Largest aperture scope on a German equatorial

[View2]

With a mount load of 35 lbs(ieq45p) , what would be the largest aperture reflector type scope for the mount? It has 22lb 127mm apochromatic ED triplet on their now. I've never seen a large aperture reflector on a German equatorial mount, and was contemplating the gangeliness of it...is it because the focuser is way up there?  

[Jim78154]

Would the eyepiece be any more "way up there" on a GEM than it would on a Dobsonian? Isn't that why they made the tripod legs adjustable for great lengths?

[Stu]

12 minutes ago, Jim78154 said:

Would the eyepiece be any more "way up there" on a GEM than it would on a Dobsonian? Isn't that why they made the tripod legs adjustable for great lengths?

Probably is the answer if on a tripod as you need a certain degree of stability in the spread of the legs. It would be better on a short pier.

A bigger issue is that the eyepiece position would move around all over the place as the EQ mount tracked and skewed, rather than staying at the same angle if on a dob mount. Rotating rings would be a very good idea in this case.

The biggest I've seen was a 14" Orion Optics newt on an EQ I think, I assume it worked ok. The Orion Optics tubes weight a lot less than Skywatcher for instance but you need good rings and a solid dovetail to reduce the flex and give a solid mounting config.

[Mr Spock]

Big Newts work fine on EQ mounts. However, it's advisable to have some king of tube rotation system so the eyepiece can be in a convenient place.

[John]

Here are some pics of my 6" F/12 refractor on a biggish equatorial mount. The main issues that I found were the height of the eyepiece when viewing things high in the sky and that the eyepiece and focuser could be in awkward positions (ie: nearly underneath the scope !) depending on the direction you are viewing. The latter can be countered by having a rotating focuser or by rotating the tube in the tube rings. The former can be countered by having a tall tripod or by viewing from a seated position:

https://stargazerslounge.com/topic/213471-istar-6-inch-f12-equatorially-mounted-achromatic-refractor/

I've reverted to altazimuth mounts with slightly smaller refractors on them these days - my back was complaining about setting up the above "monster"

[Stu]

47 minutes ago, John said:

Here are some pics of my 6" F/12 refractor on a biggish equatorial mount. The main issues that I found were the height of the eyepiece when viewing things high in the sky and that the eyepiece and focuser could be in awkward positions (ie: nearly underneath the scope !) depending on the direction you are viewing. The latter can be countered by having a rotating focuser or by rotating the tube in the tube rings. The former can be countered by having a tall tripod or by viewing from a seated position:

https://stargazerslounge.com/topic/213471-istar-6-inch-f12-equatorially-mounted-achromatic-refractor/

I've reverted to altazimuth mounts with slightly smaller refractors on them these days - my back was complaining about setting up the above "monster"

Very different situation to a large reflector though? Eyepiece at the opposite end of the scope so not really comparable.

[Peter Drew]

Our largest German EQ mounted telescopes are a 8.5" F12 refractor and a 14" F4 OOUK Newtonian.

[Stu]

Some relevant info here I hope.

https://stargazerslounge.com/topic/178786-12-inch-newtonian-on-a-cge-pro-mount/

This link has an example of a 14" newt on an EQ6 mount

http://www.astro.cardiff.ac.uk/sas/scopes.htm

Pic attached

Just some general discussion in this one.

https://stargazerslounge.com/topic/81796-skywatcher-16-400p-on-a-eq6-pro-mount/?page=1

[John]

33 minutes ago, Stu said:

Very different situation to a large reflector though? Eyepiece at the opposite end of the scope so not really comparable.

Yes Stu you are quite right

I mistakenly thought the original poster was interested in a large refractor but on re-reading the post thats what he currently has and a reflector is what he is pondering.

Apologies to the original poster for wasting his time with my post

[View2]

Thanks, that clears that up. And yes, when looking overhead I'm climbing under the thing almost

[View2]

Do you think I will be able to see the North American nebula using this telescope and a 2" ES 40 mm EP with an Orion ultrablock filter from a dark sky with milky way obvious?  

[michael.h.f.wilkinson]

33 minutes ago, View2 said:

Do you think I will be able to see the North American nebula using this telescope and a 2" ES 40 mm EP with an Orion ultrablock filter from a dark sky with milky way obvious?  

No, you are better off with 15x70 bins, or a scope like my APM 80mm F/6 triplet with the Nagler 31T5 "Panzerfaust", and potentially a UHC filter. The North America Nebula and Pelican together are more than 4 degrees across, so you need a huge FOV. My bins manage 4.4 deg, the little 80mm 5.3. The latter scope has given me far better views of the North America Nebula and Pelican than anything else.

 

BTW, listing the maximum load by weight is a bit misleading. Typically, mounts will handle much heavier short scopes like SCTs and Maks than long ones like slow fracs and Newtonians. The length of these later scopes increases the torque on the mount. Big Newtonians in particular act as a sail, and catch a lot of wind, requiring a much stiffer mount than with a SCT. I would be much more comfortable with a C14 on an EQ6 than a 14" Newtonian.

[View2]

Well, how is it that an 80mm f/6 frac will see what a 127mm ED APO triplet will not. I'm confused? Also, the ultrablock is a UHC?

That was my thought on the mount and big scope too. I used to have a C8 and my try that one day.  The mount is the ieq45p.