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Celestron 9.25 EdgeHD and Poorly Designed Focus Motor Mounting Plate

Celestron accessories equipment
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#1 jtbrower

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Posted 23 January 2021 - 08:07 PM

Introduction

Hello Everyone, my name is Jason.  This is my first time posting on CN and admittedly I am also new to backyard astronomy / astrophotography.  Being a double newbie sure begs the question, am I qualified to make a bold statement such as "poorly designed focus motor mounting plate"?

 

Although this wonderful hobby is new to me, I have over 20 years of Software Engineering experience, half of that with companies that manufacture in-house devices. I have enough of a mechanical aptitude to have rebuilt cars, engines and just about anything I can get away with taking apart.  That said, my newness to this industry has me turning to this forum to see if anyone else has noticed what I have noticed.  I think these design flaws might be causing some of the issues I have seen others speak about in other online places.

 

The Equipment

I bought a new 9 1/4 EdgeHD along with plenty accessories including the Celestron focus motor.  I figured what good is it to remotely control a telescope if you cannot remotely control the focus?

 

Considering the scope and add-on focus motor are both manufactured by Celestron, I didn't expect to find the issues I am seeing.  Although I overlaid text descriptions of the issues on the included images, I will describe the problem in text so the search engines can index the problem.  I only have experience with the 9.25, I am willing to bet the same problem might apply to smaller sized scopes that use the same focus motor mounting plate.

 

Problem #1

 

Background

The stock "focus knob mechanism" for the EdgeHD 9.25, uses a rubber knob slid onto a brass tube that has a bearing connected to it. This lets the end user direct the angular momentum into the tubes mechanical focusing mechanism. Except for a round gasket separating the two, the bearing sits directly on the metal of the rear of the OTA, however the bearing sticks up past the mounting location for the plate by approximately 1 mm.  IMO, this is purely by design.  The plate that covers the bearing (on the stock part) has a recessed area machined out of it that the bearing sits inside of.  This gives a mechanical engineer an easy way to control the amount of pressure on the bearing.  Less recession, more pressure, more recessing less pressure.

 

The Issue with the Focus Motor Kit is the fact that the motor mounting plate that replaces the 9.25 scopes and under, does not have this recessed area machined out of it.  This causes 100% of that mounting plate to be contacted on the bearing and 0% contacted on the rear of the OTA except via the three original screws.  Not only does it make the screws appear too short to some people, but you cannot properly tighten down the motor mounting plate without over-torqueing the bearing of the focuser's brass/bearing mechanism.  This also places all of the torque from that electric motor on those three screws and the bearing alone.

 

Unless they properly machine a corrected mounting plate, Celestron's focus motors are likely to damage some people's OTA's.  They might wobble out the threads for those three screws, a screw might come lose and cause other damage IMO.

 

bearingHeightNotatedSm.jpg

stockBackingPlateNotatedSm.jpg

focuserBackingPlateNotatedSm.jpg

 

Problem #2

 

Background

As all companies hope to accomplish re-use, sometimes the desire to make "one size fits all" components can sacrifice overall quality.  The Celestron focus motor kit was design to fit a larger diameter focus knob tube than found on the 9.25 inch scopes and under.  For the smaller scopes, you have to use an insert, or "adapter sleeve" as it is called in the manual.  The sleeve has a slit cut that provides a way for the setscrew to clamp down upon the smaller diameter focus knob mechanism.

 

The Issue from what I can tell is that as you clamp down that sleeve with the set screw, the round shape starts to become oblong.  This less than a perfect circle shape causes the focus motor to rotate the focus mechanism's shaft in a non-perfect circular motion.  (If you hold a flashlight into that hole and put magnification over your eyes you might be able to see what I have been looking at.  Even when you have mounted the entire mechanism as intended and directed, you can see the end of that brass tube's center screw rotate out of axis.

 

To confirm this wasn't the motor itself, I removed the unit, re-sunk the set screw (to prevent damage) and ran the motor off the scope.  It turns perfectly circular and makes a lot less noise at that.

 

focusMotorImageNotatedSm.jpg

 

Summary

When I first started writing this thread, I had hoped that just maybe they failed to fully machine the mounting plate that I received.  If so, this would take care of part of the problem.  However, as I re-read problems other people demonstrated on YouTube and Amazon, I have a feeling that this is purely a design flaw.

 

As badly as I want that focus motor to work, I removed it from my telescope.  I just don't see how they overlooked this.


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#2 ryanha

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Posted 23 January 2021 - 08:55 PM

Welcome to CN!  Good write up.  You hit most of the major points.  The other point of lacking is that it focuses by moving the primary mirror which can cause issues under the name "mirror flop".

 

ZWO makes a focus motor and bracket for SCTs that address some of these issues.  And and with that option at least you have access to the pate screws so you can keep it just the right amount of tight and tighten them as needed (I believe this is the case, though I have not used this one myself as I have the one you have).

 

The best solution for focus for SCT is to lock the primary mirror and use a focuser that moves the imaging plane (like a crayford or rack and pinion drawtube).

 

All that said, the Celestron focuser is good enough to get your feet wet.  I used it for my first few months of imaging and got it working for auto focus.  Eventually you realize that there is always a better and more expensive piece of gear that you must get :)

 

Good luck, welcome, and clear skies!

 

--Ryan



#3 ryanha

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Posted 23 January 2021 - 08:58 PM

Here is a link to the ZWO bracket and motor:

https://agenaastro.c...af-c8-c925.html

https://agenaastro.c...f-standard.html

 

Note that I have not used this motor bracket on my SCT, so I can't speak to its quality but I do have the motor and it seems good enough for the moment.

 

And if you want to try again with the Celstron motor, I found that a little locktite helps keep the mounting plate screws in place for a while.

 

--Ryan


Edited by ryanha, 23 January 2021 - 08:59 PM.


#4 jtbrower

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Posted 23 January 2021 - 10:03 PM

Here is a link to the ZWO bracket and motor:

https://agenaastro.c...af-c8-c925.html

https://agenaastro.c...f-standard.html

 

Note that I have not used this motor bracket on my SCT, so I can't speak to its quality but I do have the motor and it seems good enough for the moment.

 

And if you want to try again with the Celstron motor, I found that a little locktite helps keep the mounting plate screws in place for a while.

 

--Ryan

Hello Ryan, thank you for your hospitality and insight. 

 

The only way I would use Celestron's, would be if they corrected their issues (I have little hope that it would happen anytime soon).  That leaves me with third party options, or machining my own parts for Celestron's.  Since I can't keep up as it is, I am all ears on third party solutions such as that from ZWO.

 

I saw that focus motor when the Celestron option failed, but since it wasn't directly compatible with SCT's I didn't entertain that idea further.  Now that you have showed me that mount, I am more open to something in this direction.

 

I purchased a ZWO ASI 2600MC Pro camera when I bought my scope, does using the ZWO focus motor provide advantages since I already have one of their camera's?

 

I wonder if replacing the focuser all together might be best.  If that ZWO mount doesn't account for that 1 mm bearing height, I will be dealing with the same issue.  Something like a feather touch with a focus motor?

 

I will stand outside before I put something as half baked as what Celestron came up with.  Some minor tweaks and it would be great.

 

BTW, I am switching over from my motocross hobby after breaking my back in 3 places.  Needless to say, scopes are more economical than racing.  I know I jumped in headfirst for a newbie, but I decided that I wanted to do this properly if I was going to do it at all.



#5 ryanha

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Posted 23 January 2021 - 10:16 PM

Not sure about the feather touch but moonlite has an SCT focuser that will also accommodate a focal reducer.

#6 ryanha

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Posted 23 January 2021 - 10:18 PM

Not sure about the feather touch but moonlite has an SCT focuser that will also accommodate a focal reducer.

#7 jtbrower

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Posted 23 January 2021 - 11:00 PM

Update : I was reading a long thread elsewhere and a gentlemen mentioned that after working with Celestron, they told him to leave the original focus plate installed, but remove the screws and place the auto-focuser plate atop the original and then use longer screws to secure it all in place.  Apparently, they sent him the longer screws.

 

In fact, the ZWO bracket that @rynha mentioned above, is also installed on top of the one the scope came with.

 

If I used this approach with the Celestron unit, it would resolve the worst of the two issues I reported, but would not solve the second.

 

The ZWO option is viable, but it isn't nearly as low profile as what Celestron's is.


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#8 jtbrower

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Posted 24 January 2021 - 05:52 PM

Update 2 : after becoming frustrated with a lack of solid options and really wanting the Celestron design to work, I gave it another shot with the work-around I spoke of above.  That is, I removed the screws from the stock plate, but left the stock plate on.  I then took longer screws and placed the focus motor's plate over the stock plate and secured it in place.  It is as firm as it can get with this particular design.  As for the "out of round" spinning of the focuser, it isn't quite as apparent, but definitely still exists.  I am going to go against my original decision to return the unit and try to give it a shot in practice, once it stops raining outside!  It has rained every day since my scope came in.  Cheers.



#9 jmiller1001

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Posted 24 January 2021 - 05:58 PM

My advice - and I suspect that it may be echo'ed by a few others:

- Your SCT is a great scope to learn visual astronomy, BUT it's a challenge to learn astrophotography on it due to the long focal length.   Trust me, this is the voice of experience (I struggled with my 10" Meade SCT before setting it aside and learning astrophotography on a Stellarvue 70mm refractor).  For example, I (personally) would not even bother to automate the stock focuser on an SCT - the mirror flop is a design aspect of an SCT that you just can't get around. I lock the mirror on mine and use an automated Moonlite focuser, but that's a $400+ "investment."  For this type of money, you're well on you're way to buying a quality widefield refactor.

- Spend a few months learning your equipment and learning the night sky and spend as much time on CN asking for advice and educating yourself on the myriad of issues.  My analogy would be jumping on a motocross bike for the first time and entering a race the next weekend. Likely not advised. This is a hobby that is infinitely rewarding - and incredibly technical (even for the most technical among us - I'm an Aero/Astro, Mechanical and Electrical Engineer - who is very mechanically and software oriented) and I still learn a TON every week from CN and my own bone-headed "lessons learned."

- Learn astrophotography on a widefield refactor like a 70-100mm.  It's so much easier and the targets are numerous.

- Can you learn astrophotography on an SCT?  Yes, but the road is littered with people that started there andd grew very frustrated in the process.

Jim


Edited by jmiller1001, 24 January 2021 - 06:06 PM.

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#10 jtbrower

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Posted 24 January 2021 - 09:46 PM

My advice - and I suspect that it may be echo'ed by a few others:

- Your SCT is a great scope to learn visual astronomy, BUT it's a challenge to learn astrophotography on it due to the long focal length.   Trust me, this is the voice of experience (I struggled with my 10" Meade SCT before setting it aside and learning astrophotography on a Stellarvue 70mm refractor).  For example, I (personally) would not even bother to automate the stock focuser on an SCT - the mirror flop is a design aspect of an SCT that you just can't get around. I lock the mirror on mine and use an automated Moonlite focuser, but that's a $400+ "investment."  For this type of money, you're well on you're way to buying a quality widefield refactor.

- Spend a few months learning your equipment and learning the night sky and spend as much time on CN asking for advice and educating yourself on the myriad of issues.  My analogy would be jumping on a motocross bike for the first time and entering a race the next weekend. Likely not advised. This is a hobby that is infinitely rewarding - and incredibly technical (even for the most technical among us - I'm an Aero/Astro, Mechanical and Electrical Engineer - who is very mechanically and software oriented) and I still learn a TON every week from CN and my own bone-headed "lessons learned."

- Learn astrophotography on a widefield refactor like a 70-100mm.  It's so much easier and the targets are numerous.

- Can you learn astrophotography on an SCT?  Yes, but the road is littered with people that started there andd grew very frustrated in the process.

Jim

Hello, nice to hear from another engineer.  Much respect!  Ugh, I really thought I did my research, splurged and got a stellar system, but I trust in what your telling me and I feel deflated as a result.  Would those comments hold true even at the F2 focal length?  I assume so.  Bummer.

 

Well, at least my CGX-L mount will handle about anything I can dream of in the near future, unless I travel and need weight reduction.  Is the ASI2600MC Pro a good buy?  I got lost in days of articles between CMOS and CCD and was convinced to go color CMOS for the ease of use.

 

I do appreciate your analogy on motocross too and why I have been cuddling with all of this equipment nightly without actually using it yet.  Read the manuals cover to cover and it feels like I am savoring the experience like a bottle of wine.  It has rained every freaking day since I bought the equipment, but I was saying on a social media video that I am glad because it reduces my temptation to begin using anything before I understand it. 

 

I did enter this cautiously from the standpoint that I was prepared to be patient.  I kept running into articles and videos for far more experienced people who showed frustration at times. 

 

The price of the refractor that you mentioned is reasonable.  I suppose I could mount it to the top of my other scope like I have see others do, or should I avoid that?

 

Thank you again for your information, its much appreciated. 



#11 jmiller1001

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Posted 24 January 2021 - 10:46 PM

Hello, nice to hear from another engineer.  Much respect!  Ugh, I really thought I did my research, splurged and got a stellar system, but I trust in what your telling me and I feel deflated as a result.  Would those comments hold true even at the F2 focal length?  I assume so.  Bummer.

 

Well, at least my CGX-L mount will handle about anything I can dream of in the near future, unless I travel and need weight reduction.  Is the ASI2600MC Pro a good buy?  I got lost in days of articles between CMOS and CCD and was convinced to go color CMOS for the ease of use.

 

I do appreciate your analogy on motocross too and why I have been cuddling with all of this equipment nightly without actually using it yet.  Read the manuals cover to cover and it feels like I am savoring the experience like a bottle of wine.  It has rained every freaking day since I bought the equipment, but I was saying on a social media video that I am glad because it reduces my temptation to begin using anything before I understand it. 

 

I did enter this cautiously from the standpoint that I was prepared to be patient.  I kept running into articles and videos for far more experienced people who showed frustration at times. 

 

The price of the refractor that you mentioned is reasonable.  I suppose I could mount it to the top of my other scope like I have see others do, or should I avoid that?

 

Thank you again for your information, its much appreciated. 

Here's my 2 cents:

When you say F2, I believe that you are referring to focal ratio, right?  F2 is incredibly fast and incredible sensitive to tilt, spacing, and it likely requires $$ filters for an extremely fast focal ratio.

 

The mount is great.  Stick with it - and learn how to do an accurate polar alignment with it (I highly recommend a Polemaster).  The ASI2600MC-Pro is a great camera, but this is where doing your homework will pay off: You'll need to understand things like pixel-ratio, binning and thee physics of a Bayer matrix.  Check out the AgenaAstro overview of ZWO camera's - it's a great primer on cameras.  

 

A mono camera has 4 pixels worth of data for every 1 pixel of a OSC camera - since the RGGB matrix of a OSC camera requires 4 pixels....before spending that much on a camera, I'd do a LOT more homework.  I have a 1600MM-Pro and 071-Pro (OSC) - and a number of filters and other cameras for different objects (planets vs. DSO; dark skies, etc.).  I went directly to CMOS and did not consider CCDs - again, this is a choice with trade-offs as well.

 

Yes, you can piggyback the refactor on the SCT.  Personally, I don't do it - but I do see it pretty often.  

 

When it comes to gear, I tend to buy used - but, you have to do your homework!  



#12 ryanha

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Posted 24 January 2021 - 11:36 PM

tbh, I started on an 8" SCT and found it to be not too bad and most of my images (link) are with that scope.  That said, I live in So Cal and when I started I had 60 days of consecutive clear skies to experiment with. Also the planets were out at the time and I got to learn a lot by starting with planetary imaging.

 

Also, despite starting out with the SCT with decent results, I recently ended up just upgrading to a very nice refractor, partly because my other choice was going to be to put a $600 focuser on the $1000 SCT, and partly because I was having columation issues which did not feel like a good "part of the fun of the hobby" to me.

 

I do agree with @jmiller1001 that a safe path would be to take a step back and get a refractor (F5 - F6 at < 700 mm FL) with a suitable guidescope and guide camera, you will have a good set of things to learn:

- Polar alignment

- Learning the software (sequences, auto-focus, meridian flip)

- Guiding (likely PhD + guide scope + guide camera)

- Imaging (target selection, framing, plate solving, exposure times, gain settings, dithering)
- Processing (calibrating, registration, integration, post-processing)

 

Your other option if you stick with the SCT would be everything above plus:

- Focal reducer (this will get you down to F7 or so and 1300-ish FL)

- OAG (here is a thread on selecting an OAG: link)

- Columating (though you should be ok for a while as the effects of poor columation are subtle)

 

The F2 comment you made I assume is regarding a hyperstar.  Some people love them. I have no experience with it but you could ask around for people that image with to gauge their experience with it.

 

The community here is pretty amazing and if you post specific questions (e.g. which OAG to get) you will get the entire spectrum of answers, so don't hesitate to post!

 

If you are not too worried about spending a bit of money (as you say this is less expensive than a toy hauler and motorcycle), then don't worry too much, just try to learn on what you have and upgrade things as soon as you understand why you want the upgrade. For example you could learn how to set up the software and learn auto focusing on the SCT.  You could take some images and learn image processing.  That could be one way of helping you learn what you really care about.   

 

#1 most important thing is to not get too frustrated.  You will mess up, its part of it!

 

 

--Ryan


Edited by ryanha, 24 January 2021 - 11:40 PM.


#13 jtbrower

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Posted 25 January 2021 - 12:14 AM

 

#1 most important thing is to not get too frustrated.  You will mess up, its part of it!

That's what I am reading and I think this one is to my advantage.  I truly enjoy problem solving to the point I won't even get up to go to the restroom because I become laser focused on the solution.  A big reason why I decided to dive into this was because I knew I would have endless challenges and problems to overcome, things to learn.

 

 

The F2 comment you made I assume is regarding a hyperstar.

Yes, I liked the versatility of being able to reduce from an F10 downward rather easily.

 

 

OAG (here is a thread on selecting an OAG: link)

The off axis guider purchase is happening as soon as I make my mind up, so thank you for the link.  

 

 

When it comes to gear, I tend to buy used - but, you have to do your homework!

Nothing wrong with that.  I always buy new, I never want to inherit other peoples mistakes they made while learning.  Just a personal preference.  I came from the sport of motocross, had a 40 foot Toy Hauler, Sprinter Van and 2 to 4 bikes at any given time.  After the back injury I sold it all and for 17 months I have been trying to decide what hobby I would approach next.  Needless to say, I don't enjoy wasting money, but was prepared to spend after researching hundreds of hours before purchasing everything.

 

 

before spending that much on a camera, I'd do a LOT more homework

The reason I went with a CMOS camera was due to its ease of use, something I learned from "doing research".

 

I was initially concerned when @jmiller1001 shared his thoughts on Astrophotography with the SCT.  However, after reading a somewhat heated debate here https://www.cloudyni...aphy-telescope/ I think I now have a better understanding of why the refractor seems to be the recommended beginner scope and I am no longer disappointed in the purchase I made.  My gut initially sank because I thought the scope was somehow inferior for imaging.  The fact that I will need to make some upgrades (for example to help avoid mirror flop) is something I actually enjoy.

 

In my younger years I would always take the best beginner route when jumping into a hobby, but then quickly finding myself spending a lot more money as I shuffle to the more advanced equipment.  Tired of doing that for decades I now dive in head first.

 

That's not to say that I won't be asking myself plenty of questions and some of them on here!  My overall sentiment is that I am doing this for my love of problem solving and knowledge.  It sounds like I will have plenty problems to overcome with the SCT and will certainly learn a lot.

 

I already plan to assure the scope is collimated and have read documents and watched videos on it and polar alignment, but I am eager to try it out as I won't feel confident or comfortable until doing it hands on.

 

Although it has been 12 years already, I use to work in anti-counterfeiting hands on with CCDs, spectrometers and curve fitting algorithms.  Although it doesn't directly translate, I am excited to get closer to imaging again.


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#14 speedster

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Posted 25 January 2021 - 03:58 AM

Howdy Jason!  And welcome.  Don't let anybody rain on your parade.  You have great stuff and seem to have realistic expectations of patience, learning curve, etc.  My 2 cents?  Don't buy any more stuff until you get comfortable with what you have.  Don't try to do it all at once.  Start with mastering sky alignment and polar alignment.  Then master a camera, then guiding, then just keep adding skills.  I know you won't do it that way so just jump in with both feet, keeping in mind that some nights are just not going to turn out like you want and work on one issue at a time.  A word of advice, learn to like issues like the Celestron plate and enjoy solving them.  Almost nothing works without some additional screw, adapter, spacer or tweak.  It's always something.  Look forward to seeing your work! 


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#15 jtbrower

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Posted 25 January 2021 - 03:19 PM

Howdy Jason! And welcome. Don't let anybody rain on your parade. You have great stuff and seem to have realistic expectations of patience, learning curve, etc. My 2 cents? Don't buy any more stuff until you get comfortable with what you have. Don't try to do it all at once. Start with mastering sky alignment and polar alignment. Then master a camera, then guiding, then just keep adding skills. I know you won't do it that way so just jump in with both feet, keeping in mind that some nights are just not going to turn out like you want and work on one issue at a time. A word of advice, learn to like issues like the Celestron plate and enjoy solving them. Almost nothing works without some additional screw, adapter, spacer or tweak. It's always something. Look forward to seeing your work!


Thank you very much for the confidence boosting words, I have a lot to learn and I just hoped all that research didn’t lead to me buying a junk scope.

Before I decided to spend nearly $9K in to all the filters, focal reducer, camera, mount and etc, I feared that my usual “upgrade-itis” would bite me shortly after buying a scope that bored me and as always I would end up spending more money in the long-run.

Oddly I enjoy the feeling of being overwhelmed by technology and tying to piece things together. I love the mystery of looking at a huge pile of parts and slowly putting the puzzle together.

You have sound advice of trying not to go buy everything I need until I get to know the equipment I have. Although this was the initial plan before I added an off-axis guider and any aided polar alignment unit, I found myself overwhelmed with trying to choose those “last” pieces. Probably didn’t help that it was about 2AM :), but before I went to bed I told myself to figure out what I already own, there’s plenty to do. So hearing it from you prevented me from changing my mind and placing those orders.

Your positivity is appreciated. BTW it’s sunny out today and the sky’s will be clear tonight. Polar alignment is top on my list to feel comfortable with and then I might give collimation a shot (since shipping journeys are rough). I want to assure there are no immediate issues so I can notify the seller ASAP.

They shipped my camera with very little surrounding packaging and what was there was popped flat as a pancake. I let them know about this and they were really nice about it.

I appreciate everyone’s feedback. My only expectation for my “first light” experience is to polar align and assure nothing is broken.

My back yard is a swamp pit right now so I will probably need to shoot from my driveway’s sidewalk as my driveway itself is significantly sloped.

I’m in a Bortle level 5 area of North Dallas. I was hoping that 9.25 aperture along with the Light Pollution Filter I bought could help me overcome less than ideal conditions.

I’m thinking I might pour a small concrete pad in the backyard (eventually) to always assure a clean, solid surface. If this new hobby sticks with me, I’m positive I will have an observatory because I usually can’t tame my enthusiasm.

Switching from motocross to telescopes is an odd jump, so I did a tremendous amount of research out of fear I would spend the money and not enjoy it. Part of my goal was to assure whatever I bought had great resale value. I became familiar with this website and the popular YouTubers of Astronomy. I found documents at observatories and the more I learned the more I realized this wasn’t something that was going to bore me anytime soon.

This all started on Christmas when my father bought me a 4” refractor on Amazon. At some point he picked up on me talking about doing this, I must have mentioned the research I was doing (Breaking 3 upper thoracic vertebrae and trying desperately for 13 months to find a doctor willing to do the risky surgery AND accept my insurgence was tough. This gave me plenty of bedtime!) .

The Amazon scope was tough to use as the stand was short, finder scope wasn’t helpful and the diagonal had metal shavings from manufacturing that were sitting on the lens.

I felt bad about it, but we talked and I decided to return the scope and throw in more cash to get a good one. Although I initially considered staying under $5K I went all in. (I did feel like a kid again when I opened his gift.)

As my parents are aging, mom has been through cancer, I’m the family member worried about them constantly. I wanted to do this with my father before it’s too late and to share the views with my mom.

Sending my dad the pics got him pretty excited. (I staged a photo with the CGX-L legs fully extended and scope above my 6’2 height.)

When I woke up the next day after buying it, I walked into the living room and said to myself, “dear lord, this should be an interesting journey”.

I am doing my best to not compare astronomy to motocross. It’s like losing an amazing girlfriend and then searching to find her replacement, it never works that way.

However, I am trying to replace the passion, enthusiasm and love I had for motocross with something that doesn’t continuously break my bones, lol. Since I’m a huge science nerd and have spent a lifetime taking things apart to see how they work, I think this will click with me. The thought that we can view nebula thousands of light years away is a mind blowing enlightenment feeling. I have a lot of work before I am producing such images, but I’m looking forward to that future.

#16 ryanha

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Posted 25 January 2021 - 05:17 PM

Thanks for sharing your story!  

 

I too use astrophotography partly as a way to connect with my dad.  He has been a photography enthusiast his whole life and it is fun connecting with him in this area. I have had hours-long zoom sessions with him, my mom, and my aunt talking them through all of the processes.  They understand about 10% of it but love to hear about it and ask questions along the way.

 

Another good project to start with is getting auto-focus to work using software like NINA, SGP, Voyager, or other.

- Here is an awesome NINA playlist tutorial (includes a video on auto focus): link.

 

Also during the day you could start to learn image processing tools like PixInsight (which has a free 30 day trial).

- Light Vortex has sample RAW images and tutorial (data download link)

- @cfosterstars has an excellent doc with his PI guide (pretty advanced content) (link)

 

Even if you get a refractor, the SCT is a keeper, yours is a very nice scope.  When the planets are back in view, that is the perfect scope.  Though keep in mind that planetary imaging is completely different (different capture software, different tracking, different focusing, different processing software, and different camera requirements). 

 

Couple notes on what you said above

- Having a permanent ( or semi-permanent ) setup is game-changing.  I have my scope setup under a telegizmo cover and I have a scope-mounted PC, so for me 'setup' is just taking the cover off and turning on the power and then going back inside to program in my sequence for the night. Not quite an observatory and I still bring the scope in when there will be bad weather, but fortunately for me in SoCal that is not frequent.

- At high focal length especially, you may want to keep the legs as low as possible to the ground (retracted all the way).  More stability, less vibrations (you would be amazed that you can "see" when someone is walking next to the scope in terms of guiding, etc.)

 

--Ryan


Edited by ryanha, 25 January 2021 - 05:17 PM.

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#17 ryanha

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Posted 25 January 2021 - 05:34 PM

And here is a thread talking about configuring NINA with the Celestron Focuser (link) if you want to try it out.

 

--Ryan



#18 jtbrower

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Posted 26 January 2021 - 08:28 PM

 

I too use astrophotography partly as a way to connect with my dad.  He has been a photography enthusiast his whole life and it is fun connecting with him in this area. I have had hours-long zoom sessions with him, my mom, and my aunt talking them through all of the processes.  They understand about 10% of it but love to hear about it and ask questions along the way.

I wish I could get my mother to use Zoom.  While I was moving to Dallas from Iowa about15 years ago, she was diagnosed with breast cancer.  Timing was not good, but she survived.  I bring this up because she was one of the rare occurrences of people who lose their hearing to chemo.  She became legally deaf and had a cochlear implant inserted.  It tough for her to talk on the phone so I have not spoken to her on one in 15 years.  I always felt Zoom would be perfect, but I tried to setup a conferencing system for the parents about 10 years ago and she wasn't enthused.

 

For Christmas I bought my father an iPhone so we could facetime and I could drag them in slowly to something like zoom :)  So I like that you are able to do that.

 

@ryanha I had my first night of astronomy and that **** Celestron Auto-defocuser had to come off.  Even though I installed it over the top of the stock plate and inspected it to determine it couldn't be improved further, it bound up last night.  I think it must have been around 1AM I realized it had to be removed.  Upon removal determined that it over turned the focuser knob in the clockwise direction so that the motor felt it was at the end stop when it attempted to run counterclockwise.  With as much as I invested, I am definitely taking some of your earlier advice by obtaining a crayford style focuser then locking the primary mirror with the two lock knobs this scope comes with.

 

Its unfortunate, because IMO turning a knob with a stepper motor doesn't require extraordinary mechanical engineering skills.  This seems a basic problem.

 

 

- Having a permanent ( or semi-permanent ) setup is game-changing.  I have my scope setup under a telegizmo cover and I have a scope-mounted PC, so for me 'setup' is just taking the cover off and turning on the power and then going back inside to program in my sequence for the night. Not quite an observatory and I still bring the scope in when there will be bad weather, but fortunately for me in SoCal that is not frequent.

Last night I was already plotting in my head how I could do something similar.  I injured my back in 2019, had surgery Oct 2020 and I still have not wrapped my brain around my new limitations.  My mind still thinks its capable of what it did the last 47 years.  So I really have to find a more permanent solution, once I feel assured that this passion will stay and or continue to grow.

 

@ryanha thank you for the great tips.  I think I am going to go and create a new thread making a fool of myself sharing my first night / first light experience.



#19 ryanha

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Posted 26 January 2021 - 08:47 PM

Happy to give tips!  I get really involved in hobbies (like semi all consuming) and love talking about it so I am never at a loss for words you could say.

 

Sorry your first night was frustrating.  It will get better for sure.  Sometimes I find just doing something easy helps reduce the frustration.  Like manually focusing and at least getting some shots of the moon or something :)

 

I am looking forward to your post about your first night experience!  

 

Upon removal determined that it over turned the focuser knob in the clockwise direction so that the motor felt it was at the end stop when it attempted to run counterclockwise.  With as much as I invested, I am definitely taking some of your earlier advice by obtaining a crayford style focuser then locking the primary mirror with the two lock knobs this scope comes with.

One quick question on this.  Did you run the calibration routine on the focuser?

 

Either way, I think you will be happy with an external focuser.

 

I would suggest looking for one that will accommodate a focal reducer and give you enough back focus distance for an OAG when you eventually add guiding to your rig.  I know that moonlite has one where you can optionally insert the focal reducer inside the focuser itself (link).  I have not used that one but I am told that it drips with quality.  It certainly looks well made, but it is always worth asking around for people that have used it and get their specific experiences. 

 

--Ryan



#20 jtbrower

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Posted 26 January 2021 - 11:42 PM

 

Sorry your first night was frustrating

I should clarify what I originally said about making a fool of myself.  I definitely was not frustrated.  I do not get frustrated very often with anything I do EXCEPT when searching for products on Amazon lol.gif .  The plethora of choices along with a now rigged review system drives me insanely frustrated.  I can't begin to think of the number of hours I spent searching for a de-humidifier.  LOL  (I guess I have also been frustrated with this back injury, a long, never-ending nightmare.)

 

I can become so deeply focused on problem solving that I won't eat, won't go to the bathroom and have a tough time walking away when its late and I should be in bed.  If this backyard astronomy / astrophotography journey frustrates me, it will be outside my normal personality and I will know I picked the wrong hobby.

 

Now, just because I am not frustrated, doesn't mean that some good humor couldn't be had when experienced folks watch a newbie trying to figure out an advanced system when they told them to buy something much easier to use, lol.

 

What the heck, I may as well create that post here and share the outcome.  At least I know I have a kind audience here.

 

Night #1

Here in North Texas, we have had so many days of clear skied sunshine that while my parents where in-town for a few months, my mom kept commenting on the perfect weather.  THEN I bought a telescope.  Now I  know it seems to be a running joke that when you buy a new scope it does nothing but rains, but that joke became a reality here.  Rained something like 7 days straight and when that happens, it takes about 3 days in the winter to dry my backyard up.  

 

So, when yesterday/night was clear skies I was going to make it work.  The position in my yard that had the least obstructions from houses was the wettest spot possible.  However, the CGX-L tripod sitting on some flat bricks put down for each leg turned out to be solid.  It remained level through the night.

 

The first thing I had to figure out was the screw thread pitch and size needed to mount the finder scope that my OTA came with since the QA person that inspected my shipment must have had a bad day.  I wanted to avoid going to the store so I sat down with a huge box of odds and ends screws until I spotted what I needed.  They worked perfectly, but by the time I solved that puzzle it was 9PM.

 

I ended up forcing myself to quit at 3AM because I had to be up for obligations in about hours.  For 6 hours I went to town in my Carhartt's fighting the cold weather.

 

There were perfectly clear skies and a bright moon out.  Some might turn to the moon right away, but I didn't do that until around 2AM.  I am willing to bet that I spent about 3 hours learning how to polar align.  My most challenging problem was light pollution.  Not only are there porch lights everywhere, but car headlights in the distant as they head past my fence up the road.  It was really tough to identify if I was looking at the north star or not.  The problem is that some of the stars in common constellations were easy to see, but enough of them to faint to know if I was looking at Ursa Minor or not.

 

I was standing there wishing that I had some light pollution filtered prescription eye glasses!  I think part of the issue is the fact that my night vision has gone to hell over the last 5 years.  

 

I would align on that star and then tell it to goto the moon.  Can't mistake the moon for something else.  It would make it close to the moon but not nearly close enough.  Eventually I nailed it.  As simple as this might be for others, I really had a sense of accomplishment and excitement that it was going to wear I told it.

 

Next I am looking at stars and I ended up googling what I saw (insert laughter here).  Perfect white circle with another perfect round black circle in the center.  I of course found that this was the secondary mirror obstruction and that it was merely out of focus.

 

It was out of focus because the celestron auto-defocussing product is a pile of junk.  Which leads me to.....

 

One quick question on this.  Did you run the calibration routine on the focuser?

Indeed, I did and this is partly what made it even worse.  So I had it fully calibrated and working good the day before.  Then I try to use it last night and its not going to where I want it to.  It stops prematurely before the target step number.  Try it a couple more times and then it heads to it.  It also liked to be off by one several times.  Tell it to head to 2000 and stops at 1999.  So I decided to run the calibration routine again.  This made it much worse.  Now its only stepping about 1000 or so increments.  That's when I pulled it off the mount and removed it to find it turned in too far and was still able to back out slightly until the torque required to overcome the tension was not enough.  

 

From the start of this OP, it is clear that this thing is not going to be acceptable for my needs.  I am now definitely going to move into a crayford style focuser.

 

Once I was able to use my hand to focus the scope, I was able to achieve near pinpoint stars.  Since it was cold, I was standing in a swamp and my hands were locking up, I decided to save collimation for another day and then try out some of my three eyepieces, filters and etc.

 

I looked at the moon with a moon filter on and it still temporarily and partially blinded my eye.  I expected that filter to make it safe enough to view but I learned that lesson the hard way.

 

Outside of the moon, I am slewing around the sky just looking at near pinpoint stars and knowing I still had to tear everything down, finally making it to bed at 4AM.  Needless to say, I just wrote this potentially overdetailed post on 4 hours of sleep.

 

Luckily it is cloudy again tonight.  Lucky because my back needs some rest and I have plenty to learn and buy before my next session.

 

I am considering something like the Celestron StarSense auto-align.  With my poor night vision eyesight and Bortle 5 skies I think it would help me tremendously.  It doesn't have to be the StarSense though, could be another product.

 

So I have been spending tonight researching all the pieces I plan or will buy so that I don't end up making purchase mistakes where something is not compatible with something else, or ends up duplicating the job of another piece already in the puzzle like a laptop.

 

I know I want an electronic filter wheel and an OAG so I was reading through the ASI catalog and came across setups like the one below, but with the 2600MC Pro Camera I already have.

 

Well that's about the extent of the night, now I just want to make sure I can fully control this rig remotely so I can eventually leave this in a personal observatory and power it from my laptop.  That thought then led me to looking at the ASIAIR PRO.  I downloaded all of their PDFs and reading up on them now.  Have a good night.

6200-55mm-backfocus-solution-5-2.jpg



#21 ryanha

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Posted 27 January 2021 - 10:58 AM

Well that is progress at least!  Eventually you will be able to just set your tripod and mount up and be pointing within 1-deg of polar alignment just based on feel.  But it does take a bit at the beginning to know where you are pointing!

 

I love hearing these stories, so please keep them coming!  

 

I am going to give you my opinion on some of the things you mentioned:

 

- Light pollution:  If you eventually go the route of a monochrome camera and narrowband filters, light pollution becomes not really a problem.  Some of the higher end filters have 99% reflectivity of non-signal light so for example when my kids turn on the back porch lights I literally don't even see any impact on my subs. Good reading material: Narrowband FAQ, Narrowband presentation. Monochrome and NB filters will be "hard mode" and others can talk to benefits of light pollution filters + one shot color cameras (OSC).  I think some people also use NB filters with OSC cameras, so maybe post a question specifically about that and some ppl can give you their thoughts.

 

- Celestron Focuser:  I am kind of torn on this one tbh.  In some ways I find astrophotograhy to be largely about solving hardware/software/life riddles.  So in some ways I feel like maybe it is worth trying to get it to work and figuring out specifically what is wrong, even if your plan is to replace it.  On the other hand I do hate wasting time and it for sure it not a great design.

 

- StarSense: I would not bother with this. If you are going to end up doing automated astrophotography you will be using a technique called "plate solving" to find stars. Essentially the PC takes a picture of the starfield and does image analysis and uses it as a fingerprint to determine where the scope is pointing, then the PC issues commands to the mount to correct any minor adjustments as needed. For most mounts the PC will also send sync commands so it essentially uses your PC in place of the StarSense. Link to a great video on this: link.

 

- OAG:  I personally would recommend the Celestron OAG.  It is a really nicely built piece of gear (heavy duty).  It also has a large prism and has a mechanism to allow easy rotation of the whole imaging train and it has a helical focuser built in.  Note that to take advantage of the big prism you would also need a guide camera with a larger sensor like the ASI174mm. The nice thing about the bigger prism is you likely will never need to worry about finding guide stars.  The only down side is for tight setups where back-focus is a challenge (not the case for your scope). But even in those cases most of the time it can be worked around with the worst case of needing a custom connector part. Actually the other down side is the cost. The other option is the ZWO OAG.  Some people use these and have no problems with guide stars, others complain about it so do your research if you want to be sure you pick the right one for you.  I had a ZWO OAG but I sold it.  It is not a bad piece of gear, I just preferred the Celestron and was able to work through the back-focus issue on my refractor.

 

- ASIAIR vs. Mounted mini PC: I don't have experience with the ASI but what I did was got a nice i7 NUC (16G + 1TB SSD) and mounted it on my scope (link).  So I just remote into my NUC to set up sequences.  Another nice thing about this being a general purpose PC is that sometimes I will offload image processing on it (mostly calibration).  Some of the image calibration steps can take several minutes to complete (think of it like a compiler) so it is really nice to be able to run PI on the scope PC as well as on my main imaging PC so I am not sitting around waiting for the process to complete.  However, I hear the ASI is very easy to use and is a nice product, so for sure do your research.  Also the used market is pretty good for gear so there is no harm buying it and if you end up changing your mind you can probably get 85% of what you paid for it.

 

My suggestion to you for a next step would be to learn auto-focus and learn plate solving. A bonus is that you could do both of these with the existing gear that you have:

 

- AF Videos:  Auto focus Video, Setting up Focuser, Celestron Focuser Settings

- Plate Solve Video: Plate solving and auto-center

 

 

--Ryan


Edited by ryanha, 27 January 2021 - 11:59 AM.



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