Magnification Vs Aperture?

Question

While it is true that a larger apeture helps in collecting more light on a reflector to be able to see more of a planety or deep sky stuff.

However dosen't magnification help in dealienating the surface or other things on a planetry surface as opposed to apeture. So say if I wanted to see more details on saturn through my P130mm 650 focal would it make sense that things would be more detailed with higher mags as opposed to simply increasing the apeture. Atleast going by the rule of 50X per inch of apeture.

Are there any other ways besides barlows to see more planetry surface details by keeping the same apeture.

Thanks

P.S I am not overly concerend with the field of view which ofcourse relates inversely to mag what I seek is an ability to see details to the best to p130mm 650's ablities.

Answer 1

Astronomical observations on planets is rarely limited by lack of lumination, as planets are fairly bright compared to nebulae and galaxies. For this reason, the telescope of choice for planetary observations is the refracting telescope with a high magnification, because of ease of use and durability of the instrument. However, aperture still matters, since for a given magnification, greater aperture will give you sharper pictures, and this is because of the wave properties of light. Resolution is limited by the diffraction limit of the Airy disc. See wiki article on diffraction, check "Diffraction limit of telescopes". There is no way to improve the resolution of your telescope beyond this fundamental limit, but of course I don't know how much you're able to see right now with it.

Oh, I take that back, there is a way to improve image sharpness with your telescope, but it requires sophisticated time sampling and image reconstruction. Trust me, it's cheaper to get a bigger scope.

Answer 2

You would think, huh? 8^)

The best way to answer this is to ask the 'scope. Saturn is a bit of a demanding target and good exercise in "seeing". So try each of your eyepieces, spending at least several minutes on each one (the longer you look, the more you'll see, and the more practice you get "seeing", the better you'll get at it). You'll probably find a band or a ring gap that seems to disappear when going to the next higher mag eyepiece.

For perhaps as good or better of an example of this effect, try doing the same thing for the Cat's Eye nebula.

Keep in mind that your 130mm light bucket only focuses so many photons no matter what eyepiece or balow is installed, that adding a barlow not only spreads a fixed number of photons over a wider area, but also the lenses of it absorb some of those precious photons, and that you eyes are limited in response to some minimum photon count per second per"pixel".

Happy viewing-

Answer 3

try to avoid barlow lenses, unless you have some superior optics in that barlow! the more lenses you add to your telescope, the more bending and unbending light has to go through. also, you lose lumens for each lens you add, too! aperture is the only way to get more detail from any magnification. with your telescope, you should be able to see saturn's rings nicely as well as some of the banding of the clouds, but nothing more. there's really not much more to see, anyways. sorry, but if we could get more detail out of a small aperture, why would anybody ever have built large aperture telescopes, right?