Evaluating a first telescope

[Dhalphir]

I'm considering an 8" Dobsonian Skywatcher telescope for my first telescope.

I'm looking for a pretty general astronomy experience - viewing planets, the moon, some nebulas. I live in a decently low light pollution area - northeast Perth metropolitan area, in the Swan Valley.

Is there anything I really need to keep in mind? The Skywatcher standard Dobsonian runs around $500, is that a reasonable price bracket for a first telescope? Aim lower, higher?

[LightningNZ]

You could always look at picking one up 2nd-hand but really I don't think you can go wrong with these scopes. Just make sure that every part looks in good condition on arrival. A friend of mine has a crack in their primary mirror cell. Skywatcher swapped it out for no cost but sometimes you get a scope that was apparently made on a Friday. :)
-Cam

[Allan_L]

Hi Chris,
Welcome to IceInSpace :welcome:
You have picked an ideal first telescope.
And if new, that is a good price.
If second hand, it is probably $100 over priced, unless you are getting a whole bunch of useful additional accessories with it.
Good luck with your purchase.
And feel free to ask questions as you come across them.

[Dhalphir]

Thanks the help guys. Is this telescope going to be able to be used (with more equipment down the line, obviously) for astrophotography too?

[Renato1]

It won't be much good for astrophotography, except for shots of the moon.

When you get it, you have to check collimation - at high power throw a star image out of alignment and look at the bulls-eye pattern. If you have a nice bulls-eye pattern, all is well. If not you have to muck around with the three screws at the back of the main mirror and adjust till you get it right. Then you will have nice images.

When you get the telescope, you'll have to align the finder scope with the main tube by aiming at a star or distant street light. The one thing the manual doesn't usually tell you is that, after aligning, when aiming your straight through finder at a star in the sky, you are better off using both eyes open. I struggled for years using one eye, as I would when aiming a rifle, then read that handy tip and was amazed at how much easier it was with two eyes open.
Regards,
Renato

[Dhalphir]

What would I be looking to get later on for astrophotography?

[The Mekon]

A bank loan

[brian nordstrom]

:rofl::rofl: sad but true , can get very expensive , very fast . Stick with visual for the start and enjoy .
Brian.

[rustigsmed]

Hi Chris,

there are a few options.

1. A dslr camera on a tripod taking night scape shots of the milky way. (check out the nightscapes section for some inspiration - as these can be amazing). You can also take timelapse videos of the night sky with this too. a wide angle lens is best.

2. a webcam / dslr attached to a dob like you suggested, which makes it possible to take photos / videos of the moon and planets (note that planetary astrophotography usually involves taking a movie of a couple of minutes and stacking the sharp frames in special (free) software. As it can appear to be shimmering like when you're underwater.

eg - the dob you have suggested and a t-ring etc to mount the camera to the telescope.

3. A goto dob that tracks can allow planetary shots but also 'short' exposures with a dslr of up to around 25 seconds (after that there is field rotation in the image). you can get some nice results from this method on the bright deep space objects (check out my flickr page).

eg http://ca.skywatcher.com/_english/01_products/02_detail.php?sid=359

4. A 'proper' deep space astrophotography is getting a lot more complicated. A german equatorial mount allows exposures past 25 seconds to about 1 minute (if you can polar align accurately). You would need at a minimum for a mount a skywatcher HEQ5. Then you could get a ED80 refractor or 8" newt on top. To go past 1 minute exposures you need to introduce a guide camera that corrects errors in tracking, which is either done through a small finder telescope mounted onto the main telescope or through and Off Axis Guider which is in front of the main imaging camera (it uses a small prism to direct a bit of light to the guide camera). You will need a computer to run this and a number of programs running.

eg: http://www.bintel.com.au/Telescopes/Reflector/Bintel-BT200-f/5-HEQ5-Pro-GOTO/1006/productview.aspx
http://www.bintel.com.au/Astrophotography/Autoguiders/Orion-Mini-Deluxe-AutoGuider-Package/1547/productview.aspx
- note this would be a minimum system the price / quality goes up literally astronomically from there ;)

As for cameras ...
- a webcam can be used for planetary photos.
- there are purpose planetary cameras, one shot colour and mono (black and white) cameras. (people use Red Green Blue filters to create a colour picture with the monos).
- A dslr is an all round camera, takes videos and can take long exposures.
- modified dslr cameras -to allow more wavelengths in (much of the red gas in nebulas is outside the spectrum of normal dslrs).
- cooled dslr cameras (running dslrs introduces noise into images especially in summer.
- deep space astro purpose cameras, they come in one shot colour or mono. with mono you will need a filter wheel and filters etc. these are usually cooled too.

I think that's a lot to take in! :question:

feel free to ask more questions :thumbsup:

Russ