sct v. Newtonian

[speach (Simon)]

Well can you please explain the difference, not the actual telescope, but what are they better at doing between the two the two types. For a start off it'll not be moving it once installed. I've built an area solely for astronomy and it's got a pier, and I've a 6" SCT that I'll take with me when I go bush.
I'll explain what I want to do that may help. my mine interest is in DSO's and also have just started A/P, don't know if that interest will last seems to be very involved, But I know that an interest in astronomy will, Been a eye and bino observer since I was 6 that's 60 years ago!
Also the simple Newtonian is a lot cheaper, as I'm looking for 12' or larger. Also while I'm at it any recommendations for a mount, as Ill not be moving it I thought an Equatorial would be the go?

[The_bluester (Paul)]

I think the biggest difference (Apart from the obvious physical size) is that an SCT on an EQ mount is likely to have the eyepiece in much easier places to deal with than a Newtonian.

On the other side, if you are looking for DSO's and AP, the field of view restriction of an SCT might be a bit of a killer. I know on my CPC925 the FOV is very much limited compared to other scopes.

I like my SCT but there are times when I would love a greater FOV to play with.

[loc46south (Geoffrey)]

How about a refractor to start with - something like an 80mm or 100mm Skywatcher ED- I know it sounds puny when compared with the might of a 12" or 16" scope but I think you would be pleased and surprised with the results they will achieve. Large apeture scopes are difficult to manage for AP and take skill and experience to produce good images - I know I fell into the apeture trap when I started. There are a number of good imagers in IIS - take a look at their web pages and the equpment they are using - you may be surprised.

Cheers

[traveller (Bo)]

Newts usually have fast focal ratios of 4-5 and is best value for money in terms of aperture. Being a fast scope, it also means it is very forgiving in terms of tracking errors and so on. On a newt you need less time to expose DSO compared with slower SCT (usually f10) and refractors (usually f6-8).
For visual purposes, DSOs also show up much brighter in a newt.
I had a vintage 114mm newt and the views I get on that is better than my 200mm SCT.
The main disadvantages of newts are its open tube and the need for coma corrector for the fast ratio, but other than that, I'd recommend newts over SCT if the scope is permanently mounted (SCT are good travel scopes due to their compact size and sealed tube).
My 2c.
Bo

[Amaranthus (Barry)]

SCTs don't need to have a small FOV. I regularly use mine with the f/6.3 FR in when doing visual work, and it's terrific (it also flattens the field). It stays there for all DSO observation and only comes out for planetary.

At f/6.3, my 8SE has a FOV of 1.2 degrees with my 1.25" Panoptic 24, and well over 1 degree with my Nagler 16. Not too bad! The higher mag also gives great contrast, especially under light pollution.

[Renato1 (Renato)]

Newtonians can have a smaller central obstruction than SCTs, so that they give better contrast.

Newtonians are longer than SCTs and have the focuser at the top of the tube, whereas SCTs have them at the back.
So, it is much easier to be able to sit down and look through an SCT, than to be constantly either standing up or sitting down to look through a Newtonian (depending on where it's pointed).

If you are going to be using your pier mounted telescope a lot, comfort has to come into it.
Cheers,
Renato

[Camelopardalis (Dunk)]

IMO don't tie yourself down and keep your options open...pick a scope for each

One scope for visual - whatever takes your fancy. Don't get distracted by "narrow" fields of view, bigger scopes by necessity have narrower FOV than smaller ones, keep a pair of binoculars or a small refractor to hand for the largest/extended objects and sweeping the Milky Way...
One scope for imaging - small, fast refractor would be my choice. Gather data quickly and it's easy to mount.

The mount is most important if you're going to be imaging.

[cometcatcher (Kevin)]

There must be a hundred ways to image DSO's. Keep in mind SCT's and refractors don't need collimation. Refractors are the easiest. No collimation, no mirror flex to worry about. But you don't get much aperture for a refractor compared to a Newtonian.

Newtonians are the best bang for buck. Those 8" F4 astrographs really pack a punch. A great combo for DSLR's. But they need adjustment and mirror flex can be a pest unless you use an OAG.

Fast Newts need a coma corrector, not a problem just factor that in, same as most refractors need a field flattener and/or reducer.

GSO also make RC astrographs, another design to consider.