How much more detail in a 14 than a 10?

[Manok101]

I was just wondering how much more detail I would see in a 14 inch than my current 10 inch dobsonian? Would it not even be worth going up another 4 inches in diameter?

[Ags]

If you can't manage the considerable bulk and weight of the 14", you will see considerably less with the 14"... :-(

Read up about exit pupils. The greatest brightness for a fuzzy object you can get though a telescope is when the exit pupil is around 5mm (maybe 6 or 7mm if you have young eyes). I can get a 5mm exit pupil with my ST80 at 16x magnification. In your 10" you will get maximum brightness at 50x, and the 14" at 70x. In all three telescopes the surface brightness of the fuzzy object is the same - all you are getting with the larger telescope is a bit more magnification.

[Ags]

How do you edit posts these days? Anyway, I wanted to add that the maximum brightness (for fuzzy objects) that can be delivered by any telescope is simply the brightness of the object to your naked eye. So even a huge telescope will show M31 as a dim blob, but the telescope might require such high magnifications to get the exit pupil down to 5mm that M31 won't fit in the field of view.

Big telescopes do make stars brighter - this is why globular clusters in particular look great in big telescopes. On the other hand some people complain that open clusters look lost in the richer star field a big scope delivers.

[LukeSkywatcher]

I recently upgraded from a Skywatcher Heritage 130P "Dob" to a 200mm SCT and the difference is VAST in the views.

Granted, neither scope is what would be considered "BIG and BULKY".

At the end of the day, its NOT about aperture. Its about portability. There is no point in buying a 14" Dob if you cant move it from A to B.

A 10" Dob is one thing..............a 14" Dob really is a another thing.

But, if you can afford it and can move it about easily then yes the investment is worth it.

[Qualia]

I was just wondering how much more detail I would see in a 14 inch than my current 10 inch dobsonian? Would it not even be worth going up another 4 inches in diameter?

It's not a perfect sum but let's just assume your eye pupil size on a perfect night is about 7mm, then your 10" (250mm) has a relative light grasp of about 7.75 magnitude. The 14" (350mm) about 8.5 mag. Now let's assume you're in a LP area where your eyesight can resolve stars down to about 4mag, then the 10" will punch through to about 11 mag stars (11.75) and the 14" to about 12.5. If I've got my calculations right, you're jumping about an entire star and a half magnitude.

[swamp thing]

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How do you edit posts these days?

Have you not seen the announcement and ensuing thread? Here:

http://stargazerslou...-editing-posts/

A 14" scope is a big lump when compared to a 10". I would go and have a long look at one before ordering. It will resolve considerably more than a 10" but only f you can get it outside to use it.

[Manok101]

Well it's not going to be a solid tube dob, it will be one of the truss tube designs I've seen. Will moving just the base and the secondary mirror and the trusses? I don't mind moving all the sepreate parts, if they're not a 100 lbs or something seperately.

[umadog]

You will see substantially more with a 14" compared with a 10", particularly from dark skies. However, the mass-produced scopes become very unwieldy by the time you exceed 12". There's just a LOT heavier and bulkier than they need to be. There's a debate on CN right now about the new XX16. The base alone weighs over 100 lbs. It's crazy. Teeter's 15" has a base that weighs 26 lbs: http://www.teeterstelescopes.com/catalog_classic.html If I were looking at a Dob >12" I'd be looking for a premium one. You could buy a Teeter structure, put GSO mirrors in it, and pay only about $400 more than what Orion is charging. Yes, you won't have the goto but you will have a scope that weighs half as much, takes up less room, is better built, better designed, and will accept Servocat at a later point in time should you want it. Alternatively, you could add an EQ platform and get tracking, which is really what matters in a big Dob.

[Manok101]

I was thinking of either the XX14 or looking for something with at least a push to capability, it's not really in the plans right now just was daydreaming of being able to see more where I live. I like looking at stars planets and the brighter DSOs

[vlebo]

I have an Iphone and I have dowloaded an Inclinometer app called Spiritlevel and together with the built in compass and Skysafari and a 30mm eyepiece it gets me in the right area for many objects that I would struggle to find otherwise. The apps available now make having goto almost obsolete . They certainly get you in the right area and a little scanning in alt and az and you will find what you are looking for.

[vlebo]

Sorry I haven't finished. Personally I would spend the cash on better optics like the Orion uk series of large dobs and not worry troo much on finding stuff as there are other ways of acquiring targets .

[Manok101]

My funds are limited so I doubt I'll ever get another scope, wish I had the money for all that.

[umadog]

Look second hand. You'll find some real bargains on astromart. Save you funds and you can buy a premium Dob, perhaps with tracking, for around half the price it cost new. Look for something in the 14" to 18" category. Orion's design just doesn't make sense above 12". Even the 12" is bulky, IMHO.

[James]

I was just wondering how much more detail I would see in a 14 inch than my current 10 inch dobsonian? Would it not even be worth going up another 4 inches in diameter?

You'll see quite a lot more in a 14" over a 10". I made the same move up a year or two back and the difference is quite major, for example M33 - easily visible in the 10" but usually without any real detail, in the 14" quite a bit of mottled details are visible. With M13 - it's great in the 10" - but in the 14" the 'propellor' is easily visible every time. Other globs like M92 look almost as good as M13 does in the 10". The Veil nebula looks brighter (as it should of course). The Ring is much brighter and Stephans Quintet which I've never seen in the 10" is visible in the 14" (well, a couple of the Quintet anyway :-) )

Aside from the other comments on size and weight (all valid, 10" is easy to shift, 14 isn't) there's a pretty big difference in going up to 14".

James

[acey]

What you're looking for is best view per effort, where view is a function of sky darkness, aperture and experience, and effort is a function of cost, weight, size, set-up and maintenance. Everyone's different - one person's dream scope is another one's heap of unused surplus equipment.

Going from 10" to 14" is a theoretical 0.7 magnitude improvement. For a beginner that might be barely noticeable, for an experienced user it's huge. What anyone would notice is the extra weight. If both scopes are used in a light polluted area then even an experienced user might see little improvement. If both are to be transported to dark sites then the 14" will take much more effort, but if the user is capable of seeing the difference and willing to put up with the effort then it's worthwhile.

[Moonshane]

I went from 12" to 16" and the upgrade is therefore pretty similar. the weight of a 16" vs a 12" is large but manageable. I made my own base for my solid tube scope though and it weighs maybe 30 lbs. I live in a badly light polluted area and mainly observe from home.

for me the jump in aperture is well worth the effort. everything is better without exception. nebulae are relatively detailed, galaxies are fuzzy blobs and globs are spectacular. open clusters are bright and packed with stars and background peppering. the moon and planets are bright and detailed and double stars are round points of light with 'perfect' airy disks. for these latter three types of object I tend to use an aperture mask reducing to 170mm (and f11). at dark sites, this scope is just jawdropping.

If you can afford it, carry it and use it then it's worth it. if not then your current 10" is a fine scope - enjoy it!

[ollypenrice]

The points about exit pupil simply require you to choose EPs which give a workable exit pupil.

Of course you see more in a larger scope provided you respect the exit pupil.

How much more? Less than you might think, I suspect, and as has been said earlier a lot depends on experience.

Olly

[Manok101]

I know it's probably not possible, but all I'd like is to do is be able to look at X blob in the sky and know it was a galaxy, I don't need to see dust lanes, or any features like that. I'd just like to be able to see oh, that's a galaxy and not just a blob. The best dark site I went to about a year ago, I could do that with my 10", but here I can only see the brighter galaxies, and even then I'm not sure if they really are galaxies or just my imagination half the time.

[umadog]

To see more than just a blob means you will need to be seeing features! Otherwise it would be just a blob. So you should be striving to see dust lanes and structure in galaxies with your 10". As you say, your scope is capable of revealing such details from a dark site. Galaxies are very much attenuated from a light polluted site and a 14" scope isn't going to fix that for you, I'm afraid. Once the sky brightness has overwhelmed a DSO then it's lost to all apertures. A larger aperture scope isn't totally wasted from a light polluted site, however. The extra light gathering power is a boon for UHC and OIII filters, so you can expect to get better views of emission nebulae from your LP site with a larger scope. Planetary nebulae will come out better even from an LP site, as will globular clusters. Leave the real galaxy hunting for dark sky trips.