Highest power eyepiece in UK skies/seeing conditions.

[Guest]

I was fretting about selling my 150 mm Maksutov. But it is too good a scope to let go. But at a focal length of 1800 mm it would be easy to ramp up the magnification to over 300 x .

But what is a happy mean magnification here in our turbulent UK skies. I have been changing my eyepieces ( Explore Scientific 82°) so as I can fund a higher quality brand eyepiece. I think that a magnification of 230 x with the Maksutov would be the tops. That would mean an eyepiece with a focal length of between 7 & 8 mm.Perhaps there would be the odd night where seeing conditions would be fantastic so magnification could be satisfyingly ramped up to approaching 300 x. That would be a 6 mm eyepiece. Is it cost effective to invest in a 6 mm good quality, high priced eyepiece for that odd good night's seeing?

So I already have a Naglar T4 22 . I would add a 7 or 8 mm. I wonder what two additional focal length eyepiece would compliment these?

Edited December 28, 2020 by Guest

[Louis D]

I look at it from an exit pupil perspective.  You've got an f/12 scope, so your 22mm is producing 1.8mm, or just about the ideal exit pupil already.  You could move up to a 12mm to 13mm for a ~1mm exit pupil.  I generally don't go below 0.7mm most nights, so that would equate to an 8mm to 9mm eyepiece.  Taking these two together, you would do well with a 9mm and 12.5mm Morpheus set without giving up much field to the ES-82s while gaining viewing comfort.

I would look to add a 2" 40mm SWA to a 56mm Plossl widest field eyepiece as well for viewing nebulae with a 3.3mm to 4.7mm exit pupil.  You don't need to go super expensive with an f/12 scope for nebula observing, either.

[Don Pensack]

21 hours ago, Grumpy Martian said:

I was fretting about selling my 150 mm Maksutov. But it is too good a scope to let go. But at a focal length of 1800 mm it would be easy to ramp up the magnification to over 300 x .

But what is a happy mean magnification here in our turbulent UK skies. I have been changing my eyepieces ( Explore Scientific 82°) so as I can fund a higher quality brand eyepiece. I think that a magnification of 230 x with the Maksutov would be the tops. That would mean an eyepiece with a focal length of between 7 & 8 mm.Perhaps there would be the odd night where seeing conditions would be fantastic so magnification could be satisfyingly ramped up to approaching 300 x. That would be a 6 mm eyepiece. Is it cost effective to invest in a 6 mm good quality, high priced eyepiece for that odd good night's seeing?

So I already have a Naglar T4 22 . I would add a 7 or 8 mm. I wonder what two additional focal length eyepiece would complement these?

40% jumps:  31mm>>22>>16mm>>11mm>>8mm

33% jumps: 30mm>>22mm>>16.5mm>>12.5mm>>9mm>>6.7-7mm

50% jumps: 33mm>>22mm>>15mm>>10mm>>6.7mm

25% jumps: 27-28mm>>22mm>>17.5m>>14mm>>11mm>>8.8-9mm>>7mm

I'd go with 40% for a smaller set, and where you could spend a little more on each eyepiece.  Use a Barlow for the occasional super-still night for ultra-high powers.

[mikeDnight]

I find that a power of around 180X is my most used magnification on the Moon & planets, as on most nights there's little to be gained by going higher. Of course much depends on your target object. Stellar targets can take very high power during moments of steady seeing. So if you're looking at double stars, its not unreasonable to use 300X to 500X, and if you use a tracking mount you can even push 1000X if you can cope with the tiny exit pupil. Barlows are a great alternative to a shorter focal length eyepiece if you'd rather not spend a lot.

[Paz]

I've got a Mak with 1.9m focal length and I would say 12mm is usually good so 160x and then as I go up past that the law of diminishing returns kicks in with higher mags being useful less often. By 8mm or around 240x it is very rarely any good.

That's a smaller aperture though (127mm) but it's seeing rather than aperture that is usually the limiting factor.

[SiriusB]

The good,the bad & the ugly.....

One rare night i had my mak 127 @ 375x on moon, no atmospheric wobble whatsoever in the view & not a soft image.

Could i see any more detail than @ half that mag? Nope.

Mag for what purpose Grumpy?

everyones' eyes are different but...

My rule of thumb is anything >  1.5x aperture in mm for planets, 1x aperture in mm for moon shows me no more detail. Your mileage may vary.

Doubles are a little different.

Often the seeing in UK doesn't allow me to hit 1.5x aperture for planets, regardless of aperture i find north of 150x  not happening on an average night.

That's just one persons location & optical train though.

Can you borrow a few EP's to try before you part with hard earned cash?