SteveNickolls

Hi Elp, thanks for your feedback and for showing and describing your working arrangements. A picture paints a thousand words so they say. Nothing is going to happen fast here developing a dual-rig set up for use on the GEM28 but the potential to collect upwards of x2 the light in a session is a very strong motivator if money is no object. Cheers, Steve

Hi Elp, thanks for this practical advice regarding a dual rig set up. I had considered alignment of the two optics and there are a number of products on the market to allow adjustment of one of the pair. https://www.teleskop-express.de/shop/product_info.php/info/p9974_TS-Optics-Dual-Mount---parallel-mounting-with-fine-adjustment.html Price 285 Euros. You can get two of the adjustable units at more cost. Avalon X Guider (c300Euro’s). With both these you have the concern over balance. Presently I'm at most using 3 minute sub-exposures and dithering every 2+ frames. With such a dual-rig arrangement this would have to be decresed in frequency. Here is my updated write up, it is based on my particular control arrangements but there might be somethnig useful in it for you. I don't intend going down this line despite the attraction of almost doubling available imaging time. Cheers, Steve Project Tweedledum and Tweedledee.docx

I do like the idea of using two lenses on one mount to capture more data in the same time and have looked into the pro's and con's of it all. It would be very useful for making the most from our uncertain weather. Do you incorporate any dithering in the image capture sequence since one camera can be syncronised to the dither and will not lose sub-frames that way but the second camera will be affected? Anyway I hope you can obtain better balance in the future and so lengthen your sub-exposure times and remove spoilt frames. Cheers, Steve

Hi Elp, thanks for your message. These photos show the current payload on the GEM28, I recently added a Hyperpod unit to hold a ZWO EAF and a Williams Optics Vixen plate to give more space for fixing the Pegasus PowerBox Micro unit. Typically I stopped weighing individual parts last season since the payload capacity of the mount (12.7kg) was clearly well in excess of the intended use it would be put to but my best guess is the total payload is modest at around 4kg plus cables. I do now use the original 4.7 kg counterweight for balancing. As regards balancing I agree you have to work hard at it, I have found adding a spare Omegon Tri-finder (weighing around 210g) to the side opposite the EAF has helped balancing in the 'z' axis. It is my understanding that the internals of the mount head are not symmetrical and lead to imbalance in the 'z' axis'. In its design the mount can accommodate the iGuide accessory kit (weight 200g) on one side and think this is meant to help balancing on the 'z' axis without making the issue noticeable. I would suggest adding some mild additional mass on the side of the mount head where the iGuide accessory can be loated and see if this helps overall balance and performance. Your HEM with it's semi-harmonic gearing neatly side steps any RA issues with balance and is a nice feature. The Samyang has the virtue of having just 135mm of focal length and with the ASI533MM-Pro the resolution of the set up is 5.74" per pixel the longest sub-exposures I've needed to take have been 3 minutes but apart from cloud spoilt frames I do not expect to get bad frames. Sharpcap Pro controls dithering and have not had issues relating to settling down at all. If you do try to balance by adding a small mass to one side of the mount head I'd be interested hearing how you fare. Cheers, Steve

September 2023 Update I hope to continue posting data taken with my GEM28 set up to help inform prospective users and existing owners of the performance data obtained during imaging. This season I have had six occassions to image and these are the guiding values from PHD2 and which show consistency in the values obtained. iOptron states that the mount should have Peak values of <10"- PHD2 RMS, Peak and PAE Values from GEM28 Imaging Sessions Date RMS Peak PAE RA DEC RA DEC 7.8.2023 1.12” 0.78” -4.71” -5.71” 1.6’ 15.8.2023 0.87” 0.89” -6.40” 5.15” 1.0’ 20.8.2023 0.87” 0.74” -4.75” 4.81” 1.0’ 21.8.2023 0.77” 0.57” -4.05” 3.42” 0.5’ 4.9.2023 0.92” 0.62” 4.37” -6.04” 0.8’ 5.9.2023 0.99” 0.85” 4.77” -5.19” 1.0’ Cheers, Steve

I was able to image this week and try out the rearranged cabling hoping to use the USB hub on the ASI533MM Pro to connect the guide camera and ZWO EAF. The EAF worked well with control made using SharpCap Pro however SharpCap Pro was unable to see the guide camera with the cable arrangement so no dithering this time. PHD2 however saw the guide camera. During the imaging run until around 1.40 AM x56 frames with the OIII filter were taken so the GEM28 is proving itself for allowing a good widefield imaging set up with control at a considerable distance. I hope to add more OIII data as clear evenings allow. This is the first composite image I've made from 102 x ninety second Ha sub-frames and x56 two minute OIII sub-frames, both with master flats and darks stacked in DSS and processed in StarTools, Starnet++ and GIMP. Cheers, Steve

Another competitor enters the ring with a special trick up its sleeve- Cheers, Steve

Don"t fret. A while ago I contacted Pegasus Astro about them making a ring mounting systems for the Samyang to use together with their own EAF. It is something they hope to get around to in tbe future but have other priorities currently. If they can make mounting platforms to take diffferent makes of EAF they can have a share of the EAF/Samyang market, at the moment third parties make EAF platforms but just for ZWO EAF. Cheers, Steve

Great to see a new Pegasus product, as a company they are excellent in quality and attentive regarding queries. I'm waiting for them to release an iOptron EAF conversion kit for the Samyang lens. Cheers, Steve

Well last night we had clear skies over Nottingham so I was able to get outside and trial the ZWO EAF and whether the EAF and guide camera could share the USB 2.0 hub on the main camera (ASI533 MM-Pro) and connect to the StarTech USB over Ethernet hub. The good news is the EAF worked fine using the Hyperpod ring system controlled using Sharpcap Pro and I was able to have the EAF connected alongside the guide camera while imaging with the main camera. I had received two new shorter USB 2.0 cables in the post to connect up the EAF and guide camera to the main camera hub. This is now the control and power arrangements on the GEM 28 mount- Cheers, Steve

All we need now is for him to champion reducing light pollution, gave up on others in the media some time ago. Thanks for the heads up, will recod his show. 👍

I think better cables are always a good idea and trying not to make and break connections to save on wear and looseness of ports. Do let us know how any re-testing goes on. 👍 Cheers, Steve

Thanks Ratlet, I've done a test indoors with the EAF conected to the main camera and will see if additionally connecting the guide camera (ASI 120MM-mini) works under the stars. A friend has sucessfuky run his guide camera, a 224 through his ASI 533MC-PRO along a single USB cable and which has prompted me to just try. Cheers, Steve

The time of the year and the poor weather in the UK have both conspired to limit adding new posts on this thread, however in the background I have been steadily working towards imaging in the coming season using the GEM28 mount. GEM28 Update July 2023 This coming season I’m intending to use the GEM28 set up to principally obtain OIII data for several nebulae and add this to the Ha data obtained last season. In preparation a number of new items have been added to the imaging rig- An Astronomik Max FR OIII 12nm filter. The work of Brian Mantooth has demonstrated that the Samyang 135mm lens at f/2 is best served by a 12nm filter rather than a 6nm one. Reference- https://www.youtube.com/@BrentMantooth A Hyperpod ring system with ZWO EAF holder. I had intended buying an Astrodymium ring kit but recent shortages mean an alternative supplier had to be sourced. ZWO EAF. I would have preferred to use a Pegasus EAF but presently the company do not make an adapter to secure the EAF on the Samyang lens. William Optics 290mm Vixen dovetail plate. This provides more space to attach the Pegasus Power Box Micro unit in line with the main weighty items on the dovetail. To help balance in the ‘z’ axis I have added an Omegon tri-finder accessory. This has added to the overall mass of the set up, and I needed to replace a smaller 2kg counterbalance weight with the standard 4.5kg iOptron weight originally supplied with the mount. The imaging rig however remains portable if heavier. I am going to experiment using the USB 2.0 hub on the main ASI533MM-Pro camera to see if it will operate while taking the USB cables from the EAF and guide camera. Presently the guide scope is connected to the StarTech USB 2.0 hub directly by its own cable but the cable is long and could in this way be shortened to just 0.2m in length. The present arrangement is shown below. If the weather becomes kind and we get some clear nights soon I hope to be able to try out the new arrangements showing what the GEM28 can do and will report back on progress. Regards, Steve iOptron cable USB/RJ11 USB cable

Sorry to read your plea, still a problem shared is a problem halved, so they say. The light nights from June to early August make any night time astronomy difficult but you could try solar or imaging in the NIR during daytime. They do require the absence of clouds but a grab and go set up allows prety rapid set up to get the most from a clear spell. You could try meteor detecting using reflections from the Graves radar in France, that operates 24/7 except odd times when the system in under maintenance. Tbe truth is we get these periods unsuited to the hobby and sometimes they linger too long and patience is tested. Some turn to retail therapy, a hope that better kit brings better prospects. We must also remember our collective duty means new ponies for the children at Christmas in the many FLO households. It will however all come to pass and on that first clear, dark night all troubles will fade away as you gaze up to the night sky. "I stood and stared, the sky was lit, The sky was stars all over it, I stood, I knew not why, Without a wish, without a will, I stood upon that silent hill And stared into the sky until My eyes were blind with stars and still I stared into the sky." Cheers, Steve

That's excellent advice. I've highlighted the same advice in my set up list, just got to follow the list now! There's been a numer of updates to iCommander over the last several months that may help with using the GEM28, I like the "Bug fixes: Lots of minor bug fixes"- 2023-02-07 9.06 Bug fixes: iOptron Commander will fail to connect to iOptron devices when running under Windows 11 and "Terminal settings" has been chosen to "Windows Terminal". ASCOM driver for electric focuser now registered to the correct type. 2023-01-13 9.04 Bug fixes: In rare cases, iOptron Commander may failed to connect to mounts. 2022-12-23 9.03 Bug fixes: Sometimes the altitude and azimuth may refresh incorrectly. For some mount model, the hand controller model may display incorrectly. 2022-12-12 9.02 Major update! New features: Added support for a batch of new mount models (HEM, HAE, HAZ series). Now display distance of Solar System objects. Now attempt to connect to all available COM ports after program launched. Improvements: Performance optimizations. No console windows will be displayed when connecting. List of COM port will be refreshed when in "Port Settings". Local apparent sidereal time and star coordinates will be refreshed more frequently. Buttons will auto scale when moving window between screens with different DPI. Bug fixes: Lots of minor bug fixes. Cheers, Steve

Can I enquire the version of the GEM28 software in use when you had these slew issues? It's good however to know that restting the zero position worked regardless of the hand controller firmware version. Cheers, Steve

As regards the zero position every session after polar aligning I set the new zero position in iCommander. As I use the main camera and Samyang lens with a fov around 5 degrees this is ideal to use with SharpCap Pro and removes any cone error I was previously getting after polar aligning with the iPolar. Cheers, Steve

Hi Elp, sorry to learn of the problem you are having. Unfortunately I don't use an ASiair to control imaging but hopefully someone on SGL will be able to assist. I have heard of some ASiair users having odd problems with recent software. Yesterday I was getting my firmware and iOptron software updated to use this coming season and a couple of matters strike me. Have you replaced the button type battery in the hand controller as it discharges very quickly? You could say it was a 'feature' of the hand controller but best to call as it is-a bane. Before I replaced the battery I noticed date and time were incorrect and the offset for time zone completely wrong both on the hand controller and in iComander 9. There is a relatively recent firmware update too- CEM26/GEM28 Firmware Package including 8409 hand controller (v230305) which adds a new version for the hand controller and DEC. I've yet to try the updated mount outsdie due to the time of year. I will be very interested in what the solution to the problem you are having is. Cheers, Steve

Yes I've found thd software fine and now have removed PIPP, Astrostakkert and Registax from my pc. Cheers, Steve

Not so much as you'd think. Much more explanation here. Cheers, Steve

Thanks for posting I hope you are able to resolve the issue you are having. I've had the same unit for focusing my StarTravel 102 for a number of years now and while basic does the job fine. When you get the unit back working you might check this replacement controller unit and wi-fi unit to replacec the stock SW brand item. https://www.firstlightoptics.com/skywatcher-focusers/4tronix-focusrf-remote-control-for-dc-focus-motors.html It actually has an on/off switch and a better build, no more removing battery between uses. The wi-fi unit allows control over a greater distance if that brings more to the table. Hope you get the problem fixed. Regards, Steve

That is special, do you work in marketting? 👍

The most intriguing part is naming the product the 'SeeStar S50' so expect more models in the future with wider objectives and different focal lengths, maybe. Understand the device is currently limited to 10 second sub-exposures too which might relate to build quality? Years ago I was lucky to have a good example of the SkyWatcher Synscan Alt Az mount where 60 seconds was achievable before the mount mechanic limitations showed up. Seems a good device for travel. Cheets, Steve