since widest Canon lens is 24mm, and Sony would be 50mm of ff equivalent.

But I'm willing to work on composition so presumably 50mm is more than okay.
 
I've also been looking at lens options for Astrophotography. The consensus is to pick the brightest lens with little CA and distortion. Wide angle lenses work better in minimising star trails and deliver brighter images by maximising exposure time. Interesting article here which ranks various focal length/aperture combos for untracked Astrophotography:

http://www.lonelyspeck.com/lenses-for-milky-way-photography/

Having done my research, I am leaning towards tracked solutions such as iOptron Skytracker2 / Vixen Polarie so i can use my existing lenses and not be limited by focal length / exposure considerations.
 
Thanks. I would lean towards Canon f4 aperture, 24mm and crank up iso not to risk seeing any unintentional star trails.
 
If you DON'T want star trails... just remember the 500 rule. It's a rough guide to determine the maximum speed for any lens. Divide 500 by the (effective) focal length to give you a shutter speed in seconds that will not record any earth rotation and hence give trails. I say EFFECTIVE focal length... and that's important. If you use a 50mm lens on a full frame camera that will mean 500/50 = 10 seconds... however... a 35mm lens on a crop sensor camera will also be 10 seconds, as it's the same magnification (50mm equivalent)

Not something to worry about on the 6D though.... just 500/actual focal length.

use mirror lock up and a cable release/remote release. you'd be surprised how much the higher magnitude stars can becomes blurred through camera shake when initially opening the shutter.
 
Thanks for the input guys, things are much more clearer now than before, yet still I've got question arisen - having camera lens not on auto focus, but rather in manual focus setting and have it set to infinite would be proper technique to capture all of the skyline, am I right about it?
 
Personally speaking unless your objective is to go out and capture just photos of stars rather than star scapes (landscapes under the stars) I'd be taking the 6D with the f/4 lens on that body an f/4 lens is fast enough to get decent star scapes without too much concern as it performs really well on the ISO front...
 
Thanks for the input guys, things are much more clearer now than before, yet still I've got question arisen - having camera lens not on auto focus, but rather in manual focus setting and have it set to infinite would be proper technique to capture all of the skyline, am I right about it?

It's dependant on the scene your photographing, personally my preference is always to focus on the scene rather than the stars as an OOF landscape/foreground always IMO looks stupid where as having it in focus will hardly 99.9% of the time have any detrimental effect on the stars obviously if focusing on something very close to the camera you may have to consider merging exposures for the different focus positions
 
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