GEM or Fork - what to buy ?

[KMachell]

Hi guys,
I have read many of your posts with interest and realise more and more how little I now about all things astronomy.
I am thinking about buying either a Celestron GEM C11-SGT 11" XLT or fork mount CPC 11" GPS XLT.
I understand the fork mount CPC will suffer 'field rotation' without additional equipment (derotator or wedge), but it will probably be a lot easier to align.
I have had problems aligning a GEM (I have a 5 year collection of star trails) and I wonder if anyone has tried using the alignment functions of the Celestron GE mounts.
Basically for $500 more the fork mount self aligns, but needs hardware for photography, while if the GEM gives me too much difficulty I will never use it (for photos anyway).
any comments or advice would be greatly appreciated.

Cheers, Ken.

[ausastronomer (John Bambury)]

Hi Ken,

Is this going into a permanent observatory or will you be transporting the scope on a regular basis ?

CS-John B

[KMachell]

I will mainly use it from my backyard in Melbourne, although I plan to take it away up the country every few months.
Either way it will be mounted on the (2" steel) tripod it comes with.

Ken

[MYK]

Hi Every:
I am some what new to astronomy. Have been involved for about a year now. I am thinking to buy a Celestron CPC 1100 XLT 11" (fork mount) for astrophotography. Any comment and suggestions.

Thanks

[jase (Jason)]

If your primary goal is astrophotography, you're better off with a GEM. While others may disagree, a GEM can be a little bit of a pain just for visual use - need to rough polar align etc. The electronics behind the Meade and Celestron telescopes are quite impressive especially when used in Alt/Az modes.

Comes back to what your interests are and the quantity of time you intend to give your passion. Don't rush into anything. There are plenty of people in this forum that can help you along your journey.

[AstroJunk (Jonathan)]

GEMS are better all round!

In particular - they break down into smaller parts for transport, and that's a big factor when you are talking about a 11" SCT!

Nothings perfect, there are issues, but if you harbour any aspirations to be the next big thing in astrophotography, get the gem.

Otherwise, spend your money on the biggest Dob you can afford (like me).

[rogerg (Roger)]

You can use either for anything, I don't think there is a technical limitation of either. However, I prefer fork, no doubt about it.

Things I like about the fork:
- eyepiece/camera doesn't travel as far, easier for managing cables and looking through an eyepiece.
- no meridian flip
- no big counterweight bar to get in the way of things
- a GEM like a Losmandy takes up considerable space. I would estimate that a OTA + GEM would take a reasonable bit more packing space in a car than a OTA on a fork mount.

I find my fork scope and my GEM scope both as easy as each other to balance.

I get better precision from the fork, but that is not so much a factor of the mount type as which is tuned more. I guess a consideration is though that you can get high precision from either.

HOWEVER, if you're thinking about a large portable scope (greater than 10+) I'd go GEM because the fork + OTA assembly of 12" + are significantly heavier than just OTA of a GEM setup.

Roger.