Best 8" f4 newtonian Orion astrograph or Skywatcher quattro

[Krackedace]

I ordered an explorer 200pds but after a bit more research I cancelled the order because it seems f4 will be better for astrophotography.

Having researched both im struggling to decide which will be suit the build I'm putting together. Which of the tubes will be stronger and therefor have less flex (skywatcher is heavier does that equate to strength?) . How useful is a cooling fan as the orion comes with one whereas the quattro doesn't. Lastly I've read that there can be some vignetting due to the small secondary mirror on 1 of them I forget which but they seem to have similar sized secondaries so is that an issue that will affect both of Them? Is there a solution to overcoming the vignetting?

I'm purchasing an eq6 r, and probably a zwo asi 294 colour as that should be lighter than a dslr and will hopefully reduce any tube flex.

However I'm struggling to work out which coma corrector would work with either of them. I've been looking at the Badder mcc III and the skywatcher aplanatic the latter of which seems to be better but I don't know if it would work with the Orion.

My other concerns in terms of CC are achieving the correct amount of back focus and also avoiding focuser intrusion.

Any advice would be greatly appreciated.

[rl]

I'm running an Orion Optics CT8 which is f/4.5, with a carbon fibre tube. Also a Skywatcher aplanatic coma corrector. Mount is an AZ-EQ6. 

I can recommend all 3 items; the OTA might be expensive but it holds collimation well and the CF tube is light and rigid (but scratches fairly easily). With a DSLR and the coma corrector, big finder the weight is about 12kg which is a perfect match for the AZ-EQ6. The CT8 is an expensive route to a 8" Newtonian but it's also a stonking visual scope; it's my "keeper" scope. But the Skywatcher / Orion options won't be far behind and you don't need the last degree of optical perfection for prime focus photography.

The skywatcher Aplanatic is a bit expensive compared to the simpler CCs but it does what it says on the tin...coma is indeed corrected all the way to the corners of a APS-C sensor and the focal plane is indeed flat. It also works down to f/4. You need the special 58mm adapter which is a nasty little sting. 

In retrospect I wish I'd bought the EQ6R since I've never used the Alt-Az facility but the Az-Eq6 does a brilliant job.

The whole setup can be moved outside and set up in 15 mins by a 60-year old so it's not too onerous. I prefer it for visual over my grab-and-go 80mm ..the extra aperture is worth the setup time.

 

[Neil H]

Hi I have an Orion Optics 8 inch telescope they are really nice and do hold Collimation well

[Ricochet]

Orion Optics (UK) is a different company to Orion Telescopes (USA). Orion (USA) is owned by Synta, the manufacturer of the Skywatcher brand, and I think it is highly likely that both the Orion (USA) and Skywatcher products under discussion are made on the same production line and optically identical, with only a few minor details in the mechanics, for instance the Orion has a slightly longer tube to cut down stray light a little better. Which one would I buy? Whichever was cheapest, unless someone knows of any major differences.

3 hours ago, Krackedace said:

I ordered an explorer 200pds but after a bit more research I cancelled the order because it seems f4 will be better for astrophotography.

Also, no. Both have effectively the same aperture so they gather the same amount of light. The difference will be in image scale, with the Explorer having a slightly larger image scale due to a focal length of 1000mm vs 800mm. The Quattro will be better for astrophotography than say, a 100mm aperture, 800mm focal length f/8 telescope, because if you compare by f ratio, you have to fix focal length.

[alacant]

Hi

ES pn208 , 208mm f3.9 here. Build quality a notch and a bit above anything sw offer. Aluminium alloy or carbon fiber tube. I have the Al version. 85mm secondary eliminates vignetting and will cover the 294 sensor easily. Specify a big dovetail and it will hold collimation all night. 

For galaxies and smaller dsos I'd go for the f5.

Cheers

[Skipper Billy]

A pal of mine is selling an upgraded model of the scope that @alacant linked to - cooling fans, ES flattener the whole shooting match. It was mine from new so I can vouch for it - its completely flocked and all the screws have been changed for stainless steel etc - its a cracker. I don't know where you are located but the scope is in Glasgow. I can put you in touch with him (and translate for you 😉 ) if you wish.

[johninderby]

What about the Ztelescope Express offerings?

https://www.teleskop-express.de/shop/product_info.php/info/p49_TS-PHOTON-8--f-5-Advanced-Newtonian-Telescope-OTA.html

TS has a “like new” example of the carbon tube one on offer.

https://www.teleskop-express.de/shop/product_info.php/info/p12116_Like-new--TS-PHOTON-8--F5-Advanced-Newtonian-Telescope-with-Carbon-Tube.html