Starting out

[butlermike]

Hi,

I'm just starting out with astronomy in terms that I'm taking the leap into getting the equipment right. I've always enjoyed looking up but I now want to 'see' and hopefully takes images as well.

I'm an enthusiastic photographer and have a couple of cameras and some lenses. I have done a small amount of 'astro' work with what I have but only with wide lenses at a max of 30 seconds or so in a lot of light pollution. The results weren't exactly inspiring. But having read this forum and a couple of other thousand sites I see there's a lot more too it than I thought...

So, I have a lot of questions. I'm going to put them all in this post which I hope is ok!

To start off I've seen a lot of nice images taken with just a guided DSLR so although I've been looking at different scopes etc. I have managed (maybe) to reign myself in and save my wallet from a bashing, and thought I would start with the 'basics' and use what I have. But go for guiding as well in order to increase the shot time.

That leads me to my first (and probably most important by the sound of it) thought, the mount. Should I go for something and 'future-proof' myself, i.e. a EQ5 as a minimum or should i get something a bit more affordable and start small considering I'm starting with just the camera and lens. I don't want to build a barn door mount. An Astrotrac looks good but expensive for what it is and definitely won't be able to take a scope in the future. So would an EQ3-2 (or similar) be my first port of call or will it not be very cost effective due to upgrading later. I don't see much of a 2nd hand market for them. I looked at the EQ1 mini (I think its called) but it doesn't sound very stable after reading reviews. I would like to get into guiding as well as tracking fairly soon I think so perhaps I'm answering my own question really and but wanting to add bits on already I'll need a sturdier mount. Perhaps I'll start with the EQ5 after all...

Regarding guiding over tracking, at what focal length (assuming DSLR lens' for now) would you need to start guiding approximately. I use the 650 rule for still photography to avoid star trails, but was wondering how good tracking is before you need to guide. I realise this probably depends on how well its polar aligned and how good the mount is but is there a general rule?

And for guiding I have an M42 400mm f6.3 manual lens which doesn't get used much as its not great quality for photography as it was cheap but could it be used as a guide scope? and if so are there attachments to go from a guide camera (web cam or CCD) to a M42 fit?

Another guide question but a bit of an odd one. Does the guide scope have to point in the same direction as the imaging lens/scope? if there's not a bright enough star to use can you, for example turn the guide scope to 90 degrees (or whatever angle)? All the stars are moving (yes the earth is moving... ) at the same rate so it shouldn't matter where it points, should it?

For imaging I have a Canon 50d and a 350d. The 350d I've just bought for astro work (picked it up for £45) and I'm going to take the IR filter out. A couple of questions about this. Once the filter is out do I need to put anything else in its place or can I just leave the sensor to flap about in the wind!? I've read that there's a Baader ACF filter that leaves the Ha red in that you want for DSO's but do I need to go to that expense? Is it right that the usual lenses won't focus properly without something in place of the IR filter even if its just a piece of glass?

Now I realise that I'm probably way ahead of my self already but regarding the future and scopes, and considering I'm mainly interested in imaging should I just go straight for a refractor? Probably too wide a question to answer definitively but I thought I'd ask.

is it worth starting with a non APO version for monies sake, or does the CA ruin pictures? I'm more interested in DSO's by the way rather than planets.

I've got a load of other questions about what scope for what mount but I'll worry about that at another time further down the line.

I hope this post isn't too long and I didn't loose everyone along the way but I needed to get the questions down on 'paper' even if it was just to get them out there!

Oh and yes I am currently reading 'Making Every Photon Count'...

Hopefully here from anyone who's managed to get this far!

Mike