To 14" or not to 14"

[Sfarndell]

I must admit that I suffer from severe aperture fever and currently have a 12" Meade Classic (Pier-mounted in an obsy), which was recently acquired to upgrade me from a 10" Meade classic. My 12" is optically great, with good goto and fantastic tracking, and since it is permanently mounted, it negates the need for a GPS model.

But....

I have an opportunity to upgrade again to a meade 14" GPS at a bargain price (genuine seller that I have been in contact with!!). Seems like a good deal.

My question is: How much better is a 14" vs a 12"?

[MikeP]

The main advantage is about 36% more light gathering power (I think).

Mike

[Sfarndell]

True, but is it 36% more visual "WOW" for the price differential. I would even take 20%...

The difference for photography is minimal as it can be compensated for with slightly longer exposures. I am looking for more visual impact...e.g. would it make the crab nebula filaments much clearer than the just-more-than-a-fuzzy blob that I currently see?

[MikeP]

I took my 12" FlexTube to LightBucket's place a few months ago and he had his 16" Lightbridge set up, so that is the closest comparison I can make.

There is no doubt that the extra light gathering made a difference but for me only to whether I could see the fuzzy or not. Detail on the dimmer DSOs just isn't visible to my eyes but Sam could certainly make out details better with the Lightbridge. Maybe he'll spot this thread and comment.

Mike

[Andrew*]

I remember hearing once that the step from 8 to 10 inches was negligible. The difference between 12 and 14" will be even less. I'm of the suspicion that you might not even notice the difference unless you have them side by side. Worth the extra cost and back pain?

Andrew

[RobH]

Unless you're in a very dark site you won't really notice any difference visually.

My old 10 inch in a truly dark site knocked spots off my 14 inch in a moderately light polluted backyard.

Photographically, I would think a 12 is a bit more flexible as the FOV of a 14 is very small.

In terms of light gathering power, photographically the 14 knocks the 10 into next week. Better resolution and with a 6 to 10 minute exposure you can gather a lot of data, especially with focal reducers.

The 14 inch GPS is regarded by many as the best scope mechanically that Meade had made up to that point. For the 14 they upgraded the gears etc as compared to the previous models, and the drive can easily take the weight and guide accurately.

Cheers

Rob

It's a big scope though....make sure you've got the room!!

[Sfarndell]

Thanks Rob

Excellent advice and more food for thought. I would need to modify the obsy to allow for the extra height of the scope, but since it is just a shed with a removable roof, it won't take much effort. Never thought of the gears...The 12" does take some strain with my 80mm refractor + DSLR + guidescope +++ mounted.

My skies are 'medium' light poluted - Can see mag 5 stars relatively easily from +-30 deg above the horizon but as my location is fixed, the extra aperture would make some difference.

My other option is to spend the christmas bonus on a 16" lightbridge instead so that I can have a "portable" scope to take on camping weekends...

[Whippy]

My skies are 'medium' light poluted - Can see mag 5 stars relatively easily from +-30 deg above the horizon but as my location is fixed, the extra aperture would make some difference.

Medium LP? I'd kill for mag 5 skies!

Tony..

[John]

There was a thread like this on Cloudynights recently and the general conclusion of most posters was that the difference would be negligable.

I'm in a similar position having just sold my 8" and looking into more aperture - I've come to the conclusion that 12" is the step to make now rather that "just" to 10".

John

[GazOC]

I went from a 8" to a 12" and there is a significant difference, I've got a 14" now and I don't remember the 12" showing much less but I had 18 months or so inbetween those scopes so I didn't make a direct comparision.

[marksward]

Could be money well spent on lenses etc rather than an 'upgrade'. I looked through my scope with some borrowed lenses and WOW! Shame I had to give them back

[RobH]

Another thing to consider with a big SCT is dewing.

Even with a dewband running full power, unless I have a dewshield on my 14 will dew up on most of the corrector plate. A dewshield stops this but I can only use it when there's no wind, as it's rather large and acts like a sail!

Cheers

Rob