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Hermas
11-04-2008, 09:21 AM
Hello my friend.

I am still shopping for a scope. The last one I've spot in the Classified is a Bausch & Lomb Professional 560X. I'll have more info on it this week end.
The reference number is 780560. And I am just curious about this one...
http://www.telescopes.com/telescopes/refracting-telescopes/meadeetx60bbbackpackobservatorytele scope.cfm?source=gbase&gbid=Meade_ETX_60AT_BB_Backpack_Obs ervatory_GoTo_Telescope


I know it's not the summit of scope but still...It has all the bells and whistles of the pros.

Any of you have ever played with one?

Does it do really all it says in the description, even good for astrophotography and it has a GoTo and plug in to your PC?

Hermas

Kokatha man
11-04-2008, 07:25 PM
Hi Hermas - I'm afraid I personally couldn't endorse this 60mm refractor: it may have some bells and whistles in the mount but 60mm is really supermarket size stuff. You could surely, where you live, get a much better scope secondhand for not much more. Refractors under 4" (100mm) are not ,imho, worth considering, as are reflectors under 5"-6" (125mm-150mm.)

A good manual EQ mount on a stable tripod with anything of the above (or more) aperture would be far more useful and entrancing/encouraging than a tiny scope on a (slightly) swish mount - secondhand units that are able to be demonstrated as in good condition would be a far better proposition and scarcely much more in cost!

Any telescope (in this case the quoted Bausch and Lomb) that identifies itself by magnification/"power" is instantly suss to say the least - they should describe the type of scope, eg newtonian reflector, refractor etc, and the aperture (mains mirror/lens diameter) as well as the focal length and the types and focal lengths of the eyepieces at least. I say leave this one well alone.....

These are my personal opinions but I think they are a good generalisation.

Regards, Darryl.

JethroB76
11-04-2008, 10:21 PM
Was my first thought too...

As for the ETX in the link, I think they're meant to be nice little scopes but, they sure are little - 60mm thats not much bigger than some eyepieces

[1ponders]
11-04-2008, 10:42 PM
Don't even go there Hermas. As Darryl has said, if they are advertising the magnification then it will be a disappointment. You will be regretting the decision. Sure you could get it up to 540X, hell you could get it up to 5400X if you really wanted to. And you would see about as much. Nothing. The maximum usable magnification on that thing is around 120X on a good night.

If that is the sort of scope you are looking for (computerised goto) then the smallest I would even consider is the Meade ETX-125, but even then an LX90 200mm would be much better. Don't expect to do any imaging on them though unless you put them on a wedge.

If you want to image get a good size equatorial mount (mototized), absolute bare back minimum EQ5, preferably HEQ5 or bigger.

Sorry to say this but unless you are prepared to go for an 8" Dobsonian (which would be a great scope at a reasonable price) then good quality fork or EQ mounted telescopes don't come cheap.

Hermas
12-04-2008, 10:51 AM
Big thanks for your advices my friends.

I'll be back when I know all the specs about the one that says 560X.

Have a great week-end.

Hermas

acropolite
12-04-2008, 12:01 PM
Hermas, anything that is advertised at high magnifications isn't going to be suitable, as the others have already stated, manufacturers who use such figures only do so to catch the unwary.

There is a rule of thumb which says the maximum useable magnification is around 40 to 50 times the aperture in inches.

For example an 8 inch diameter telescope will be useable up to around 320-400 x... IF... and it's a big if, the atmospheric conditions are suitable at the time. For average conditions 150x or less will be the maximum magnification that's useable, only on rare occasions will any higher magnification be useable.

Often the best views are low magnifications giving wider fields of view. So when Paul is telling you that the 60mm refractor will be useable to a maximum magnification of 120x it's a limitation that is determined by the physics of the apparatus, not by a simple multiplication that doesn't take in to account any limiting factors.

The 60mm refractor works out to 2.36 inches, multiply that by 50 and you have around 120x which is the figure Paul quoted you. Finally there is no substitute for aperture, the old addage, size matters, is applicable to telescopes.

An 8 inch will gather 4 times more light than a 4 inch and around 11 times more light than the 60mm, so the 8 inch dob Paul has recommended would allow you to see far more and as time goes on you will realise that you have lost nothing by not having go-to capabilities.

dannat
12-04-2008, 12:21 PM
hermas - how often do you want to use it? If you want to watch your budget you might think about the etx-80 they have on the same page - (290) comes in either a backpack version or less portable(the tripod on this one looks sturdier). It would probably do for occasional use
As for photos - you aren't going to produce great or even good shots, but I'm sure with some effort you'll get something - you will probably need to buy some exp gear (not really worth it for photography)
You probably need to have a look thru one before you buy - the highest mag you are likely to get out of it is 150x,