hy-the telescope own is 130p dobson skywatcher heritage-the eyepieces are the standard basic 2 that comes with basic starter telescopes of this type-The question is needed to achieve the maximum magnification of x260 ? Does it need other eye pieces or something else? Or is the telescope to small to do this x260?
the smallest eyepiece is 6mm so its only about x100-
secondly between MAKSUTOV-CASSEGRAIN sky watcher 150 and dobson 200p-which is better for deep space and high magnification?
This is a great question. Generally, in most conditions, telescopes struggle to give quality images above about 40-50X the aperture in inches. Since your scope is basically 5 inches in aperture, the highest usable power is going to be in the 200-250 range.
Your eyepieces each have a number on them. One of them is probably about 25mm...and that will give you a 25x magnification,. The other one is probably 10mm--which would give you about 65x. That's a long ways from 200x
One option is to use an even shorter focal length eyepiece---but these are hard to use, and have very little eye relief--so you need to get your eye right up against them.
The better solution is to use a Barlow lens. You can probably pick these up for under $50, and they will give you roughly 3X your magnification. So a Barlow lens with your 10mm eyepiece should get you to right around 200X And I wouldn't try to go beyond that until you played with that combination. My guess is that you'll find it pretty hard to use most nights.
And your second question is easy. The Mak/Cass will be better at high magnifications. And the larger aperture of the dobson 200 will gather more light for deep space objects.
hope that helps