Concordia000

I think for a crop size sensor, neither scope will suffer from coma. Even my miscollimated RedCat performs decently when I cropped it down to APS-C size. I do love my RedCat and my gripes with it is more about it’s not performing “as good as it could be”. Part of that was down to some user error too; my collimation efforts were not the most gentle. Hopefully FLO can fix it. But I do wonder, from time to time, whether I would have been more happy with a FS-60CB with flattener-reducer or the FL55. I particularly love the looks of the FL55 and would love to own one. But given the price (2x as expensive when all accessories are included) I simply can’t say it’s a better choice than the RedCat. K-Astec has a comparison of the three scopes. FL55 is using the flattener reducer here: http://k-astec.cocolog-nifty.com/main/2018/11/post-3.html

The Heritage 130/150p seems to be a good choice. No electronics whatsoever, good optics and quite compact. Combine that with a good astro book and a free app would be a good start

I don’t own the FL55 but I’ve done some research. It seems the FL55 suffers from coma compared to the RedCat without a flattener. The FL55 is more flexible because you can use it for visual more easily, while the RedCat is a dedicated astrograph — almost. You can remove the tilt corrector to install the diagonal, but I can’t recommend this as it caused me a ton of troubles. FL55 also comes with a better focuser (imo) and can be used in two focal lengths. It is however much more expensive. The RedCat has better image quality out of the box and it’s not even close. It’s a Petzval design that has a very flat field and very well corrected for CA and coma. The downside is that it is very sensitive to tilt, and despite the marketing it doesn’t quite support a full frame chip: the edges can have deformed stars. Collimation is a nightmare, I’ve attempted but I am probably going to send my scope back to FLO for help. The helical focuser is very good during daytime but not as precise at night. On a side note, I own the RedCat + Lightrack combination myself. Your wedge is very important in this setup, since it affects your polar alignment. I don’t recommend using a ball head for the RedCat either: while it will work for <=2min exposures given very good PA, it will introduce a large moment on the mount and might cause it to turn if not sufficiently tightened. Even if your ball head is good enough, it will over-tighten your ball head and make a pain to take off.

M31 is a fun object to see though. It’s a fuzzy patch but a big one at that; it barely fit in my 90mm APO’s view at 20x. I recall seeing a little bit of spiral features but that might be my imagination. I live in London and it’s amazing how much more I was able to see by going to the countryside. I could easily find M31 with my naked eye while in London I struggle to find it with a scope. I was also able to count the stars in Pleiades without a scope. Given the compact package of the Heritage, OP might benefit a lot from taking the scope to darker sites rather than dropping money on even more accessories.

I don’t have the 150mm Dob but I have a Borg 90FL, which is a much smaller refractor, albeit one with excellent optics. I use the BST 5mm. At 100x it gave me some fantastic views of Jupiter. I even tried to use a cheap Barlow to push the power to 225x, but that is a bit too far for my small scope. The Heritage 150p should fare just fine with the 5mm. 150x should be well within the capabilities of your scope.

I am going to throw a wrench into the arena here: the AZ-GTi + wedge, the Rainbow Astro RST-135 and the Hobym Crux 140 Traveller. Those mounts are lightweight, compact, fully GOTO, and very versatile; they can be used in both Alt-az and EQ configurations. In fact, all of them have similar weight compared to each other when fullly equipped. AZ-GTi + wedge costs about as much as the SWSA. The AZ-GTi + wedge will probably cover most of your needs. It can handle a DSLR + wide angle lens easily, but it can also handle a small refractor, like a William Optics RedCat 51, a Takahashi FS-60CB or any other 60-80mm refractor if your setup is under 4kg. With autoguiding and counterweights you can do a fair amount of astrophotography. For travelling and wide field it will not be as easy to use as a SWSA because the lack of a polar scope and the need for external power banks, but it is a GOTO mount which makes pointing at stuff and automation that much easier. It can also be used as an Alt-az mount for visual observation. RST-135 and the Crux 140 cost 10 times as much, but they have similar concepts. Those mounts have ridiculous payload capacity (about 3 times as much for the Crux and about 5 times as much for RST) and can sling a C11 SCT (12kg by itself!!) around with counterweighting. Most people will never get big enough scopes to overgrow those two mounts, but then again, most people will not drop that much money on a telescope mount. You will eventually outgrow the AZ-GTi but it will remain a nice grab-to-go setup to accompany your heavier, stay at home setup. I wish I knew the AZ-GTi existed before I bought my Fornax Lightrack, which while an excellent startracker, isn't a substitute for a real mount. Even as I am preparing to buy the RST-135, there's still a part of me that wants to buy the AZ-GTi --- it would be a very good "outreach" mount along with my old C5, since both of them cost and weigh next to nothing.

I can dream... The fixed dew shield is a problem, actually. Unless I move to the suburbs permanently, I will need a scope with a short-ish tube to handle it up and down the stairs or up and down the lift. Unfortunately a Tak is currently not on my priority list, because I got fed up with my janky mount and decided to splurge for a good mount. After that my 90FL still needs many expensive components to be imaging-ready... Then I want a C8 or something for visual... Then cameras... It will be a while until I can think about a refractor upgrade, and when I do it, I might go for the other 4 inch Tak...

My rig is light enough --- no more than 12kg altogether. I have no problems bringing it on a train or a bus. The issue is Ruislip Lido is a bit far from where I live, about an hour by public transport one way. But not far/dark enough to justify staying a night. I much prefer somewhere I can go, stay in some accommodation for a night or two, and observe/image at my leisure, but it seems most of those places require a car to get there 😕

Central London

Thanks for the reply. It looks like they are going to have a star party this week but Kelling Heath is quite far...

Greetings, I live in London and unfortunately I need to travel away from London to get some decent dark skies. However, I can't drive, which makes it rather difficult to move around. Weather foils my plans quite often too. May I ask where you usually go for observation near London? Clear skies, Jerry

Man the FC-100DZ is a beautiful scope. Saw one at the local star party and immediately made me want to buy one. Sadly it's a bit too long and big for me and I ended up getting a used Borg 90FL... which made me wonder whether the FC-100DZ will still be a good buy in the future.