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What is the biggest sensible aperture for the UK?

osbourne one-nil

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osbourne one-nil

osbourne one-nil

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And a right-angled finder, but then, I'm just being greedy!

It's the dark skies I have here you see - I want to be able to take advantage of them and my head was saying a bigger scope would be great, but my over-reading suggested it wouldn't make much difference. I'm glad I asked!

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Naemeth

Naemeth

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And a right-angled finder, but then, I'm just being greedy!

It's the dark skies I have here you see - I want to be able to take advantage of them and my head was saying a bigger scope would be great, but my over-reading suggested it wouldn't make much difference. I'm glad I asked!

I think the only other limit for aperture would be the point where your target was actually fainter than the background LP you are looking through - at that point aperture is irrelevant from what I've read. Other than that, and especially with a dark sky, you're good to go. Were you thinking of a 16" / 18" - or something larger perhaps? :)

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ollypenrice

ollypenrice

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Yes, this makes sense to me too.

There is absolutely no contest between my 12" dob and my ED120 refractor on deep sky objects, with the exception of those that benefit from the wider field of view that the shorter focal length 120 gives. 

On lunar and planetary viewing, the ED120 does get surprisingly close to the 12" and can better it if the seeing is unstable. The "moments of best clarity" can be fewer with the 12" scope but when they come you can see what the aperture and quality optics can do. The ED120 presents a more consistent image of the planets quite often though, if that makes any sense. 

This is exactly what I find with the TEC140 versus both the 20 inch and the 10 inch SCT. The TEC is usually the best on the planets but not absolutely always. 

Since big Dobs are about making faint things bright, and since faint things are often large, I really would labour the advantage of a fast F ratio. Also the difference in height between a big F4 and a big F5 is literally giddying.

Olly

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scarp15

scarp15

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There are a number of us on the forum who use one of these; Orion Optics UK VX14. For myself it provides a great combination of aperture, portability, wide field of view at F4.6 and comfortable seated observing.  The tube is quite manageable to maneuver, the base is easy. I can fit it into my compact skoda and drive to a dark site. The optics are great and in my opinion do not require a coma corrector.  I have noticed a difference in light grasp on familiar objects compared to my former 12" dob. Occasionally (such as this) they come up second hand to.

The only set back is that the weather has been so awful that it gets used only occasionally.

post-22819-0-05620000-1392218560_thumb.j

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Mike73

Mike73

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I really like the VX14, for me 12" was right on the verge of seeing spiral arms in galaxies so I should imagine the extra 2" with Hilux coatings should make a great difference. 

If I was looking for a large dob again then this is what I'd be on the look out for but I wouldn't want to pay the full price that OO ask. :)

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osbourne one-nil

osbourne one-nil

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I really like the VX14, for me 12" was right on the verge of seeing spiral arms in galaxies so I should imagine the extra 2" with Hilux coatings should make a great difference. 

If I was looking for a large dob again then this is what I'd be on the look out for but I wouldn't want to pay the full price that OO ask. :)

I've just checked that price...they're being serious yeah? It's not a joke? And that's before adding another 20% on!

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Earl

Earl

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I've just checked that price...they're being serious yeah? It's not a joke? And that's before adding another 20% on!

Yeah OO add the date to the price, and of course we have the seeing in the uk to benefit from the higher quality optics..... once every year or so, in a good decade... :D

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osbourne one-nil

osbourne one-nil

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If you looked through one you would say they are worth double that

I've got OO optics in my Sumerian, and yeah, they're good...but that good?

This thread has certainly got me thinking though and I'm seriously thinking about shifting my TV85 for a 6inch Newt to put on my Portamount!

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jnb

jnb

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I suppose one way to look at it would be to say that it's always worth getting a bigger telescope until you reach the point at which it would be cheaper to build something remote controlled abroad or even move abroad. So my university just bought an Alluna Optics RC 20 (35000 euro), that makes sense because it's a teaching and outreach tool and the students can't afford to pop over to some remote location. Even a private individual might justify something like their RC24 at 60000euro on a similar basis. However if you get up to something like the CDK700 at $200000 then you're at a point that you have so much money that you can probably afford to pop over to the canaries and have you own observatory there.

So until you get to silly levels it's probably a case that having a big telescope in a bad location is better than having a small telescope somewhere you can't get to.

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John

John

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If you looked through one you would say they are worth double that

sent from my Sony Xperia

The reason to buy Orion Optics scopes is for their mirrors. The tubes and fittings are not really any better than chinese scopes in my opinion, at least in their VX range, although the OO dob base is innovative, light and compact.

Their new pricing is high but then quality mirrors take time and care to produce and we are talking about UK labour prices rather than those in the far east.

My Orion Optics based dob has a 12" F/5.3 Hilux mirror set with a 1/9th wave PV primary and has cost me around about 1/3rd the cost it would have been new. I bought the tube secondhand and a member here made a superb dob mount for it which emulates the OO design dob mounts.

Having owned a Meade 12" Lightbridge in the past I'm very sure that the Orion Optics mirrors out perform that one by a noticeable margin especially on planetary and lunar viewing.

I can completely understand the scepticism over Orion Optics new pricing when you can buy a chinese 12" dob for under £600. Such decisions on whether to spend more to get higher quality are common in this hobby though and I guess everybody has to reach their own conclusions on that. 

At least with forums like this you can get independent feedback on the range of options available and hopefully make better informed decisions.

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lensman57

lensman57

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"Biggest sensible aperture can be different if you re married or not. The words "What the hell is that?" and "You are not keeping that in here!!" make a significant difference on the scope size".

That is why I like my WO 71, I can almost keep it in my coat's pocket.

Regards,

A.G

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Moonshane

Moonshane

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I have a 6" f11 (used on an equatorial platform), a 12" f4 and a 16" f4. all are solid tubes. I have also built an 18" f4. my thread http://stargazerslounge.com/topic/174263-when-scopes-start-to-get-big/ shows the last two. the 16" is a very large step from the 12" in bulk and weight and the 18" was also a large step from the 16". my 12" is my most used scope as it is small and light and quick to set up.

the other thing to consider is that if you have a truss based system it makes a large scope much easier to transport and set up.

I agree that light gathering is more important when it comes to aperture than resolution. that said, my 12" dob provides better planetary detail than my 6" and my 16" better than the 12".

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