whats the best scope for planets?

Hi, im a bit confused by this, I was told that bcos planets are so bright that the apleture of a telescope is not too important as long as the magnafication was the same, ie, the same views from a 5inch at x200 as you would from a 10inch at x200. I was also told that among the reflectors the schmidt cassegrain are best, why? Is is true that a 6inch refractor could give better views than an 8 or 10 inch schmidt cassegrain? Finally, how dooes a 6 inch refractor compare to a 10 inch newtonian for deep sky? Sorry if this is complicated but i wuold be grateful 2 u if u reply,
fionn

Depends on the 6" refractor.... And the 10" Newt.

If you have a quality 6" APO refractor (e.g. Astro-Physics) and a mass-produced 10" Newt, I'd say hte 6" APO will give far better views of everything.

Magnification I guess is part of the equation but its not the only consideration. The quality of the optics (OTA and eyepices) will have a larger part to play than magnification. A smaller view of a really crisp Saturn will always be better than a large splodge...

HTH

Dave

Becasue planets are bright, the focal length is the big factor, in in particular, the f number. Big focal lengths result in errors in the primary having the least effect on the image.

The public observatory in Belgium that my uncle works at have a telescope just for planets with a 3m (I think) focal length, gives amazing views of Saturn and Jupiter.

Bart.

Hi, im a bit confused by this, I was told that bcos planets are so bright that the apleture of a telescope is not too important as long as the magnafication was the same, ie, the same views from a 5inch at x200 as you would from a 10inch at x200. I was also told that among the reflectors the schmidt cassegrain are best, why? Is is true that a 6inch refractor could give better views than an 8 or 10 inch schmidt cassegrain? Finally, how dooes a 6 inch refractor compare to a 10 inch newtonian for deep sky? Sorry if this is complicated but i wuold be grateful 2 u if u reply,
fionn

Fionn, there's no easy answer to the best telescope but what you were told is incorrect. Resolution is a function of aperture so a 10-inch telescope will give more detailed planetary views at 200x than a 5-inch telescope at 200x, assuming of course, similar optical quality both for the scopes and eyepieces (also very important). Televue's Radians are excellent planetary eyepieces, so are orthoscopics.

Schimdt-Cassegrains are jack-of-all-trades, good at most things but can be bettered by other scopes on specific astronomical targets. They are not ideal planetary _observing_ scopes because the large central obstruction takes away some contrast and sharpness that scopes with no obstruction or smaller obstructions retain. So, a 6-inch refractor should quite easily better an 8 or 10-inch SCT but some top quality 6 or 8-inch Mak-Newts could give a 6-inch apo refractor a good run for its money. Good quality newtonians should also better similar size SCTs on the planets due to considerably smaller central obstructions. It's rare to get a poor SCT these days from Meade or Celestron, most are as optically good as the design allows with Celestron's 9.25-inch perhaps topping the list and of course, SCTs make excellent imaging scopes.

For most deep sky work (e.g. excluding double star observing), a 10-inch newtonian should prove much superior to a 6-inch refractor as it provides almost three times the light-gathering power.

When choosing a telescope, one has to bear in mind that aperture, optical quality, set-up time, ease of transport, imaging ability, observing interests, cost etc all play a part in deciding what's best for you.

Well put Gordon.

If you have a quality 6" APO refractor (e.g. Astro-Physics) and a mass-produced 10" Newt, I'd say hte 6" APO will give far better views of everything.

I guess that's too broad a brush. I guess I was thinking of something really cheap and nasty - certainly not the mainstream, respected and quality-driven manufacturers.

Dave

I seen Saturn through my 12" Dob and it was amazing :!: I seen the Cassini division in the rings and I seen the cloud belts on the planet.
I used a 6.4mm eyepiece to deliver 230X mag.