Rainer

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Hi, Well yes I think I have written this here in SGL a few times 🤓 but as it looks like as I am the only one with that theory it is not taken serious 🤣 The mount builders now incorporating encoders in their mounts have stirred up the Amateur Astronomy community and a lot do not know how to handle that 🤔 and many assumptions and guesses were made but also due to marketing in one or the other mount producer website ... Well, the future will tell ... Rainer

Maybe but I see a design problem in the way the whole head is attached to the base. The CEM 60 has a broader foot ... and therefore is more stable IMHO = In My Humble Opinion Rainer

Hi, I image at 2424 mm or sometimes up to 3203 mm focal length and make exposures of up to 1800 seconds as my main targets are the Arp Galaxies. Rainer

Hi, No, that is an Urban myth. Honestly I do not know from where this comes that people think encoders are for unguided imaging. Question: Without Feedback how does an encoder know if it is pointing and maintaining the desired object in the center ¿? It does not ... Only by having a guide camera and fixing the whole Shishkebab with it then it will stay in the center ot whichever position you want to ahve your object. Encoders just kill the Periodic Error but do not help you with a bad Polar Alignment nor Atmospheric refraction. Mechanically we have reached a limit in tolerances and a worm and worm gear will always have a periodic error. I have two CEM 120EC2 and before that I never reached the performance I have now and yes I do guide but I do guide with a cadence of 15 seconds and not 1 or 2 maybe 3 seconds. I correct for bad Polar Alignment and perhaps Atmospheric refraction. iOptron says they have implemented in the algorythm a atmospheric refraction compensation. IMHO = In My Humble Opinion and yes it was worth to spend US $ 3,000.00 more for each mount. Instead of US $ 3.998.00 I paid US $ 6.998,00 for each mount and got a carrying capacity of 52 kg (without counterweights) Rainer

I am iOptron biased 🤓 With that beast only a CEM 60. Moment arm not weight is here important. CEM 40 is too small for that even if it could carry it 40 lbs ~ 18kg ... And if the budget allows it a CEM 60EC 🥰 Rainer

Hi Chris, I am strongly biased but I would go for the CEM 60 and if the money does allow go for the EC version. Rainer

Hi, That is a nice example of how to specify the real carrying capacity of a mount 👍 What are you going to mount on the new mount you intend to buy ? Rainer

You are welcome. BTW I took Losmandy as an example nor for bashing but because I had two G11 for about 18 years and know them in and out and as now I have two CEM 120EC2 I can talk about this and I am not making any assumptions. This is real world experience ... Just in case somebody feels offended why I took and image of the Losmandy mounts 🤔 Nowadays one has to be careful 🙄 🤣

Hi, I admit I am very strong biased but based on my experience I would go for a CEM 60 because of the fact that the RA and DEC axis are resting on a broad basis, two sliders well apart and the EQ6 has a narrow fork and inside one part. Look at the images what I mean. Rainer

Hi Chris, At first when I got my two CEM 120EC 2 I was guiding at 5 seconds. After changing from PHD2 to SKyGuide and having many many e-mail exchanges with Dr. Gaston from IF I experimented with longer and longer exposure times and yes the result were getting better. Now I am testing the predictive guiding of Sky Guide and to my surprise even better the guiding. The fact is the encoders do a good job killing the Periodic error and so the thing we have to guide out is our bad Polar Alignment as well as sudden atmospheric refraction changes. You can have a thin stripe of the Jet Stream pushing your star to some other position an then suddenly it disappears. Be aware that the EC2 mounts do use temperature and barometric pressure for compensating the atmospheric refraction when moving from the Zenith to the horizon or viceversa. This was confirmed to me by iOptron. The fact is a lot of people out there still do not understand what encoders are for and so they recommend not to get them and I dare to say if you have them but do not use them there is no harm. The latest firmware v190318 is very stable and good. So far in the last 14 months since I have my mounts iOptron has done a lot of improvements based on many of my findings over the moths. I would say the CEM 120EC2 as well as the other smaller siblings are ripe mounts. I fully understand that but it is proven that EC mounts can go with such long exposure times. We guys with more then 15 or 20 years experience in this are also now confronted with new technology but we need to shake off what we got glued onto us and we need to think now out of the box ... Invest some time in learning this new technology and learn from people who are already doing it ... Rainer

Hi, For these two scopes the CEM 25 I would not recommend the CEM 25 from iOptron. Looking at the dimensions of the Newtonian then a CEM 60 would be the minimum ... Because of weight and moment arm ... regards Rainer

Hi Freddie, You do not need to apologize. I am the one bringing chaos into this. 0.005 seconds move would be more or less a move of 15" x 0.005 = 0.075" 👍 this is at a guide speed of 1X and OK, at a guide speed 0.5X then it would be 7.5" x 0.005 = 0.0375" and so on ...

Hi Freddie, No, I am not confused. PHD2 yes specifies it in arc seconds but SkyGuide of Innovations Foresight https://www.innovationsforesight.com/ specifies it in seconds of time. They calculate how much seconds the mount has to move after having calculated the distance the star has moved so in both cases it is the same. See ? I am not confused as it is just a matter of how they did program it. There are more guide programs and not only PHD2 😉 regards Rainer

As far as I know yes but if they feel that it is necessary to disengage the worm from the worm gear, that can only mean that the clutches still have a friction and so hinder a good balance ¿?

https://www.cloudynights.com/topic/663250-cem60ec-some-questions/

Hi, I have been guiding my CEM 120EC2 in the last weeks with 100% aggressivity, 0.005 minimum move and 15 seconds guide camera exposure time but with SkyGuide. Much better then before as when I still used PHD2. My RMS values are around 0.25" - 0.30" arc seconds with focal length of 2424 mm guiding using the OAG of my QSI 540wsg cmeras. Why 0.005 sec minimum move because that is the time for one step and under that I do not think the stepper motor will react. Maybe it is even just my imagination. Condition for guiding like this are mounts with really 0 zero backlash and that is what the iOptron mounts with their worm / worm gear assembly have. Rainer

Sorry but that is misleading ... ANY mount with a worm / worm gear has this risk if not treated correctly ... Why everybody has to be beating on the iOptron CEM's ? What a nonsense ... I thought " Premium Mounts " are inmune to user errors ? At least reading many of the misleading posts you get that impression ... BTW common sense prevails when one does think a bit about that, and disengaging a worm from a worm gear with an unbalanced axis will destroy any mount irrelevant of the BRAND ... regards Rainer

I have not seen a single plane at night reflecting the Sunlight ¿?

Hi, The title " Soon ... " is very optimistic ... 🙄 It is not soon, it is real ... http://darksky.org/starlink-response/?fbclid=IwAR2cpUHORSPNpvgTdMNG8ripHZAwfzn236rdgrc6mQNOKtxH-MhTr_ExH7M Rainer

Hi Palantir, Encoders do make guding more comfortable. Guiding and ecnoder only fight each other if the guide frequency is too often. I ahce CEM 120EC2 mounts and my guiding frequency lately went up to 15 seconds a guide command not more often. If you have encoder then you only guide for drift in RA and DEC due to Polar alignment and atmosferic refraction errors. Rainer

Finally we got some stars to look at. These were missing in the actual list as we do not have enough we need 12.000 more ... 🤑🤑🤑🤑🤑 So when it is cloudy we can at least clean up our wide fiels images from that Garbage up there ... SARCASM off This will be interesting to see how many will light up every night ...

Hi Stratis, Any news about your project about downgrading from CEM 60 to CEM 40 ? 😲 Rainer

For me that is not a problem. But are you sure a Dome inhibits Air Currents ? I have never had a dome but the wind gets in everywhere ¿ or ? Rainer

Yes when there is no real load on it ... as far as I know. I have measured some wall outlets and they measured up to 20 v but were clearly labeled as 12 Volt power sources ...