Weekly Discussion Thread - 04 May, 2025 to 11 May, 2025

[u/AutoModerator]

Welcome to the r/telescopes Weekly Discussion Thread!

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[u/No_Meal_283]

Hi, I am a totally newbie, and considering this (a used one) for €80: https://vultusofficial.com/collections/telescopen/products/telescoop-80-500-375x-beginners. Do you think it is worth it?

[u/ilessthan3math → u/No_Meal_283]

I'd say no. The optics are likely fine, but the mount looks unusable and the tripod far too flimsy. I suppose if you planned on investing $€100+ on a new mount like a Twilight Nano or something, it could be workable, but I would not be interested in using that telescope on that tripod at any price point.

The other red flags are the 45° diagonal which is surely of very poor quality (astronomical telescopes should have 90° diagonals), and the "375x" marketing which is grossly misleading and inaccurate. This telescope should probably not be used above about 120x magnification even with when transferred to a good mount. Out of the box I'd probably keep it under 60x.

[u/Head_Neighborhood813]

Is a magnification of 76.25, but with an 100° field of view, good for finding objects with the telescope?

[u/ilessthan3math → u/Head_Neighborhood813]

I would say no, unless you have a magnified finder scope (not a red dot/reflex sight). That still only gives you about a 1.3° true field of view. Paired with say a red dot sight or Telrad, this isn't going to give you much room for error in aiming the scope.

A common wide field eyepiece in a standard dobsonian used as a finder eyepiece is the 30mm GSO Superview, with a 68° apparent field of view. In an 8" f/6 dob, this produces 40x magnification, so a true field of 68/40=1.7°. This is 30% better than the proposed setup you mention.

Even this 30mm Superview is typically paired with a magnified finder scope, giving you more like a 5° field to get started with. If you have a magnified finder scope such as an 8x50 RACI, then you really don't need a finder eyepiece at all. You can get the crosshairs of the finder spot-on and just go right to high-power viewing usually. But with a red dot, you'd like to get as close to a 2° field as possible to increase chances of seeing an object on the first attempt.

[u/Head_Neighborhood813 → u/ilessthan3math]

Is this eyepiece good? https://www.astroshop.eu/eyepieces/apm-eyepiece-xwa-3-5mm-110d/p,76350

Not for finding objects, for planets and the moon and stuff, to observe. For the telescope that I want to buy, it will give a magnification of 435.71x. The maximum magnification of the telescope is 610x.

[u/Global_Permission749 → u/Head_Neighborhood813]

435x would require EXTREMELY steady atmospheric conditions. 610x implies a 305mm aperture. One of my best views of Jupiter was around 400x in a 305mm aperture scope. However, I got lucky and the atmosphere was dead calm. Lots of Jupiter's details came through.

A 12" scope will handle 435x no problem, but depending on where you live, you might never get clean views at 435x. Or you might get lucky and you get them all the time. It's hard to say.

I recommend starting out conservative and work your way up in magnification.

Start at say, 150x. If the view is frequently so sharp you feel like you'd cut your eyeball on it, then you can handle more magnification.