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Is the CEM 60 built better than the IEQ45, or just higher payload?

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#1 Ballyhoo

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Posted 12 October 2019 - 02:26 PM

I know this is crazy but I am thinking about upgrading my mount. If you look at my astrobin you will see I have been doing a heck of a lot of imaging since I started and I would like a more trouble free mount. Not that the IEQ45 pro is that much trouble, bt it does require trouble shooting more than I want. Sometime I will be scanning my subs from the night before, finding random subs that have star trails, etc, oblong. I think it could be because sometimes I do not calibrate PHd2 each session. But also, even of the CEM 60 is not made better, it has a higher payload, so it could handle my telescopes easier. Bt there was an argument that put the IEQ45 Pro in a class of "budget" or "low-end" and these same people that call the IEQ45 Pro low-end say the CEM 60 is "premium."  Is that so? I could afford a CEM 60 a lot easier than a Mach 1 (unless I could find a good Mach 1 on the aftermarket but they do not come up so often.)

 

Another question: Is anyone using the IEQ45 Pro completely without hitches, every time? Maybe it is my technique. Maybe someimtes I am sloppy. But I would like a mount in which if I failes to dot an i, or cross a t, it would still work okay. 



#2 Whichwayisnorth

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Posted 12 October 2019 - 02:49 PM

The CEM60 is not premium by any means and those who say so are just wrong.    I think they are fine but not much of an "upgrade" over what you already have.  It may be time to start saving for a real premium mount.  Places like OPT offer payment plans...



#3 Ballyhoo

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Posted 12 October 2019 - 02:55 PM

The CEM60 is not premium by any means and those who say so are just wrong.    I think they are fine but not much of an "upgrade" over what you already have.  It may be time to start saving for a real premium mount.  Places like OPT offer payment plans...

Well, presumably it would be an upgrade in the sense that my telescopes are effectively becoming smaller on the mount and therefore easier for the mount to track error free. 



#4 Ballyhoo

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Posted 12 October 2019 - 02:58 PM

This mount has a payload of 50lb, but is that a hard or soft 50? IE, does that mean I could only image w 25lbs load?

 

https://optcorp.com/...e-paramount-myt



#5 OldManSky

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Posted 12 October 2019 - 03:07 PM

The MyT could carry a 50-lb. imaging payload.  Probably without batting an eye.

However...if you change your setup and don't calibrate your guider, you won't get any better results with that (or with the CEM60) than you're getting now.  I think the CEM60 would be a towards-premium upgrade for you, and will track better (with more of a payload) than the iEQ45-Pro.  But you will still need to calibrate your guider.

 

Astrophotography is all about crossing t's and dotting i's.  

Make a checklist.  Bring it with you (or tape it to the mount).  Follow it.  That's what will increase success rate, not throwing more money at inconsistent operation. :)


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#6 Ballyhoo

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Posted 12 October 2019 - 03:47 PM

The MyT could carry a 50-lb. imaging payload.  Probably without batting an eye.

However...if you change your setup and don't calibrate your guider, you won't get any better results with that (or with the CEM60) than you're getting now.  I think the CEM60 would be a towards-premium upgrade for you, and will track better (with more of a payload) than the iEQ45-Pro.  But you will still need to calibrate your guider.

 

Astrophotography is all about crossing t's and dotting i's.  

Make a checklist.  Bring it with you (or tape it to the mount).  Follow it.  That's what will increase success rate, not throwing more money at inconsistent operation. smile.gif

so maybe this is just about my increasing my technique. If that is the case than I could save money. But I still hear that voice in my head from premium owners "it just works." 

 

 

edit,

 

so you all re cal your mount/ PHd2 every session?  Do you need to do that w Myt?


Edited by Ballyhoo, 12 October 2019 - 03:48 PM.


#7 ksouers

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Posted 12 October 2019 - 06:29 PM

Sorry, I can't compare the CEM60 to the iEQ45. My opinion, I think it is a slight upgrade. Not a lateral move, but not a major step either.

And, no, neither the CEM60 nor the CEM60EC are "premium" mounts. Mid-level is a better description.

 

Re-calibrating the guider is a function of PHD2, not the mount. You will have to do it regardless of the mount.

 

I may not re-calibrate every night, but I do it frequently. Maybe about every other session. But my rig is on a pier and doesn't move much except for maintenance.

It needs to be done any time you move the guide cam, even a little bit. Any rotation will throw off the calibration. If you are tearing down and setting up each time, yes, you need to re-calibrate your guider.

I will especially recal whenever I adjust focus or after a drift align, or even just unplug the USB cable on the chance that I rotated the cam. It only takes a couple minutes.

 

Honestly, this hobby is very much about process. There really are no shortcuts. You can do it with minimal equipment, you can do it with inexpensive equipment, but you have to create a successful process and follow it religiously to make it all work.

 

 

Kevin


Edited by ksouers, 12 October 2019 - 06:32 PM.

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#8 OldManSky

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Posted 12 October 2019 - 08:26 PM

so maybe this is just about my increasing my technique. If that is the case than I could save money. But I still hear that voice in my head from premium owners "it just works." 

 

 

edit,

 

so you all re cal your mount/ PHd2 every session?  Do you need to do that w Myt?

I re-cal PHD2 every session.  And my mount is on a permanent pier, but most nights I image I re-mount the telescope setup on it.

Because if I don't, I have no idea if my guiding is going to work or not, and it's a huge waste of time to start imaging and find out guiding isn't working, wasting hours of imaging time.  A re-cal takes 3 minutes.  And guarantees consistent guiding.  So I do it every single time as part of my startup routine.

 

And yes, if you tear down/setup every night, you will need to do that with a MyT, too.


Edited by OldManSky, 12 October 2019 - 08:27 PM.


#9 mikeyL

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Posted 12 October 2019 - 09:06 PM

I can chime in with some experiences that might be helpful, given that I previously had an iEQ45 and now have a MyT. Here are some of my experiences and takeaways:

 

- The iEq45 was my first serious mount, prior to that I had used an Astrotrac or piggy-backed on someone else's mount.

 

- I found the iEQ45 to behave about as you say, capable of getting decent results, but inconsistent and prone to issues of one kind or another. The number of times I was able to just go out, set up, and then image, with no issues whatsoever was very low. Most times there would be some kind of a problem - bad tracking/guiding, unexplained slews requiring turning off power and starting over on alignment, etc etc.

 

- I would always have subs with bad stars I would have to throw out. Sometimes a few, sometimes many, sometimes all. I will say that iOptron tech support was very responsive and helpful, but in the end, I just came to not trust the hardware to give me reliable performance and decided to get something better.

 

- Conversely, once I got the MyT, things were just so predictable. Alignment using TPoint was always spot on, and the other features of reliable and fast plate solving meant I could find any target in the sky and center on my camera detector with no issues. Guiding was good, but with a sufficiently large TPoint model (still do-able in 30 minutes or less) and using ProTrack I could run unguided and still get long subs if I wanted to as well. And Bisque service and support were excellent as well.

 

In reality, the MyT and the iEQ45 are just different classes of mounts altogether, and that is of course reflected in the price difference. But if you are serious about getting good results, it all starts with the mount in my opinion. Now there are of course plenty of folks getting excellent results with less expensive mounts. But for me the combo of the Bisque hardware and software are just a super powerful and capable combo. And of course there are other excellent top end mounts to choose from too - but all are in a similar price range I think.

 

So lust one person's opinion but I think the best approach is to skimp on everything else if required to be able to afford a better mount. If you stay in the hobby, I doubt you will regret that decision down the line. 

 

 

ML


Edited by mikeyL, 12 October 2019 - 09:07 PM.

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#10 schmeah

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Posted 12 October 2019 - 09:49 PM

I can’t remember the last time I recalibrated PHD. And it doesn’t seem to have affected my guiding at all. But I don’t alter my imaging train at all between sessions, just move the rig in and out of the garage. Your images have improved remarkably in the short time that you have been imaging. If you can spring for a MyT, go for it. It will get rid of those inconsistently oblong stars and wasted subs. However, it will do nothing for all the other things like inadequate calibration, exposure time, etc. 

 

Derek


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#11 WadeH237

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Posted 13 October 2019 - 07:07 AM

Sometime I will be scanning my subs from the night before, finding random subs that have star trails, etc, oblong. 

This happens sometimes.

 

If you have a high percentage of subs that are fine, but a few that show problems, I would not necessarily blame the mount first.  I would look more towards a guiding problem.  Last summer, I lost a couple of nights of dark sky site data to a guiding problem that took me a while to run down - and this was with my absolute encoder equipped AP1600.  The problem was maddening.  Most of my subs were fine, but more than a few showed distinct star trails - sometimes in a stair-step pattern.  The guide logs showed many instances of guide star loss, even though the nights were perfectly clear from dusk to dawn.  The guide logs also showed periodic large excursions in both axes.

 

After noticing the problem, I reviewed my guider settings and made some adjustments - but the next night's data was the same.

 

It was on the third night, when I gave up on the automation and run everything manually that I found the problem - and it was subtle.  At some point, I noticed that I heard a soft hum at the start of a sub every now and then.  It turned out to be the focuser running out backlash.  It didn't dawn on me right away, that it was happening on a filter change.  I use filter offsets for to account for slight differences between the filters.  When a filter change required a few counts of in-focus, everything was fine.  But when the change required a few counts of out-focus, it would trigger backlash compensation.  During the backlash run out, mirror shift was pushing the guide star off of the subframe on my OAG sensor.  And this was happening right at the start of the sub.  With the subframe, it was looking for a guide star on a tiny area of the sky with nothing there, and it was chasing pixels in the noise.

 

I solved the problem at that time by setting a small maximum move in PHD2 that prevent it from locking onto noise pixels before it finished taking up backlash (which put the guide star back in the guider subframe).  After making this change, I did not lose another sub to this problem.  I remembered later that there is a setting in SGP to disable guiding on filter change.  I had forgotten to set it when I made a configuration change that required re-setting up SGP from scratch.

 

Anyway, my point in all of this, is that there is no such thing as trouble-free astro imaging.  I'm a big fan of Adam Block and his video tutorials.  On some of his walkthroughs, I've seem him blink a stack and have one of the subs be really awful, with streaked stars and other problems.  When this happens, he usually stops the blink and makes some comment about "what in the world happened here?"  He then shrugs it off an continues with what he was doing.  I take some heart that if it happens to the best of them, I shouldn't be surprised when I see the occasional stinker sub.

 

If it were me, I wouldn't try to buy my way out of a problem with an upgrade, until I fully understood it.  This means that I would want to know why my current gear has the problem, and how a new piece of gear would specifically solve it.

 

YMMV.


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#12 kingjamez

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Posted 13 October 2019 - 08:02 AM

The CEM60 is a fine mid range mount, but I’m not convinced that it would do any better for you or save you any subs.

I’d suggest diving in deep on finding why your subs are not coming out well. Inconsistency is not something you should get with the IEQ45. It may not be able maintain very very low error rates but it should be consistent in its performance.

Watch it close when subs don’t turn out, look for things like the PHD2 star profile changing (clouds) and watch the corrections, eliminate hanging wires, miss balances, etc. save your self some money.

-Jim

Edited by kingjamez, 13 October 2019 - 08:04 AM.

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#13 schmeah

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Posted 13 October 2019 - 08:18 AM

But I think that more expensive mounts are more resistant to the minor perturbations in atmosphere, wind, brief clouds etc, that affect individual subs on less expensive mounts. It is consistency, not only from mount to mount, session to session, but also from sub to sub that sets higher quality mounts apart. I saw it immediately upon upgrading, going from having to discard probably 30% of my subs to discarding none in most sessions. And that is without any improvement in technique or additional knowledge. So perhaps the having to discard subs frequently due to star oblongation is not technique related in Ballyhoo’s case, but due to the mount’s lesser tolerance, and a higher capacity mount would eliminate this.

 

Derek


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#14 kingjamez

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Posted 13 October 2019 - 08:41 AM

Not having a premium mount, I can’t talk to the mount overcoming atmospheric issues. However from a theory perspective I can’t quite wrap my head around how that could happen. Except for wind of course and yes, I can see where a more solid mount would help with wind.

I can see how that would be if going unguided as the mount will be steady no matter the clouds or bad seeing. However if guiding, the mount is completely at the mercy of the guide software’s view and what it thinks is right. If the guider’s centroid is skewed due to atmosphere it’s going to command the mount to move and even a premium mount will do what the guider says.

I see high, barely perceptible, clouds roll in all the time and it causes PHD2 to jump all over the place, and thus the mount jumps all over the place as it’s told to.

By jump all over the place I mean move an extra few tenths of an arc second and raise the guiding RMS from something around 0.5” to 1”.

Again, I don’t own a premium mount so if there is something about them that makes them immune to this, please teach me.

-Jim

Edited by kingjamez, 13 October 2019 - 08:44 AM.


#15 WadeH237

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Posted 13 October 2019 - 08:52 AM

But I think that more expensive mounts are more resistant to the minor perturbations in atmosphere, wind, brief clouds etc, that affect individual subs on less expensive mounts. It is consistency, not only from mount to mount, session to session, but also from sub to sub that sets higher quality mounts apart. I saw it immediately upon upgrading, going from having to discard probably 30% of my subs to discarding none in most sessions. And that is without any improvement in technique or additional knowledge. So perhaps the having to discard subs frequently due to star oblongation is not technique related in Ballyhoo’s case, but due to the mount’s lesser tolerance, and a higher capacity mount would eliminate this.

 

Derek

I agree with most of this.

 

The one area where I'm not sure is on sub-to-sub variation.  For night-to-night differences, absolutely.  I would even think that a steady change in performance over the course of the night - for better or worse - might be due to the mount, since balance can change as the mount tracks.

 

But if you get three good subs, then one with oblong stars, and then three more good ones, I would not turn to the mount first.  I mean, it could be the mount, but I would look elsewhere first, probably starting with the guide stars.  And if it happens very infrequently, I might just shrug it off and not investigate at all.


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#16 WadeH237

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Posted 13 October 2019 - 09:03 AM

If the guider’s centroid is skewed due to atmosphere it’s going to command the mount to move and even a premium mount will do what the guider says.

It might be more accurate to say that a premium mount will do what the guider says, and that other mounts will do their best to try and do what the guider says.

 

Much of the functionality in PHD2 is built around trying to guess what the mount is actually going to do, rather than what it tells it to do.  In fact, running PHD2 with defaults is not necessarily the best way to work with a highly accurate mount.  After they did much testing with PHD2, the Astro-Physics folks came out and suggested using the LowPass2 algorithm in PHD2, because it's the one that does the least amount of compensation for mount behavior and consistently gives them lower RMS errors than the other algorithms.  And this is consistent with the PHD2 documentation, which also recommends LowPass2 with accurate mounts, especially those with high precision encoders.


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#17 schmeah

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Posted 13 October 2019 - 09:08 AM

Not having a premium mount, I can’t talk to the mount overcoming atmospheric issues. However from a theory perspective I can’t quite wrap my head around how that could happen. Except for wind of course and yes, I can see where a more solid mount would help with wind.

I can see how that would be if going unguided as the mount will be steady no matter the clouds or bad seeing. However if guiding, the mount is completely at the mercy of the guide software’s view and what it thinks is right. If the guider’s centroid is skewed due to atmosphere it’s going to command the mount to move and even a premium mount will do what the guider says.

I see high, barely perceptible, clouds roll in all the time and it causes PHD2 to jump all over the place, and thus the mount jumps all over the place as it’s told to.

By jump all over the place I mean move an extra few tenths of an arc second and raise the guiding RMS from something around 0.5” to 1”.

Again, I don’t own a premium mount so if there is something about them that makes them immune to this, please teach me.

-Jim

 

I don’t profess to be a teacher. So I won’t argue theory. Just observations related to upgrading that many including myself have. But even slight wind gusts are better handled by a study mount. Guide responsiveness, backlash, periodic error are all factors that affect individual subs. When brief cloud cover causes guide software to lose a guide star, a higher quality mount with low periodic error or less drift will be more tolerant of these shorter periods of non guiding. I agree that loss of subs with some mathematical frequency or period would not related to the above. But less expensive mounts may have  sharp spikes in PE, that guiding cannot handle. Why do we buy more expensive mounts if not to minimize this sub to sub variation?

 

Derek


Edited by schmeah, 13 October 2019 - 09:11 AM.

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#18 EFT

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Posted Yesterday, 12:08 PM

To answer the original question "Is the CEM 60 built better than the IEQ45, or just higher payload?", the answer is "no" and "maybe".  Manufactures generally make mounts of a similar level of quality throughout their entire line (with the exception of the truly garbage level of mounts).  While the designs a manufacturer has may be different with some begin significantly better than others, their quality of manufacturer generally remains the same.  Quality is a philosophy and much as it is a result.  While there are some businesses that produce products of specifically different "quality" (e.g., accuracy) based on the customers' needs, the telescope manufacturing business is not one of those.  A manufacturer may over time increase the quality of their products overall, it's generally not going to be a poor mount versus a better mount within the mounts at a general level (e.g. mounts costing greater than $1000 in this case will basically all be of similar quality).  Difference in design may equate to differences in performance, but the quality of the manufacturing will remain the same.  This could change within the industry at some time, but it is not the case now.

 

When it comes to capacity in these and similar mounts, it's a complete crap shoot.  The capacity ratings are all over the map with no explanation as to what they are based on much less what they are good for (e.g., visual vs. imaging).  Two mounts of similar size may be given different capacity ratings but one person may find that they can hold more on their particular mount with a lower capacity rating than another person finds they can hold on their mount with a higher rated capacity.  That can easily be the case with mounts at this level.



#19 F.Meiresonne

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Posted Yesterday, 12:18 PM

I think the concept of the mounts differ also. The IEQ45 is a 'classic' design the CEM a more new design.Weither you like most is up to you.

Personally i like the more classic design but that more because i just a traditional guy. I have the smaller IEQ30 pro and i must say i like it. Nice buttons you can tighten by hand. I see the CEM60 will need a tool to tighten the buttons unless i see it wrong.

 

Then again both nice mounts IMO, and if the software works and there are no QC issues, they are very nice products.



#20 kingjamez

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Posted Yesterday, 01:19 PM

Full moon nights like tonight and last night are great opportunities to diagnose problems. You don't feel like you are wasting valuable imaging time, yet you are still able to fully diagnose any issues that the mount has.

 

-Jim


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#21 spokeshave

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Posted Yesterday, 06:22 PM

Another question: Is anyone using the IEQ45 Pro completely without hitches, every time? Maybe it is my technique. Maybe someimtes I am sloppy. But I would like a mount in which if I failes to dot an i, or cross a t, it would still work okay. 

There is no mount made that will work okay if you make an error or omission when setting it up. If you change your guide camera or OTA orientation and don't recalibrate PHD2, it won't work well, if at all. No mount will. Before throwing money at the problem, you need to know what the problem is. Astrophotography can be a tedious hobby that is very intolerant of operator error. Find out what is causing your guiding problems. If it due to operator error, don't blame the gear. If you find that you are forgetting important steps, create a checklist and follow it every time you set up.

 

Tim




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