SteveNickolls

Hi, thanks for your posts. I can't speak for the SW HEQ5 but I have a thread on the iOptron GEM28 you might like to wade through, it's a 'warts and all' report- I've had my GEM28 since October2021 and have got on fine with it. I'd imagine it's a lot quieter in operation than the SW model and easier to move around. The set up I use overcomes the fact my imaging pad is set up at the bottom of the garden each night so I employ USB over Ethernet as documented above. I can thoroughly reccommend the Star Tech hubs, simply plug and play. I have recently added a Pegasus PowerBox Micro unit which is proving a cracking buy in distributing power to the mount, main camera, StarTech remote hub and dew heaters. I had no issues with either iCommander 7 or 8 and was able to use the mount with the hand controller, by USB cable and wirelessly but have moved on to USB over Ethernet as I mention. It was a labour of love originally sorting out the iOptron software (basically poorly described in the manual). I'm shortly going to add some data from PHD2 into the thread which I've been able to gather ovr the last week of clear skies. Basically I think I have a decent example of the GEM28. The two issues that spring to mind about the GEM28 were the scuffed tripod legs and the iPolar. I have since moved over to using SharpCap Pro's polar alignment so could have saved a few hundred pounds. My view of iOptron and software has steadily improved over time but their lack of an Android App to control the iPolar is verging on criminal but from what I've gleaned they can't create an App so it's waiting on an 'add on'. I decided to jump ship to the SharpCap Pro polar alignment tool. I hope this and the other comments to your query will help you on making a decision. I did note the price of the GEM28 had recently gone down at FLO. Cheers, Steve

https://binocularsky.com/binoc_object_file.php?object_id=Cr70&aperture=50

Almost he he.

Collinder 70. Cheers, Steve

Kinda similar. Cheers, Steve

I give a +1 to M40's use of USB over Ethernet. I employ a StarTech USB over Ethernet set up which has every thing controlled from a laptop in the living room via a USB cable to the inside StarTech unit which connects to a 25m length of Cat 6 Ethernet cable to near the rig. At the rig end there's a StarTech hub with x4 USB ports which link to the mount, main camera, guide camera and Pegasus Powerbox Micro unit. The 4x devices use USB cables to share the 480mbps USB 2.0 bandwidth of the system without hiccup. The Cat 6e Ethernet is rated at 1Gbps but drops to USB transfer rates. If you were doung planetary or lunar imaging or had a big main camera sensor this approach using lower bandwidths wouldn't work for you. My set up with a ASI533MM-Pro, ASI120MM-Mini guide camera, GEM28 mount utilising ASCOM/Stellarium and the Pegasus unit controlling power to mount, main camera and dew heaters works very well together. Hope you can get sorted with a solution that works for your set up. Cheers, Steve

Thanks for the heads up, will enjoy watching. Cheers, Steve

GEM Guiding (continued) The recent clear but cold nights in the UK have allowed more imaging to be done with the GEM28 and I have been able to check if altering the PHD2 algorithm to 'PEC' improved the RMS values. Previous session details- First guiding run 14.12.22- Second run same night- Changing to the PHD2 algorithm doesn't seem to have altered the heights of the errors so I will be reverting back to the 'Hysterisis' setting in PHD2. Cheers, Steve

Best to keep warm indoors and control everything from there using wi-fi or Ethernet. There's the setting up and take down and polar alignment of course requiring a presence outdoors but those jobs can be organised to complete as fast as you can. Last night was cold for here, around -4.6C but the mount and tripod were free of ice in the wee hours. 🥶🥶 Cheers, Steve

Hi, regarding USB cables. Control over distance is quite possible using USB. For years I successfully used active 20m USB cable to control imaging from indoors. Not all pc USB busses are the same though. Good luck. Cheers, Steve

Thanks Ratlet for this, I will watch the video with interest. 👍 I'm sure you will get a lot of use out of your set up. Cheers, Steve

All looking very good, well done. 👍 Often thought about a dual rig set up, and often thought how the side by side dovetail is then connected to the mount sadle? Can you enlighten? Cheers, Steve

GEM28 Guiding Examined I didn't know until watching a Cuiv recent video concerning PHD2 guiding that the periodicity of small errors in the manufacture of a mount's worm and cogs could be determined and improved through changing a setting in PHD2. Yesterday I took up the tip to use an option within PHD2 Log viewer to have the frequency of the errors from my GEM28 analysed, this is what I found. I find it fascinating that the workings of the mount can be viewed in this way and improvement applied. The worm in the GEM28 is 600 seconds duration and the analysis of my last auto-guiding sesion in November yeilded several components- The main values occur each cycle of the worm at times of- 6 seconds of 0.1" 21.35 seconds of 0.2" 99.9 seconds of 0.1" 112.6 seconds of 0.25" 150.4 seconds of 0.17" 161.3 seconds of 0.45" 198.8 seconds of 0.2" 601.3 seconds of 0.1" In future I will alter the guide setting in PHD2 from hysterisis to PEC which according to Cuiv will train the mount each session to anticipate periodic error rather than react to events, hopefully reducing both the levels of each error and a smoother guiding session. Will post the results of future guiding examination to perhaps help others with the GEM28. Cheers, Steve

Late November Update November here in the UK has been a pretty poor month for imaging and I’d like to think others using the GEM28 have had better conditions and more opportunities to actually get out imaging under clear skies. I was however able to image the North American Nebula and Pelican Nebula area on the very clear night of the 13th capturing around 3.5 hours before the targets dropped too far into the western sky. The equipment all worked fine. The image below is composed from stacked 180 second light frames plus master dark and flat frame stacked in DSS and processed using StarTools. Equipment GEM28 mount, ASI533MM-Pro and 12nm Astronomik Ha filter. The GEM28 performed well all night guiding without any problem and PHD2 reported the following data from the session. I do intend in the future to use the 'PEC' setting in PHD2 as advised by Cuiv in one of his videos. The result of the night's imaging- Since then I have added a Pegasus Pocket Power Box Micro unit to the imaging set up in an attempt to remove power cables and weight of power adapters from the tripod legs. The new unit powers the GEM28, main imaging camera, two dew heater straps and eventually will also power the StarTech remote hub which requires a 5V/2A input. I have been able to locate the Pegasus unit at the back end of the dovetail holding the imaging gear and the environmental senor which automatically regulates power to the dew straps is locate at the front of the dovetail. Velcro provides the means to hold everything in place. After setting up which outlets I wanted to provide power on start up and updating the firmware of the Pegasus Utility Platform everything is working fine. I remain wary until I have used the set up more of trusting the variable output port to provide 5V for the StarTech hub but so far in testing the Pegasus unit has properly booted up each time. Pegasus Astro have a very responsive Tech Support even advising me over updating firmware on a Sunday-very good service indeed that goes well beyond the norm. 👍 This photo shows the amount of cables, power adapters and dew heater controller wiring I have been able to remove by using the Pegasus unit on the GEM28. The Pegasus unit can be used in a stand alone mode or connected to a computer which provides immediate viewing of power outputs and graphs. For anyone else in a similar position requiring better power control over long distances the Pegasus unit is well worth considering. It is the 'baby' of their stable with other more able units providing both USB and power solutions. Cheers, Steve

Now, now, this type of attitude will mean no more ponies for the FLO children this Christmas. 🏇🏇🏇 Best wishes, Steve

Hi, your son will be making many large jumps all at once getting to terms with all the new equipment and it can be daunting as well as getting very expensive quite quickly. The good folks on SGL will be able to give advice on matters etc as he progresses. 👍 May I ask what the average sky is like where he will image from as if you have a very bright location the deep sky objects results could be poor for many targets with a OSC? Filters are avaialble to help reduce the effects of light pollution. One area I would stress brings ample reward for dedication is getting adept with a processing software that he finds he likes to use, there are many on the market some are free others at cost. Good luck, Steve

Yes let's hope its all sorted pretty quickly for you, even a swap with a new camera does not seem out of place. Cheers, Steve

Hi Ratlet, thanks for your reply. Sorry to learn you have had to return the 533C but you certainly need to have the glow sorted out. Ahh, I had suspected a better Bortle scale sky in your neck of the woods, enjoy the better conditions. 👍 Cheers, Steve

Interesting space based energy weapon with other uses. Cheers, Steve

Year Review-GEM28 It hardly seems possible but the end of October has come around meaning a whole year has passed since I took delivery of my iOptron GEM28mount-where does the time go in this hobby? The past year has provided just 22 occasions when DSO imaging was possible for me, not nearly as many as I would have liked but that’s what circumstances and the great British weather have allowed. I do however feel able to write a review of the mount its abilities and foibles. While a lot of research went into choosing the GEM28 (it is likely the last mount I will own) its purchase was an instinctive one. I had been keeping a watching brief on stock levels at FLO and steadily saving up the ££’s required so that when a delivery became available in late October 2021 I immediately hit the buy button for the bundle comprising mount, 1.75” Lite-Roc tripod, iPolar and storage box. The price was then £1,282.95 (it's now risen to £1,620 an increase of 26%). My first unboxing reactions were of a well built, small, solid mount literally only physically marred as I have previously mentioned by the condition of two tripod legs showing cosmetic scuffing. I have found the RA and DEC axes were very smooth in motion meaning no more ‘East heavy’ loading needed from now on as with my previous CG-5 mount. The mount has proven really quiet in operation, no more coffee grinder moments capable of waking up neighbours at night. The mount arived with a glossy set up short manual but I downloaded the comprehensive manual for the mount from the iOptron website. The biggest advance that the mount has brought to the table was providing up to date technology being ASCOM compliant and ideal for control on a Windows computer. The mount and tripod provide a relatively lightweight set up and with my wide field gear the whole package can be carried out to the imaging location as one unit saving greatly on the setting up/taking down time spent each session. Being overall lightweight the imaging equipment can be left attached to the mount between nights including many cables. Over the year the mount has proven a sound, robust vehicle to use with SharpCap Pro (Imaging)/ASTAP (plate solving)/PHD2 (Guiding)/Stellarium (Slewing/Go-To). iCommander v7 (Slewing/Go-To and ‘Zero Position’). I have found the mount can be controlled fine using a variety of options- · Go2Nova hand controller. · USB to hand controller and pc. · Wi-fi control from pc to the inbuilt iStarFi in the Go2Nova 8409 hand controller. Decent range but just not enough for my location. · And my current preferred method-USB over Ethernet for long distance control from the comfort of the living room. The main weakness of the mount really comes with the pre-installed iPolar, a problem that was unexpected having used another iPolar in the past on my CG-5 mount without issue. I consider the problem was down to a faulty iPolar unit and/or a USB cable that didn’t meet standard. To help users the iPolar manual should be rewritten with emphasis explaining the important steps in the process, and presently users are left to discover their own solutions. My final solution was to employ the polar alignment tool in SharpCap Pro instead. I must say that my supplier FLO were very prompt in replacing the faulty Polar/Cable and deserve another mention. As an aside I have found that the iPolar camera is detected by SharpCap Pro. However I have not (yet) tried using the camera for this purpose in SharpCap Pro. My initial thoughts are that the field of view of the iPolar camera is too wide for SharpCap Pro to properly use. Set Up. In the past year after polar alignment I have quickly gone from using a nightly set up involving using the hand controller and three star alignment to control involving USB over Ethernet and employing the plate solving ability (ASTAP) with SharpCap Pro to slew to a nightly imaging target, sync and commence imaging. This has greatly reduced the time getting ready to image and mount control and imaging can all be done from inside the house, a more pleasant and social arrangement not to mention being much warmer in the winter. I have found the Light Roc 1.75” tripod very stable in use and have sometime pondered whether the more lightweight carbon fibre tripod weighing just 2.29kg and costing £298 extra (the 1.75” Lite Roc tripod weighs in at 7.5kg) could be worth considering in the future to decrease overall weight by another 5kg. Polar alignment tip. One aspect of polar alignment requiring care is the re-tightening of the two hex bolts for adjusting polar alignment. I now initially start with the payload at 90 degrees and return the payload to the ‘Zero Position’ when completing polar alignment in SharpCap Pro. This way I know I have maintained the best polar alignment while carefully re-tightning the hex blts when back in the ‘Zero Position’ for the session. Cone error. I found that my iteration of the mount presented some cone error after using the iPolar method which could be reduced with the use of a thin shim (around 0.7 mm thick). However I now polar align using the main optics/camera which eliminates the need for a shim. Balancing. I have found exact balancing requires the patience of a saint and resolved this by adding a small weight (short M4 threaded rod and nuts) at the top of the payload offset to the left of the guide scope mounting. This small weight (13g) acting around 290mm from the centre of mount rotation offsets the tendency for the mount to move regardless of orientation. I understand that the internals of the mount along with other models is not exactly bilaterally balanced. iOptron sell ‘z’-co-ordinate balance weights for other models. Firmware upgrade successful. I updated the firmware on the hand controller successfully following the iOptron guidance. Something I would never dare try on my older CG-5 mount. Software. Advice on what planetarium software will/won’t work with the mount would have been appreciated when first setting up I was however able to get Stellarium working straight way. I have found iCommander 7 and Stellarium interchangeable for slewing and robust and at some future time will migrate over to iCommander 8, probably when we get a new main pc. I am intending getting a GPS module basically to save having to manually check and adjust local time with the hand controller, bit of a luxury really. Would I repurchase the GEM28 again? Yes indeed. Knowing what I do now I would forgo the iPolar unit and save some money. The mount has brought so much capability to imaging (ASCOM compatibility) to help with the hobby. I hope this review helps others when deciding over the GEM28. I hope if you do plump for the mount that you enjoy what it brings to the hobby. Cheers, Steve

Thanks very much for this I will enjoy reading the thread. 👍 Don't know if you have watched any of these astro-videos, the author has made a number of videos on the subject of filters and fast optics which I found most useful with my set up on the GEM28. https://www.youtube.com/c/BrentMantooth Cheers, Steve

Hi, and thanks for the +1 Elp I do appreciate it. I hope your results with your C6 turn out well, incidentally can the C6 use a Fastar? The Sadr region is a rich area to choose to image and good for making mosaics if that's what you like doing. I've just processed the RAW data from last night and stacked in DSS and processed using StarTools. Good luck with your processing. Cheers, Steve

Hi folks, last night we had a clear night for imaging so thought I would report how the GEM28 performed etc. Polar alignment using SCPro's polar alignment tool went fine and I had these logs out of PHD2 concerning the calibration and subsequent guiding. The values will be of interest to others with similar set up's. Equipment on GEM28 were Samyang 135mm lens at f/2 with ASI533MM-Pro astro-camera with Astronomik 12nm Ha filter. Guide scope ZWO mini guider and ASI120MM-Mini camera. I was able to take 140x ninety second exposures using SCPro's Live Stacking and this is a 'rush' from the session showing the area around Sadr in Cygnus- Samyang 135 mm lens at f/2, ASI533MM-Pro camera with 12nm Astronomik Ha filter. 140 x ninety second exposures plus master dark and flat frame stacked in DSS and processed in StarTools. Cheers, Steve

Hi Ratlet, I'm now on the main pc where it's better to type replies than the tablet. 😁 My iPolar routine mirrors your own though I was getting to question whether the camera centre value ought to be removed each session to let iPolar populate it's new value. Do you find you need to rotate the payload to position 2 or that the iPolar software instantaneously it seems does a second plate solve (in what is position 1)? I have tried covering the iPolar before moving to position 2 then taking off the dust cap to let the software do a second plate solve in position 2. I have to place my mount outside each seesion but have marks on the imaging pad which give a close positioning to the NCP. When I used Sharpcap Pros polar alignment tool a few nights ago this showed initially the gear to be pointing around 5 arc minutes off the NCP so the original alignment just using the marks on the concrete were doing their job. I would be pleased to hear how the iPolar compares in operation to using NINA. I'm pleased to hear you have found iCommnder v8 an improvement for you. I still use v7 as I can be lazy and if everythnig is working ok in v7... In the future when I get a new main pc for the house I will migrate over to the latest version. In v7 I always use the same USB port on my laptop to control all USB peripherals using the StarTech USB over Ethernet device to avoid any issue with phantom USB ports. As mentioned before it's really good news that the GEM's 12V output port will power your 533C. Just need to buy a cable now to duplicate this. 👍 I've found that one needs to take care when securing the GEM28's RA and DEC clutches in place as you can easily slightly miss the 'right' positions and so the mount is not properly in its normal Zero Position. You more have to feel the connection is correct than any visual clue, especially in the dark. My next step is to use my tablet to control the SharpCap Pro polar alignment process and leave the laptop connected up indoors to later control the mount and imaging. A friend introduced me to some software called 'spacedesk' https://www.spacedesk.net/ which permits the tablet to be used as a pc monitor. I'm going to set up an external wi-fi extender so I can get network coverage from the imaging location. Ultimately it will mean I wont have to replace the laptop in the future and shift control to a new more powerful main pc. I find the USB over Ethernet solution very convenient in the colder months being able to control the mount and camera from the living room, a bit more social than standing freezing outdoors or alone in the kitchen. Hope you get some clear, dark skies. Cheers, Steve

Thanks for this report on your new camera. Didn't expect you would find the glow at the bottom left, is this usual? Your images are lovely, can I ask what conditions you image under (SQM value or Bortle value)? Pleased the camera is working well with your software. Best wishes for the future. Steve