Moon detalis w/ D40

Started Jul 20, 2008 | Discussions thread
MirceaR
Regular MemberPosts: 234
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Re: 2965mm
In reply to Richard Murdey, Jul 22, 2008

I haven't pointed the scope to them earthlings, it's hard to do, we're talking about a 2.7 meters (9ft) telescope on an equatorial mount that's built to look up :).

And when you have such a baby attached to your camera, all you want to do is to get your stars and planets and other astro shots. Time passes very-very fast when you do that

A decent 5-600$ apochromat telescope (and that's a D80mm, F~500mm, F/D~6 one) refers to the optical tube only, for the majority of astro photos you must have a decent equatorial mount (mainly for deep sky objects) that starts at 300$ and upwards.

I for one would buy a Maksutov Cassegrain telescope, D 180mm (7"), F 2700mm, F/D15.

And I would use that for planetary work only. That is planets, Moon, Sun (with a serious porper filter ONLY!), even if such a scope is overkill for the Sun, asteroids, double/multiple stars and some star clusters. And it costs in the range of 1500$-2500$, together with an EQ mount.

The image quality comes close to the 'perfect' one out of an apochromat telescope that, with the same specs costs in the area of 10k+$. No kidding.

There are some drawbacks for a Maksutov scope, but I don't care too much for them.

For deep sky (nebulae, galaxies) and comets, plus some star clusters I'd go for a 10"-12" Schmidt-Cassegrain, it allows for f/d ratios of 10 and with some adapters it can go to f/d6 ot f/d3.3.Also in the range of 3000+$.

Now, I don't have 1k, 2k, 3k$ lying around, so I'd go for a good D 8" F/D6 Newtonian telescope, w/ a good motorised EQ mount, to use for deep sky, and for the planetary work I'd get me a very good 2x/2.5x Barlow lens ( teleextender). All of this would be at most 1000$. Which I'm trying to put together.

But then again, there's some lenses I'd buy first, so then I just go to the local astronomy club where I'm a member and use their (our) instruments

An about the lack of mirror lockup on D40 I haven't seen yet the need for that.

For long exposures, in the order of minutes for deep sky objects it's not a must-have.

For planetary work it may become a necessity, if you attach the camera to a rather light telescope and not such a sturdy mount. Haven't got the occasion yet

As for the focal length, it's the focal length of the telescope. Conversion for APS-C has no relevance here. Not to me.

So clear skyes and keep shooting ya'all.

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