Refractor suggestions …. Upgrade from Evostar 80ED Pro.

[Ouroboros]

I’m thinking of moving on up from my SW Evostar 80ED. I have in my sights something with more aperture (100mm, 130mm).  It will be used for imaging, almost certainly an astrograph, but must also be useful for visual.  I mainly do deep sky imaging.  It’s got to have a flat field at least over an APS-C sensor and preferably suitable for full frame.  It’s got to be light enough to be carried on my AZ-EQ6.  I’m expecting cost of 1 to 3.5k -ish.  I’ve been looking at the Askar range, but I’d also like to hear about other brands recommended/suggested.

Any thoughts,folks?  

[Lee_P]

I know you're after other brand suggestions, but just chipping in quickly to say that I recently bought an Askar 130PHQ, and it's really excellent. (I'll be writing a review in a few weeks, but can send you some sample subs before then if that's useful to you). It is a bit beyond your stated budget though, and the 107PHQ is cheaper but has an excellent reputation. I'll let others make suggestions of other brands as you actually requested 😁

[tooth_dr]

I was going to suggest an APM LZOS 105.  It is just within your budget, but I'm not sure when they will be available again.

105mm APO Telescope - APM Telescopes 105/650 APO Refractor (astrograph.net)

[ollypenrice]

You just might find a used TEC 140 at that price. If so, buy it.

Olly

[900SL]

Any of you chaps (chapettes) use the SW Esprit 100?

[Ouroboros]

12 hours ago, tooth_dr said:

I was going to suggest an APM LZOS 105.  It is just within your budget, but I'm not sure when they will be available again.

105mm APO Telescope - APM Telescopes 105/650 APO Refractor (astrograph.net)

Nice scope. I don't really have an upper limit on the budget, except at some point my sensible side will say … enough!  I notice with these more expensive scopes they don’t  come as a complete set to work visually out of the box. So I do need to budget for the necessary  accessories for visual, although I have suitable eyepieces initially anyway.  I notice the APM 105 requires a field flattener. I’d really like not to have to use one in order to avoid back focus issues. 

[Ouroboros]

12 hours ago, ollypenrice said:

You just might find a used TEC 140 at that price. If so, buy it.

Olly

How often does that happen?  I bet they’re snapped up too. Nice looking scope though.  

[tooth_dr]

2 hours ago, Ouroboros said:

Nice scope. I don't really have an upper limit on the budget, except at some point my sensible side will say … enough!  I notice with these more expensive scopes they don’t  come as a complete set to work visually out of the box. So I do need to budget for the necessary  accessories for visual, although I have suitable eyepieces initially anyway.  I notice the APM 105 requires a field flattener. I’d really like not to have to use one in order to avoid back focus issues. 

No problem, the back focus distance is 76mm with this flattener so there is a bit more wiggle room.  I never do visual so I never thought about the potential for needing accessories.  All I know is that it really does deliver very nice tight stars across at lease APS-C sized sensor.

[Ouroboros]

21 minutes ago, tooth_dr said:

No problem, the back focus distance is 76mm with this flattener so there is a bit more wiggle room.  I never do visual so I never thought about the potential for needing accessories.  All I know is that it really does deliver very nice tight stars across at lease APS-C sized sensor.

OK.  It’s a x1 flattener too isn’t it so the full f number of the scope is utilised. Then they also offer a reducer.  So there’s a range of focal lengths available there.  I’ve been put off a bit by back focus issues with my ED80/reducer hence my leaning towards an astrograph.   

[Ouroboros]

15 hours ago, Lee_P said:

I know you're after other brand suggestions, but just chipping in quickly to say that I recently bought an Askar 130PHQ, and it's really excellent. (I'll be writing a review in a few weeks, but can send you some sample subs before then if that's useful to you). It is a bit beyond your stated budget though, and the 107PHQ is cheaper but has an excellent reputation. I'll let others make suggestions of other brands as you actually requested 😁

Oh, quite happy to hear about people’s experience with Askar scopes. I have been looking at the 130PHQ too.   Do you have the 0.7 reducer? 1000mm is nice but a bit long for many deep sky targets. Sorry I don’t know whether you’re an imager. Where would you put a guide scope?  

[KP82]

If you must have a quadruplet (or even more lens elements) flat-field refractor larger than 80mm for imaging so that you don't have to deal with separate flatteners, your options will be quite limited.

Askar 107PHQ, 130PHQ
Sharpstar Z4 (sextuplet, new release, no review yet)
TS-Optics APO100Q, 121SDQ (made by Sharpstar)
Tak FSQ85, FSQ106EDX4

Askar petzvals are very popular lately, so a lot of reviews/personal experiences to be shared around. Unless you're willing to increase your budget to get the Tak 106, the Askars are probably your best bet.

[Lee_P]

1 hour ago, Ouroboros said:

Oh, quite happy to hear about people’s experience with Askar scopes. I have been looking at the 130PHQ too.   Do you have the 0.7 reducer? 1000mm is nice but a bit long for many deep sky targets. Sorry I don’t know whether you’re an imager. Where would you put a guide scope?  

Yep, I'm an imager. I don't have the reducer. (Note that if using the reducer, you need to achieve the specific backfocus). There's a standard bracket for a guidescope near the back.

 

 

[Ouroboros]

@Lee_P Thanks. Nice arrangement. I moved my evoguide ED50 guide scope off the finder shoe partly because I thought it was less stable than attaching it to  the top of the scope. The finder is also a convenient place to put my ASIair. I was wondering whether the slot in the carrying handle was meant for attaching accessories of this sort. I see there are also threaded(?) holes in the frame holding the scope. 

[Lee_P]

13 minutes ago, Ouroboros said:

@Lee_P Thanks. Nice arrangement. I moved my evoguide ED50 guide scope off the finder shoe partly because I thought it was less stable than attaching it to  the top of the scope. The finder is also a convenient place to put my ASIair. I was wondering whether the slot in the carrying handle was meant for attaching accessories of this sort. I see there are also threaded(?) holes in the frame holding the scope. 

If you have an ASIAIR Plus then it'll fit beneath the OTA -- but only just. An ASIAIR PRO wouldn't fit.

 

You could attach items to the handle, but I wouldn't recommend it if you plan on actually using the handle! Yes, the tube rings are threaded, so you could use those as attachment points. FWIW I've found the guidescope attached to the finder bracket to be stable enough.

[Ouroboros]

That’s good I have the plus. 

[Lee_P]

1 hour ago, Ouroboros said:

That’s good I have the plus. 

Mind you, if you're thinking that 1000mm is too long, you might be better off with the 107PHQ. I doubt that would fit an ASIAIR in the same way, but can't say for sure. 

[Ouroboros]

OK.  Well …. there are always ways to do it. 

[Ouroboros]

Just a follow up question on this subject ….. 

I was at the IAS today looking at various refractors.  One of the vendors was very insistent that astrograph refractors are not good for visual use.   This rather surprised me because several of the suppliers’ and manufacturers’ web sites state that although optimised for imaging, these scopes are good for both.

Does anyone here have any experience of using them for visual?

Edited October 14, 2022 by Ouroboros

[Dan_Paris]

On 12/10/2022 at 20:14, Ouroboros said:

I’m thinking of moving on up from my SW Evostar 80ED. I have in my sights something with more aperture (100mm, 130mm).  It will be used for imaging, almost certainly an astrograph, but must also be useful for visual.

 

According to your signature, you have a Skywatcher 200mm Newtonian. Why not upgrading it for imaging  (solid focuser and good coma corrector) ?

And also, which kind of objects do you want to image ? Large nebulæ or galaxies ?

 

 

[cajen2]

Would a Starfield 102 not be a good compromise?

https://www.firstlightoptics.com/starfield-telescopes/starfield-102mm-f7-ed-doublet-refractor.html

Only a doublet, but with Ohara FPL 53 and Lanthanum glass, plus an F/7 focal length which should suit visual and a R/F to take it to F/5.6 for AP.

[Ouroboros]

8 hours ago, Dan_Paris said:

 

According to your signature, you have a Skywatcher 200mm Newtonian. Why not upgrading it for imaging  (solid focuser and good coma corrector) ?

And also, which kind of objects do you want to image ? Large nebulæ or galaxies ?

Thanks for the suggestions. At one time I only imaged with my 200p, and with some success.   I tried a corrector which sort of worked but I got a lot of reflections especially from brighter stars.  I tend to only use the 200p for visual now - particularly of the Moon, planets and small deep sky fuzzies.   I prefer my refractor for imaging. It’s very convenient to keep it all together - scope, guider, ASIair - ready to be taken out as a unit and plonked on the mount. I also prefer stars free of diffraction spikes.

I want to image deep sky objects of all sizes.  Ideally I’d have several telescopes with a  range of fields of view to suit different targets.   

[Ouroboros]

7 hours ago, cajen2 said:

Would a Starfield 102 not be a good compromise?

https://www.firstlightoptics.com/starfield-telescopes/starfield-102mm-f7-ed-doublet-refractor.html

Only a doublet, but with Ohara FPL 53 and Lanthanum glass, plus an F/7 focal length which should suit visual and a R/F to take it to F/5.6 for AP.

Yes, that looks a nice scope doesn’t it?  I shall add it to the list.  I see what you saying about the f/7 for visual and f/5.6 for AP.  It would be a step up from the SW ED80. I wonder if it gets me much further on though. I’ve added it to my list of possibles though. 

[scitmon]

Would the StellaMira 90mm triplet be too small to consider?  That's what I have just replaced my 80ed with.

[Ouroboros]

On 17/10/2022 at 11:46, scitmon said:

Would the StellaMira 90mm triplet be too small to consider?  That's what I have just replaced my 80ed with.

Hi.  Yes, I’ve been reading about that scope.  How well have you found it to perform?  

[scitmon]

1 hour ago, Ouroboros said:

Hi.  Yes, I’ve been reading about that scope.  How well have you found it to perform?  

I've not had a chance to test it out yet, its exclusively a imaging scope for me and i'm still putting the rig all together.  The build quality is night and day compared to the ed80 though.  This thread has some images others have taken with it: