GSO/Bintel vs Skywatcher 8 inch f/4 Newt for AP

[Nortilus]

I'm thinking instead of refurbishing my old GSO 8 inch f/5 newt (needs new secondary and upgrade the focuser) and just getting a new 8 inch f/4 newt.

The question is do I go a GSO/Bintel which I think would do the job fine or do I pay extra for a Skywatcher which I think just has Pyrex mirror over the BK7 Glass. I doubt this really matters but I just would like to here opinions on this.

It'll go on an EQ6 mount using tube rings obviously and I'll be using a SX CCD (SXVR-H9C), autoguided as well.

[Shiraz]

FWIW, I started out with a GSO 200f4 with a steel OTA. It needed a complete rebuild to get reliable image quality (tube strengthening, mirror holder modified, new focuser etc), but it eventually worked pretty well (has a nice mirror).

Upgraded to a 250f4 Skywatcher carbon fibre and, with a digital focuser add-on, it was OK out of the box. It has required a couple of tweaks and a Moonlite focuser to get the best possible results, but the overall design was pretty good to start with (apart from the black paint in the tube - it dissolves in dew).

The Skywatcher is more stable with temperature than the GSO - could be the mirror material or the CF tube, but it makes focusing a bit less of a chore.

In summary, neither is top shelf gear out of the box, but the Skywatcher started out closer to "very good" than the GSO. The optics in both are impressive - the GSO is possibly just ahead in mirror figure, but both are able to resolve down to the atmospheric seeing limit with no trouble.

How much work do you want to do to get a good scope?

[Marke]

Telescop Express sell upgrades for the GSO Newt including CF tubes and you can even change backfocus as well as upgrade bits. https://www.teleskop-express.de/shop/index.php/language/en

[Nortilus]

I plan on using this as my main imaging scope once it is all setup. I have had a old meade 8 inch SCT as my main but with all the issues I have using it I want to goto something a bit more forgiving and usable. I am going to actually sell the meade as I think i wont use it in the future anymore and the funds from that can go towards the new scope.
So I guess do I spend more now that needs less upgrading to get a better scope or just start with good enough and upgrade as I need. Are there other 8 inch f/4 newts out there I should look at maybe.

[Shiraz]

if you really want something forgiving, suggest that you keep well away from a low end f4 Newtonian - they can be very high maintenance and just possibly the least forgiving of all scopes. Maybe look at a Skywatcher 200 f5 Newtonian fitted with a Moonlite focuser - f5 is much more tolerant of minor mechanical errors etc. than f4.

[glend]

You could consider using your current GSO as a parts donor to a TS carbon tube (which is pre-bored for your gear). And f5 is more forgiiving, plus giving you a bit more reach at 1000mm vs 800mm. Even a new GSO f5 is pretty cheap, just to get the new mirrors, and sell off the old one you have. I have a custom carbon strut 10" f5 which uses GSO parts and it's a great imaging scope. In your price bracket I would stick with GSO.

[ChrisV]

Those TS ONTC newtonians look temptingly nice. Has anyone tried one?

[Nortilus]

I have been in a very slow email back and forth with TS in Germany and you can actually order any scope minus the parts you dont need for a reduction in cost. This is very tempting but for now I have a lend of a f/4 newt to give it a go to see if this is for me.

[ChrisV]

Thanks Josh. That's useful to know. Christmas is not far off ... hey! Fathers' day is even closer