CCD Imaging

[TonyS]

I do not currently own any filters - could anyone recommend types / makes that will make a difference for DSO for relatively short exposures ?

I use a Meade LX90 8 inch scope with DSI imager at the moment. The max exposure duration I can manage is maybe 1 min with the best / luckiest polar alignment.

Thanks.

[Mike]

A set of RGB filters would enable you to do colour imaging. Remember that your exposure times will triple when doing colour imaging or will quadruple if including a lumince or Ha layer.

A Ha filter would only be of real use to you if you were able to do relatively long exposures. Though a one minute exposure is fairly long so maybe it might be worth you borrowing one and trying it out before buying one as they are not cheap (Approx £80). A Light Pollution (LPR) would be of use to you maybe?

What you need to remember is that as soon as you put a filter in front of your camera your exposure time will need to increase as the amount of light being let through is reduced.

I use the Astronomik filters, which are very good.

Tony - Can you identify yourself at the next meeting to me please as i'm sorry to say I have no idea who you are (I probably do know the face though)

[Rocket Pooch]

Hi Tony,

I have an LX90 until about 3 weeks ago, you can image for much longer than 1 minute, but you will need a wedge and also a guide scope and APM box.  I've sold most of my old LX90 stuff, but I still have some basic guide rails and also an APM box if you are interested?

Also if you would like to e-mail me with you're contact detail I'll explain some of the things you will need to consider with this scope.


Chris

[TonyS]

Thanks Mike / Chris - very useful.
I do actually use a wedge with the LX90 but do not use a guider scope - any recommendations on type - someone recommended a SkyWatcher 804 ? What sort of exposure times can you get to with a guider ?

Cheers, Tony

[Rocket Pooch]

Hi Tony,

Do not use anything heavy, I'd suggest a Skywatcher 80mmF5 or something like one of the new william optics ZS66 scopes.  The LX90 will not take the weight of a ED80 easily and you will end up with counter balance weights all over the place.

With my old setup 5 minute+ exposures on CCD are no problem, some Lx90 users have done 10 minute exposures with CCD's and 25 minute using film.  So its well within the capability of getting some good quality images; however, you will need an APM module, guide scope, rails and a second guide cam, this is going to add up.  With the DSI you can use a F3.3 focal reducer or a .5 or .63 focal reducer with no problems.

Regards



Chris


P.S. www.jumpers4goalposts.org.uk has some LX90 pictures on it, the DSO are piggy back images except M57.

[Anonymous]

Chris - this has been really useful. I have been thinking about DSI II and presumably if i up grade i can use the original DSI as the guide cam. On a budget what would recommend first - investment in some filters or guider scope equip ? I'll let you no how I get on. Cheers Tony

[Rocket Pooch]

To be honest both, but the guide scope and the camera you will need ultimately, the thing I learnt is you can't go about this half cocked.  from a filter point of view you won't go far wrong with a Ha filter from Astronomik, but to use this I would n ot suggest you put it in front of your Colour DSI, you will get Red images.  But the Pro II imager uses a 1/2" CCD and will be a much better camera, if you are on a budget and knowing that the LX90 mount is not the most stable get the DSI II, guide scope and then get the filters later, but buy a cheapo LPR filter now, I would really recommend the Antares LPR filter its really good for £40 and is not too small for either camera.

Chris

P.S. did I say I had second hand piggy back rails available for the LX90?  At home now!

[TonyS]

Roll on Pay day !

[Mike]

Tony where you at the last meeting as no-one approached me?

[TonyS]

Hi Mike - sorry for delay in replying.

I'm not a paid up member at present ! I notice there is an observing session on Sat 17th June so I may pop along and see what's involved.

Tony

[Mike]

Tony,

The session on the 17th is an Imaging Session at my house. You are welcome to come along to see some kit in use (weather permitting).

PM me if you want my address and number.

Cheers

[Anonymous]

Mike,
the session on 17th is at High Elms and is Saturn and Mars [close proximity with each other] and the imaging session at your place is on the 23rd.


Tony G

PS sorry I didn't sign in

[Mike]

Eeep!

Apologies,  yes you are right !! DOH !