Saturday 23 March 2013

One small step for man ...

After many years, I am, in my late forties, about to get a "proper" telescope.
I placed an order with Scopes'n'Skies on Monday, and the courier is supposed to be delivering the stuff in two days time.
I have ordered a
TAL-120 telescope, along with an adapter to fit my Sony dSLR and an adapter to fit my daughter's Canon compact camera.

The manufacturer's description for the TAL-120 is as follows:

"The TAL-120 incorporates an integral multi-coated negative achromatic lens in the base of the focuser to provide an effective focal length of 805mm in a very short tube. The result is a Newtonian reflector with an aperture of 120mm (4.7 inches) with a focal ratio of f/6.7 that is just as powerful but lighter and more compact than conventional models. The mounting and accessories are identical to those included with the popular TAL-1 model, except an adaptor for prime-focus photography with a 35mm SLR camera is also included."

The TAL-120 is a slightly old-fashioned design, and has a steel tube, rather than a lighter aluminium , glass fibre, or carbon fibre one. It also has a rather heavy stand, a single-leg steel column (apparently called a "pier").
The weight, however, is an advantage - it gives the telescope stability, and stability is important for getting a clear image.

I chose the TAL-120 model over the similar TAL-1 model, because the TAL-120 is designed for astrophotography, while the TAL-1 is designed for visual photography. Both the TAL-120 and the TAL-1 have the same list price, and can be distinguished by the shapes of their telescope tubes - the TAL-120 has a 120mm mirror and a tube which is shorter and fatter than that of a TAL-1 (which has a 110mm mirror)

Doubtless you will read that a TAL-1 gives a clearer view, and no doubt to the eye it does (that's a consequence of the TAL-120 being a "hybrid" design with an extra glass element in the focusser, while the TAL-1 is a "pure" Newtonian design, with no glass elements except in the eyepiece).
However, when one buys a reasonable priced adapter eyepiece (one that costs less than half the price of the telescope!) for the TAL-1 in order to take pictures with a dSLR (using the telescope in place of the camera lens), suddenly the advantage of the TAL-120 design becomes apparent - it already has such an adapter built in, and that extra lens is matched to the characteristics of the telescope!

One could always buy a TAL-1 and a really expensive adapter lens for photography, but that rather defeats the point - why not just buy a bigger telescope which will give better views anyway!

So the TAL-120 looks like a balanced starting point for the photographer on a modest budget.

Of course, "a modest budget" means different things to different folks, but to give you an idea of what I mean by budget, the TAL-120 has a list price of about 200 pounds (240 euros, 320 dollars), while a dSLR mount adapter to fit the universal photo adapter on the TAL-120 will cost an extra 10 quid (12 euros, 16 dollars) or so - you could probably even pick one up on ebay from China for less.

So there we go
210 pounds (c. 252 euros, 336 dollars) for my set up, plus a dSLR camera I have owned for about four years.


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