Andrew_B

An A6000 should do a fine job and avoid any star eater problems provided you stick to exposures of no more than 30 seconds and avoid using the bulb setting entirely. It's older than 5 years, but those 24MP Sony sensors are very good and can still hold hold their own, and I suspect my X-A3 (released in 2017) may use the same or a slightly upgraded version of that sensor. As for clip filters, they are very useful but I'm not sure if anyone makes them for the APS-C Sony cameras or whether they're limited to being made for the full-frame ones. It's a nuisance to have the lens and be restricted to which camera you can use, but if you got your as-new 14mm lens for just £160 then that's a terrific price and I would have thought you could easily sell it on and make a few quid if you wanted options other than Sony. The best out of the box cameras are probably the lower end Fujis due to their greater red sensitivity and lack of annoying 'features' like noise reduction that can't be turned off. Pretty much any make will work a lot better once it's modded, although I'd advise looking for a camera that has already been converted rather than buying something and paying for a conversion. I paid just £180 for my modded camera which is less than the cost of the modding services I'd seen and only a little more than I'd have to pay for a secondhand un-modded model. Mirrorless cameras are great due to their small size and the short distance from mount to sensor which allows a lot more flexibility when using adapters and lenses from other systems - I've got a screw-mount Leitz 5cm Elmar that I use which wouldn't work on an SLR. It also gives greater room for adjustment when setting back focus on telescopes if you're trying to fit in filter changers and the like. The best supported cameras though are still Nikon and Canon which makes them the only choice if you want to use them tethered to a computer for remote control.

I looked at getting a Sony mirrorless camera (NEX-5N) when I decided to try and get back into astrophotography and in stock form their red sensitivity isn't as good as you might want, especially in comparison to your 600Da. I ended up getting a secondhand Fuji X-A3 which even in stock form has reasonably good deep red sensitivity that's good enough to get nice bright images of nebulae and is even usable with narrowband filters. The Fuji was also easier to use with a cheap wired intervalometer, and while the Sony can be modified to do the same, it apparently involves some soldering. I then managed to break the X-A3 and replaced it with an X-T100 which has the same (or very similar) 24MP sensor that may be the same as the one in the A6000, and which has similarly good out of the box red sensitivity as well as a few extra features that made it better for normal photography. I was considering repairing the X-A3 and doing an astro conversion when I found a secondhand X-A3 that had already been full spectrum converted that cost no more than I would have spent on parts to repair and convert my existing camera. The conversion that had been done was to remove the hot mirror covering the sensor and replace it with a fused quartz window which has a very wide bandpass from UV through to well into infrared (something like 200-2000nm). It works brilliantly and I've been blown away by how much it records with an H-alpha filter even with integrations of only 60-90 minutes The Sony looks good but I've read that it is one of a number of Sony models affected by the 'Star Eater' bug where overly aggressive noise reduction that can't be switch off ends up removing fainter stars because it thinks they're noise or hot pixels. This problem kicks in when bulb mode is used and is obviously a problem for astro although 30s and shorter exposures aren't affected. Apparently the NEX-3 / NEX-3N and NEX-5 / NEX-5N models don't have this problem so they could be worth a look. Hope this info is useful and hasn't come too late!