parallaxerr

Could be very tempting should one come along!

Haha, "a solution, must I find".

Some great conversation and input in this thread, thanks to everyone that has contributed! I was worried another this scope vs that scope thread would be a dud. The information about how the EQ5 (or Orion SVP in my case) handles the various OTA's is especially helpful. Strong arguments for all types of scope but also little to chose between them I think, at least from an optical performance point of view. I don't think I can make a "bad" choice here. It all comes down to the readies now really. I have found NEW barebones C8 OTA's for £1099 which is top of budget but would need to add a visual back, or more likely a focuser knowing myself. That's pushing the cost up to roughly twice that of a 150mak or more in the case of the CC. A 180 mak sits in the middle then at ~ £800-900, I do rather like the look of the Celestron version, though stock is nil. Should have bought one from David Hinds before they shut shop. Then there's the cheaper 150mak & 6" CC. Both very safe options with respect to how the mount will handle them. Now for a curveball question.....I have found few definitive (if there's such a thing in astronomy) answers to this, just some OLD posts on CN...... Recent MEADE vs SYNTA Maks (specifically the 150mm) - Any difference (Synta vs JOC maybe?)? And if so, any ranking with respect to quality and optics?

Thanks everyone for the responses, I have found them very insightful. @johninderbyyour experience with all three cassegrain types helps a lot. You have confirmed my suspicions that optically there's not really a bad choice but the CC wins on practicality. One question....spider vanes during planetary obs, any diffraction spikes? @Johnand @dweller25 I had discounted the ED120 based on my experiences with the 120 F8 achro, I found the objective mass at distance from the mount to be the primary cause of wobble woes, hence I bought an F5 120mm achro for DSO and am now considering the lighter objective of the 102mm for planetary. @nfotisand @Nik271nice info on the Maks there, thanks. It sounds like the EQ5 is capable but the 150 would be a better fit. All things considered, I really "fancy" the 150mak, but the 150 CC is making lots of sense. I'm not sure there's any point overloading the EQ5 with an 8" scope when conditions will often prevent it delivering the best views. There are a few 6"CC options now, I see Altair have added it to their inventory too along side FLO and TS etc. Maks are a little thinner on the ground, though Orion list them as due very soon. So a little time to ponder, but I think it's going to be a 6" Mak or CC.

I'm having another analysis paralysis scope dilemma! It really should be easier than this, especially considering the simple criteria..... A visual planetary only scope, under £1k, to sit on an EQ5 mount....easy right? So why am I fussing so much!?!? I narrowed it down to a 102mm F11 ED refractor or a 150 maksutov...at least I though so. The only dilemma here is that I prefer refractors, but worry the length of the frac will cause the wobbles - I hate vibrations when observing. The Mak is likely to be far better in this respect being physically shorter despite the additional focal length. Of course, I've also considered a 6" SCT and Classical Cassegrain....Then I start looking at the 8" versions thereof and either the weight or the price becomes an issue. Now a 180 Mak just scrapes in price wise, but may be at the mounts limit and reportedly is poor at reaching thermal equilibrium. I'm also reading that people are preferring the view through a CC to a Mak, though I'm not sure why that should be the case. Especially with the 6" versions, the CC's CO is quite significant. Then there's the fact that atmospheric conditions often dictate the quality of the view, which leans me back towards the frac which will likely perform excellently 99% of the time....darn it. I will say that in my own personal experience, aperture and thus resolution have proven to give me the best planetary views, which makes me reconsider the frac......and so the cycle starts again 🙄 So, you have an EQ5. Do you mount a relatively cheap, long but lightweight 4" frac on it, a mid-priced best compromise 6" Maksutov, or a more expensive and heavier 180Mak or 8" CC???

Good to see you back at it Jules. I have also had a bit of a sabbatical, but I am now gearing up for the darker nights too! 👍

Ramping up astro-operations again and I'm back with another ST(umpy)120, this time the Orion version. I've finally accepted there's no one scope for all, so this is to be my widefield/DSO scope and I plan to add something more planetary specific in time. Maybe an F11 ED frac or a 150 Mak. My previous ST120 always impressed me on DSO's very much a sweet spot with respect to reach vs size & weight. I already had the dual speed crayford and TS CNC tube rings from a previous scope so this made a nice little package with the addition of a Stellamira Losmandy dovetail bar. Realising (once again) the AZ4 was too limiting, I added an Orion SVP mount (EQ5) to the 2" CG5 tripod and ATLAS pillar along with an ADM dual saddle. I'm quite the Orion fan boy now it seems, but to be fair their stock availability has been good and prices now seem more aligned to, or even better than SW equivalents in some cases.

Very interesting indeed. As John says, combined with a decent barlow could be the answer to my planetary eyepiece quandary. Being a manual "alt/az'er" I was planning on the APM 100°EP's, but this could be far more versatile. Watching with interest.

Very nice indeed John, this was on my wishlist when I had the AZ100. Now that I am downsizing (again), I'll likely be going for it's smaller 100mm brother.

NUMBER 2!!!

OK on my Android

Liking the new theme. The bottom navigation bar is a great improvement 👍

New and much needed grab and go frac! Cloud cover and rain has been ridiculous recently with only small windows of opportunity, so this little fella should get some good use.

I've run out of things to sell. At this rate I'll have no scopes left, but I'll have the best mount ever!

Happy to report that tonight's first light with the Omni 120 (since collimating) was a great success! Much better snap to focus, scope took higher mag, sharper image.....allround better EVERYWHERE! Star test showed better results outside of focus where it was mushy before and X400 on a bright star showed a very nice airy disc. I tested out my new 27mm eyepiece on Andromeda and despite the bright sky due to the Moon rising, I could definitely make out more than previous attempts. Star of the show was Mars. The scope held X200 rock solid for over an hour before dew started to hamper proceedings but in that time I observed lots of surface albedo, the southern polar cap, despite being small and all with good colour. Super happy with the result of collimating the frac, it's really shown what it's capable of now.

A little update. Having sold my CG5 2" tripod some time ago, I'd lived to really regret the move. Searches for a replacement turned up nothing but I stumbled upon stock on David Hinds' website over the weekend, don't know why I didn't look their before. Anyway, order placed and shipment notification received today. I think a 10" is back on the cards.

Thanks John, I did some more calcs and realised the exit pupil was getting too large with the 10" F4, requiring shorter EP's. Great for mag but FoV was suffering. Not a problem if I wanted to invest in Ethoi and a paracorr, but that's not on the cards right now. The 8" really is looking like a solid option.

Yep, that is very much on my mind Paul, especially with the uneven nature of my garden, I don't really want to be standing on a box/steps! It's a bit more weight to the 8" argument.. A bit of evening research and I discovered the TS optics PHOTON line of newtonians, they look rather nice and have better focusers than the SW equivalents. The 8" is particularly well priced, but the 10" F4 also caught my eye as the shorter tube goes some way to combat the issues discussed above and provides a larger FoV. But, will an F4 be suitable? I'm aware it will require more precise collimation, but have some other questions: 1. Will I need a coma corrector @ F4 with 68° EP's? 2. Will the larger central obstruction really be noticeable, especially considering the faint fuzzies?

Yes, my garden! It's really not astro-friendly and is made up of tiers and what tiers there are aren't flat. The tripod allows me to get the AZ100 level but I fear a dob would rock and roll all over the shop.

Hey Rob, it sounds like your thoughts are very much aligned with my own. It's interesting what you say about the larger scope in the wind, definitely something to consider especially with my less than ideal tripod. I feel a 10" would also require the addition of a Berlebach so the cost is doubled, say £800-£1000 for 10" OTA + BB vs <£300 for just an 8" OTA. I'm probably leaning towards an 8" right now, especially as it will provide a wider FoV without upgrading EP's and is a modest introduction to reflectors. A 200p is cheap enough and could be upgraded at a later date.

Yes, a shame I sold my black version (for CG5) a few years back. Not sure I could stand a white tripod with the AZ100 on top!

......as the pictures in one of John's post confirms

Ah, I'm surprised as the tripod looks quite beefy compared to the skytee II. I've seen your images of the AZ100 on the Uni, obviously it's a fair bit chunkier.

Thanks John, good info. I'd be using ES 68° EP's and don't typically obsess over edge of field performance. I must have inadvertently denoted this thread for comment from John's only!? 😂

Thanks John & John. The different perspectives of those pictures really help. @johninderby, is that a Uni or a Planet? Planet I suspect. That's another consideration, I'm currently on a 1.75" steel tripod which is fine for the frac, but I wonder if it would struggle with a 10" on the AZ100? I do use it all but fully collapsed, only extending an inch or so of one or two legs to level, so may be OK.