First go at astrophotography... Think I'm hooked!

[Ianska]

Hey all. I've had a look around the forums today and really liked the look of some of the images you could produce with just a camera, never thought the amount of detail you could get was possible. I found a great tutorial on Vimeo (http://vimeo.com/16833554) so thought I'd have a go tonight as the skies were pretty clear in Tea Gardens (about 1 hour North of Newcastle, NSW). Here's what I came up with just from out the back of my house. Gotta say I think I'm hooked :)


Pic 1 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4780.jpg) ––– Pic 2 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4785.jpg) ––– Pic 3 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4793.jpg) ––– Pic 4 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4794.jpg)

[Osirisra]

Nice work! Welcome to the endless pit of Astrophotography :)

[Poita]

Nice detail on the 3rd shot.

What are you shooting with?

[[1ponders]]

Nice shots! Welcome to the Night Side. ;)

[leon]

Yep your hooked, and why not, this will keep you out of mischief most evenings, nice first go I might add.

Leon

[renormalised]

Welcome to IIS:):)

Nice shots!!!!:)

[Ianska]

Thanks all. I'm using a Canon 7D with a EF-S 17-85mm lens. That third shot was f/4, 30sec exposure, ISO 4000 @ 17mm.

Does anyone know the best way to not get the streaking on the stars? I shot these all with a 30sec exposure on a freebie tripod I got with a video camera years ago. Would a better tripod help do you think? or is there some other tricks I can try?

[[1ponders]]

Ianska your exposure time to eliminate star trailing is a function of length focal length and where you are aiming in the sky. To prevent trailing T(sec) = 700/FL of lens. So roughly where the center of your shot is (Celestial Equator or 0 deg Declination) @ 17 mm you should be able to get 40sec without trailing being obvious.

[Ianska]

So a 30 second exposure should be fine then? I think I should invest in at least a half decent tripod really.

[jenchris]

I love Nelson Bay - and Tea Gardens is a lovely quiet spot!

If you're a bit of a handy person, look up barn door tracker!

And yes a decent tripod will influence your photo ability - as will a remote or laptop exposure gadget

[Ianska]

I think I was reading about the barn door tracker just as you posted that lol. I'm not that handy so I'll probably won't attempt to make one :) The laptop exposure gadget sounds more up my street.

[Poita]

The only way not to get streaking on the stars is to either reduce the amount of time the shutter is open, or to have some kind of tracking platform for the camera.

A cheap way is to grab an old Celestron or Meade etc. fork mount.
These have basic tracking built in, and you could modify one to hold your camera instead of the SCT telescope tube.
A lot of people sell or discard the old fork mount when they buy a higher quality mount.
There was one going cheap in the classifieds recently.
Then you can get longer exposure times, especially at wide angles.

-P

[[1ponders]]

If your tripod is a but suss then use the timer to release your shutter rather than pushing the button, assuming of course you don't have some type of cable release mechanism.

[Ianska]

I had the timer on 2 seconds. Hoping for a clear night tomorrow so might try it on 10 just to give it time to settle from me pressing the button :)

[[1ponders]]

another thing to consider is if your shutter/mirror opens strongly. My 20D has a fair thump when a shot is taken, on a light tripod this might also be having an effect.

[Ianska]

I think that's probably it. The clip that is attached to the base of the camera has a little movement when attached to the tripod. The 7D does thump quite heavily too. If I get a chance tonight I'll try packing it out a bit to reduce movement and see how I go.

[Ianska]

Tried some new shots just as it got dark tonight. There seems to be a little less star trails after wedging the trips mount in as best I could. I also put it on a 10 second timer. Looks like it's going to be a clear night tonight so might try to get out later and get some shots in the dark :)

Pic 1 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4818.jpg) ––– Pic 2 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4822.jpg) ––– Pic 3 1900x1267 (http://www.ianmaconline.com/images/astrophotography/IMG_4825.jpg)

[[1ponders]]

That looks pretty damn good. :thumbsup:

The other thing you might notice with your images is 'trailing' in the corners and along the edges (not obvious in the shots you've taken and uploaded though you can see it at the top of the crop image). Stopping the lens down can help reduce this effect but it also slows the lens down. The 17-85s (http://www.dpreview.com/lensreviews/canon_17-85_4-5p6_is_usm_c16/page4.asp) aren't particularly good lenses for AP (but better than nothing :) ) and they will usually show this with stretched stars in the corners and along the edges.

[Poita]

Bloody hell, that last shot is a blinder!
What settings, focal length etc was that at?

[Ianska]

Hehe thanks for the comments :)

That last shot was 17mm, F4, ISO 4000 @30Secs.

Spent way too much on a new tripod and Tokina 11-16mm F/2/8 lens yesterday too (got a bit carried away in the shop... poor credit card). Can't wait for the lens to be delivered next week :)