Equatorial mount recommendations for 6 inch newtonian telescope - Forums

Topic starter

Nov 8, 2023

Hi All

I am a beginner in astrophoto, but already have 2 pieces of equipment that are not really compatible (though are often sold together): newtonian 6" f/5 telescope and motorised EQ3-2 mount. Now I am using my mount together with 200mm lens and mirrorless camera and I'm happy with that, but using the telescope for DSO photo is extremely hard.

I get used to the size/weight of my setup, if fits in my car, and I don't want to do powerlifting while transporting or setting it up.
Also, based on my location, realistically I would not expect my exposure times to exceed far more than 5-7 minutes (my sky is Bortle 5-6) and don't think my guiding RMS error needs to be less than 1 arcsec (this is the seeing limit I have in my area).

The total weight of the tube, camera, coma corrector and guiding equipment is around 8 kg (~18 lbs). The focal length is 750mm.

I have 3 options that seems reasonable in terms of the payload, portability and budget (all around 1500 EUR):

A new iOptron GEM28
A new SkyWatcher HEQ5
Slightly used iOptron iEQ30 from trusted dealer

iOptron mounts seem to be a well-balanced choice for my needs (light and precise). HEQ5 is well-known, but a bit on the edge in terms of its weight and might require belt modification.

Please advice which one would you pick, and if there are any other major factors I should be aware of with my setup, imaging conditions, and mounts options.

Thanks,
Alex

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dkamen

Nov 8, 2023 · Edited: Nov 8, 2023

The GEM28 achieves < 1 arcsec guiding with a TS Photon 6" f/5, cooled camera, guider, guiding scope and comma corrector.

But it does need an extra counterweight, the one that came with it is not sufficient. And I mount with the focuser facing down (which hides the polar scope), otherwise it needs either a third counterweight or two counterweights placed ridiculously close to the edge of the counterweight shaft.

The whole thing weights more than 15kg fully assembled, perhaps even 20 so if you don't want to do powerlifting you will have to assemble it on site. I am afraid this is unavoidable with a Newt anyway. I mean you have at least 5kg each of scope+cameras, counterweights, mount head.

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Kevin Dahmke

Nov 8, 2023

Until a year ago I had a similar telescope. I bought the Skywatcher EQ-6 R. (yes, it's a bit over the budget) but the mount is absolutely brilliant for the price and also has room for improvement, for larger telescopes such as an 8" or 10".
Unfortunately it is very heavy. But I can still carry them from the basement to the garden.

I used to have an EQ5. But it was overloaded. The HEQ 5 should also work as a middle ground.

Kind regards
Kevin

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andrea tasselli

Frequent contributor

Nov 8, 2023

I have the GEM28 which I use with the 6" f/4 newt, astrocamera, cc, tilting unit and filter holder, guidescope and electronic focuser plus cabling. All in all around 9 kg of payload. I use a 11 kg counterweight which isn't a big deal to me but I guess it might be for some. Guiding accuracy is below 1" rms when pointing in most sky areas (the whole setup isn't perfectly balanced in all pointing directions, sadly). My focuser sits upright (which isn't ideal from the moment of inertia balancing prospective) but allows me to easily collimate the scope during daytime. Weak point of the whole thing is the poor USB connection (I use wifi) and the alt-az adjustments which I find rather weak (not stiff enough and with significant backlash in the altitude gearing). Still, worth its money.

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Alex G

Topic starter

Nov 8, 2023

But it does need an extra counterweight, the one that came with it is not sufficient. And I mount with the focuser facing down (which hides the polar scope), otherwise it needs either a third counterweight or two counterweights placed ridiculously close to the edge of the counterweight shaft.

andrea tasselli:
I use a 11 kg counterweight which isn't a big deal to me but I guess it might be for some.

@dkamen @andrea tasselli thanks for sharing this, I had some doubts about balancing and having only one counterweight in the box.
In my case that makes in total around 8kg + 5kg (mount head) + 11kg (counterweights) + 7kg (tripod) = 30 kg. Important thing to keep in mind when comparing to more heavier mounts.
It can be a case that less counterweights are needed with them and it's definitely better to have more weight in the mount head rather than in the counterweights.

@Kevin Dahmke how many counterweights did you use for 6" with your EQ6-R?

tjm8874

Nov 8, 2023

I have GEM28, using it up to FL 455mm (80mm refractor), with 4.5kg + 2kg counterweights.
GEM28 can handle 150mm Newt but you need one more 4.5kg.
my 2c you should save some money to get ZWO AM5, you don't need any counterweights.
AM5 Mount + 8" mini pier + TC40 Tripod = 5.5kg + 1.6kg + 2.3kg = 9.4kg

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Kevin Dahmke

Nov 8, 2023 · Edited: Nov 8, 2023

@Kevin Dahmke how many counterweights did you use for 6" with your EQ6-R?

I had used both 5kg pieces (in total 10kg) at ca. 3/4 of the rod.
Now I use a 8" 800mm. The weights are at the end of the rod and it's a little to less for some positions

Tommy Blomqvist

Nov 8, 2023

I've been using a Skywatcher Explorer 150PDS (150/750) on my HEQ5 Pro with surprisingly little problem.
The HEQ5 in my case seems more than happy with the OTA, EFW, EAF, AAP, 50/200 guide scope and ASI533MC camera.
Often gets <0,5" guidning with it.

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Alex G

Topic starter

Nov 8, 2023

I have GEM28, using it up to FL 455mm (80mm refractor), with 4.5kg + 2kg counterweights.
GEM28 can handle 150mm Newt but you need one more 4.5kg.
my 2c you should save some money to get ZWO AM5, you don't need any counterweights.
AM5 Mount + 8" mini pier + TC40 Tripod = 5.5kg + 1.6kg + 2.3kg = 9.4kg

Thanks for replying.

Yes, I've also taken a look at harmonic mounts – not having counterweights looks very interesting, though very exotic.

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