ideal planetry magnification

[a10ken]

Hi folks, firstly a happy christmas/festive holiday to you all. secondly,could anyone sugest an "ideal" magnification for planetry observation: ie mars =X200 etc,etc,

My scope is a OO vx10l

thanks

ken

[ronin]

From the wailing and gnashing of teeth last time round 200x is a sort of minimum for Mars, many had better results at 250x, and I seem to recall a couple possibly up at 300x and 330x.

One thing I did read was put an IR filter in, Mars gives of IR and it can cause viewing deterioration.

Jupiter, well seen good at 65x, just small but sharp, aim at 80x and preferably 100x if the image remains sharp.

Saturn, saw it very good at 125x, think it was a TAL and 8mm eyepiece. So use that as a start, maybe try for 150x again if it remains sharp.

What you want on a planet is detail and too much magnification will lose the detail, so it is a compromise.

[faulksy]

as ronin says you need to keep it sharp, you can wind up the power and have a big blob but no detail so its pointless. it all depends on how stable the sky is (the seeing) some times i can view jupiter at around 300x or more buut quite often to see detail its around 250 or less, saturn likes power i managed this summer around 370x with great detail i have never managed that before, but mars similar magnification if your lucky, and if conditions are good you will see the dark regions and the white polar ice caps they are lovely

[kerrylewis]

With my scope I find the best that can usually get to is 235x with my 10mm ep. If the seeing looks exceptional with that then I try the 6mm giving 390x but that really is pushing it. Generally speaking 235x is the limit and if the seeing won't take that it's best to go lower and enjoy a crisper view as others have said.

Kerry

[John]

I think you have to be guided by the seeing conditions and be prepared to back off the magnification a little to get a sharper image with better defined contrast, albeit a little smaller in scale. This is where having a number of high power options is very useful or the Nagler 3-6mm zoom eyepiece if your scope is suitable

With my 120mm ed refractor I tend to find 150x - 200x best for Jupiter but Saturn, Mars and the Moon seem to tolerate 225x - 250x as long as the seeing conditions are decent. With my 12" dob the figures for the same targets are 200x - 250x and 300x or a bit more under fine conditions.

[nightfisher]

As john rightly said, go with the seeing conditions especially with Jupiter, at times it will take high mag and other time not so high, and when Saturn comes back to opposition that will usually take higher mags

[a10ken]

Thanks for that folks, that will be a usefull starting piont.

[Qualia]

General Useful Magnifications

When it comes to planetary viewing, I've noticed that slight changes in the focal length of eyepieces makes a big difference to what can be tweaked from the given object. In terms of general useful magnification, I have a little collection of EPs which run the following parameters:

f/10: 200x, 166x, 142x, 125x, 111x, 100x, 90x.

f/5: 250x, 208x, 178x, 156x, 138x, 125x, 113x.

A run of: 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, & 11mm.

For Lunar work, all these magnifications offer up something to be amazed by. Low powers from around 50x to 70x help frame the Moon, the mid-range frames craters and seas and mountain ranges and the high-power helps tweak out subtle features like terraces, tiny craters, ray grazes etc.

For Jupiter, I typically use mags between 140x to just over 200x. I have gone to 250x on a number of occassions but generally find I'm working between 180x to 200x in the 10" and between 140x to 170x in the 4".

For Saturn - Again I have found 140x to over 200x useful mags to play around with. You can go higher here, but a lot will depend on the night's atmospheric conditions.

For Mars, I figure Jupiter is about 3x the size of Mars and to see Jupiter nicely is, say, at around 200x which means that for me to get a 'similar' view of Mars I need 600x. Well, I'm just not going to get that kind of viewing quality. So, a compromise is needed, say, around 250x which still means seeing conditions will have to be very good. As such, I haven't found Mars a particularly giving planet.

For Solar work in white light I find about 50x a good working magnification which can be upped in gentle increments to around 100x when sky conditions allow.

General Rule of Thumb

The brightness of an object will decline as you up the magnification. If you up the mag twofold, you are reducing the image brightness by a factor of four. If you keep on doing this, eventually details just disappear.

On the other hand, increasing the mag does make detail more apparent, so, as you can appreciate, we're now at a trade-off: will increasing magnification gain more detail even though I'm making the object fainter?

I've found that playing around with this trade-off - dependent on the evening's seeing (LP doesn't really affect planets, Moon or the Sun) - does make a difference. Even as little as 1mm increase or decrease in the mag - about 10% to 15% difference of magnification - can be quite surprising which is the main reason why most planetary/solar system observers will have quite a run of high-mag EPs.

Final Thought

Whenever possible try to sit with your given planetary object for a peaceful sixty minutes or more. Try to be active in your observation, ask yourself questions about what you're seeing, try to name features etc. Bit by bit you'll find that they'll be moments of great clarity and seeing which will surrender a wealth of information. By practicing this kind of attentive sitting you come to notice more and more detail from the given object.

[a10ken]

Thanks Qualia, what a smashing post.

[acey]

The ideal is the magnification which shows most detail. This depends on your eyes, your observing experience, the quality of your optics, and atmospheric conditions. Start low, work up through your available powers, and when the planet starts to look mushy go back to the previous power. Jupiter at x100 in a high-quality scope with a high-quality eyepiece will look far more detailed, colourful and contrasty than Jupiter at x200 in a poor quality one. Jupiter at x100 on a night of very good seeing (steady air) will show more detail than at x200 with the same scope on a night of very poor seeing.

[LukeSkywatcher]

Magnification means nothing if the seeing conditions are not right.It really is hit and miss, depending. On good nights of seeing, you can crank up the magnification. On poor nights of seeing........you need to pull back on the magnification.

In general,no matter what scope i use...............i find on average that an 8mm eyepiece gives me the best views of the planets.

[Grotemobile]

I think a lot of it is down to the EP you are using,A good one,

will allow, more mag, than a poor one.You only pay, for what

you get.

Steve

[bomberbaz]

If you read through each post you will find that everyone is highlighting various things that effect viewing, (scope size, conditions, eyepieces) so all this neds to be taken into consideration but without doubt the biggest factor are the conditions imho.

steve

[Kirscovitch]

Everything said above is spot on.

One night about a month ago on a really good night I managed to see Jupiter with a 3mm EP (216x). It looked pretty good. Bands were amazing and plenty of detail.

Tonight I was out and the best view I got was with a 9mm and 2x barlow (144x).