First Apo...

[Ian McCallum]

I'm thinking of going down the route of getting an Apocromatic refractor, for either visual or astrophotography. 

At the moment, I have a Sky-Watcher Evostar 120 achromatic. I would like another Sky-Watcher, but my budget would be upto £500.

Any suggestions? 🤔

[NGC 1502]

Skywatcher ED80 is a great choice but above your budget at £599 at FLO, but they’re often available second hand.  Or there’s the ED72 version at under your budget.

The ED80 has been around for many years, tried and tested and a favourite with many without breaking the bank.

All the best with your choice, Ed.

[ONIKKINEN]

I recently bought a Long Perng 90mm F/5.5 refractor. It is sold under the "apochromat" section in TS but i would classify its more as like a half achromat. It is obviously not colour free, and the extension of the aberrations are not completely filterable away.

That said, i have been satisfied with mine, and with the Baader fringe killer that lives in the diagonal 24/7 i have found it to be an acceptable fast focal ratio scope. Jumping back and forth between my completely aberration free 200mm newtonian and this one leaves me with fairly obvious (in comparison, maybe not in solitude) spherical aberration and some colour aberrations inside and outside of focus. But perhaps more importantly there is a point in focus where planets can be observed with reasonable satisfaction. Its not perfect but for the money, maybe worth considering?

[iapa]

1 hour ago, NGC 1502 said:

Skywatcher ED80 is a great choice but above your budget at £599 at FLO, but they’re often available second hand.  Or there’s the ED72 version at under your budget.

The ED80 has been around for many years, tried and tested and a favourite with many without breaking the bank.

All the best with your choice, Ed.

Any particular aperture?

Are you imaging or observing?

What sort of target(s) are you aiming for?

 

Edited September 5, 2022 by iapa

[NGC 1502]

5 hours ago, iapa said:

Any particular aperture?

Are you imaging or observing?

What sort of target(s) are you aiming for?

 

Hi iapa, I’m thinking you must have intended to quote the OP rather than myself?

No worries at all😊

[Clarkey]

I would agree that the ED80 is a good choice for AP and visual. For around £500 you should be able to get one second hand with a field flattener. (One sold yesterday on Astro B&S for £510). The colour correction is good but you will get some CA on brighter objects. I think for £500 you will be pushed to get a triplet or true APO, even second hand. 

Looking at your signature you have 'planetary' cameras, whereas the ED80 is a wider field scope. If you are thinking for planetary imaging you could consider a Mak. Maybe clarify your viewing and imaging priorities and it would help with the guidance.

[dweller25]

@Ian McCallum Just want to point out that your 8”Dob has Apochromatic optics and better resolution than any £500 refractor 👍

[Stu]

1 hour ago, dweller25 said:

@Ian McCallum Just want to point out that your 8”Dob has Apochromatic optics and better resolution than any £500 refractor 👍

Will you be selling me your FS-128 then sir? 😉

[dweller25]

2 minutes ago, Stu said:

Will you be selling me your FS-128 then sir? 😉

No - because it is not a £500 refractor 🙂

And it isn’t Terrys - it’s MINE 😂😂😂

Edited September 6, 2022 by dweller25

[astrolulu]

I have been using the SW 120ED for a while. In the case of photos, it gave noticeable chromatic aberration - there was a purple halo around the stars, and on the moon you could see an aberration not only on small, contrasting details, but also overall effects such as a colored border running along the edge or a rainbow discoloration running near the terminator. Of course, I am talking about minor effects knowing that residual CA can be observed even in the case of SCT - but it is worth remembering that SW ED is not the same as the expensive 3-element APO.

[Ian McCallum]

1 hour ago, dweller25 said:

@Ian McCallum Just want to point out that your 8”Dob has Apochromatic optics and better resolution than any £500 refractor 👍

True, but I can't mount it to my EQ5 mount and would need a coma corrector, I believe.

[Ian McCallum]

4 hours ago, Clarkey said:

I would agree that the ED80 is a good choice for AP and visual. For around £500 you should be able to get one second hand with a field flattener. (One sold yesterday on Astro B&S for £510). The colour correction is good but you will get some CA on brighter objects. I think for £500 you will be pushed to get a triplet or true APO, even second hand. 

Looking at your signature you have 'planetary' cameras, whereas the ED80 is a wider field scope. If you are thinking for planetary imaging you could consider a Mak. Maybe clarify your viewing and imaging priorities and it would help with the guidance.

I originally bought the planetary cameras, as they were cheaper than the more expensive cooled versions.  I've been moving away from planetary imaging and to be honest, have never used the cameras for any planetary bodies, other than the moon.  I've done some DSO imaging with them, but I know they are far from ideal...

[Stu]

6 minutes ago, Ian McCallum said:

I originally bought the planetary cameras, as they were cheaper than the more expensive cooled versions.  I've been moving away from planetary imaging and to be honest, have never used the cameras for any planetary bodies, other than the moon.  I've done some DSO imaging with them, but I know they are far from ideal...

I still don’t think we are clear about what you want to achieve with the scope. Are you talking mainly visual with some casual Imaging or looking for full on guided long exposure DSO imaging with no planetary?

The answer may well be the same ie ED80, but some more info would certainly help.

There is also the SW Evolux 82ED At £575. These are fairly new and I haven’t really seen any results or reviews that I can remember but I’m sure there will be some out there.

https://www.firstlightoptics.com/pro-series/sky-watcher-evolux-82ed-ota.html

@johninderby has one I believe but he has been missing in action for sometime so I hope all is well with him and he can comment here.

[Ian McCallum]

1 minute ago, Stu said:

I still don’t think we are clear about what you want to achieve with the scope. Are you talking mainly visual with some casual Imaging or looking for full on guided long exposure DSO imaging with no planetary?

The answer may well be the same ie ED80, but some more info would certainly help.

There is also the SW Evolux 82ED At £575. These are surly new and I haven’t really seen any results or reviews that I can remember but I’m sure there will be some out there.

https://www.firstlightoptics.com/pro-series/sky-watcher-evolux-82ed-ota.html

I've gone to mostly imaging these days, when clouds permit.  I tend to use Astroberry, K-Stars and EKOS, etc.

[dweller25]

Perhaps as you have gone to mostly imaging it may be worth considering selling all your current scopes to raise a bit more cash to buy an 80ED ?

[Clarkey]

15 minutes ago, Stu said:

There is also the SW Evolux 82ED At £575.

You would also need a FF at £229 for imaging.

It will be interesting to see how they compare against the ED80 which has always outperformed its price-point. It does have a R&P focuser which is probably better than the standard one on the ED80 but I suspect it is no longer FPL-53 otherwise they would be selling it as such. For widefield imaging there is always the option of a slightly smaller refractor around 70mm.

FWIW there is a TS Photoline 80mm triplet for sale on Astro B&S for £475:

U.K. Astronomy Buy & Sell (astrobuysell.com)