[Keshdogga (Casey)]

Originally Posted by RobF

I sometimes remark to people that astrophotography is like a house of cards. You carefully lay out a wide foundation (collimation, polar alignment, balance, focus, dew prevention) then the next layer (guiding, Periodic error reduction), then if your lucky you get away with collecting good data with the final top layer (decent exposures, then processing, etc). If you don't concentrate its not too hard to knock it all over and get nothing

Seems like very fair analogy there.

Originally Posted by RobF

(just listen to the colourful language on the imaging field at about 8pm any night if you get to Qld Astrofest some time...!)

can't wait to get there next time.

Originally Posted by RobF

Ha really needs at least 10-20min exposures, so you want to make sure you love AP and can get all the basics down pat. About $350 in Aus (less from overseas possibly).

That would be great if I could get a Ha filter for $350. 10-20 minute exposures couldn't be too hard with a good polar alignment and autoguiding right?

Originally Posted by RobF

A good light pollution filter like the Hutech IDAS LPS is about $250 and allows you to shoot over a few minutes in the city without fogging out too bad.

Uhh oh I've never hear the term fogging out before. I always thought a longer exposure reduced the S/N ratio? Or are we not talking about noise here and just blatantly refering to light being diffracted into the OTA? Edit: This sounded stupid whe i read it again haha. I suppose I just wanted to ask what 'fogging out' was without explaining to myself what noise is

Originally Posted by RobF

My suggestion would be having at least half a dozen goes in your new backyard and making sure you can collect decent 2-5 mins subs without too much trouble first, before worrying about filters. If you won't be travelling very often or at all then perhaps the IDAS first. Having said that, the Ha filter will actually filter out the most city light IF you can get the longer exposures (they'll only be mono though of course unless blended with other data).

I doubt I'd be travelling alot once I move. Well at least not alot with my imaging setup (probably will get annoying carrying 4 cases full of gear around on a train ).

Originally Posted by multiweb

Let's put it this way. You need a lot of rehearsals in your backyard and get your routine in gear. When you can do it with your eyes closed 110% then you take your rig to a dark skies site and stick to your routine, only what you know will work. Don't get creative on the field. RGB from a light polluted backyard is not very rewarding. Ha is. You can still get a decent result from home. Then when you're ready for the big gig. Take your rig to a remote site on a clear new moon week-end (winning Lotto's more like it right now ) and you'll kick a$$.

Sounds like a great plan Marc. You seem to be strongly recomending this Ha filter (and no wonder your pics are just amazing! ). How much would it cost me for a Ha filter? I've looked up a 6nm filter by Astronomik http://www.astronomik.com/en/astrono...nm_filter.html and it's looks like it's translating to about $420. I'm not sure if this one: Mounted filter in 2" cell is the one to look at. Maybe you could refer me to another website But I was wondering, when you say RBG isn't very rewarding from a light polluted backyard is that assuming no filter? Or is it comparing a light pollution filter to a Ha filter?

I did have a look at your website and duddeee... that's an absolutely fantastic set of pictures you have there Wish i had the time to comment on each one!

Again, thanks to all for the words of widsom