What would you choose for a high payload mount? CEM120EC vs Non EC

[oymd]

I am considering the IOptron CEM120 for my remote Obs setup. 
 

I am not too fussed about guiding, and I believe that at this price bracket, guiding will be needed anyways. 
 

Imaging will be with an EdgeHD 1100 and an Esprit 100ED. 

I am leaning towards the vanilla CEM120, as I have read a LOT of posts on CNs where the EC version seems to have a lot of problems with SDE (sub divisional error) and many of the EC owners are actually trying to find ways to disable the encoders on their EC mounts!

issue is, I can get a really good deal on a CEM120 EC, but I’m very very worried regarding the issues with the encoders. 
 

The vanilla CEM120 owners seem to be very happy with their mounts. 
 

I would very much appreciate some feedback from the CEM120 EC owners? Should I stay away and stick with the vanilla mount?

Please do not suggest Mesu, used 10micron or AP. I am set on the CEM120. 
 

Many thanks

Ossi

[Neil27]

The 120, non EC version was very much on my watch list before pressing buy on the ‘mount we shall not name’  😉

I see no reason going for the EC version if you want to guide.

Happy hunting.

[oymd]

Are there no forum members who have an EC 120?

[newbie alert]

Vanilla 120??  I've only ever seen them black 

[jschella]

Hi, 

 

I'm a little late to the party here, but I have the CEM120 (non-EC) version and would recommend it.  I run at a focal length of 2100 mm (an EdgeHD 800 at F10) and guide using a ZWO-L (large prism) OAG with an asi174mm guide camera. My seeing is typically around 1.8-2.0".  My guiding (PHD2) is almost always between 0.30-0.40" total rms.

For me, I am now seeing limited for imaging, so even if I could guide better, I would not see it in the images.  Therefore, I would be wasting money using encoders.  Yes they can get you down to 0.2" rms but this has no impact for me (or I think anyone with similar or worse seeing conditions.

The only I see to need encoders here would be to do unguided imaging.  And the only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

 

Jason

[oymd]

6 minutes ago, jschella said:

Hi, 

 

I'm a little late to the party here, but I have the CEM120 (non-EC) version and would recommend it.  I run at a focal length of 2100 mm (an EdgeHD 800 at F10) and guide using a ZWO-L (large prism) OAG with an asi174mm guide camera. My seeing is typically around 1.8-2.0".  My guiding (PHD2) is almost always between 0.30-0.40" total rms.

For me, I am now seeing limited for imaging, so even if I could guide better, I would not see it in the images.  Therefore, I would be wasting money using encoders.  Yes they can get you down to 0.2" rms but this has no impact for me (or I think anyone with similar or worse seeing conditions.

The only I see to need encoders here would be to do unguided imaging.  And the only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

 

Jason

Its a bit too late for that...

I've already ordered and received the CEM120EC last week.

Just unboxed it for now. It's HUGE btw...

 

 

Edited December 1, 2021 by oymd

[ollypenrice]

One of my robotic clients returned a defective new iOptron mount and, interestingly, the person at Telescope Service who dealt with the return said he wouldn't recommend iOptron mounts for robotic use. I can't give you any more information than that.

Olly

[oymd]

28 minutes ago, ollypenrice said:

One of my robotic clients returned a defective new iOptron mount and, interestingly, the person at Telescope Service who dealt with the return said he wouldn't recommend iOptron mounts for robotic use. I can't give you any more information than that.

Olly

Thanks Olly

Time will tell how it will go. Early days. I'm still months away from setting up the remote obsy.

I appreciate that the CEM120EC will be no where near as good as a similar load capacity Paramount, 10Micron or AP, but I could not justify spending that sort of money on a hobby. A beautiful, fun and exciting hobby, but a hobby none the less.

[bluesilver]

On 02/12/2021 at 04:43, jschella said:

The only I see to need encoders here would be to do unguided imaging.  And the only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

Hi,  sorry to jump in on this,  but i am also just looking to get a iOptron CEM120 mount,  just the standard version not the encoder versions.

I plan to use PHD2 for guiding.

I just came across this post and was interested to find out a little more on what was meant by,

The only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

Is it just as simple as imaging / guide ratio that you can get from astronomy.tools the only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

I have a Skywatcher esprit 150 with a ASI2600mc camera,  guide scope is a Orion 60mm guide scope and the guide camera is a ASI290mm mini

Putting this number into astronomy.tools i get a imaging / guide ratio of 1:3.37

If anyone can please clear this up for me, it would be appreciated.

Thanks.

[Viktiste]

On 01/12/2021 at 19:39, ollypenrice said:

One of my robotic clients returned a defective new iOptron mount and, interestingly, the person at Telescope Service who dealt with the return said he wouldn't recommend iOptron mounts for robotic use. I can't give you any more information than that.

Olly

Having just bought a CEM70 I think I know why. It will pinch the RA axis just a few degrees below horizontal. 

Edited December 13, 2021 by Viktiste

[jschella]

On 07/12/2021 at 23:22, bluesilver said:

Hi,  sorry to jump in on this,  but i am also just looking to get a iOptron CEM120 mount,  just the standard version not the encoder versions.

I plan to use PHD2 for guiding.

I just came across this post and was interested to find out a little more on what was meant by,

The only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

Is it just as simple as imaging / guide ratio that you can get from astronomy.tools the only real reason I see for that is if you can't fit an OAG/ONAG within the backfocus of your telescope.

I have a Skywatcher esprit 150 with a ASI2600mc camera,  guide scope is a Orion 60mm guide scope and the guide camera is a ASI290mm mini

Putting this number into astronomy.tools i get a imaging / guide ratio of 1:3.37

If anyone can please clear this up for me, it would be appreciated.

Thanks.

Sorry, just saw this now.

  The problem is, if your image sensor is not at the proper backfocus distance, especially critical for telescopes with a built in corrector (like the EdgeHD or when you add one yourself, then you will not be able to achieve the best/roundest stars across the entire imaging plane. 

Hope that helps,

 

Jason

[RafalT73]

On 01/12/2021 at 18:49, oymd said:

…I've already ordered and received the CEM120EC last week.…

Hi, as I am waiting for my new CEM70EC I  am very interested in yours experience with CEM120EC especially in terms of reliability of encoders. Have your concerns about the operation of the encoders come true? Are you satisfied?

[oymd]

33 minutes ago, RafalT73 said:

Hi, as I am waiting for my new CEM70EC I  am very interested in yours experience with CEM120EC especially in terms of reliability of encoders. Have your concerns about the operation of the encoders come true? Are you satisfied?

I will certainly update here when I get to use it.

It's still in the box! I plan to open it and start using it when the obsy is ready.

 

Edited February 16, 2022 by oymd

[Same old newbie alert]

2 hours ago, oymd said:

I will certainly update here when I get to use it.

It's still in the box! I plan to open it and start using it when the obsy is ready.

 

Did you buy the 120?  Standard or EC?

[oymd]

4 minutes ago, Same old newbie alert said:

Did you buy the 120?  Standard or EC?

The 120EC version. Fingers crossed!

[Same old newbie alert]

Oooh nice...

Wondered where those storms have come from