8" Dob v 6" C6-S

[pediman]

Thought i'd got it all sussed by getting my choice down to an 8" Dob.But then saw the discounted C6-S from FLO.

Now i don't know which way to go.

Anybody out there can help?

I haven't got much of a back garden so would need portability(Harperigg nearest decent place i gather!)

It will be my first scope but also want it to be fairly future proof.

Not thinking about imaging, but then you know how these things have a habit of biting you pretty quickly, so would never rule it out.

Any ideas??

Matt

[SteveL]

If you have ANY intentions of imaging in the future with your first scope, then the Dob is a non-starter for that (apart from maybe some self guided shakey planetary sequences).

Of course, an 8" dob @ f/5 (or thereabouts) will be better for visual than a 6" SCT @ f/10.

I know that hasnt helped much

[russ]

I had the C6-SGT briefly and it's a good little scope. Did everything quite well and could easily be moved around as a whole without having to take it apart.

There are some downsides that will add expense to that price. Dew prevention is essential with an SCT, not an option. Depending on your location a dew shield may not suffice. In which case you will need a dew controller and heat strap. My location is terrible for dew. The controller is £59 and a combo shield/heater is £48. So that's £107 added before you get started.

There are also some pitfalls with the SCT design that the Dob is less prone to. We have covered the first....dew! The other is cool down. Until the SCT has adjusted to the outside temp it's performance will be pretty dire. Cool down times all depend on where you store the scope and the outside temp. From a warm house out to winter conditions and you could be looking at 2-3 hours before the scope is ready to provide really good views.

The dob has these issues to a lesser extent. The secondary mirror can dew up in extreme conditions and it will also require time to cool. But neither are any where near an issue like the C6.

The dob will also outperform the C6 in most areas and match it in others.

Just seen Steve's post. Number one drawback of the dob is the zero imaging possibilities.

Russ

[FLO]

So that's £107 added before you get started.

The SCT being more prone to dew is something that needs considering. If you don't live near a body of water or live at a higher altitude then a standard flexible dew shield will suffice. This can of course be made very cheaply from a camping-mat or similar material. If your area is prone to dew then some heated dew prevention will be necessary. A six inch dew heater tape and a 12v dew heater supply cable will totally eliminate dew. A dew heater controller is only necessary if you wish to run more than one heater tape and/or wish to regulate its output. The flexi heat dew shield and controller Rus refers to is the posh/expensive solution. A standard shield costs around £20 and a heater tape with lead around £40. Have a quiet chat with Blinky and it might cost even less...

HTH

[John]

Dew prevention accessories should be standard equipment for all SCT's sold in this country IMHO - I've owned 3 SCT's ( 2 C5's and a C8) and I found that it was not even worth setting up without a heated dew band in place and a dew shield on particularly bad nights.

I'm not sure you can really have a future proof scope when you are starting out as you just never know which aspect of the hobby will really catch your interest in the future. Perhaps the best compromise would be an eq mounted 8" newtonian rather than a 6" SCT ?.

John

[pediman]

Thanks guys! Have certainly given me something to mull over.

Pretty much sure it will be just visual for a good while. At least until i learn where everything is in the sky.

Think i've talked myself into a Dob!!!

Now just need the cash!

Cheers,

Matt

[russ]

Personally with only visual on the cards for a 'good while', i would be leaning towards the dob. The 8" dob is going to outperform the C6 visually and save you money to boot. And is all round less hassle.

[dweller25]

The Skywatcher 8" F6 Dobsonian is an excellent choice for a beginner or seasoned astronomer and will perform extremely well visually - you cannot go wrong with a scope like this.

[Whippy]

Another thing to take into account is you can put solid tube dobsonians onto an equatorial mount. Just add tube rings and a dovetail.

Tony..

[dogfish]

I love SCT's. Had a C6 previously and now a C8. Where you're planning to observe is definitely dew city (next to a reservoir) so dew prevention is a must (or a 12v hair dryer, which also works, and is the cheapest way to control the stuff). However, if I were you I'd go for a dob and a telrad finder and pester the hell out of Paul (G1ZmO) to get him to show you how to find your way around. Advantages are, much cheaper for the aperture you get, shorter learning curve, less set-up hassle, and you learn the night sky.

HTH, Martin