14"vs16"

[HCR32 (Peter)]

Hi ppl

My question is,

Is there much visual (through an ep planetary detail) difference between a 14inch scope and a 16inch scope taking into consideration everthing else is equal?

[qld]

Originally Posted by HCR32

Hi ppl

My question is,

Is there much visual (through an ep planetary detail) difference between a 14inch scope and a 16inch scope taking into consideration everthing else is equal?

yes there is,and you have differences beween scopes of the same arperture it all comes back to how good the mirror is.

[pgc hunter]

It would not be worth paying that extra grand for the 16. The 16 has an additional 0.03" of resolving power over a 14 which is much too tiny to get any appreciable gain in resolution, and with typical seeing conditions you are unlikely to see any improvement in planetary performance. THe magnitude gain of a 16 over a 14 is only 0.2, which is barely noticable by the human eye. On some objects a small improvement might be seen, but really, for planets, you won't see any noticable improvement.

[Sylvain (Jon)]

seeing is the limiting factor, esp in planetary.

[wavelandscott (Scott)]

The is a formula you can use to calculate the difference in amount of light gathered between the two (I don't have it at hand at the moment)...

Bigger is almost always better....but, best get the size you are most likely to use. A 16 inch mirror in the storage shed won't see much.

[Scorpius51 (John)]

There is approximately 30% more aperture with the 16" over the 14". It's basically the ratio of the squares of the diameters (or radii). Not a lot of difference - but the cost probably would be!

Cheers
John

[Sylvain (Jon)]

The 16" will collect more light than the 14", that's for sure.
For planetary observation (DSO IS a different story), more light is useful to bring out tiny contrasts at high magnification. The max usable magnification however depends on the seeing conditions of the day you observe. Under normal seeing conditions you won't be using the 14" to its max theoretical magnification. Whether you observe with the 14" or 16" the max usable magnification will be the same because the apertures of the scopes are fairly close to each other (for example if comparing a 4" and a 14", the 4" might be limited by its aperture rather than seeing conditions). No matter the instrument you use (14" or 16") the max resolution depends only on the seeing conditions of the day you observe.

However the larger the aperture, the more sensible to seeing conditions a scope becomes. Therefore on a average night I do not expect the 16" to outperform the 14", they would perform the same, the 14" might even take a slight edge.
To exploit the "full power" of the 16" will take one of those perfect seeing nights like it occurs once a year or so where you can push the magnification to stupid numbers. You'll enjoy the extra light from the 16" but I reckon the contrast you have with a 14" is good, so i doubt the 16" will make a significant difference on the details you manage to see.

At this stage, maybe more important than aperture, is quality (& of course collimation) of the optics. If you've got a mass-produced 14" mirror, you might want to consider getting yourself high quality mirrors rather than getting a 16" upgrade.

In my opinion, the upgrade isn't really worth it for planetary observation.

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