Skywatcher 8" vs 10"

[sneeka]

Hi all, first time poster, long time lurker

After many months of studying the skies with two sets of binoculars (10x50s and 15x70s), I think I'm now ready for a scope. The Skywatcher Skyliner dobs seem to get favourable reviews, so I've set my sights on them.

My dilemma though: 8" or 10"?

The 8" is lighter, so I guess it would be easier to hump in and out of the garden, not to mention a hundred quid cheaper (which could go towards eyepieces). However, would the tradeoff in aperture be worth it? Anyone bought an 8" and wish they had a 10" instead? Does 2" really make that much difference? (ahem)

It might be worth saying that I'm just into viewing at the moment, no photography. Mainly interested in DSOs with maybe a planet or two, and of course the Moon.

[Demonperformer]

For DSOs, aperture is king - 10" gives you 50% more light grasp than an 8" - but be aware that the 10" is a big beast - I could never get on with mine, and eventually sold it on, but if you have the facilities (including dark skies) to use it there is no contest.

[PeterM]

I'm in the market for both myself and while I can't speak from experience I'm going for the 8" (200p), mainly on the grounds that at f5.9 it should be a lot more forgiving of eyepieces that aren't in the super premium category than the 10". This is only theorising mind, and I'm sure someone that's actually used one or the other will be able to give you a better basis for comparison.

[Chris H]

I have a 10" dob and went through a similar thing when I got mine. In the end I thought if I got the 8" and I was viewing DSO's I would always wonder what they would look like had I bought the 10". I don't move my scope very far it lives in my shed in the garden, when I want to use it I carry it out in one piece no problem (i'm just an average guy 5'11" tall and 12 stone in weight) but I only have to go 5 metres. I have been on a couple of trips to different locations and the tube fits nicely across my back seat in my car and the dob base just fits on my passenger seat.

Collimation is pretty straight forward now I've done it a few times and yes it is more demanding on ep's but I like super widefield views so have a collection of Ethos', a nagler and a Pentax not cheap but they work really well.

It is great on both DSO's and planets and yes initially I thought this is massive but now I'm used to it it no longer seems that big.

As DP said on DSO's aperture rules.

[dweller25]

I have the 8" F/6 and it performs very well on the planets. It is light and can be mounted on a GP/CG-5/EQ5 type mount. It cools quickly and is VERY easy to collimate.

I compared it side by side with a 10" about a month ago, The 10" made the 8" look like a toy and needs an EQ6 mount to hold it. Cooling will take longer but it's resolution will be better as will it's light gathering.

It's a tough call but if you can live with the extra weight of the scope and mount then go for the 10" or you will always wonder what you were missing....you can always downsize if it's proves too big.

[acey]

I got an 8" in 2000 (an Orion Skyquest dob, pretty much like Skywatcher) and thought it was massive. Started taking it to dark sites in the car and it soon got to feel "just right". In the end it felt like "grab and go". I upgraded to a 12" flextube last year, it felt massive at first, now feels just right. I could lift the complete 8" plus base with one hand - handy for shifting it when my target disappeared behind a tree. You can maybe move 10" in one piece, but the 12" definitely has to be moved in 2 separate bits.

Whatever aperture you get, you'll wonder what it would be like if you had more. Important thing is that your scope doesn't feel too big or too small. Upgrading by 2" isn't really worth it - going from an 8" to a 10" or a 10" to a 12" won't give you the "wow!" factor, but you'd feel the extra weight. Going from 8" to 12" is definitely a wow.

If you think that in future you might want to go to larger aperture then choose 8". If you think you'll never want anything bigger then go for the 10" and learn to live with the weight and bulk, or go for 8" and give your back an easier time.

With an 8" at a dark site you can see hundreds of DSOs, many of them with interesting amounts of detail. I found mine a great all-rounder, good on planets too. My 12" is shorter focal length and not such an all-rounder, really a deep-sky scope. Can't speak about the 10" but it should make a decent all-rounder, though the extra aperture will make no difference on planets, and the shorter focal ratio might.

[sneeka]

Thanks for the all the advice so far

I suppose I'd have to think about light pollution as well. As a benchmark, I can see M3 and M13 quite clearly through my 15x70s, and can only JUST make out M81. Would the light pollution make the size difference moot?

I guess I could drive to a dark site, but then I've got to think about size there too, as I only have a Fiesta.

I dunno. My heart says 10" and my head tells me 8" ... Argh

12" is definitely out though

[nicnac]

reading sky at night today and its group test had both the meade and the skywatcher, if weight is an issue, the 10" meade lightbridge came in the lightest and got a better review for its optics

[Crusader]

I had the same dilemma when I bought my first scope. I went for the 10" Orion XT10 and have never looked back. As far as size is concerned there is very little difference between the 8" and 10" when it comes to length. They both have the same focal length. The major difference is in weight and the 10" is a bit heavier. It's still easy to handle though (after you get used to it).

Personally I'd go with the largest aperture you can afford, provided that you have enough space to store it and that you won't have to navigate stairs and long distances to carry it by hand.

Also bear in mind that this hobby is addicting and aperture fever/scope fever is severe. When I got the 10" 2 years ago I told myself that it would be my first and only scope - yeah right! I've got 3 scopes already and busy contemplating ways to afford a fourth!

[brantuk]

Go for ten inch - it'll be well worth all the humping around - you won't regret it. The 12's a beast but I'm allways glad for the views once it set up and running.

If you got for SW then get the auto - it'll track fine and is upgradeable to goto at a later date - you might also benefit from an RDF or RACI finder.

[sneeka]

Yeah, I'm not really bother about the tracking/goto really. I'll be happy with manual (I think). If I get into photography later on I can always put it on an EQ6 as said above, but for observing purposes the manual 'nudge' tracking should do me

In anycase, it looks like 10" is slowly becoming the winner here. If I end up in traction I'll send you lot the bill