Which Refractor?

[Kaliska]

So, I've now got hold of a good mount (AZEQ6 GT) and and modded 600D, so now next on my most wanted list is the OTA. I started out looking at a fast Newt for imaging, but I'm slowly being pulled in the 80-100mm refractor school of thinking. I've got a budget of around £600-£800 which should include and flatner. Any recomendations you guys have would be greatly appreciated.

[Uranium235]

You can't go far wrong with an 80ED, tried and trusted by many!

[PhotoGav]

+1 for Skywatcher Evostar 80ED DS-Pro Outfit (£469) with 0.85x matched flattener (£169) available from FLO. You can use the finderscope for guiding (with an adapter, probably from 365 Astronomy) when you get to that point. As Rob says, it's a tried and trusted system that just does the job!

[PeterCPC]

Another for ED80. I would also get one of these or click lock as the ring provided is not that good.

Peter

[newbie alert]

I love my 80ed for imaging..portable..no collimation  or cool down time..id suggest if you have a chance to use both before purchasing as we're all different..some like frac's others prefer newts..your mounts capable with both types..

[Dave In Vermont]

You might find this thread a good read:

 

Quite recent thread that went in this same subject.

Enjoy!

Dave

[Gina]

I went with the ED80 DS Pro for some time including adding another for a dual rig both with reducer/flattener.  Now I have the Esprit ED80 Pro which is really superb but more expensive, of course.

Interesting point actually, I may try that dual rig again with ASI1600MM-Cool cameras.  Could be a good choice for galaxy season

[Kaliska]

Yes, the ED80 does look like a great scope. I've also been looking at these two (would these need a flatner as well?): -

http://www.rothervalleyoptics.co.uk/explore-scientific-ed-apo-102mm-f67-essential-ota.html

http://www.rothervalleyoptics.co.uk/explore-scientific-ed-apo-80mm-f6-essential-ota.html

[PeterCPC]

Yes they would.

Peter

[Uranium235]

3 hours ago, Kaliska said:

Yes, the ED80 does look like a great scope. I've also been looking at these two (would these need a flatner as well?): -

http://www.rothervalleyoptics.co.uk/explore-scientific-ed-apo-102mm-f67-essential-ota.html

http://www.rothervalleyoptics.co.uk/explore-scientific-ed-apo-80mm-f6-essential-ota.html

The 80mm of those contains FCD1 glass, not on the same par as the FPL53 (synthetic fluorite) found in the Skywatcher 80ED. FCD1 is similar to FPL51, and will therefore not be as well colour corrected as FPL53. Go with the SW 80ED, you will not regret it.

Source from Cloudynights in regards to dispersion:

Here are the Abbe numbers (Vd) of some commonly used ED glasses:
FPL-51 (Ohara): 81.54
H-FK61 (CDGM): 81.61
FCD1 (Hoya): 81.61
OK-4 (LZOS): 92.1
FPL-53 (Ohara): 94.93
CaF2: 94.99 (Fluorite)

[MartinFransson]

How is the colour fringing on the 80ED, being a doublet?

[Uranium235]

Rather acceptable, being as its f7.5. Its blue stars that are the real test of any refractor, be it a doublet or triplet - the latter obviously performing better, but at a cost.

[MartinFransson]

This ED80-thing is also a bit confusing for someone not into refractors yet, since there are obviously a lot of different ED80-s, like the Orion ED80T CF Triplet. I´m guessing that one is a nice one, but at a higher cost.

[Uranium235]

6 minutes ago, MartinFransson said:

This ED80-thing is also a bit confusing for someone not into refractors yet, since there are obviously a lot of different ED80-s, like the Orion ED80T CF Triplet. I´m guessing that one is a nice one, but at a higher cost.

Yep, that CF triplet is the best part of 1k to buy - thats why the SW 80ED is such a bargain. It really is hard to beat at that price (actually, it cant be beaten!).

[Sp@ce_d]

Yup SW ED80.. Been through a few fracs & didn't find anything less than the Esprit (at a grand) to beat it. Even though I've not used mine for quite some time now, I still have to change the subject when the Wife asks when I'm getting rid of it... old faithful...

[Kaliska]

Well, after taking in all your your greatly appreciated advice, I was just about push the button on the SW80ED then this happened...

https://www.firstlightoptics.com/pro-series/skywatcher-evostar-100ed-ds-pro-outfit.html

Those pesky people at FLO dropped this in. Now, with the setup I'm going for (with the reducer/flatner and upgrade to the Crayford Focuser), the 80ED comes in at £767, but the 100ED comes in at £848. So, for an extra £81 I can get the next model up from this. Is this a no brainer?

 

[Sp@ce_d]

The 100 is f9 so slower. Have you played around with a field of view calculator (on FLO's astronomy tools site) to see how different setups will frame your intended targets. Generally speaking the 80 is the most versatile.

[sloz1664]

The S/W ED80 Pro + dedicated flattener is by far the best value you get for your money.

Steve

[Adreneline]

I also love my SW-ED80DS-Pro + flattener - it works really well with both my Canon 70D and Atik 414osc.

The only word of caution I would add is that my experience with the supplied focusser was not good; I wasted a lot of imaging time because the focussing unit would tend to slip during imaging. I tried the published fixes but for me it did not solve the problem. I am aware others have found it to be satisfactory or they have found the fixes to work.

I solved the problem by fitting the Baader Diamond SteelTrack - since then it has been perfect and holds its focus irrespective of load/position.

Adrian

[Kaliska]

I've come across a second hand ED80, Schott Glass Edition. Is this any different than the new ones sold now?

[Sp@ce_d]

According to OVL the UK distributor they do.. http://www.opticalvision.co.uk/astronomical_telescopes-sky-watcher-ed_refractors/evostar-80ed_ds-pro_ota.html

"These high-end telescopes all feature a doublet objective lens. One element is made from premium Japanese Ohara FPL-53 Extra-Low Dispersion (ED) glass, which virtually eliminates chromatic aberration to deliver true colour reproduction. Top quality Schott glass is utilized for the Crown element."

[alan4908]

On 11/10/2017 at 11:25, Kaliska said:

So, I've now got hold of a good mount (AZEQ6 GT) and and modded 600D, so now next on my most wanted list is the OTA. I started out looking at a fast Newt for imaging, but I'm slowly being pulled in the 80-100mm refractor school of thinking. I've got a budget of around £600-£800 which should include and flatner. Any recomendations you guys have would be greatly appreciated.

When I started astrophotography I went for the Evo star 80 ED Pro + FF/FR. Overall, it is excellent value for money and I would recommend.

The main strength of the ED80 is the optics which,  for the price, are excellent. Until your post processing skills get to a certain level, I suspect you probably will not be able to tell the difference between the images produced by this and the much more expensive Esprit or similar scopes. When you do reach that level, you can correct for the minor optical issues via various post processing techniques.

The main weakness of this scope is the focuser,  which whilst adequate, is not great.  However, the good thing is that this is easy to upgrade - after about a year, I decided to go down the automatic focusing route and so replaced mine with a Moonlite.

Alan