Refractor for Astrophotography?

[Rachael]

Hello one and all.

So, I have been using a Skywatcher 200P on a EQ5 mount which I upgraded to be motorised and been happy with what I have achieved so far with my Cannon 250D. However, I am now looking to purchase a Refractor OTA c/w Field flattener to help improve the sharpness of my pictures and for ease of operation and weight. I have looked at 3 OTA's and cannot make up my mind on which way to go.

These are the Rother Valley Optics Horizon 72 or 80, Skywatcher Evostar 80ed or William Optics Zenithstar 73 III APO? I do not particularly wish to go beyond £1000.

 

I would very much welcome any opinions on these, positive or negative to help decide on my purchase. I have read about lens quality's and finishes and get a little confused. At the end of the day I want an OTA that will suffice for the longer term.

 

Many Thanks.

Edited September 15, 2022 by Rachael

[+Graham]

If you go on Astro buy and sell there is a Williams Optics GT 81.

Brilliant scopes.

U.K. Astronomy Buy & Sell (astrobuysell.com) Ad number 190767

https://www.astrobuysell.com/uk/propview.php?view=190767

Edited September 16, 2022 by Graham

[Rachael]

Thanks Graham, that does look good. I assume it would be advisable to get a Field flattener as well? 

[Nightspore]

I don't do any AP but these Altair doublets are reputedly very good for AP. 

 

 

I have the 60EDF.  It has an excellent Strehl number.

 

[+Graham]

6 hours ago, Rachael said:

Thanks Graham, that does look good. I assume it would be advisable to get a Field flattener as well? 

 

I have had mine for years and years and only got a FF / FR after I got my QSI Camera because of its larger chip.

The GT 81 does not need a FF as it produces a near perfect flat field of view.

They are that good the only thing I would change mine for would be a large Takahashi.

[Bob Dobber]

I am loving my SharpStar 61EDPH II triplet, well under your budget but perhaps too short a focal length (225mm with dedicated flattener/reducer - perfect for Orion!) looking at the others you are considering, but they have "longer" ones if so desired.

[Bob Dobber]

PS - if you wanted a Rolls Royce of a refractor, the Explore Scientific ED102CF is an absolute beauty. I had it with a Starizona Apex 0.65x reducer (sell a kidney for that alone) to bring it down to f4 or something like that, focal length 464mm. Not a day goes by when I don't regret selling that, I was too new to the hobby and didn't appreciate what I had, and thought I needed to try a big gun like a 200mm reflector. DOH!!

Edited September 17, 2022 by Bob Dobber

[Rachael]

Food for thought many thanks for the advice, everyone. It is too easy to over think all of the options and get a little confused.

[Bob Dobber]

14 minutes ago, Rachael said:

Food for thought many thanks for the advice, everyone. It is too easy to over think all of the options and get a little confused.

 

There's _so_ much choice it's impossible not to overthink. I've been through six scopes in just over 2 years, just be warned... Skywatcher 72ED, Explore 102CF, SW200PDS, SW130PDS, SW190MN, SharpStar 61...