Clarkey

I don't disagree with any of the comments - I was just looking at options, but to a price. Given the OP original budget and FL requirement it would still be an option in my opinion. With a flattener reducer it would also give quite a fast system for AP. Personally I would go with the RC6 with a suitable flattener/reducer and bin the camera. This would remove the false colour and give a fast system at a good sampling rate. Good value too.

There will undoubtedly be some CA at F6, but nothing that could not be removed relatively easily in processing or with an L3 filter. However, looking at the specifications again the Starfield is probably a better bet. I do think there is a bit of an obsession with FPl-53 over FPL-51. A well made FPL-51 is likely to perform as well as 53

I have not used one, but I am guessing your EQ2 with a RA motor drive would be usable as a star tracker. You can use this to mount you camera as a starting point. Next stop I would suggest would be fleabay. There are expensive ED lenses which are ideal for AP, but to start with a standard widefield lens or two would get you started without having to empty your bank account. I just got a 100mm F2.8 prime lens for £30. This plus an intervalometer for the camera will get you started as a very simple set up. Yes, it will not give perfect images but you will be surprised what you can achieve. It will also allow you to try stacking and image processing before entering the financial black hole of AP. Trust me, it is addictive and expensive😁

The other thing to consider is the mount. For the longer FL you will need good tracking. What about the SM 110mm F6 doublet? Slightly more money but probably better suited to AP and a good price.

I think they are generally quite well collimated out of the box. I think many have been made worse by 'tinkering'. My method for collimation is to remove everything xcept the focuser and get the secondary perfectly aligned. I use a TSKOLLI or Reego, but you can use a simple Cheshire for that part. Once the secondary is right I use the DSI method for the primary using a star test. https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.deepskyinstruments.com/truerc/docs/DSI_Collimation_Procedure_Ver_1.0.pdf&ved=2ahUKEwi62bCmhJX5AhVMPcAKHcvBBws4ChAWegQIKBAB&usg=AOvVaw1TQ8YAhohC9_gr_IRXBo3x This works for mine but my focuser and primary mirror appear well aligned as I get no tilt issues. If this is not the case it is more tricky - but the DSI method should still work. My main advice would be adjust it SLOWLY and try to remember what you have done to put it back again. There is not a lot to say about the scope itself. I do have a home-made secondary dew heater, but I have never had a problem with the primary and dew. Cool down is pretty rapid too as it is an open tube. I have only used it with a ASI1600 which gave a good flat field. With a larger sensor you might need a flattener. I still need to try it with my IMX571 camera to determine if it is OK with and APS-C size sensor. I did change the focuser to a Baader ST. The original was OK in terms of tilt, but it did slip slightly with the autofocuser. I hope this helps. Here are a couple of images with the scope. Just remember I am far from an imaging expert!

Still a couple of weeks to go☹️

As an RC8 owner, I must say I am a fan. In terms of value for money I think they are excellent. As I am sure you have read, collimation can be a bit tricky initially - but once set it does not need much adjustment. I typically bin 2, but in all honesty, with my seeing bin 3 is probably more realistic. Also, although F8 it never 'feels' slow except when compared to my F4 scope.

I have used Cheap Astrophotography as have many others on the forums. Juan provides a good service and sells ready modified cameras.

FWIW I use a Mele Quieter 2 and I added extra nvme for data storage but left the operating system and programs on the existing emmc. Technically it may be better to put everything on a new drive, but I have had no issues running 2 x NINA with PHD2 on my dual rig. If it ain't broke.....

How about a 115mm triplet such as a TS photoline? There are a number of 'clones' too. Probably the limit for an HEQ5 but could be used at native FL or with a reducer.

It's astro gear. What do you expect?😆

I have 2 Baader ST's, one on my 6" f4 Newtonian and one on my RC8. I found them to be excellent for imaging. With regards to the scope collimation, the f4 is a right PITA to collimate. I share your pain. However it is much better with a good focuser - the original TS one was pretty awful. Maybe avoid the laser if you are struggling with it?

I used to use a 12v powered hub on my mount, chopping off the 240v plug and replacing it for a 12v. This was connected to an active cable. https://www.amazon.co.uk/RSHTECH-Powered-Extension-Charging-Individual-Red/dp/B07RS31T3Y/ref=sr_1_9?crid=1BHL2DWLICKVV&keywords=12v+usb+hub&qid=1658258974&sprefix=12v+use+hub%2Caps%2C147&sr=8-9 Most of the time it was OK but it did get temperamental with my ASI1600. Eventually I changed to a mini PC on the mount (Mele Quieter 2) which I should have done from the start. Works very well and no connection issues.

Looking at the image above suggests it is more than just distance from the sensor - possibly some tilt as well. The star shapes are certainly not consistent with purely a back-focus issue. If it is was purely distance all of the stars would be pointing away from centre or around the centre - but this is a mixture.

From my experience of the RC8 I found collimating the secondary worked well with the TS collimator (even though it is the world's most expensive LED light with a hole in). Following this I use a star test to get the primary aligned. Whether this is the 'right' way is another question but it works for me. I have tried some other methods including the laser version which completely ruined my relatively good collimation. Once right I think they are excellent imaging scopes.

I have used a similar system to Budgie1 above without a problem. (The asi1600 was temperamental with the hub but the cable was ok). You can get 12v powered hubs which make it easy to use a standard astro supply. I have now converted to a Mele Quieter 2 mini PC at the mount for convenience which is just easier for me.

I have not used the 2" version but the 7/8 position wheel I have has been absolutely fine. I am not aware of any specific issues with the larger wheel but I am guessing most of the control is pretty the same. I do multi filter imaging and flats without a problem.

I would suggest if you are struggling to balance the scope the axis are too stiff. I would recommend a strip down and regrease to loosen the whole thing. My HEQ5 was stiff (but not that bad) but is now very smooth and easier to balance. I would also add that if the axis is that stiff the guiding will undoubtedly be affected also.

You should be able to go into the handset and reset the NPE value to 0 in the settings menu.

I am happy to use a bahtinov mask if necessary, but statistical measurement is easier as I am always connected to a screen. I generally get the same result either way.

I'm glad I'm not the only one.....😂😂

A couple of things come to mind. Firstly, I assume the sensor distance from the camera front to the sensor is the same for the ASI and QHY? In theory the focus point with the same kit should be at the same place so the 20mm difference does not make sense. Secondly the star shapes seem to be getting worse as the distance increases (although I am looking on a small screen). Are you sure it does not need to be closer? Probably not much help, but it is all I can think of.

I struggle to track the moon so I am suitably impressed. That is truly excellent.

I agree that the dithering frequency needs to increase. Every 10 frames is only 6 times in the hour which will not be enough to 'staitstically' remove the noise. You could adjust the clipping algorithm but you will probably start loosing detail.

Keep her away from your scope🤣 Looking at the image I would say there are two things that will improve your guiding. Firstly a bigger and better mounted guidescope to ensure no flex. Secondly adjust the mount to get the RMS down.