Vixen 8" F4 Newt OR WO 132mm Refractor?

[Ross G]

Hello,

I have a Vixen R200SS 8" F4 Reflector that has sat in my garage unused for over a year.
I am currently using a WO 110mm refractor (M110).
I am now thinking of upgrading.
My choices are either sell the Vixen and WO and buy a WO 132mm refractor or save the money ( I do not have) and start using the Vixen R200SS.
My question is, will I see a difference between the 8" Newtonian and the 132mm WO refractor and if so, will the difference be enough to justify the $3,500 difference between the two?
The scopes will be used to photograph DSO's through a QHY8L ccd camera.

Thank you.


Ross.

[Profiler (Profiler)]

Hi Ross

I can give you some limited advice but with all things astronomy there are compromises which have to be taken into consideration so although something may seem initially good there are some catches.

Advantages
Firstly, I do not have a WO132 although I have looked through one a few times and it is an excellent refractor (or at least the one I looked through was) and in my view will certainly outperform an 8' reflector (excuse the general statements). Additionally, WO is one of the few manufacturers who sells direct to the public via WO online and you can get some remarkable deals through them - better even than what some local vendors may offer - worth checking out. Moreoever, due to the exchange rates the prices of astronomy equipment have come down remarkably everywhere and so things are only getting cheaper so now is a good time to buy - btw I have no connection with WO

Disadvantage
There is only one real disadvantage and it is not the price because for the performance I think the WO132 is a fantastic OTA. The one catch is that not only is the WO132 a great refractor it is also getting to be on the 'big' side of things so don't have any illusions of grab and go or 5-10 minute set up. It is not immovable etc - but is certainly a noticeable step up in size from your average M110, M120 or FLT110 etc. You can certainly carry it around - but you will probably carry it slowly.

[Waxing_Gibbous (Peter)]

Although I'm an unapologetic refractorholic, and appreciate their fuss-free viewing, they ARE somewhat limited in what they will show by aperture. Also, big ones (5" and up) are BIG scopes as Profiler points out. A lot of the fun of refractor viewing goes out the window when you're trying to manhandle a 15kg scope onto your mount 4 feet in the air.

As far as application goes:
If you're going to do astrophotography, are a fan of widefield viewing or splitting uneven doubles, I'd go for the 132.
For everything else, especiallialy globular clusters, nebulae and planetary observing I'd choose a good reflector of some sort like your Vixen.
A well-figured 8" Newt of f5+ will show you much more detail than even the largest, most expensive AP, TEC or Takahashi refractor currently available - just ask Yuri or Roland.
The visual downsides to a reflector are slightly less contrast, coma (increasing the faster the scope), and for me, diffraction spikes.

I'm not personally familiar with the 200SS, but I believe the only real gripe people have against them is the thickness of the spider vanes (causing big fat spikes), and a CO that's just a bit large for lunar and planetary viewing. There are quite a few aftermarket spiders and secondaries available that will cure this.

My advice would be to save the dosh (maybe get a 3-4" quality refractor for all-round use) and enjoy the Vixen.

[Alchemy (Clive)]

Originally Posted by Ross G

Hello,

I have a Vixen R200SS 8" F4 Reflector that has sat in my garage unused for over a year.
I am currently using a WO 110mm refractor (M110).
I am now thinking of upgrading.
My choices are either sell the Vixen and WO and buy a WO 132mm refractor or save the money ( I do not have) and start using the Vixen R200SS.
My question is, will I see a difference between the 8" Newtonian and the 132mm WO refractor and if so, will the difference be enough to justify the $3,500 difference between the two?
The scopes will be used to photograph DSO's through a QHY8L ccd camera.

Thank you.

Ross.

I have seen some excellent images taken with the 110, the 200ss do tend to have fat spikes. An 8 inch reflector can deliver fine images.
I have a 132 FLT and am very happy with it, the color on even the brightest stars shows no blue halos, there is a slight amount of flaring but I have seen this even on astrophysics refractors. The difference between F4 and F7 Is substantial, I do 20 min exposures with mine and a qhy8 so you will need a mount that can dish up long exposures plus mount a suitable guidescope.
Which would I pick given the choice..... The 132. I've had reflectors and just prefer a refractor now, no spikes, no collimation, less physical surface area for wind to affect, plus personal taste I guess.
As for your situation, use the 200 and exploit it's low f4, see if you can hook up with someone who has a large refractor for a night and test drive it, see if it is really where you want to be.

[badabing82]

slighty off topic but still on topic if that makes sense,

Is resolution and light grasp determined by clear aperture surface area or just the bigger is better rule?

if say a 8inch newt has a 1 1/4inch secondary does that mean it's a much closer comparison in both light gathering power and resolution? to a 6inch apo that is....

[Profiler (Profiler)]

Some very good advice here from both sides of the fence. I should clarify that while I have no connection with WO I too am a refractoroholic and I am biased towards favouring refractors. I find the age old debate between reflectors and refractors typically arises over a 4inch refractor versus an 8inch reflector. Hence the WO132 might be better. But as one reviewer on CN stated it is wrong to compare refractor/reflectors as it is really an apples versus oranges comparison. My feeling here is that judging by the fact that your reflector has been in the garage for a year and you have been using a M110 you are subconsciously leaning towards refractors anyhow - it is the price which you really feel troubled by - to this connundrum - you only live once.

[gregbradley]

Oh that's easy. The 132 without a doubt. No comparison.
I have had a Vixen R200SS F4. Very very widefield, needs a proper coma corrector, fussy and hard to collimate. Fat diffraction spikes. Cheap and nasty focuser. Overall a poor build quality. Not an impressive scope at all. Having said that I have seen good images from them if the owners perservered though the setup and handling of them.

The WO 132 is more of a premium APO. APO images are usually more popular because they are sharper, usually no or less coma, no diffraction spikes, simpler to use, less problem with tube currents and cooldowns and smaller and more colourful stars. The 132 I imaging is considerably heavier and may require a larger mount. It is less likely to be wind affected compared to the large tubed Newt.

Newts mean the imaging gear is hanging off the side of the tube. This means unless it is well made flexure with heavier gear will be a problem.

Even the venerable Tak 180ED F2.8 Epsilon gave inferior images to the FSQ106ED even if a bit faster at F2.8. Star sizes are larger and therefore the image is less appealling. You don't hear much about that scope anymore but it was all the rage when it first came out.

I think though Newts come into their own in the larger apertures or the more high quality ones like the Orion Optics AG or ASA's when they work.

Greg.

[Alchemy (Clive)]

Some other comments about the 132, you will a field flattener, I use the large Williams one and it works a treat. The standard focuser has absolutely no problems with the weight of the qhy8, cooling shift is minimal, plus with the graduated focuser it's easy to repeat night after night.
I use mine on a g11 I know you will find all sorts of people saying they use less, my advice is check out the quality of their images and exposure times... You WILL need long exposures at f7

Again I suggest you find someone to hook up with to see if it's what you want, if you were in melb I'd let you run a few frames on mine but.....NSW is a long way away.

[Ross G]

Hello all,

Peter, Clive, Profiler and Greg, thank you for your time and informative advice. Your views have made me feel better.
My fear was that I would spend $4,500 on the WO132 refractor and then find my images were no better than what I have captured with the Vixen!
Profiler, you are right, I do think I lean towards refractors. The Vixen was meant to replace the M110, however, a constant problem with movement in the DEC which I didn't have the experience to work out whether it was the mount, the focuser or flexure resulted in the Vixen going into storage. Greig, you are correct about the quality of the Vixen, you do get what you pay for.
The M110 on the other hand has been a pleasure to use with absolutely no problems over the last year. The results have been excellent and it so portable, which is important when you live in suburban Sydney.
Clive, thanks for the kind offer.
I think I am at the stage where I want to upgrade and the WO132 seems the logical progression. Maybe, I will give the Vixen another attempt...just to make sure!
So, thanks again guys. You have given me the confidence I needed to take the next step.

Ross.

[gregbradley]

I am not sure how familiar you are with your Vixen 8 inch Newt but I found with mine collimation suddenly became easy once I got the little cheapy laser collimation tools. The one with the cutout and a bullseye painted on that reflects the laser beam back. I could collimate it then in only 5 minutes. Without that I got lost in collimation very quickly.

Greg.

[Ross G]

Hi Greg,

I used the Vixen R200SS for about 10 months before it was banished to the garage. I had it collimated at the start by Astro Optical and despite being driven around NSW, the optics remained stable (..to my untrained eye at least..).
I know if I start using it again, collimation will be something I will have to learn and do.....maybe another reason to get the refractor!

Thanks

Ross.

[madwayne (Wayne)]

Ross

If I were to spend the type of money you are looking at spending on an FLT132 there is a 10" RC for sale in the classifieds http://www.iceinspace.com.au/forum/s...ad.php?t=73623

I know that doesn't answer your question about your 8" Vixen vs FLT132 but it is another option that would leave you with some change for other goodies. I also think that Greg and the other posters on your post have more than adequately answered your question.

I wish to point out that I do not know Doug or have any knowledge of his telescope that he has for sale. I am merely someone who if I had 2,500 sitting around gathering interest in a bank Doug would have sold his telescope by now and I would be off to Victoria to pick it up.

All the best and what ever you do please sneak this new kit in to Sydney as I for one am jack of no images for over 12 months except for an hour of Rosette very early on in the season .

Wayne

[tlgerdes (Trevor)]

Wayne, if he got the 10RC, Ross would have to get a bigger mount as well, that eats all his change and then some

[gregbradley]

A 10RC would be tempting. A different type of image but these GSO RCs are awesome instruments. Longer focal length and probably a bit heavy.
I am not sure what your mount is but you'd probably want a decent mount for that sort of scope. Long focal length is harder get round stars with autoguiding so everything has to be upped in quality and accuracy.
But it does open up a world of galaxy images which is appealling.

Also not sure what the pixel size of the QHY8 is. You ideally strive for around .66 arc seconds /pixel with an assumption of 3 arc second seeing which is common and in some cases it would worse than that.

I have just been trying out my ML8300 camera on the CDK17 and I was surprised to find it had quite a bit worse resolution than my Proline 16803 camera. I put that down to smaller pixel size and less sensitivity (not by much though) and smaller well depth (how many electrons a pixel can hold).

So that .66 becomes more important with a longer focal length scope.

The WO132 would be a nice wider field more forgiving instrument.

You could also put a Tak 1.6 extender on it and get a longer focal length for images as well. Another advantage of good refractors, they are potentially 3 focal lengths - short with a reducer, native and long with a barlow or Tak extender.

Greg.

[Ross G]

Hi guys,

Thanks for the suggestions.

It really is a domino effect...4" to 5" to 8" to 10"......!

I think the long focal length of the 10" would bring me new problems with tracking, flexure and mounts.

Living in Sydney, portability is a very important factor. Wayne, you mentioned the lack of clear nights in Sydney. We get away to Coonabarabran every couple of months where we have been lucky with clear nights. The portability of our equipment allows us to do this.

Greg, the QHY8L has 7.8um square pixels. My M110 refractor has a focal length of 655mm. The Vixen is 800mm and the WO132 is just over 900mm.

Trevor, how is your 8" F4 performing with the new camera?

I think the WO132 is starting to look the best compromise for me.


Thanks again for your help and advice.


Ross.

[madwayne (Wayne)]

Originally Posted by tlgerdes

Wayne, if he got the 10RC, Ross would have to get a bigger mount as well, that eats all his change and then some

Thanks for pointing that out Trevor but given the FLT 132 weighs in around 15kg (mentioned earlier in this thread) and the 10" CF RC weighs in around 17 or 18kg per Doug's ad I was under the assumption Ross has a mount more than capable of carrying the FLT132 otherwise this whole thread becomes a waste of space.

Wayne

[Ross G]

Hi Guys,

The reason I started this thread was that I am getting a Losmandy G11 so I was investigating my telescope options.

Thanks again.

Ross.

[gregbradley]

Well a G11 expands your selections quite a bit.

The GSO RC would be handleable by a G11 surely.

As you point out though longer focal length does add to the challenges so perhaps it is smarter to go down the road of wider field images and do longer focal length when you've exhausted all the usual targets.

Greg.

[tlgerdes (Trevor)]

Ross, you'll hear about it on Wednesday if you turn up.

Originally Posted by Ross G

Hi guys,

Thanks for the suggestions.

It really is a domino effect...4" to 5" to 8" to 10"......!

I think the long focal length of the 10" would bring me new problems with tracking, flexure and mounts.

Living in Sydney, portability is a very important factor. Wayne, you mentioned the lack of clear nights in Sydney. We get away to Coonabarabran every couple of months where we have been lucky with clear nights. The portability of our equipment allows us to do this.

Greg, the QHY8L has 7.8um square pixels. My M110 refractor has a focal length of 655mm. The Vixen is 800mm and the WO132 is just over 900mm.

Trevor, how is your 8" F4 performing with the new camera?

I think the WO132 is starting to look the best compromise for me.


Thanks again for your help and advice.


Ross.

[Ross G]

Hi Greg,

I believe in small steps and my skill levels currently are no where near capable of imaging with the 2000+mm focal lengths of the GSO RC's. Their size and weight would also make quick trips to Coonabarabran or Wiruna less likely.

Thanks.

Ross.