EQ Mounts and their ratings

[baggywrinkle]

This might be a silly question but is there a link anywhere which tells you the difference between EQ1,2,3,4,5,6,...ad infinitum?

I have an EQ5 which I know is nice and heavy and I think my iOptron smart EQ is equivalent to a 1, or 2.

What do the number mean...is there an ISO type rating or is is down to the maker?

[michael.h.f.wilkinson]

Makers rate their mounts themselves. Most just give a maximum payload, and this does not make sense. Vixen had a more sensible way of rating the GP mount I have as suitable for an 8" SCT, 6" Newtonian or 4" refractor. This took both weight and torque into account: a long scope of a given weight needs a sturdier mount. Vixen tends to be more conservative anyway, which is sensible. Under-mounted scopes are a key factor in people getting disappointed. I would rather have an 8" scope on a stable mount, than a wobbly 11".

In imaging, focal length, or magnification on the chip also plays an important role. The longer the focal length, the more accurate the guiding needs to be. This has less to do with payload than with precision manufacturing.

[baggywrinkle]

/\ I somehow thought this might be the case....

By ISO rating I was refering to some international standard...not the speed rating.

[r3i]

No international standards for rating mounts, the mount naming is supplier defined.

This site lists a load of mounts with prices, capacities and PE: http://lambermont.dyndns.org/astro/pe.html It's aimed at comparing mounts for astrophotography and tends to focus on the higher end offerings.

[kirkster501]

Also be advised the ratings are with the sun shining and a fair wind at their back. In other words they are very optimistic. Also, if you want to do imaging there is an unwritten rule to keep the load <60% of the mounts rating.

[laser_jock99]

Also be advised the ratings are with the sun shining and a fair wind at their back. In other words they are very optimistic. Also, if you want to do imaging there is an unwritten rule to keep the load <60% of the mounts rating.

Not that I would particularly recommend it- but the EQ6 can image okay with a 40Kg payload.

My permanent imaging rig.