Gina

I can certainly recommend Astrodon 3nm NB filters. Absolutely superb.

I could probably swap connectors at a pinch but I think a USB2 cable would be a lot less effort. The only way I might want USB3 in that camera would be if I went over to RPI4 and used it for planetary imaging.

Connection diagram.

Found the information on high speed (or superspeed) USB3 connectors on Wikipedia. Hadn't realised there were these extra connections. The RPi doesn't do superspeed USB3 - only USB2 which only uses 4 connections.

Got the ASI 120MC-S apart and managed to prise the PCB out. Changing the USB3 connector looks a bit tricky. Big soldering iron for the case prongs and little one for the 9 signal connections. I know what the 4 in a square do but not the 5 in a row. USB2 only uses 4 wires so I'm wondering whether to just connect a USB2 cable and take it out through a hole drilled in the casing.

Can't match other today but essential items none the less. Buck converters for running the RPi off my main 13.8v supply and a packet of M6 x 20mm screws to attach imaging rig parts to dovetail bar.

Yes indeed, I have read that. I think there are advantages of having two separate RPi control units, even if using one RPi for 2 imaging cameras, 2 focusers and a guide camera is possible. I think all that traffic could be a problem on just the one RPi. Having separate systems means you don't lose both if one goes down (as mentioned in the INDI forum). Finally, I think the extra complexity would be difficult to get working - a lot of work for a relatively small gain. In fact, my aim is a number of RPis controlled from indoors. Dual imaging rig (2 RPis), all sky camera (imaging and dew heater), roof control (open/close roof, show state, detect rain, check for faults) and finally a weather station with multiple sensors.

I'll take a look tomorrow.

I have been investigating connections as these are a common cause of intermittent faults. Compared the USB3 input port on the ASI16000 camera with that on the ASi120.

I thought of a possible problem with guiding. Thought it might stop while the main image was downloading but it seems that knro has fixed this by giving guiding image download priority. That's from KStars version 3.0.0. I have 3.3.1.

I don't know how it performs when it's darker as I've only been testing for an hour or so. Exposure does seem to be very critical.

I run Ekos on my Linux Mint tower indoors. I have been on the INDI forum and got info direct from the author. I want to use Ekos for autofocus and plate solving etc.

The ASI120MC-S seems to have an intermittent fault going from normal image to this :- The wavy line is on the ground/trees to sky interface. I also have an ASI 178MC camera which seems to work. Focus is very critical even stopped down.

Seems to be an intermittent problem with the ASI120MC-S that I'm using for guiding. It shows as changing between a normal image and this The rig is pointing southwards to a far hill with trees and the wiggly line is where the land/trees meet the sky.

Since Ekos can only handle one imaging system currently, separate instances of KStars/Ekos are needed to handle dual imaging. It does handle a separate camera for guiding. Each imaging camera will have it's own RPi for capture and focussing the lens. These will have different Computer Names for identification from KStars/Ekos. Each will have it's own Ethernet connection from an Ethernet switch on the pier. One RPi unit will just connect to camera and focuser whilst the other will also connect to the mount and guide camera. It isn't considered necessary to provide remote focussing for the guide system. My experience with dew heaters has shown that (at least in winter) I never run with the dew heater turned off so I see no need to have remote dew heater control. If I don't want dew heater control, it will simplify both hardware and software. The current WF rig does have this control but the second RPi and HAT can do without it. I can just ignore the dew heater control on the current RPi control unit and connect the dew heater directly to the 13.8v supply. In other words all three dew heater would be connected to the main supply via a fuse and maybe a toggle switch (or I could simply remove the fuse if dew heaters are not needed). The photos below show the RPi plus HAT (Hardware Attached on Top) which was originally designed for use with the Esprit 80ED Pro telescope but now used with the WF rig.

Since Ekos can only handle one imaging system currently, separate instances of KStars/Ekos are needed to handle dual imaging. It does handle a separate camera for guiding. Each imaging camera will have it's own RPi for capture and focussing the lens. These will have different Computer Names for identification from KStars/Ekos. Each will have it's own Ethernet connection from an Ethernet switch on the pier. One RPi unit will just connect to camera and focuser whilst the other will also connect to the mount and guide camera. It isn't considered necessary to provide remote focussing for the guide system. My experience with dew heaters has shown that (at least in winter) I never run with the dew heater turned off so I see no need to have remote dew heater control. If I don't want dew heater control, it will simplify both hardware and software. The current WF rig does have this control but the second RPi and HAT can do without it. I can just ignore the dew heater control on the current RPi control unit and connect the dew heater directly to the 13.8v supply. In other words all three dew heater would be connected to the main supply via a fuse and maybe a toggle switch (or I could simply remove the fuse if dew heaters are not needed). The photos below show the RPi plus HAT (Hardware Attached on Top) which was originally designed for use with the Esprit 80ED Pro telescope but now used with the WF rig.

200mm for guiding and various lenses for imaging up to 200mm. May try a pair of 55mm f1.8 for imaging again - got poor results before. Otherwise, 105mm f2.8 and 200mm f4.

So does the Esprit 80ED. Not all telescopes provide for rotation though. One good point about the Atik EFW2 was that it provided for rotation. Unfortunately, mine is dead! OAGs can provide limited rotation capability. I'm not aware of any commercial T2 rotator unit - I think someone should make one, I reckon it would sell like hot cakes!!

@wimvb - I don't plan to use the 55mm lens for guiding so won't have the information as to whether it would work. Could make up a test rig to see, if you or anyone else is interested. Seems to make sense to start with something more likely to work well though.

Ordered some "proper" M6 screws from ebay (GWR Fasteners - which I've used before) which should arrive Wednesday or Thursday. Meanwhile, if I'm ready with everything else, I have M5 bolts and nuts. I need to build another control unit plus casing and print focuser parts for other size lenses so still plenty to do yet.

The Baader Click Lock is good but why not use threaded connections throughout? More rigid.

Printer is playing up - need to sort it out! Ordered some M6 socket head screws which came today but the heads were oversize and won't fit into the dovetail!! GRRRR!!! 😡😡

A packet of 20 M6 socket head screws for screwing my imaging and guiding kit onto a dovetail bar. Unfortunately, the heads have turned out to be bigger than usual and don't fit in the dovetail bar!!! Drat and double drat!!! 😡

Another rethink on arrangement for dual imaging with guiding, resulting from a suggestion from Wim, for which I'm grateful. I now plan to use a 15" Losmandy-style dovetail bar at 90 degrees to normal with an imaging rig at each ends and guider in the middle. This photo shows the arrangement though with just one imaging rig ATM.

Brackets printed for the guider now printing the ones for the imaging rigs.