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Will the Moon take higher magnification than planets?


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I have an 8” SCT, focal length 2030mm, and for viewing planets such as Jupiter I’m told that 200X (so with a 10mm EP) or even less is the optimal magnification before the image gets washed out. This is true since I tried the TMB 6mm EP (gives 338X) on Jupiter and the resolution was a lot worse than with the 200X.

So my question is does this also hold true for viewing the Moon? Would 200X also be the maximum magnification for viewing, or since the Moon is relatively very near, with far less atmospheric interference etc, could I realistically use more powerful EP’s such as a 6mm or 5mm or will the images of the Moon be poor resolution at this magnification just like Jupiter is?

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The atmospheric interference is the same for the moon as it is for any solar system object or DSO because you have to look through our atmosphere whatever your viewing. The moon however will take higher magnification because it is so bright, I have used x480 on the odd occasion.

With Jupiter I find that x140 gives me the best views.

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I was using my 4mm UWAN (443 X) with my 13.2 inch on the moon last night and the views were fantabulastic! As the moon was high up and the atmosphere fairly steady the image was momentarily very detailed 30 percent of the time and contrasty. Jupiter is quite low from where I live so is affected more by atmospheric distortion.

Edited by perrin6
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Why you can use more magnification is because the contrast features you're trying to observe are very high contrast features. So if turbulence transforms the features into images that "wobble" a bit, your eye can still pick up what the features are.

For other contrast features, larger but more subtle, the eye/brain combination won't actually be able to tell that it's small features behind something that makes them wobble a bit, and you'll end up with a "fuzzy" view.

When bad seeing occurs, it actually destroys these larger but subtle contrast features first, much earlier than it destroys those smaller high contrast features.

If you want to see subtle colour variations in the maria, then you're likely not going to be pushing magnification as far as when oyu want to see stark contrast features close to the terminator. The moon actually has quite a bit of "Jupiteresquely" subtle detail once you look for it...

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The other night I was viewing Copernicus and ended up using my 6.4mm EP with 2x barlow. That works out to 375x magnification.

Lovely sight :)

Mars in January wasn't far away on one magic night. Otherwise Jupiter is usually best for me in my 12mm EP giving 100x magnification.

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as you'd expect I completely concur with the previous comments. with both my dobs (see signature) but especially the 12" the moon is the only target (apart from double stars) where I can use my Nagler 6-3mm zoom successfully. the magnification is between 267x-533x and I can occasionally use it at the higher level on the moon. it's always usable but you really don't gain much detail apart from really steady nights.

with eg. Jupiter the view is far better at between 120x-140x and then starts to break down somewhat - I'd sooner see small and sharp than larger mush.

now if we lived in darkest Arizona.........

Edited by Moonshane
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Hi Martin, i think the wealth of available lunar detail is the reason we can use higher than the 'recommended dose' of magnification on the Moon.

For about 10 years, i've been observing Luna with an 8" LX-10 and a 9mm UO ortho (222x). Although the sharpness pops in and out with variations in the seeing, the views are quite satisfactory. Orthos compliment SCT's very well, because their wonderful contrast partially makes up for the loss of contrast created by the SCT's central obstruction.

On rare nights of extremely steady seeing, i've barlowed the 9mm and kicked the power up to 622x... incredibly, the views were comparable to what i'd normally see without the barlow.

Man, i sure wish that'd happen more often. :)

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