Astromaster 130/650 f5 true Highest Useful Magnification

[Jazzmatazz]

Hi guys, looking to my scope's specs on the manual, the given value for Highest Useful Mag is 306x (!)

I've read a bit and I understand that this value is dependent on EPs used as well as observing conditions, so my question is, given the specs what would be your top Mag, or. what would be the most powerfull EPs you'd use?

Thank you All!

[John]

Hi Jazz,

On a good night 180x - 200x might be useful on the Moon, Saturn or Mars. 130x - 150x perhaps on Jupiter.

Maxing out the magnfication is not really what scopes are about though - when viewing deep sky objects low or medium magnifications are much more useful.

[baggywrinkle]

Generally the 2xObjective/Mirror diameter is a good guide, so in your case 260x . But that would be under ideal conditions.

200x would be achievable on good nights. User lower mags for sweeping. Work up to higher powers as the seeing allows.

Sorry about the script change..not sure why that has happened.

[Alfian]

Hi Jazz, for reasons unknown Celestron tend to "overstate" the magnification possibilities of their scopes in their brochures. Having cut my teeth on the 130EQ I was "lulled" into chasing big magnifications and as a consequence bought a 3x barlow,  that has only seen starlight a handful of times! As baggy' has said even on a good night 200x might be possible but for most of the time it will be less. Its worth pointing out that at 180 - 200x objects move out of view very quickly. Its useful to have a "high power"(150-180?) eyepiece or barlow equivalent but if you need to spend money on an eyepiece(s) that will be more used I'd be looking sub 100x.

[ronin]

I would say 180x to 200x, half the problem will be getting a good eyepiece at 4mm or 3.2mm to display anything. A barlow+eyepiece combination again means both components need to be good.

Wonder if the BST 3.2mm Starguider would perform????

I have noticed that one the eyepiece gets below 5mm then the actual eyepiece becomes a costly item for the process of viewing.

[lensman57]

Hi guys, looking to my scope's specs on the manual, the given value for Highest Useful Mag is 306x (!)

I've read a bit and I understand that this value is dependent on EPs used as well as observing conditions, so my question is, given the specs what would be your top Mag, or. what would be the most powerfull EPs you'd use?

Thank you All!

Depends on the seeing. With perfect seeing 200X might be possible on the bright planets other than that about 120X is the probably the MAX as you really don't have a lot of aperture to gather enough light for high MAG viewing.

A.F