Clarkey

I think the RC6 is your best option out of those listed. This will give you 0.7" / px which you could bin2 to give a decent light grasp and pixel scale. I suspect for the 6" scope you might need a flattener too. The 8" you probably wouldn't need the flattener with the 294. Another option would be look for a 150PDS or something similar and crop out the surrounding skies. This gives you 1.27" / px which is also about right. You would need a coma corrector though.

I'm not sure about it being the same as the AA one - possibly the same internals, but externally different. Initially I had some problems, but it turned out to be down to a couple of things. Firstly, I think I suffered from some dew on the sensor glass, which I didn't realise at the time as it had never been an issue with the ASI1600. Once I made sure the internal dew heater was on (and I added the ZWO stick-on one for good measure) all was good. I also had a bit of problem with flats which I think is down to some slight sensor tilt. It's not bad, so I am just living with it. Also, I am not used to OSC processing - mono is much easier to get a good colour balance. The only real negative that I have found is that there is some dust inside the camera which I cannot remove without dismantling. It calibrates out OK with flats, but it is a bit annoying. Overall, I think the camera is very good for the money compared with the UK offerings. There is always the risk of something going wrong and then you have to deal with the minefield of import / export etc. However, as it was not far off half the price of the ZWO offering I felt it was worth the risk. I guess I was lucky as I paid no import duty or VAT so it was a flat rate price too.

I know, it's like Blackpool. Worst offender is the golf driving range. Apparently, golfers need the sky illuminated!

The wonders of global warming....☹️

Definitely. I have the Rising Cam version of the 2600 and use it at a number of FL's. Yes, there is a theoretical sweet spot, but there are a lot of other things that will impact the quality of your images long before the pixel scale starts to come into play.

Sorry but I can't help with the PHD2 / ASI Air interface, not something I have experience of. In PHD you can set a backlash value in milliseconds so you could try adjusting it to see if things improve. On my HEQ5, when I have got it as good as I can this is still around 800 milliseconds. Can you run PHD2 independently of the ASI Air to allow you to measure the backlash?

Oops - my mistake. You are quite right. Ignoring the guiding assistant bit, I think the declination backlash still looks like the culprit.

Looking at the trends PHD does seem to be doing what you are asking (10 pixels equating to about 25"). However, it seems to be struggling to return the declination back to normal. There is no declination backlash in the settings, so I am guessing this may be the problem. Do you run the guiding assistant? It usually recommends a declination backlash setting.

This has come out well given the low integration time. I imaged the same target a couple of years ago and although I managed to get about 7 hours on it, I still felt it would benefit from more time. Maybe I can add to my previous data at some point - see what come out of it.

I have a Rising Cam IMX571 which is the same sensor size as the 2600 and I get some vignetting with a non-reducing flattener. Given the reducer is giving you a smaller image, it is likely to be worse. Also, what size filters are you using? If they are 1.25" you are likely to get some vignetting. Is it so bad you cannot correct it with flats?

It's may not be so obvious now, but despite endless hours I really struggled to get rid of the star 'walking noise'. Even running all 87 frames thought star Xterminator then comet stacking, still left star trails. Eventually combining about everything I could think of and a bit of blind luck, I managed to get this. Now I just need to remove the 254 Gb of data PI has deposited on my SSD!!

Whatever the knack for comet imaging is, I don't have it! I have spent 3 days fighting to get something half-decent from my imaging session from the 12th. I'm still not happy with the background, but I decided to stop before I got over-stressed. Anyway, this was about 1.5 hours of OSC data . Imaged using a Rising Cam IMX571 and Altair 115mm Starwave. Process in PI, Affinity and APP.

Simple answer - yes. For visual use once it is collimated it should only need minor adjustments, usually the primary. For photography collimation tends to be more critical.

I recently purchased the combined Antila OAG and filter drawer. A bit costly but has a large prism and makes changing the filter doddle. The one major negative of an OAG is having to recalibrate the guiding when re-framing targets. In theory you could set up the framing in advance, but I have found this challenging. As soon as you rotate the field, the calibration needs repeating. I have bounced between OAG and guide scopes for a while and I think I am starting prefer guide scopes where possible. Even at 1600mm using the RC8, the st80 works very well for guiding. I do have everything very secure to avoid flex. I think at long FL, such as an SCT, OAG is really the only option. Fwiw, I see not real difference in guiding or star quality between the OAG and the guidescope. Seeing is way more influential on the results.

Another option I would suggest is to try Russell Croman's Star Xterminator tool. It is not perfect, but I have found it does a better job of dealing with 'haze' and small galaxies that SN removes.

I would certainly be interested in your results. I currently run 2 min subs, but the theory tells me I should be looking at much lower. I have thought about reducing further, but the amount of data it would produce per image would be pretty serious. A full night session is already about 10 Gb and takes a lot of number crunching. I think I'm going to need a bigger drive......

I'm not an expert in glass, but I think in a doublet you would certainly see the benefit of FPL53 over 51. At F6 you will still probably get a small amount of CA, but it should be minimal. I cannot comment of this specific scope as I have no experience. However, for a small wide field scope, it should be OK. I assume this would be for imaging?

Nothing special. A basic laptop with an SSD and USB 3 will be fine for deep sky or planetary. I use a very low powered mini PC for deep sky (with additional storage). For planetary, using faster download speeds I have a pentium gold with SSD. If you want it to run stacking and image processing, you will want something a bit better (the faster the PC the quicker the stacking / processing).

If you want ease of use, the general advice would be the Asiair. Simple out the box. I use a mini PC running windows on the scope. Equally, you could just use a laptop. There are plenty of other options too. Ultimately, it is personal choice - particularly if you don't want to be tied to Zwo products. Have a search on the forums, there is quite a bit on similar subjects.

I am no expert on mounts, other than the occasional strip down and re-build, but there is a clear periodic error cycle of around 2 minutes in the RA axis. To me this suggests a mechanical issue of some type in the mount. The worm period is around 400 seconds - so it is not that. I wonder if something internal is slightly bent, such as a motor shaft?

I must confess I have found NINA meridian flips pretty painless. I use the framing tool in NINA and I have quite tight tolerances set for the accuracy and it has always worked faultlessly. It is adjustable in the plate solving options.

I'll add my image to mix. Total of about 14 hours integration taken at the same time on two scopes and mounts. Part OSC on a 115mm triplet and part mono on a 90mm triplet. IC447 and IC2167, both quite dim and not ideal targets from bortle 6. All imaged on 25th January. Edited to have my 'triffid' the right way up!😄

I really feel for you. AP is hard enough without the issues you are having. I also feel very lucky - the week before you purchased your scope I brought a second hand 130mm triplet in the SGL classifieds. When I saw your scope come up I felt a bit of envy at missing out. With hindsight I missed a bullet. If it makes you feel marginally better, I sold the 130mm scope a few weeks later as my observatory was about 5cm too small. Unfortunately, I don't have any words of wisdom to help. Given how much you have paid out already, it is a real quandary. All I can say is I hope you get it sorted. Just out of interest, what did the seller have to say? They must have been aware of the issues with the scope.

I think I'll try deleting the config file in EQMOD. I'm still not sure why it is parking as it is - but I'll try deleting and reconfiguring. If that doesn't work, I will just create a new custom position.

I am hoping there is someone out there who can help me with an issue with my home position. Some time ago, I moved the home position (in ASCOM mount control) from the standard 'Park to Home position' to 'Park to defined position'. This worked fine and allow my mount to park safely below the level of my observatory roof. For various reasons, I now want to get the mounts to 'park to home' again. However, whatever I seem to try, the mount refuses to go back to the standard home position and I have no idea why. I have changed the command in the set up and tried re-synching the encoders - but the mounts (HEQ6 and AZEQ6) refuse to park to home. Normally the command is at the end of an imaging session, so the mount knows exactly where it is. Also, when I turn the mount on it is in the normal 'home' position. Does anyone know how I get the mounts to 'park to home' properly? I am out of ideas. Thanks in advance.