Erm... how do I use my telescope?

[marcosscriven]

Hi

I feel somewhat embarrassed asking this... That's a lie, very embarrassed.

I bought a WO 72mm Megrez today, with a 2" dielectric mirror, and 2-4mm Televue. I got it on the basis of its portability, only a couple of kilos, and comes in a tiny bag.

Thing is, I'm just trying it now during the day to try and focus it, in the hope I could try it tonight. I'd like to take a look at Jupiter, and the skies are clear (although I guess a little turbulent what with the heat today)

For the life of me though, I couldn't focus on chimney pots a good couple of hundred metres away. Of course I had the 2-4 eyepiece on the 4mm setting.

As you focus it shows the distance, ranging from 0 to 70mm. I went the the full range and at no point did I see anything in focus.

Finally, I'm now wondering if I need a finder? I thought this had a wide enough field that it didn't need one (in fact, I've read of people using this scope itself as finder on a larger scope)

So, tail between legs, can anyone help?

Thanks

Marcos

[Kevdan]

2-4mm eyepiece is a bit powerfull, have you got a 10mm or bigger to try, I think that this may be the problem.

Kev.

[Demo johnny]

Looks like a hefty bit of kit, I am sure someone on here will put you right.

I am newb but want to help, does it have an extension tube between the ep and the focuser if it does take it out and see if that works.

[SniffTheGlove]

2-4mm eyepiece is a bit powerfull, have you got a 10mm or bigger to try, I think that this may be the problem.

Kev.

Even 10mm is pushing it for a first time use, try at least with a 32mm EP, this way you should see something throught the EP when you focus, also how good is your pupil, 4mm might be to much for your eye to handle.

In this country you will be very very luckly to get good focus on Jupiter with a 4mm EP as it's way way to much mag.

Also as you seem to want wide field then 4mm is totally at the wrong end of the EP range, look for a 32mm or 40mm or bigger (if you can afford)

[Capricorn]

Although 4mm is small the Megrez should take it, may struggle at 2mm, also the eyepiece is a TV so pretty good.

Obvious answer is simply that you had pointed towards a couple of chinmeys but the scope was a little off. Best to aim at something you cannot miss, the buildings the chinmeys were on if big enough. Also something that has a high contrast to the sky.

Also as the eyepiece was at 4mm the angle of view would have been a bit small so as said more chance of pointing towards but not at the chimneys.

A 4 mm eyepiece would give about a half degree view, fairly narrow to get something in view first time.

You don't need a finder, just a 25mm or 32mm eyepiece. Stick that in, use the Megrez initialy as the finder, stick in a shorter eyepiece to see the detail. Although something like an RDF wouldn't do any harm, and would come to a similar cost as an inexpensive eyepiece.

By the way nice scope. Once you get sorted it will do a good job on things.

[marcosscriven]

Thanks for the response. I guess I shall have to wait (not my strong suit), and get a longer EP next week. Frustrating with Venus and Jupiter sitting out there right now, in a crystal clear sky!

Any ideas, though, where in the 0-70mm range I have that I'd need to be setting the focus, with the eyepiece at 4mm?

Will also need to invest in a tripod with finer settings. Have it on my Manfrotto tripod at the moment.

[brantuk]

I have no trouble focusing mine on planets using a 5mm and 4mm eyepiece. However - if you're using it for the first time it will be very difficult to do this - especially with no finder - you really need 25mm or longer to start with. You'd need pretty good conditions to use the higher powers - which we just ain't getting recently.

I find a red dot finder indispensible when using this scope for observing - particularly on alt/az

[marcosscriven]

Thanks Brantuk

May I ask you two questions since you have this scope (and a lot of other it seems from your sig!)

1) Can you recommend and 25mm EP?

2) what do you mount your 72mm on (unless you're mounting it on a larger scope that is)?

[brantuk]

For grab and go I mount it on an AZ4 alt az manual mount. But I use it primarily for imaging side by side with an ST80 guide scope on neq6 pro.

Any of the Meade 3000/4000/5000 25mm eyepieces are very nice (I use a 25mm 3000). I've heard the Celestron Xcels are good but not used one myself. I like the William Optic Swans - the 32mm is a nice piece. And any similar size TV's will work ( I use selected Radians) - oh and baader hyperion 24mm.

[Catweazel]

I have the Megrez72 and can recommend the red dot finder as well, it makes finding stuff much easier. I always start off with a 32mm GSO plossl, and then increase the mag once I get the object in the centre of the FOV.

I use a Horizon 8115 tripod for grab & go with the Megrez, and an EQ5 when doing AP with it

[Peter Drew]

Have you tried it with the diagonal?, one we tried this evening would not come to a focus without it.

[marcosscriven]

@Peter : Regarding focus, you're right. I needed to use the diagonal.

I popped over to Astronomia in Dorking (was only about 90mins door to door from SW London). Really helpful service.

I tried out a Manfrotto with a 410 'Junior' head. What marketing genius came up with such a diminutive name I don't know.

I went outside the shop, with a 9mm EP, plus the diagonal, and hey presto it focused at 40mm. Even better, twiddling the gears gave me amazing control. I think it's the best option for me for travelling, so went ahead and got it.

Also, I picked up a 25mm EP, through which I was able to find things.

[brantuk]

Great news Marco - glad you're sorted now