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Saturn - magnification advice


iamjulian
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Hello

I first saw Saturn through a university telescope years ago, but hadn't seen it again until last night. I was viewing through a Sky Watcher 150P and a 6mm wide angle EP which gave a 250x magnification. It was tricky to get the focus right, but it was close enough to get a nice view of the ringed one.

I only had about five minutes viewing time so I didn't get to play with different magnifications, but my initial thought was, I should buy something to give me even more magnification. I know pushing magnification isn't always the way to go, but do you think it will be worth getting closer or even beyond the scope's theoretical maximum of 300x? Will I benefit? On nights of good seeing of course.

Have any of you had good views of Saturn at more than 250x magnification? All advice much appreciated.

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Saturn does take high magnification better than other planets. x250 is an achievable, worthwhile magnification on a good number of nights, x300 a lot less so.

I guess it depends on whether you want to shell out for an eyepiece you may not get to make use of that often?

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Most nights x250 is the max in the UK, that seems to be when we get our weather from the West.

However, recently seeing has been good enough to support x300 to x400 on Mars - we have been getting our weather from the North or North East.

So for the few nights when seeing is really good a 5mm eyepiece will be a good addition.

Clear skies.

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Hello

I first saw Saturn through a university telescope years ago, but hadn't seen it again until last night. I was viewing through a Sky Watcher 150P and a 6mm wide angle EP which gave a 250x magnification. It was tricky to get the focus right, but it was close enough to get a nice view of the ringed one.

I only had about five minutes viewing time so I didn't get to play with different magnifications, but my initial thought was, I should buy something to give me even more magnification. I know pushing magnification isn't always the way to go, but do you think it will be worth getting closer or even beyond the scope's theoretical maximum of 300x? Will I benefit? On nights of good seeing of course.

Have any of you had good views of Saturn at more than 250x magnification? All advice much appreciated.

I have the same scope and you get 250X with the 6mm AND 2X Barlow. Is that what you had? If not you would have only been 125X

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Most nights x250 is the max in the UK, that seems to be when we get our weather from the West.

However, recently seeing has been good enough to support x300 to x400 on Mars - we have been getting our weather from the North or North East.

So for the few nights when seeing is really good a 5mm eyepiece will be a good addition.

Clear skies.

I hadn't noticed that, I'll keep an eye out (pardon the pun!) for that in future.

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The thing is that, generally, additional magnification won't show any more detail -what is needed is time at the eyepiece so that your eye and brain become accustomed to teasing out the detail that is already in the image and seize the fleeting moments of excellent seeing to build the best image that the combination of scope and viewing conditions can deliver.

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Thanks everyone. I won't go for more magnification then. I shall play about with various magnifications in the 150x - 250x range.

Hubblebubble, sorry yes, forgot to mention the 2x barlow.

That's your best bet. Just play around with different magnifications until you get something that works for you. Whether that's 150x or 250x. Just a case of getting the best combination of image scale and clear, sharp image.

And as Dweller says, each night will vary. So what works one night may not work on another night.

Russ

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Thanks all. Tried again last night. A moon filter (the only filter I have at the moment) didn't work, but at 125x the image was much sharper, and only slightly smaller (or so it seemed). Cannot see any banding yet, but it is a beautiful planet. Cannot wait for the rings to open up a bit more.

Thanks for the telescope simulator link - as in thanks for making me want a 16" scope with a 5mm Televue Nagler :eek:

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I learned a bit of a lesson on this subject the other night which i shall share....

i always view planets with the highest magnification the night will stand, if its a choice of two different eyepieces which are straddling the limit for the night i always go for the higher magnification one, over the years i have got the best results this way and i am very happy with it.

But the last time i was out i spent 2 hours observing mars and saturn at what i thought was 370x (my scope is 200mm diameter so this is close to the theoretical limit but not over it, and the seeing was excellent), picked out loads of detail, and was thinking about calling it a night when realised i had the wrong eyepiece in the focusser! i had been observing at 270x not 370x. I changed eyepieces over to give 370X and although the image was bigger and did not degrade noticably (infact it still looked sharp ) i didn't really pick out much more detail, it was just bigger.

I was pretty suprised by this, but the thing is that at the lower magnification the details were slightly sharper with slighly better contrast, which made them visible.

But then at the higher mag the details were bigger, so really there wasn't much to choose between high and medium magnification. You couldn't see the datails any better either way, it was just different!

In future i think i will play with the magnification a bit more to see if it helps with seeing the details, and not just go for the higher end automatically.

so i suppose my advice would be buy an eyepiece, try it for a few nights and if you don't think it is an improvement sell it on, then at least you know one way or the other.

A televue plossl or edmund RKE are quite inexpensive and very high quality for the moneys on planets.

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The whole issue of maximum magnification also depends critically on an extra factor: your personal visual acuity. Average acuity is 1.0, curiously, many nearsighted people (like me) have high visual acuity (1.6 in my case). This means you tease 1.6 times more detail out of the image. The Abbe limits on magnification are actually tailored to people with high visual acuity.

However, I have always stuck close to or just above the optimal magnification (150x for my old 6", and 200x on my current C8). I go to 250x max on my C8 now.

BTW, Jahmanson was dead right in that it is the brain that needs to be trained. Visual acuity goes up with training.

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I'm probably not the norm. I have quite a few annoying 'floaters' in my eyes which make it very difficult to see detail on small bright objects. Because of this it is easier to magnify as high as possible (without the image getting too fuzzy) to see the details. Saturn always seems to stand high magnifications better than the other planets. despite being very low in the sky I was getting good views at x400 last night (200mm scope), whereas Mars was a fuzzy mess despite being much higher. Could have just been luck with Saturn, but I seem to recall having my best views with a 6" scope at x375. If my eyes were any good I probably wouldn't have to go so high. At least it doesn't affect my averted vision for the 'faint and fuzzies' I suppose.

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oh the floaters, they drive me mad!

they are not so bad if the image is dimmer, like you say bish higher magnification helps and i also use filters for this reason too. But any unfiltered planet and i struggle.

I wonder if you will be able to have the lasered away soon?

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Binoviewers help greatly with the floaters. I have no idea how because after all they are still there but somehow the brain chooses to ignore them or cancel them out when using both eyes. Had seen other people mention it and wasn't sure i believed it but it was the first thing that struck me when i first used my binoviewers.

Edited by russ
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Glad I'm not the only one - but please don't take that the wrong way as I don't wish them on other people! Mars is very difficult because unless it's really magnified the floaters can obscure half the planet. When I reached my mid thirties my eyes just suddenly seemed to be full of them. Snow and grey but bright days drive me mad. Think I will try different filters like Chris. Binoviewers sound good too but I would probably have to save up for them. When I was a kid I lived in the countryside with completely dark skies and excellent eyesight. I loved the stars but didn't like going out in the cold! Now I'm middle aged I will spend all night out in the freezing cold surrounded by street lights and security lights trying to see small details with my rubbish old eyes. Sorry - gone off the subject a bit!

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I find the floaters vary hugely. Some nights are really bad and it's hard to avoid them getting in the way. But other nights there's hardly any. I remember them being a problem when i was a teen and trying to observe was sometimes difficult. I used to get quite worried until it was pointed out it was quite normal (but bleddy annoying).

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The brain cancels out floaters when using two eyes by constructing a more-or-less self-consistent model of the field of view. The actual image transmitted by the retina to the visual cortex is dismal, with all sorts of garbage superimposed. The brain reconstructs a good image all the time. Unless the floaters are in complete sync in both eyes, they are considered part of the usual interference and ignored.

You actually see with your brain, more than your eyes. This is why when I go to the optician to have my eyes checked, my visual acuity depends on my state of fatigue.

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