Choosing Refractor for Imaging

[AstroEthan]

Hi

Im trying to choose a refractor for imaging with my dlsr For deep sky

whats the skywatcher-startravel-102 like?

[ronin]

Shortish fast achro, loads of CA.

Why the 102 ?

If the idea is a cheap scope for playing and practicing with until you buy an ED 80 or better then maybe, however then you may as well just get the ST 80 and not spend as much as the 102 costs. You could then keep the ST 80 for a possible guide rig later on.

Really no is the answer, unless there are other reasons for the 102 that are not imaging related.

What mount have you, or are you intending to get?

[baggywrinkle]

Welcome to SGL.

I had a SW ST120 and found it needed some correction for chromatic abberation on bright objects so I also used a fringe killer  filter which helps reduce the effect on short focal length refractors.

The focusing is OK for visual but a 10:1 focuser would make a big difference.

You might be better looking at a new or second hand ED type refractor.

[Davey-T]

As above, you may as well get the ST80, good starter scope and will always be useful as a guide scope later or easy to resell.

If you have some money to spend to get into imaging get a secondhand HEQ5 and you'll be set up for a while then when you've had a practice and discovered it's not as easy as it looks you can invest £500.00 / £600.00 on a decent S/H refractor, or decide it's all too much like hard work and flog everything 

Dave

[xtreemchaos]

+1 for the ED, you will save money in the long run. charl.

[AstroEthan]

Thanks everyone 

Looks like a nice scope and since its only for wide field since my reflector is for planets 

My mount is a Celestron CG-5 Goto 

I cant afford a ED refractor as there so expensive Which means ill have to get a filter to cut out CA

Would this be better?

http://www.telescope.com/Astrophotography/Sale-Astrophotography/Sale-Astrophotography-Telescopes/Orion-ShortTube-80-A-Refractor-Telescope/pc/4/c/380/sc/382/p/9947.uts?refineByCategoryId=382

[ollypenrice]

Refractors are popular amongst imagers but beware! It is GOOD refractors which are popular. Cheap, fast achromats like the ST series of scopes are, quite honestly, about as bad as it gets for imaging. I cannot think of anything worse off the top of my head. A far, far better idea would be a cheap budget Newtonian like the 130PDS. You'll need to collimate but, when you do, you'll have a scope capable of taking great images. The cheap fast achromats are badly colour corrected, have huge field curvature and a lot else wrong with them. The small Skywatcher Newts are delivering great images on SGL. The ST scopes are not. Have a look around at what's being posted.

Olly

https://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/

[Alien 13]

If the budget is tight you might be better to look at something like a prime 200mm FL camera lens possibly an old M42 SMC Takumar (plus adapter) it would probably perform much better than a short tube achro.

Alan

[AstroEthan]

Hi 

 i have a newt for planetery imaging but i need to get something for deep sky and i cant afford a newt for astrophotography 

And all of this is to go with my Zwo asi120mc(the colour one) and my cannon 400d 

[ollypenrice]

Hi 

 i have a newt for planetery imaging but i need to get something for deep sky and i cant afford a newt for astrophotography 

And all of this is to go with my Zwo asi120mc(the colour one) and my cannon 400d 

Isn't a small Newt about as cheap as it gets?

Olly

[Knight of Clear Skies]

If you want something really cheap, I can recommend the SMC Takumar 200mm f4 M42 lens. Here's the Orion Nebula taken with it.

It's an early 1970s vintage lens. I picked mine up off eBay for £22 but they normally go for a bit more than that. It's pretty flat but not perfect at about f5.6. I've now bought a 58mm-37mm step down ring for it to use as a front aperture mask, to avoid producing diffraction spikes.

[AstroEthan]

Yeah Cheap newts are but my dslr wont focus with my newt If i put a barlow in then for deep sky i loose detail 

The refractor will focus fine and since planets need barlows anyway i can always use my reflector 

will Galaxies and nebulas show CA since there so faint?

[ollypenrice]

Yeah Cheap newts are but my dslr wont focus with my newt If i put a barlow in then for deep sky i loose detail 

The refractor will focus fine and since planets need barlows anyway i can always use my reflector 

will Galaxies and nebulas show CA since there so faint?

The field stars will be the problem.

Olly

[Knight of Clear Skies]

Here's an image taken with an ST80, taken from this article comparing the ED80 with the ST. The difference is huge, even in the centre the stars don't look great, although the nebulosity has come through quite nicely.

[geordie85]

Yeah Cheap newts are but my dslr wont focus with my newt If i put a barlow in then for deep sky i loose detail

The refractor will focus fine and since planets need barlows anyway i can always use my reflector

will Galaxies and nebulas show CA since there so faint?

have you tried using a bahitnov mask? I've always managed to achieve focus with my 200p and X2 Barlow with a eos 600d and 1100d

[AstroEthan]

No its down to the fact that with the barlow on deep sky objects they loose detail being higher mag but if i needed no X2 barlow then i can get lower mag images 

Also is this the scope we're talking about http://www.firstlightoptics.com/pro-series/skywatcher-evostar-80ed-ds-pro-ota.html  ?

[Tim99]

Check out Explore Scientific's Refractors.  i got an ED80 last year for $599.  It is a great little telescope.