Telescope choice... going round in circles.

[alfingido]

Well, what I thought of as a simple choice has got me spinning.....what to go for next?

I sold my LX200 a while ago and want something now to start up again.

I thought of a Dob and looked at all the currently available ones, then started looking at refractors.

Having never looked through a refractor, I really have no idea what size to look for. I quite like the look of Skywatchers 100ed2 apo or pro series.

Whats the opinion on these. Am I going to miss much going from an 8" and 10" SCT, would the dob be better for deep sky?

Help...

Allan

[mdstuart]

The Dob would be better for deep sky (visually). Refractors are however best for imaging the deep sky. With a 100ed you are going to be restricted in terms of magnitude but on the plus side you with get superb planetary images and cristal sharp views of the brighter objects.

Mark

[Mark at Beaufort]

Allan

I just love my 4" Astro Tech ED refractor especially on a driven eq mount viewing the moon or planets. However, if you want to visually observe DSOs you need to buy a Dob. I cannot fault the 10" Flextube Dob that I have and with a quality EP the views are wonderful.

Mark

[brianb]

Am I going to miss much going from an 8" and 10" SCT, would the dob be better for deep sky?

There is NO SUBSTITUTE for APERTURE.... a 4" Apo is great for imaging and wide field views of star clusters but for everything else the light grasp & resolution of a 8" scope (even one with poor optics) will completely blow the thing away.

[jgs001]

Having never looked through a large aperture scope, I'm probably not the best to advise, but I have a pair of 3" fracs. I've been having a ball with them. I may well get a Dob at some point in the future, then I can have the best of both worlds... An imaging rig and a lightbucket for visual whilst everything else is chugging away.

[johninderby]

If I was restricted to just two scopes they would be a 4" refractor and a 12" dob.

Refractors are great for imaging, but so are SCTs. But nothing can compete with a dob for the aperture you can get for your money. The Skywatcher 100 ED refractor is very good but is nearly the same size and weight as the 120, which probably explains why you can pick up the 100 second hand so cheaply.

I use a 4" f/6 APO as my grab and go scope on a manual Alt-AZ mount as it works well on lunar/planetary as well as widefield, and can easily be carried outside fully assembled and ready to go. At the opposite end I use an 14" dob for DSO's etc. I also have a 10" dob that's very useful for when I don't want to get the bigger dob out, and finally a mak on a goto mount.

I think it's important to have at least one smaller scope that you can simply carry outside and be observing with right away. It helps to maintain your interest in observing. I've seen too many whose only scope has to be carried outside in several trips and takes half an hour to set up just loose interest as they can get into the "I just can't be bothered tonight" frame of mind. That's why many here on SGL own at least two scopes.

Whatever scopes you put on your shortlist there's plenty of opinions on the pos and cons here on SGL.

John

[alfingido]

If I was restricted to just two scopes they would be a 4" refractor and a 12" dob.

That sounds perfect, trouble is, funds re limited and I could only afford one at a time.

I got some great views of the planets with my LX90/200 but only really got great detail when I imaged them, DSO's were great in the LX200, but as John says, it gets a bit of a bind taking that up the garden every night, that was why I eventually sold it.

My thoughts were to get a 4"APO on an EQ5 or EQ6 Goto mount. Great for planets and imaging, leaving me a pretty stable platform for another larger OTA in the future on the same mount.

Or, a 12"Dob and see how I get on with that!

I will be using whatever I get as mostly visual to start with on easier to see objects. DSO can wait a while. Maybe the refracter should come first?

What sort of views should I expect of , say, Jupiter with a 4" Am I going to see many cloud bands, the red spot? Sorry to sound like a newb, but refracters are an unknown to me.

Allan

[GazOC]

I'd be wary of getting an 'only' scope and making the planets a primary concern. Theres only really 3 of them you can really get stuck into observing and one of them is only close enough to observe once every 2 years.

[johninderby]

The 4" APO will give nice views of Jupiter but visually can't begin to match the views through a 12" dob. If it can only be one scope and for visual use, then the 12" dob would be my choice, as while it will be good on DSOs of course it's also very good on lunar and planetary. And it will give you views that you can't match with any other scope for the money.

Here's a some good reviews of the Skywatcher 12" dob (both the solid tube and the Flextube) that will give you a better idea of what a 12" dob is like to use.

http://www.opticalvision.co.uk/documents/80.pdf

http://nightskies.net/scopetest/scopes/skywatcher/flextube.html

While a 12" dob is fairly large and bulky it's still "small" enough that the base and OTA can be carried outside seperately without too much effort by one average person. Adding some carrying handles to the OTA makes it much easier to handle.

Then later on when funds allow you could add an APO which would compliment it nicely.

John

[Rob]

Just to add to coments here. Take note of the size of the item here.. a 12" Dob is big. The APO will do well on DSO's.. no doubt there. But light gathering ability for the faint ones are needed. As a guide on how the 4" APO will perform.. its around the same views wise as Celestron C8 SCT.. I know lots of people will jump on this as say 'no chance' due to apature size, but trust me an Astro buddy and I did a side buy side test review on the usual targets. M13 & M3, M57, M27, M81 & M82. M92, M31, M42. The views through ED100 were better (contrast and sharpness). Planets were better also.. you can push an APO hard on magnification and not lose detail.

Luna is awsume in an APO. I have a Orion Optics SPX200 8" f6 Newt & ED80 f7. To me the best setup under UK skies. Don't get me wrong I have my sights on Flex tube 12" for later, but will always keep the ED.

Rob

[brianb]

As a guide on how the 4" APO will perform.. its around the same views wise as Celestron C8 SCT.

Sorry .... the APO may give images which look neater, especially in poor seeing, but there's nowhere near as much detail in them. Providing of course that both scopes are equally well collimated.

Have 110mm APO (a good one), used to have an 8" SCT, now have a 11" SCT. I keep the apo because it's great for wide views of brighter objects, where the long focal length of the SCT simply can't compete. And the apo is usually used on a simple altaz mount, amking it "grab & go".

IMO if you're only able to have one scope the 8" SCT is great but a 8" f/8 Newtonian will be better if you can carry it. Don't know about the 12" Dobs that are starting to appear on the market with computerized tracking, if these are reasonably well engineered they could be the answer to a lot of prayers.

[Rob]

Just another thought here. An SCT needs an Hour to cool to gain the best views. A newt is a fraction of that, and APO will take around 20mins. So if time is important keep this in mind.

[brianb]

Just another thought here. An SCT needs an Hour to cool to gain the best views. A newt is a fraction of that, and APO will take around 20mins.

Actually there's very little difference, at the same aperture.

My WO FLT 110 (4.3") takes about 2 hours to cool optimally. My 11" SCT - stored in the same location - takes a bit longer, but it already shows more than the FLT ever does with no cooling time at all. Give the SCT 2 hours to cool & the views are so much more detailed .... as well as going two whole magnitudes deeper: remember that, so far as DSOs are concerned, half the objects visible with any scope are within half a magnitude of its threshold.

[Rob]

Thats a fair coment. I've had 2 C8's in the past. One took a little longer (in fact it was covered in ice) to really nail that fine detail on planets. Also found I had to recollimate after temprature adjustment. I'm a real stickler for perfect collimation.

[alfingido]

I had to leave my old LX90 8" outside for an hour to cool, my LX200 10", nearer 2. That wasnt really a problem as long as the dew didnt beat me to it, which it did a few times.

Anyway, the circles getting smaller now, I think I have made my mind up ( thanks to all you lot) and will be seriously looking at the Skywatcher 12" FlexTtube Dob ( only so it will fit in the car for observing sessions at a nice dark site nearby)

I know I will miss the tracking of the Meades, so have decided to look at the Auto models. I dont expect tracking to be perfect, but it will make my viewing a whole lot easier, maybe allow me to get a few images with my dslr!

So, thanks for all the help, I will let you know what I come home with next week.

As long as those new Meade LX90's dont start pulling me in with their promises of flat field coma free views..............

Allan

[johninderby]

Or one of Celestron's new EdgeHD aplanatic SCTs with an even flatter field than the Meade ACF

But seriously a 12" Skywatcher Flextube Auto dob is a serious piece of kit that will give great views. I have one of the 10" versions and the tracking is pretty good. Not up to the standards of my 14" dob with StellarCAT system, but considering the Skywatcher is only a fraction of the price, I'm happy with it.

John

[barkis]

I believe the Newtonian reflecting telescope to be a wonderful instrument. In it's simplest form, on a Dobsonian mount, and with a 12" to 16" objective that is well figured, it should bring complete satisfaction to the Deep Sky observational astronomer.

Of course any thought of astrophotography is out, except in a limited way. Other instruments are needed for that task.

It should take a long time to satiate the desire of deep space object viewing, and when you have had your fill, your thoughts can then turn to the Imaging aspect of astronomy.

Whether you will be parting with your Deep Space Ship, will be a difficult decision for you. I would bet you will opt to keep it.

Ron.

[rikyuu]

Well, I don't really do any visual stuff, only imaging. So I find the compactness and low weight of a C8 SCT and C80-ED refractor very convenient. The C80-ED had a bargain new price too, not sure if they still do. I've done a lot of swapping and changes and I'm sure I'll change my mind again!

These two scopes give me a good range of focal lengths to use with a DSLR, ie 2000mm, 1200mm, 600mm (using a FR on the SCT- which I've not tried on the C80 yet, but might give me 400mm too).

[alfingido]

After a trip to the Widescreen centre yesterday, I think my mind is made up. I was shown a beautiful Orion 12"Dob, but it was just a tad too expensive for what I now have in mind. They also confirmed a 12" newt would be a struggle to set up on a mount every night, on my own!

I have decided on a Dob, a Skywatcher 300p Flextube without auto. It seems the most practical ( will go in the car) and a great price for such a huge OTA.

Then, as I really want to do some more imaging in the future, I will probably get an EQ5 Synscan mount and have a look around for a small refractor and guide scope. I dont think I will need to go up to the HEQ5, the weight I will put on the EQ5 will be within its limits.

So, plastic out tomorrow and I will be scanning t'interweb for the best deals

I'll post back later when the new equipment arrives.

Allan

[Doc]

Congratz Allan and please post a first light report.

[alfingido]

Thanks Mick, will do

I ordered the Dob today, and while I was about it, I saw a good price on an EQ5 SynScan mount, so ordered that too.

They should arrive Thursday, so expect heavy cloud from Thursday onwards!

Just need to sort out imaging scope now, but that can wait. I have a DSLR that can sit on the mount for a while to try it out at low magnification.

Allan

[albedo0.39]

Hi Allan - I'm bound to say, "good choice" - congrats on the new toy. Look forward to hearing from you in future reports

Cheers

[iancandler]

I would grab a ZS66 or megrez 72 second hand, not only do they work well as a widefield imaging scope, but are also great grab and go's as well as good little guide scopes.

I've had my 66 for ages now and wouldnt part with it, even if I did get another refractor.

I used to have both it and a 10 inch dob, so used it on the nights I couldnt get the dob out, I was pleasantly surprised by what I could see with it.