Telescope Mount - iOptron Gem28 - Unboxing / Initial Review

[@stevenickolls8016]

Hi, thanks so much for posting your unboxing and initial set up of the mount. The GEM28 is a light weight mount and easy to move around to set up. Will look forward to any other video you make using the mount. Good luck and clear, dark skies.

[@marksastrojourney]

Thanks for watching Steve! I'm finding it to be pretty easy to setup. It takes me about a 45 to 60 minutes to carry everything outside, put it together, balance it, polar align it, one or two star align it and align the guide scope. Clear skies!

[@tonynikon]

After watching this video I'm buying an iOptron GEM 28. I have no clue where to start. I got a Meade ETX125 PE that I bought second hand for $150!!! ...and an Orion 80 APO that will be on the mount featured on this video. Thanks for sharing!

[@marksastrojourney]

I’m glad you found the video helpful Tony. Clear skies!

[@Rasnark]

This video sold me after so much research

[@jbnitpou9942]

Hi Mark. Thank you for this video. I received my Gem28 iPolar with Gps module 3 days ago and I didn’t used the polar alignment cause cloudy sky ….. this mount seems to be not too much complicated at all. JB, a french follower. 👍

[@marksastrojourney]

Hi JB, I’m glad you enjoyed the video. I’ve gotten used to the polar align and it works just fine. The gps module is convenient allowing me to avoid looking that up on my phone and having to enter it into settings. I have the ioptron miniguider and have finally figured out how to get it to work well with phd2 guiding software. I may do a video on that soon. Clear skies!

[@jbnitpou9942]

@@marksastrojourney Hello Mark, thank tou for tour answer. I’m waiting for this YT vidéo impatientely. Have a great day. JB

[@marksastrojourney]

Hi JB, if you're referring to looking forward to the video on the iOptron iGuider, I hope to get that out soon. I've figured out a few key things that may be helpful to anyone else who has the guider. Clear skies!

[@Rasnark]

Excellent tutorial on alignment, thank you sir

[@marksastrojourney]

I’m glad you enjoyed it!

[@mvdeehan]

Very helpful thanks Mark. I got mine recently but am waiting on the tube holder for my telescope. TBH it looks like I have a problem in that the Vixen is too small for the Dovetail bar that just arrived today and will support my tube holder!

[@marksastrojourney]

I’m glad the video was helpful Martin! I hope you can get the dovetail bar worked out soon! I’d like to see a picture of your telescope and mount once you get it worked out. Clear skies!

[@martinwarm4041]

Easy to understand review..thanks subscribed!

[@marksastrojourney]

Glad to hear it was easy to follow. Clear skies!

[@jimcollins1922]

I very much appreciated your video. I am probably going to get a Cem26. Aside from payload weight do you know what is the difference between that and the gem28? I expect to control it with the Asiair as I am already familiar with its operation. I don’t expect to come anywhere near the 26 pound payload weight. Again thanks for a very clear and instructive video.

[@marksastrojourney]

Hi Jim and I'm glad you enjoyed the video. These are some of the key differences I see between the GEM28 and the CEM26. The CEM26 is a center-balance equatorial mount while the GEM28 is a German equatorial mount. The iOptron site gives this description of the benefits of their line of CEM mounts: www.ioptron.com/product-p/c261a1.htm "... The key to enable such ratios is the CEM design focuses the mount and payload weight directly on the center of the tripod rendering 'natural stability' ... The center-balanced design mount puts the weight of the payload at the center of gravity allowing for greater natural stability." This wikipedia page describes a German equatorial mount as follows: en.wikipedia.org/wiki/Equatorial_mount "In the German equatorial mount, (sometimes called a "GEM" for short) the primary structure is a T-shape, where the lower bar is the right ascension axis (lower diagonal axis in image), and the upper bar is the declination axis (upper diagonal axis in image). The mount was developed by Joseph von Fraunhofer for the Great Dorpat Refractor[5] that was finished in 1824. The telescope is placed on one end of the declination axis (top left in image), and a suitable counterweight on other end of it (bottom right). The right ascension axis has bearings below the T-joint, that is, it is not supported above the declination axis." The CEM26 and the GEM28 have the same mount weight of 10 lbs. The payload is slightly different CEM26 at 26 lbs. and the GEM28 at 28 lbs. Regarding the payload you plan to put on there: I'm not sure if you plan to do astrophotography or not. But in my case I'm doing that and have noticed the payload can quickly go up higher than you're thinking at first. For example, if you add a field flattener or reducer, a filter wheel, extension tubing for back focus, camera, the finder scope, a guide scope or other accessories. Also, for purely viewing (non-astrophography) purposes, some of the higher end eyepieces are also heavier than one would imagine. They come with an increased field of view and are well made, but heavier. I only have one that's like this, it's a Morpheus and it is much heavier than the eyepieces that came with my telescope. You probably already thought of these things, but thought it'd be good to mention if you hadn't. Clear skies!

[@marvinwhisman3333]

Are you happy with the GEM 28? Any issues with guiding? I just placed an order for one and am sort of having second thoughts. You still happy with your choice? Nice video. Thanks

[@marksastrojourney]

Hi Marvin. Thanks for watching the video! So far this is what I've observed about the guiding: You need to do the polar alignment first, which is pretty easy as you follow the on screen display to fine tune the alignment and then once you have it you tighten down the mount screws with an Allen wrench. Then you also need to do either the 1-star, 2-star or 3-star alignment to improve the go-to and guiding functionality. Some nights it seems to go really well and the go-to capability takes me right to the desired target. However, other nights it seems like it's off some and I struggle to find some deep sky objects as those have to be almost dead on. I haven't been able to find any option to set my local elevation/altitude (unsure if it affects it but it seems like it ought to). I see options to set the local temperature and the barometric pressure. I also bought the optional ioptron guide scope, which attaches to some pre-drilled screw holes on the side of the top part of the mount where the telescope rests. So far I haven't been able to get the ioptron guide scope to function properly. This is what I think is happening, but not 100% sure: it appears that the ioptron mount is still tracking itself and the ioptron guide scope (connected to the PHD guiding software) is also attempting to use pulse guiding - the two together seem to throw off the tracking rate; almost seems like 2 different entities attempting to do guiding simultaneously. I need to send an email to ioptron to try to get clarification as I feel I'm probably doing something wrong. BTW I am running the ASCOM Device Hub and have it connected to the GEM 28 mount (per the manual's instructions). Aside from this issue with the optional ioptron guide scope, the tracking of the mount itself seems to work very well. It's also good once you locate your desired target to center the target and then use the Synch to Target option. Compared to my first telescope (Celestron 127EQ Reflector) and its mount (horrible), it's very hard not to love this mount. The mount with the Celestron 127EQ is not stable, wobbly and totally manual. It has set screws to lock in the position, which after a few weeks no longer hold their position. I bought the small tracking motor for it and it is okay, but takes a lot of tweaking to get it to track a target at the correct rate. Also to collimate that telescope, you have to remove the Birds Jones corrective lens from the focusing tube. I hope some of that helps you! Clear skies!

[@amaar1646]

Thanks for the very thorough overview! Was just wondering how heavy was the gear that u were using when u were balancing the mount? I just order the gem28 and use a 80mm refractor telescope with a guide scope but I fear that the provided weight is too heavy for the gear I'm using

[@marksastrojourney]

Hi Amaar and thanks for watching! Regarding the weight, I'm using a 100mm refractor telescope. It's a Skywatcher Evostar 100ED APO. I also have the finder scope and guiding scope attached. The balance ends up being perfect for my setup with either the dielectric diagonal and an eyepiece installed or with my flattener, extension tubing for back focus and ZWO camera installed. With either of these setups, I find that the balancing weight needs to be almost to the end of the balancing weight bar. The one thing that pushed the limits on the included balancing weight being sufficient is when I tried to use my Morpheus 17.5mm 76 degree FOV eyepiece. Compared to normal eyepieces, it's pretty heavy. However, you can buy an optional additional counterweight if you feel your equipment would a little heavier than my 100mm telescope setup. I'd love to hear back from you regarding your GEM 28 and how thing go! Clear skies!

[@robertlennox681]

I just bought the GEM 28 and am in the process of trying to set it up, so I found this video to be very helpful. Did you install a battery in the hand controller? It looks like it powered up when you connected it but I wasn't sure if you had already installed the battery. My hand controller did not power up when I connected it and the mount was turned on, so I assume it needs the battery?

[@robertlennox681]

I think I already already answered my question on this by referring to the detailed manual. The battery in the controller is only required for the real time clock and to avoid having to re-set the time it each time you power it on. If you did install a battery I would be interested to know what size of phillips screwdriver you used to remove the back cover, as I am going to have to purchase one.

[@marksastrojourney]

Hi Robert, would love to hear how your GEM 28 works out for you! I did have to install a battery in the hand controller. I found the Phillips screws to not match up well with any screwdriver I owned - so be careful not to strip the screw heads - I just took my time with it to avoid that. Clear skies!

[@marksastrojourney]

I also noticed without the battery that all of the other settings you put into the hand controller are lost each time you power the mount off. This includes your longitude and latitude settings, etc., which if you're setting up you mount in the same general spot frequently is nice to be retained between powering off/on. I guess the battery is powering the temporary/flash memory in the hand controller. I will locate the screw driver I used to see if it has any size printed on it anywhere. If it does, I'll follow up with a reply on that.

[@Microtonal_Cats]

Thank you. How do you like it after a few months of use?

[@marksastrojourney]

Hi Michael, thanks for watching! I really like this mount and don’t have any regrets about the purchase.

[@markstump7079]

nice

[@marksastrojourney]

Thanks for watching Mark! Clear skies!