Magnification and planets

[Ags]

I'm just wondering what sort of magnification people prefer for different planets. I've read that Mars and Saturn can take higher magnification than Jupiter without breaking down.

I know it also depends on the telescope, but my experience so far is that everyone with a telescope of 100mm and above will be using magnifications in the range of 150 to 250, with a few odd people saying they use 300 or 400 mag... ;-)

I'm curious because I want to try and tease out some cloud belt detail on Saturn (I've only glimpsed such detail once) and I'm wondering if I need a new 7mm eyepiece to do the job - less magnification than my 6mm, but the image will be brighter of course.

[John]

I believe it all depends on the scope and the observing conditions (usually the other way around actually !). Sometimes 150x is too much - tonight I was using 320x on Jupiter reasonably comfortably with my 6" refractor although dropping back to 250x gave a sharper, and to my mind, more pleasing view.

Saturn seems to "take" power better than Jupiter does. Mars is pretty challenging but, on good nights, I have been able to use over 300x on it. Cloud belt detail on Saturn is always very subtle - much, much more so that Jupiter. The best I've done is to see a couple of belts and the suggestion of a white patch / spot a few years back with an 8" scope and superb observing conditions. We have been rather spoiled by Jupiter for cloud details recently I'm afraid !.

Personally I'd rather have a smaller, sharper image rather than a larger, slightly blurred one.

When Jupiter was at opposition it's angular size was pretty large so even 120x was enough to show it's features.

I don't think you can really have any hard and fast rules - you need to experiment and see what gives the best results on a particular night.

FWIW I've never found 200+ magnification usefull with my 4" ED refractor, apart from on double stars.

[Ags]

I've used 220x often enough with my 100mm Mak on Jupiter and also on Saturn yesterday morning. It brings out some details, but the image is starting to get dim. If the planet is quite high and the sky has good transparency, then I find there is enough light for 220x. But perhaps I'd have more chance of seeing that subtle Saturn banding at a lower mag...

[michael.h.f.wilkinson]

As John said, the atmospheric conditions are usually limiting. The maximum I tend to use is 250x on my C8, but I really need to get that 10mm Radian to get a more manageable 200x, which I find is usually the practical limit. However, in exceptional conditions I have used 288x (with my old Vixen LV 7mm).

Regarding dependence on which planet you are observing, my experience is Mars>Jupiter>Saturn, possibly simply due to the surface brightness.

[russ]

I've had a torrid time with Jupiter this Autumn/Winter. Never been able to break 150x. Not sure i've ever experienced such a long period of unstable seeing. Back in the summer Jupiter was taking 200x+. But as John says, the apparent size was large, so even low power gave a good view.

But already noticed that Saturn is happily taking 220x in the morning sky, with a relatively sharp view the other morning, easy to spot banding and an occasional hint of Cassini. Saturn is rising to a similiar height as Jupiter was at its best last year, about 35deg. Later this year Jupiter gains another 10deg, so that should make quite a difference.

Mars was taking huge magnification in 2009, i was using upto 400x and still getting a lovely view. Amazing what can happen when the planet is riding so high in the sky.

[michael.h.f.wilkinson]

I tried 420x (just for a lark really) on Mars, got an OK view, but no more detail than at 288x. Much also depends on visual acuity. Because mine is high, I tend to use lower magnifications.

[bish]

Saturn does seem to stand higher powers better than Jupiter. Start at about x150 and keep going until nothing is gained from increasing. Sometimes this means going up to x450 or so, other times I don't get much over x150. Small and bright doesn't really work for my eyes so I sacrifice some sharpness to have it a bit bigger.

[ollypenrice]

I often get excellent seeing in the wee hours and have some nice glass available, but I call it a day at about 250x. After that I find myself saying, 'Hey, I am using more than 250x' rather than looking at what is there... and that is a bit daft, no?

You have to play it by ear (can that be the right phrase???) just as John said.

Olly