Prefered Magnification

[matt c]

Hi there

Spent a good while on Saturn last night, and realized I'm starting to prefer a magnification of 120 instead of 200. I imagine in perfect conditions people would probably go for 200+, but generally speaking I think a lower magnification is best. Although it appears smaller you can actually see more, and the sharp focus is pleasing to the eye.

What are peoples opinions and personal preferences on this ?

:):)

[James]

I'll go for as high a magnification as I can that will still leave things really sharp and clear, for me that often ends up being 171x (7mm eyepiece) rather than 200x or 240x. I find that the clarity outweighs the 'size' of the view.

James

[hunterknox]

Low mags for me. 11x on the little refractor is a dream. It's like the best binoculars you could imagine. For planetary stuff I like the lowest magnification that gives the greatest possible detail. I read on another forum that that was Herschel's recommendation, so who am I to argue?!

[russ]

I prefer the other way round. The highest mag that still gives a pleasing view, which is anything from 100x to 400x, depending on the skies and the object. Mars has been taking huge mags in the last few months. But i prefer Saturn at around anything from 130-250x mark, if skies allow.

Taking Mars and Saturn as examples. Saturn has very few features, some banding and Cassini, that's about it. You can see those features equally well at lower powers (although i could only get a hint of Cassini at 200x with the rings so closed up). But Mars is tiny and the features subtle. Yes at low powers you will see the NPC and Syrtis Major clearly and the disk will be razor sharp but you'll never ever see the fine detail the sketchers manage to see. I haven't started sketching myself but have been studying Mars closely since October last year. Even at it's closest it still required 240-250x to tease out the really fine detail.

The way i see it is like this:

A thumbnail picture on the computer is dead sharp, doesn't show any noise, has in theory all the same detail as a large image and if you squint hard enough and get close enough to the screen, you can see most of that detail. The full size image may not be quite as sharp, there's no extra detail captured but it's a damn sight easier to see the same detail.

Russ

[brianb]

As low as shows all the detail - more than that reduces the visibility of low contrast detail. 25x to 30x per inch, in good seeing - often less when the seeing is poor.

This winter, with my CPC1100, Mars has been good at x224, a couple of times I've been able to use x311 but I haven't had a good view of Saturn at x200 so far this year. Saturn usually stands magnification about as well as Mars but it is much lower in the sky.

[kniclander]

If you have a dob you are a bit limited in my experience - I can't comfortably use mine above about 200x otherwise it becomes a PITA to keep nudging it. I see pople using 400x plus intheir dobs - I suppose with an 80deg+ e/p that might be ok.

[themos]

Whatever works: I've used x450 on the Moon (counted 13 craterlets in Sinus Iridum) and Mars on good nights. And that was on a 12" Dob with a TMB planetary eyepiece with a 60 deg FOV.

http://www.lpod.org/wp-content/uploads/2006/08/sinusiridum-WirthsLPOD2.jpg

[John]

I'll go for as high a magnification as I can that will still leave things really sharp and clear, for me that often ends up being 171x (7mm eyepiece) rather than 200x or 240x. I find that the clarity outweighs the 'size' of the view.

James

Thats pretty much what I find as well - I've 2 scopes with a focal length of 1200mm and the 7mm eyepiece gets much use with those.

[russ]

If you have a dob you are a bit limited in my experience - I can't comfortably use mine above about 200x otherwise it becomes a PITA to keep nudging it. I see pople using 400x plus intheir dobs - I suppose with an 80deg+ e/p that might be ok.

I've been using my dob at 332x on Mars with a 60deg eyepiece (even a 40deg Ortho for a while) and i just make the nudges in autopilot, just never noticed it being a problem. I could of mounted the tube on the EQ5 at any point but keeping it dob based was fine.

As can be shown by this thread, and others like it, everyone is different in what pleases them. There's no hard and fast rule to what works best.

[kniclander]

I've been using my dob at 332x on Mars with a 60deg eyepiece (even a 40deg Ortho for a while) and i just make the nudges in autopilot, just never noticed it being a problem. I could of mounted the tube on the EQ5 at any point but keeping it dob based was fine.

As can be shown by this thread, and others like it, everyone is different in what pleases them. Anyone looking at this thread for an idea of what magnification to use, the simple answer is experiment. Try some high powers on a good night and see what works. You'll find what works best for you.

agreed - that's why i said "in my experience", not "this is the case for everybody".

I would add that i have not "modded" my dob so possibly it could be made smoother and higher mags would be easier.

[russ]

agreed - that's why i said "in my experience", not "this is the case for everybody".

I would add that i have not "modded" my dob so possibly it could be made smoother and higher mags would be easier.

Sorry if my post looked like i was having go, it wasn't meant to. I always appreciate that everything we say is 'in my exerience'. And everyones different experiences are good to know.

Tinkering with the dob is well worth doing. I was not happy with the way my Skyliner moved. I replaced the pads on the base with some new Teflon and experimented with the placing to get a smoother feel. Plus tried some different tensions with central bolt.

On the altitude bearings i added some Teflon mouse tape.

It makes tracking/nudging a much nicer experience.

Russ

[kniclander]

Sorry if my post looked like i was having go, it wasn't meant to. I always appreciate that everything we say is 'in my exerience'. And everyones different experiences are good to know.

Tinkering with the dob is well worth doing. I was not happy with the way my Skyliner moved. I replaced the pads on the base with some new Teflon and experimented with the placing to get a smoother feel. Plus tried some different tensions with central bolt.

On the altitude bearings i added some Teflon mouse tape.

It makes tracking/nudging a much nicer experience.

Russ

no problem Russ

I really really need to do my dob.... not sure if "nudging" is even the right word for how hard I have to push it

[russ]

no problem Russ

I really really need to do my dob.... not sure if "nudging" is even the right word for how hard I have to push it

Yep that sounds familiar. I think it's called stiction, where it appears to have got stuck slightly. So you have to give it an extra hard push which then moves it too far.......at high power (or even medium/high) that is highly frustrating.

I was having a play with all the Skywatcher dobs at Astrofest and they all felt the same. Perhaps they had been over tensioned to stop visitors swinging them round but as a prospective buyer i would not have been impressed.

[themos]

I was having a play with all the Skywatcher dobs at Astrofest and they all felt the same. Perhaps they had been over tensioned to stop visitors swinging them round but as a prospective buyer i would not have been impressed.

There was one near the Telescope Planet stand (if I remember correctly) that was wonderfully smooth in azimuth.

[LukeSkywatcher]

Low(ish) magnification for me also. I find that in both my scopes (1000mm f/l and 650mm f/l) that i am very happy observing planets with just a 9mm EP.

[russ]

There was one near the Telescope Planet stand (if I remember correctly) that was wonderfully smooth in azimuth.

Was that the wrecked 250PX with the cracked primary mirror. Looked like something nasty had happened in transit. I didn't try moving that one but someone else had the dust cap off.

[themos]

I don't think it was a SkyWatcher, russ.

[russ]

There was a very nice Orion XX12 and Revelation 12 nearby to TP i think. Both of those were very smooth indeed, especially the Orion.

[bish]

I go as high as I can. Generally Saturn x300- x400 on really good nights.

[lunator]

I tend to use medium magnification for most work in the x110-x180.

I do use very high mags when conditions permit on tight doubles and planets in the region of x250+

Cheers

Ian