Beginners Astrophotography - Gear Recommendations

[Stu Ward]

Hi there,

Sitting here in th epouring rain under total cloud cover, but thinking of Astrophotography.

I'm new to Astronomy but have recently purchased a Dob and delighted with its observational power.

I'd love to get into Astrophotography but really need some advice on what gear to be looking at so as to not break the bank, but to also get some decent gear that has some lasting appeal.

Can anyone make any recommendations as to what Scope, mount etc a beginner should be looking at

Thanks a lot


Stu

[wasyoungonce]

Hi Stu.

This is really an open ended question that can end in advice from $100 outlay to $8k+ outlay.

Do you want to pursue DSO or planetary photography? :question:Their equipment needs are quite different.

You can do web cam (http://www.iceinspace.com.au/63-306-0-0-1-0.html) planetary (and so bright clusters & DSO) photography with the Dob, see the article page (http://www.iceinspace.com.au/63-201-0-0-1-0.html), for a modest outlay.

[Stu Ward]

Yeah i thought it would be pretty hard to answer.
But i guess i would prefer something with a tracking motor on it rather than use my dob

Stu

[wasyoungonce]

Scope:
You have an 8" dob don't you. I don't know the F ratio but I'm guessing it's an F6? Why I ask this is because longer F ratios the tubes get longer and harder to manage & stay stable on a GEM mount.

Anyway, this scope is a good basis to start and will give wonderful results. An alternate would be a smaller refractor (like an ED80) on a GEM, but, this may be a step backwards although easier to view thru & handle.

Alternatively a camera on a GEM can give very good results.

Mount:
The basis for any astrophotography is "the mount". This cannot be over stated! To mount an 8" Dob takes an EQ6, $2k. You can get away with a smaller (cheaper) mount for lets say an ED80 or camera/lens.

Then you need to know how to polar align (http://www.iceinspace.com.au/63-498-0-0-1-0.html) and drift align (http://www.iceinspace.com.au/63-405-0-0-1-0.html) your mount & scope to it tracks stars. This will allow you to at least start to take exposures.

Camera:
Well..any you can get your hands on. You would be surprised how good a result you can get even from a webcam and telescope!

But, most beginners go for a DSLR, $1k (or less). If you are this way inclined, go for a DSLR that has:
"Bulb" mode (so you can take long exposures) (all DSLRs have bulb mode);
Functions can be controlled by a USB interface over a computer;
Live view for focusing (this really is a boon).

Canon are the most used DSLRs for astrophotography. Not because they are better but because they are a pseudo std used.

Accessories:
Most cameras need adaptors to adapt to the focuser, like "d" rings.

Eventually you will want longer exposures and to do this you need to autoguider ($300) and guide scope ($250) to track the stars accurately. That said I managed 3 mins unguided (http://picasaweb.google.com/brokenback09/AstrophotographyEmissionNebulae#534 1807338770138098) exposures on an old cheap EQ5 & ED80 without autoguiding. If I could do it..anyone can.

Focuser. many users upgrade their focuser's as the OEMs are usually incapable of holding DSLRs & accurate repeatable focusing, $500

Laptop. Invaluable to astrophotography, control of the mount & camera(s).

All in all you can see it's a big step up in $ and equipment & time.

If you are inclined then why not! But do research before splurging. Maybe get an EQ6 (or GEM mount) to use your DOB to locate & track stars/DSOs more easily then slip into astrophotography later as you gain experience. Astrophotography is a steep learning curve, indeed.

Prowl the web to see what people are using and their results. A good start is here (http://www.astropix.com/HTML/I_ASTROP/INTRO.HTM).


Edit:
Forgot one thing. Some Newts need to be shortened (the main mirror moved fwd) in focal length to enable them to be used as prime focus astrophotography. If you already use an extension piece with your current eyepieces then it's more than likely you Dob is OK and doesn't need this shortening.

The reason the FL is shortened is to bring the prime focus point fwd to the image plane of the DSLR camera. Normally this focus point is inside the tube and the eyepiece focuses on this plane.

And I forgot to mention you can take astro pics thru an eyepiece in lieu of a DSLR, with a cheaper point'n shoot digital camera. This is called projection (afocal) photography and can work quite well.