12v16inch light bridge

[thomas2003]

I have been the owner of a 12inch lightbridge dob for about12 months, and would like to know if the extra 4inches of the 16 would be worth the extra cost. Has anyone compared the view from this telescope.

[janoskiss (Steve H)]

In terms of brightness it would be just like going from a 6 inch to an 8 inch. Compare those and you will have an idea. It is a significant difference. what's worth the cost and what isn't is always an open question.

If you are looking for more aperture to get more resolution, I'd be concerned with having such a large mirror not made from low thermal expansion glass.

[Rigel003 (Graeme)]

Not sure if this will help any, but have you seen the simulations of the eyepiece view of M13 on the Obsession site. They include 12" 15" and 18".

http://www.obsessiontelescopes.com/m13/index.html

[astronut (John)]

Like you I have a 12"LB. In pure light gathering terms the jump in aperture is a desirable feature. Aperture fever does take hold though, How much aperture is enough?
Onto the practicalities, the 16" gives 77% more light than the 12" but the 16" weighs approx 65kg, the 12" 38kg.
The 16" is also physically bigger and for the average person you will need a step ladder for the e/p when approaching the zenith.
The last thing is price: 16"= $2995, 12"= $1499.
You could buy two 12"'s for the price of the 16" or buy a hell of a lot of accessories.
Choices, Choices, Choices........................:lol :

P.S. But.......don't forget 12"'s is still a lot of aperture!!!!

[DJVege]

I've seen these HUGE babies, and as long as you're not going to be moving it around a lot, you'll enjoy the 16". Make no mistake...it's massive. Also, if you're going to use a high magnification to look at planets, moving the 16" tiny increments is difficult.

Images are very bright, though....i loved it!

[rmcpb (Rob)]

Originally Posted by astronut

The last thing is price: 16"= $2995, 12"= $1499.
You could buy two 12"'s for the price of the 16" or buy a hell of a lot of accessories.
Choices, Choices, Choices........................:lol :

P.S. But.......don't forget 12"'s is still a lot of aperture!!!!

A pair of 12" binos for the price of a 16". Now there is a GREAT deal

[astronut (John)]

Great minds think alike Rob!!
Now all you have to work out is the alignment issues to make them work as bino's.

[rmcpb (Rob)]

Originally Posted by astronut

Great minds think alike Rob!!
Now all you have to work out is the alignment issues to make them work as bino's.

See my thread in the ATM section

Just did the calcs and:

• a 16" (400mm) mirror has a surface area of 125714 square mm.
• a 12" (300mm) mirror has a surface area of 70714 square mm.

So a set of 12" binos costs less, will gather more light (141428 square mm) 12% more and gives true stereo 3D views with no steps or ladders required.

Hmmmmmmmmmmm

[OCULUS]

with regard to the stereo 3d image, I dont think this is correct. Stereopsis, the ability to judge objects in space with two eyes is only good for about 20 feet distance with your own eyes. (There are some arguments about the distance )

If you are looking at an object millions of miles away, to get true 3D you would have to have eyes a few hundreds of thousands miles apart.

The difference between the two images seen by the brain is called the disparity. The disparity would not register with the brain at these distances.

There are other visual cues that allow one to determine depth but these are based on movement shading etc. You would still get these with one eye (hence those with one eye can still drive etc and not hit things!)

So the argument of binoviewer v binoculars is more based on light gathering ability etc.

[Satchmo]

Originally Posted by OCULUS

So the argument of binoviewer v binoculars is more based on light gathering ability etc.

The main issue with bino-viewers is that they present exactly the same image , including optical errors and atmospheric seeing conditions , to each eye, so much of the brains binocular image processing abilities just aren't utilised. They do however provide eye comfort and portability at a relatively low price. I'm looking into purchasing a Baader Maxbright unit mainly for Solar observing

Mark

[gbeal]

Originally Posted by Mark Suchting

The main issue with bino-viewers is that they present exactly the same image , including optical errors and atmospheric seeing conditions , to each eye, so much of the brains binocular image processing abilities just aren't utilised. They do however provide eye comfort and portability at a relatively low price. I'm looking into purchasing a Baader Maxbright unit mainly for Solar observing

Mark

And while we are both getting way off the original thread Mark, the bino viewer is awesome on solar, I have used the Denks in the smaller Zeiss refractors with a solar filter, and the effect is spectacular. DSO's? Maybe, maybe not.
Gary