iOptron CEM70 - My new mount for astrophotography - first experience and first light

[@frankskeen1310]

I like the mount when it works, really would like to know any issue that may have happened to you. My power button was bad and I hope that's all that's bad.A lot of money for a mount I cant trust to work. Takes so long for help from I-Optron that the return policy has expired from the dealer. Warranty is no good if it just costs you more money with shipping on an item that was flawed from the get go.

[@ChrizzlyUniverse]

Interesting point. Except for the handcontroller light and tightening of the RA belt I had no "big" issues. Coming to think maybe I should do an updated review on the mount at some time. Compared to your points mentioned I didnt see too much negative, but Ive heard from others that quality control might be an issue for iOptron. Cheers!

[@OlliesSpace]

Very nice looking mount, nice to have a couple of rig options.

[@dankahraman354]

It is NOT my job to fix quality control issues. iOptron has other issues namely a worm gear that has to be adjusted at least once or twice a year. It is also a very expensive with respect to the payload it can carry.

[@XShadowAngel]

Love my Cem70. Fantastic mount.

[@ChrizzlyUniverse]

Agree with that statement 👍🏻

[@tomdaigon8707]

With that guide scope, I would think it would be very difficult to get a good 3D balance for the mount. Which for good tracking is VERY important.

[@ChrizzlyUniverse]

It certainly is tricky to balance out in all directions perfectly, but with my small magnetic 0.5 kg weight I can counter at least a portion of the weight offset. For reference, I achieved a guiding RMS error < 0.7" with that setup so far. So there is still room for improvement, but definitely a huge step compared to my prior setup. Clear skies!

[@anata5127]

I have the same mount combination. A lot of astrophotographers from Europe buy iOptron.

[@DSOImager]

Very nice upgrade! I started with an AVX and know the struggles well :) CS!

[@ChrizzlyUniverse]

The AVX is still a nice mount, but at one point one realizes that the max payload is not the max useful payload for AP :D Thank you! Clear skies as well! 😊✨

[@jensleuteritz6827]

Very interessting. I am researching heavier mounts since my HEQ5 and an 8"PDS seem to struggle a bit. I noticed your little counterweight; I have exactly the same from my early dobsonian times. I struggle a bit with balacintg. RA works pretty fine, but DEC is only semi. I followed an advice on cloudynights about putting the focusser downward in home position, which helped. But the problem is I get the DEC balanced on one side, but not on the other. I thought this little counterweight would help on the oppostion side of the focusser, but it doesn't and is unbalacing everything again. I know newtonians are pretty difficult in balancing, but how are your experiences here? Thanks and greetings from eastern germany! CS!

[@ChrizzlyUniverse]

Hey Jens, thanks for the comment! Tbh, I try to balance the mount as good as I can in both DEC and RA and just go with it. I pointed my focuser also towards home position, but with guide scope and mini PC as piggy back it gets imbalanced anyway, so I dont try to overthink it. My magnetic weight is mostly attached at the opposite side of the telescope, close to the primary mirror (kind of like a Z-shape whit guidescope on one end and weight on the other). All in all, the CEM70 is so heavy-duty, I feel like these little imbalances dont matter too much for me, I rather try to get good polar & mirror alignment and hope for good seeing 😉 In DEC, my scope was never that well balanced, that it would stay balanced in every position (3D-wise speaking), so my advise would be: Try to get it as good as possible, but dont overthink it ☺️ Clear skies & schöne Grüße aus dem Süden! Chris

[@jensleuteritz6827]

@@ChrizzlyUniverse Awesome! I more and more come to points where I read to not overthink things. Today I read that a precise levelling of the tripod is not neccessary as long as you are able to do a good PA. Good to know things can go easier and not always harder. 😊

[@slzckboy]

would be interested to hear your experience with the az/alt adjustment when polar aligning with this mount. another review i watched said it was tricky..jumping on the way down when mount was loaded etc

[@ChrizzlyUniverse]

I think you are referring to Astrofarsography's video, right? So far, I was quite happy with setting up the polar alignment. If there is much weight mounted on top (my heaviest case with about 35 kg total), it is a bit harder to actually screw the knob, but it still works. When using the iPolar scope, I found it quite normal to achieve good alignment. When lowering the alt-adjustment, of course the weight pushes on it, so you can "jump over" your desired amount, but you can increase it again in the opposite direction (countering the weight) and in this direction you can dose it quite precisely actually. Also, I did not notice any loud mechanical squeaking, so it might have been something with that particular mount in the other video. I recommend to set your altitude roughly when there is no weight yet on the saddle, and do the fine adjustments with the scope etc. mounted. At one time, I've polar aligned the mount only in the first night from a 7 day session and in the later nights I did not notice any major deviation, Im quite happy with it so far! :) CS!

[@slzckboy]

@@ChrizzlyUniverse Yes thats exactly the review i was referring to.Thanks for taking the time to respond.This is def on my short list for a mount with more payload capacity... Just have to decide how much is enough :)

[@kellytaylor3915]

What is the brand of Newtonian scope?

[@ChrizzlyUniverse]

Its a TS Photon, but I can't really recommend it - has some flaws (made a video on that, too) CS!

[@jackelrdhdhd4534]

Nice rig /what did you use for the side by side set up ?

[@ChrizzlyUniverse]

Hi there, thanks! I used a Losmandy rail as the base plate, then a Vixen rail in 90 degrees mounted on that Losmandy plate. On both sides of the vixen rail I added another vixen rail saddle-part. There I can put my two telescopes and swap them quick and easily (I bought the parts here at Teleskop-express in Germany). In theory I could have left the Losmandy rail away and just turn the saddle of the mount by 90°, but thats not possible and safe with the iOptron CEM70 mount, as it is fixed to the bottom and has fixed end points when turning. Hope that answers your question! Cheers!

[@KopLamp]

Nice mount! I have the CEM80... At least that is how I call my two CEM40's :P

[@ChrizzlyUniverse]

Haha thats a good one! Are you using them in parallel with the same scope for obtaining more signal in a shorter time? I'm curious :D CS!

[@nkondrashov]

Why not to turn the saddle by 90 deg?

[@ChrizzlyUniverse]

Hi! This was my initial idea as well, but upon further inspection I noticed that the saddle was not able to turn freely, so it was not possible that way or at least I feared that when the saddle hits the final point, the gears will take damage... This way, the controller knows the limits and forbids going to close to the limits. CS!

[@nkondrashov]

@@ChrizzlyUniverse I'm wondering if it's possible to tell eqmod that home is 90 deg east or west without messing with the saddle.

[@ChrizzlyUniverse]

@@nkondrashov Hm thats a good question. I'm not using EQmod so maybe there are different settings in comparison, but I think the iOptron mount was not made with that intention...Of course you could always just fasten the clutches in the 90° position, but then you have to carefully monitor the system yourself and only go for targets that are definetely safe -> would be too risky for my taste, given the price of AP equipment 😄 I could only imagine a specific handcontroller setting, but then the mount manufacturer must've already thought of this usecase initially...

[@AstronutCymru]

Really appreciate this review. The big concern I have, (and it’s no criticism of you!) is that you fixed a fairly terminal problem (in the sense that mount was basically unusable as delivered), without involving the manufacturer. This tells me how good you are with a soldering iron, but says nothing about after sales or manufacturer support. Every review seems to find something wrong; loose drive belts, bad solder joints, other annoying minor issues. Somehow all the reviews end up being reasonably positive. I’m not a tyro with a soldering iron, but I flatly refuse to spend £000s on a piece of kit that will tax my troubleshooting skills. I’m keen on electronics, but I’m not buying a kit. Is that naive of me ?

[@ChrizzlyUniverse]

Hey there, thanks for commenting. First of, you have a fair point and I can follow your logic. The mount itself worked functionally (in daylight, lol) but youre right, without a backlit screen it's kind of useless for a hobby under dark skies... I think its some kind of philosophy/mindset question, as I myself personally would rather check on this little issue than shipping it back (too much hassle), but sure, if I could not have solved it that easily, I would've contacted the support at one point and would not be too happy either. I cannot speak for others and I only have a single sample, but I give you, the quality management might not be on point here. Apart from the issue, I'm quite happy with the performance and quality overall (except with the tri pier, scratchmarks on the outer coating under normal assembly/disassembly, thats a well known issue too but it doesnt hinder the function). I would agree though, that compared with EU/US/Jap manufactured equipment, the quality might not be competing. Thing is, with mounts from e.g. Avalon (Italy) your price expectations rise with the quality (probably), so the question is how much you're willing to risk and pay. Another option I looked at before purchasing was the Celestron CG-X, but I wanted something with a pier function. Hope I could give you some insight, Clear skies!

[@AstronutCymru]

@@ChrizzlyUniverse Thanks for that. I wasn’t faulting you for saving yourself some hassle (or anything else) 😀 This is a really helpful account. I take your point - looking at other mounts with RA encoding, they are twice the price (and weight!). Thanks for the review and the response

[@frankskeen1310]

My new CEM 70 power button was bad right out of the box, it worked and then did not, and the next day it turns on but want turn off. I-Optron sent me a replacement power button I installed myself to repair their error. I was not happy. And now It,s cloudy for days and days so I cant even test the mount. My ASIAIR and cameras all quit on me, was is the power button on the main board, I dont know yet.

[@Nabby13]

The author forgot to mention what kind of guiding RMS total error he was getting.

[@ChrizzlyUniverse]

Yeah right, the comparison of unguided vs guided was missing if I recall correctly. With my setup and 240 mm and 760 mm focal length setups for guiding, I was able to get the error down to 0.7 arcsec RMS while the load was still somewhat unbalanced. CS!