ALDI have a telescope on Special on Sunday

Hey guys,
From experience the only thing I know about telescopes or binoculars, is that if you want good quality optics you must pay. You only get the quality that you pay for

Absolutely sound advice Jack.

The 2 daves pretty much said it all, you'd be better off with a bigger scope, the planetary images are small from the 90, the optics are good but aperture is king. Go for a 125 atleast!.

At some point the ETX range goes from refractors to Mak-Cass optics. I think the 90 is a Mak, which will mean much greater focal length, and better performance on the planets. I have an ETX105, which gave me some very nice views of the planets, M42 and M57, and one serious case of aperture fever that I'm still not recovered from.

I don't know about hanging a 350D off the back of one -- it's going to need quite a bit of counter-balancing and your image scale probably isn't really sufficient to light up the big CCD. You'd probably get better results with a webcam. Then again, I've never done any imaging at all, so I'd pay more attention to those who have

-- Jeff.

I don't know about hanging a 350D off the back of one -- it's going to need quite a bit of counter-balancing and your image scale probably isn't really sufficient to light up the big CCD. You'd probably get better results with a webcam. Then again, I've never done any imaging at all, so I'd pay more attention to those who have

I think you hit it on the head there Jeff. What Darragh probably doesn't realise is that most astrophotography images he will see are made by using individual frames of a movie (.avi), taken with, more than likely, a very good webcam (e.g. Phillips ToUCam) or a Meade DSI/LPI, and those frames stacked and alligned in Registax to produce a combined image. Otherwise, he will not see as much details, in some cases any at all, if planning to just do exposures with a small scope and his photo camera.

Seanie.

There is one proviso with the DSI that may be a clincher.

The DSI, when used in conjunction with a meade mount, is controlled by software that can make mosaics on the fly. You tell the software what size image you want (not resolution, though it does that too via drizzle) and it will guide the mount to cover that area of sky. As far as I know, you can get the software to image twice the area of sky that the scope/DSI combo can 'see'.

With increasing aperture, your field of gets progressively smaller. You can increase the FOV with a reducer. But, for example, the FOV for the 8" Celestron SCT I have with an F6.3 reducer, my FOV is not much more than about 15 arcmins square. If however, I had a Meade mount, the DSI software could double that area (probably about 21 arcmin square)...

So you get more FOV for your money without changing your scope. Of course, it takes longer to image, but if you can put up with that, then you can save *some* money.

Dave