C6-SGT XLT on a CG5 synscan or 200p on a EQ5 pro goto?

[palatine]

which has the edge?... want to be portable and will be imaging with dlsr and webcam....

i understand the 200p to be 2 inches bigger. will i "see" the difference?

[Dipper]

An 8" telescope will gather about 78% more light than a 6" telescope. That's purely mathematical due to larger aperture. I presume you are talking about 200/1000 and 150/1500 telescopes. That's again twice the difference in focal ratio. You are talking about two very different telescopes that are hard to campare directly. I owned a 200/1000 on a EQ5 mount and it was portable but still it's not a pick-up-and-go setup that you will enjoy carrying around every time. It's quite big and you will feel it if the wind is stronger.

As to whether you will "see" the difference, then yeah. 200/1000 will have a wider field of view than 150/1500. The first one would be more suited for wide field viewing/imaging, the second one for planets and small DSOs.

[michael.h.f.wilkinson]

Visually, the 200p will win if the mount is stable enough. The 200P is much less portable (even my C8 is far more portable). It will also strain the mount more. The EQ5 is roughly the same as the CG5, and both are more-or-less clones of my Vixen GP mount. That is rated by Vixen to be rated for an 8" SCT, 6" newtonian, or 4" refractor. Visually, the 200p may work on a mount as light as the EQ5, but it would sit far more comfortably on an HEQ5. Weight is not the only issue, torque, caused by a long tube is as important. In practice, your C6 configuration is ever so slightly overmounted (never a problem), but the 200p is somewhat undermounted (which leads to wobble). The mount could readily hold a C8, but that is rather more expensive.

The 200p will be better at DSO imaging than the C6, not due to aperture differences, but due to focal ratio. The mount is not that good for AP, unless we are talking planetary photography. In that case, the C6 will do a good job, as will the 200p (with its larger aperture). The latter may drop more frames due to wobble, but if it is well balanced it should work (when sheltered from wind). The short tube of the SCT makes it less sensitive to wind, but its corrector plate makes it more sensitive to dew. A dew shield can correct that, but adds sensitivity to wind. Fortunately, dew problems are most severe when there is no wind.

Thus, if portability is an overriding issue (as it was for me, I have taken my C8 along on holidays to see the eclipse in 1999, even when we still had a little Peugeot 106), the C6 wins hands down. If you really want to go for aperture, and cannot afford the C8, go for the 200p.

[Dunkster]

I can't add anything helpful imaging wise, but visually the 8 should show noticeably more detail. Somewhat by accident, I currently have both a C6 and C8 and the C8 shows a lot more detail in globs that the 6 shows as fuzz, although I should add that the LP is pretty bad where I am.