James1967

Got it - understood! Many thanks, the advice is really appreciated.

Thanks Viktiste. Certainly sounds good enough for me to give the OAG a try - I’d much prefer this route if I can work with it.

Hi Viktiste. Rather off topic, but I’m looking at an Esprit 80 ED too and considering OAG (vs guidescope). Can I ask how you find the ZWO OAG with the ASI 120 MC (as I have one of those already)? Recommended? Anyone else with a view would be welcome too!

Thanks for all the responses. I’m expecting to eventually progress to astrophotography and will therefore likely also get a refractor with much smaller focal length, so I’ll bear that in mind too. I’ve understood much more now (basically you can’t increase max FOV with the reducer so no point using a reducer AND 2” diagonal/EP. Need to decide on one or the other). Probably best for all that I get the scope with provided accessories and play with it before deciding on anything else. It’s not as if the stars and planets are going anywhere. Thanks again 😄

Thanks Dave. Would you recommend not buying the Evo 9.25” then? I can cancel it and get something else. Or did you mean that you spent a lot on EP’s, reducers etc trying and failing to get a wider FOV? Most DSO’s seem to be much much smaller than 1.12 deg and it’s only a few eg M31, M42 that are much bigger - or am I missing something?

Thanks Olly. Your set up sounds very similar/relevant. It also makes sense to me (as a novice) that the light path is limited to the 46 (48?) mm baffle width BEFORE it passes through the reducer, so the FOV would not be increased by adding the reducer. I guess I’ll just have to try the supplied EPs with/without the reducer first and see if the FOV is changed or just the magnification, before splashing out on 2” diagonals, EP’s etc. Maybe it’s just me but I find it bizarre that field of view impact on various set ups is not a standard piece of information provided, like magnification, focal length. Guess I’m asking too much. Ho hum.

Thanks. I guess the issue is whether the 0.63x reducer, by reducing the focal length, increases the max true field of view (baffle width/field stop x 57.3/ focal length) or not. Because the light path passes through the limited baffle width before passing through the reducer, I’m not sure the formula is valid for such a set up - but I really don’t know enough either way! If the formula is valid in this case, then a 2” 36mm 72 degree AFOV EP *should* work to give 1.75 degree TFOV and it may be worth me experimenting. I know I can always return the EP’s etc to FLO if it doesn’t work, but it would be easier all round if I could establish how it works in advance. The Celestron website is particularly unhelpful in this regard. Thanks again

If you’re still here, could you use the 0.63 reducer AND 2” EP (eg Baader Hyperion 36mm 72 degree AFOV)? Per my calculations, this would give a 1.75 degree TFOV for my Evo 9.25” (2350mm focal length, 46mm baffle width), where the theoretical max TFOV for the scope would be 1.78 degrees with the reducer. (I’m awaiting delivery of the scope so all my workings are theoretical, just using optics maths not practical knowledge)

Can I ask what maximum true FOV you can see using the reducer (and with what eyepiece, focal length, apparent FOV)?

Thanks so much, that’s all really useful. Certainly need to be careful with how high I point the scope etc especially if I have all sorts extra on the eyepiece end. I didn’t realise the reducer would fit on the standard 1.25” visual back. I had assumed I would need the 2”. The small refractor is another good option I’ll bear in mind. I’ll just have to double check when I’ve played with it ‘as is’ for a while and worked out what I want to do. Many thanks again. 👍

Many thanks Mark, that’s good to hear - eyepieces are deffo on the list once I’ve tried out the standard ones. Can’t wait 😄

Ok, after lots of research, I finally decided on the above and just ordered with FLO. Now got a few weeks wait so can keep exploring the sky manually with by binoculars and learn as many pitfalls as possible about the Evo 9.25”. The only accessory I ordered for now is a dew shield, but I’m expecting I will want to get a 2” visual back, star diagonal and wide angle eyepiece (possibly 0.63 focal reducer too) to get the max field of view possible when I so choose. Any views on whether StarSense is worth it - it seems pretty simple to align without it (I may come to regret saying this) So why am I posting? Just after any and all advice for a beginner, in particular regarding maximising field of view down the line (the relatively narrow FOV was the only real downside of the Evo 9.25” for me) and any recommended accessories to enhance my viewing pleasure over time. Any other general top tips also very welcome. I look forward to being able to help others in due course when I have something more than roughly zero knowledge and experience!

Wow! They are stunning.

That’s fantastic Ian, thank you so much for all the recommendations and tips, really appreciated.

Thanks Ian. That makes sense too, comparing with the 27kg for the 10” stated on the German website I found. Can I also ask which accessories I should buy upfront. Most people say ‘wait and see’ which is my approach, but things like dew shields or heaters seem pretty much required (I’m in North Yorkshire). Any tips warmly welcome. thanks again, James

Brilliant, that’s just what I wanted to hear. The tube seems definitely to be just over 20kg (but without carrying handles that make it feel tougher to carry I guess). It was the base/mount that concerned me, so you’ve answered my question. DIY trolley sounds just the job too 👍 Many thanks.

Thanks. The only SW website I could find was showing the one without the goto, motor drive etc, here http://www.skywatcher.com/product/bk-dob-12-collapsible/ this has the same weights that you mentioned. This one below says 46kg total for goto. Around this weight is fine (each weighing about a full suitcase - no issue for me) https://www.apm-telescopes.de/en/telescopes/dobsonians/skywatcher-dobsonian-skyliner-250p-flextube-synscan-goto-dobsonian to be honest, these are fine, but I saw somewhere on SGL (can’t find now, sorry) a mention of ~40kg+ just for the base/mount, which would be prohibitive. I’ve fired off a few emails to suppliers too now, so I’m sure I’ll get to the bottom of it. Thanks again. You don’t happen to have one to sell do you - save me waiting for the new stock? 😄

Hi Nick, I’m new on here and looking at getting a SW flextube 300 goto. My concern is the base weight as I’d prefer to put in the car and take 20 mins to a darker sky site though I would use in my back garden too. Do you know or can estimate the weight of the base (without the OTA on)? I might have to go for a 250 or even 200 if the 300 weight is too much. I’m a fairly fit but not muscly 6’2” 53 yr old bloke if that helps.