Is it possible for an EQM-35 Pro to carry a Skywatcher 150PDS (4,9Kg) and a DSLR? Generic equipment discussions · AstroTimZ · ... · 6 · 314 · 0

AstroTimZ 0.00
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I recently started to look into goto mounts and I was wondering if you can image with the EQM-35 Pro and the 150PDS.
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dkamen 6.89
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·  2 likes
Hi,

You would be close to 6kg with the DSLR, a guiding scope,  a guding camera and the corrector. It is possible but not ideal. I have been using mine with the same guiding gear (ZWO 40/120 + 120MM) and three imaging scopes:
- TS 60/360, total weight 2.3kg with DSLR, length a little less than 40cm.
- Vixen VMC110L, total weight about 2.3kg with a small astrocam, length a little more than 30 cm.
- ZSII73, total weight about 4kg with DSLR and flattener, length about 50 cm.

So with the first two performance is outstanding. 10 minute subs are not a problem, guiding error is usually below 1" RMS or maybe 1.3 if seeing is bad. I calibrate once and it holds it for weeks so long as I image within the same quadrant of the sky or so.

With the ZS73II things are more unstable. Guiding error is between 1.5 and 2.0 RMS (usually closer to 1.5) but more importantly every 15 minutes on average it throws a fit in DEC; error goes > 5" and it takes PHD a couple of minutes to fix it. When I say "on average" I am not implying it is periodic. Sometimes it goes 1 hour without issues, sometimes 5 minutes. Occasionally (not too frequently though) PHD will bail out, complaining that its attempts to correct DEC have no result. But RA is less stable too. I have to recalibrate very frequently because I've found it helps. Overall, it is functional and good enough for me. Definitely works great if I stay at 2 minute subs: statistically 90% will be keepers. But the point is: compared to how perfectly it performs with the lighter/shorter gear... it's like a different mount.

Extrapolating from my experience with the ZenithStar, I expect it to be quite problematic with the 150PDS. It would be operating dangerously close to its capacity or even exceed it. Do not forget, the mount is able to hold 11kg but that's for visual. For imaging capacity is approximately 50% i.e. 5.5kg, let's err on the side of adventure and say 6. So you have 4.9 for the scope alone, maybe 0.5kg for the DSLR, another 0.5kg for guding gear and I don't know how much for coma correctors, adapters and whatnot. And the 150PDS is also much longer than a ZSII meaning torque is much more pronounced, especially if there is wind.

In conclusion, it is probably doable but you would get to throw away many subs and spend too much time being frustrated in every session. This mount excels at compact/lightweight setups. Not a 150mm Newt with a DSLR.

Cheers,
Dimitris
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AstroTimZ 0.00
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Allan Alaoui:
Hi,

I do not recommend using that setup for AP on that mount. I own the mount and with a lot of tuning it is barely capable of guiding at 35 degrees above the southern horizon with a Zenithstar 73, Cooled CMOS, Filter drawer, Guide Scope/Cam Setup. This mount has a lot of loose adjustable ends that will move under pressure over time. So you will be tuning it every now and then with that setup which will be frustrating at best.

Clear Skies,

Allan

Thanks for the response,
On many forums an HEQ5 is recommended for AP, do you think the 150PDS would work on an HEQ5? (with camera, adapters, etc.)
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north.stargazer 0.90
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I also own this mount and I have to agree with the others. It's not ideal for an OTA over 3-4kg plus accessories if your primary focus is AP.
It's really a lightweight mount on a solid tripod and it works great for me with an 80mm refractor, but that would be the most I would put on it.

The HEQ5 sits in between the EQM35 and the EQ6R in terms of payload capacity as well as mount weight. It should easily manage the 150PDS.

Good luck!
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Taddeuccis 0.90
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I got a EQM35 pro and i use a 100mm quadruplet (6.3kg) and It works great. I don't use the autoguide, and i manage to get 60s exposure with perfect stars.  The only problem i have is periodic error, bit It is fine, the frames are good even with some periodic error. I'm sure the 150 will work great!!! Good luck and CS
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