8" f/4 astrographs (BINTEL - ORION)

[nobbygon]

Hey, Has anyone done a comparison of the orion 8" f/4 astrograph and the Bintel (GSO) 8" f/4 astrograph. I'm very interested to see which one is better in terms of build quality, optical quality, suitability for astrophotography, etc. I'm very interested in purchasing one of these scopes. Its primary use will be for AP.

Cheers for any feedback,
Angus

[cfranks]

I have no experience of either but check Paul Haese who has the 8" GSO RC and gets superb images with it. Mind you, he could get great images with any telescope.;)

[tlgerdes]

I have just purchased the Bintel one a month ago. The Bintel one is made by GSO and I believe the Orion one is as well, so I would not expect them to differ.

You will need an MPCC or other Coma corrector to go with it.

[Paul Haese]

Thanks so much for the huge compliment.

Angus, I am pretty sure that both scopes are made by the same manufacturer although they could be made by the Skywatcher Synta company. I would not think that there is much if any difference between the two.

I have heard on the grapevine that the mirrors coming out of Asia now very tight and worth way more than what you are paying for them.

I am sure you will get a good unit and if you buy it from Bintel they will look after you.

[lookus]

hi. i too am interested in these scopes. it seems to be difficult to find any reviews on them. has anyone here used one for imaging(or visual use) how would it compare in image quality compared to a skywatcher refractor for example 100mm.

any information would be greatly appreciated.
thanks

[Satchmo]

I believe that Bintel sell the plain vanilla 8" F4 GSO tube. The astrograph version ( larger secondary, extended tube and baffle rings ) is sold by Astrotech in the USA.

[Shiraz]

I have a vanilla GSO 8" f4 (from Andrews) and it is really very good optically - basically diffraction limited on planetary imaging and fast for long exposure imaging. The secondary is small, although the vignetting can be corrected for in processing and is no big deal. The major issue is the focuser - after months of messing around with odd shaped stars have finally decided to ditch it and get something that can carry a camera without sag. And of course you will need an MPCC or similar coma corrector for wide field imaging. All up though, it works much better than it has any right to at the price.

[gbeal]

Yep, whatever you get in this focal ratio, an MPCC (or similar) will be a necessity.
I have the Astrotech 8" Imaging Newtoian, and it is a nice unit. It isn't light though, so will need a decent mount. In my case I swapped out the "ordinary" focuser as well, and use a digital Feather Touch.
I am just getting started with it, but this is a recent couple of shots. The Leo Trio suffered from a horrendous centre hot-spot, even though I used flats, it took a fair bit of work.
Gary

[Shiraz]

Nice images Gary - looks like the focuser does the job.
These scopes can also do OK at high res if you relax the main mirror tabs, carefully align everything and use a couple of Barlows.
Ray

[gbeal]

Ditto, a nice lunar shot Ray. In reading your previous post we obviously have scopes which are vastly different, mine having a HUGE secondary, but after all it is pitched at DSO imaging.
The only Barlow I tried so far has been the Antares 1.6x, more as an "extender" rather than a hi-res multiplier.
I did "relax" slightly the primary mirror clips, and the F/T mod has kept me sane, I don't think I could use the stock focuser for long.
Gary

[Shiraz]

Gary
This one has 60mm secondary. Bought a 70mm but have not decided yet if it is worth the bother of fitting it - vignetting on a QHY8 is not too bad really. I routinely use a GSO 2inch Barlow to overcome some of the limitations of the supplied Plossl eyepieces for visual use - they are way below the quality of the scope at f4, but are usable at f8.
Ray

[gbeal]

Ray,
OK, sounds like mine then.
I do think though we had better let Angus carry on with his original thread, we seem to have hijacked it somewhat.
Gary

[lookus]

would these scopes be better for imaging than an ED80? that is what i am using at the moment and i want something that will be a bit better without spending $2000.

[gbeal]

Better is a loose term mate. It will provide a bigger image scale, as they are ~800mm focal length. Also brighter, at f4.
Downside is they are heavier, my AT8" is quite solid, so the mount requirements go up.
Gary

[Waxing_Gibbous]

Hi Angus,
I've got the Astrotech version which a mate is using at the moment for lunar photography.
As noted the Orion & Bintel are the same scope and both do very well for AP with slight mods.
It will ride happily on an EQ/HEQ 5 mount. Whether they are 'better" than an ED80 is kind of a toss-up. Better resolution on Luna, Planets and other solar system objects but narrower FOV and spikey stars on deep sky stuff.
Less exposure time or lower ISO than an ED80 tho' so that's a big plus.