SCT vs RC

[jmac2us]

Looking to start a little deep sky photography, but want to continue the real time watching too... I am also suffering from shrinking apperature syndrome... Can't decide whether to go with an 10" RC or 14" SCT...

Any suggestions?

[renormalised]

Welcome to IIS:)

Ok...here's the lowdown. The 14" will give you better resolution and brighter images because it's larger and has a smaller central obstruction in comparison to the primary mirror. However, unless it's one of the newer EdgeHD (http://www.celestron.com/c3/product.php?CatID=93&ProdID=576) or ACF (http://www.meade.com/product_pages/lx200_series/lx200_14/lx200_14.php) models, the off axis coma will be greater in the SCT than in the RC. The RC will most likely be a faster scope as its optics will be a little tighter than the SCT (probably an F8 c.f. F10 for the SCT's). Both will need field flatteners, though, unless it's an EdgeHD or ACF which are also corrected for field aberrations as well. Focal reducers will work in all scopes, except don't match a Meade ACF with their 0.33 field flattener/focal reducer. They don't work together at all. The 0.67 is OK, but the other one is a disaster. It'll look like you're doing warp 9 in any piccie you take:):P If you get an EdgeHD scope, you'll also get the added benefit of it being hyperstar compatible. This means you'll be able to get a Hyperstar (http://starizona.com/acb/hyperstar/index.aspx) lens system and take piccies at F1.8 to F2.0. Think of it as being a good way of taking a piccie of M16 that would normally take an hour or more, in 5-10 minutes:).

Then you have to think about your budget....what can I afford. What accessories do I want to get with it. What camera do I want to buy. Do I want to start with a DSLR or a dedicated CCD astrocamera...what else will I need with the camera etc etc etc. Then you have to think about guiding the scope for DSO pics, what sort of guidescope/guider combo you want and need...it adds up to quite a bit of cash in the end:)

Anyway, I hope that has helped you out. Anymore questions, just post away:)

[Kal]

Two problems you are trying to solve with one scope :) My suggestion - buy two new scopes! Get a large dob for your aperture fever and a smaller refractor to begin learning deep sky imaging with.

[higginsdj]

'Both will need field flatteners' - why? How big a camera does he have? What type of imaging does hw want to do? If you have a ccd approaching 35mm scale and you want to produce a 'perfect pretty picture' then maybe. When it comes to imaging keep it simple until you have a lot of experience and know what you are doing.

Cheers

David

[Bassnut]

Ill second what Carl says. Ive used both a 10"RC and a 12" ACF SCT.

In a practical sence, the RC gave much tighter detail and smaller stars, but the 12" SCT required significantly less exposure time for the same depth, or conversely for the same exposure time the 12" was much better for dim extended targets, a 14" would be noticably better than a 12" again.

[jmac2us]

Thanks all, you have given me the food for thought I needed... Now instead of 12 choices I am down to a couple... :)