highest magnification tried

Jarrod · #1 05-09-2007, 06:47 PM

hi all,

im just wondering what the highest magnifications each of you have tried, for better or worse. i have an unhealthy obsession with really high magnifications, even though i know how crappy the view can be with too higher 'power'. with a 4mm EP and 3X barlow ive tried to view at 750x with my 5" reflector many times, and i once got a night of near perfect seeing and got an amazing view of saturn

(whether you choose to believe me is up to you

.)

any hoo, im interested in the highest magnifications anyone here has tried, and the type of equipment, seeing conditions, image quality, etc.

jarrod.

Zuts · #2 05-09-2007, 06:53 PM

Hi,

I tried a barlowed 4mm vixen lv on my Celestron Nexstar 11 on the moon. That is about 1400 mag. I was surprised that i could see anything but large aperture and bright target helped. The view wasnt that fuzzy either.

acropolite (Phil) · #3 05-09-2007, 08:14 PM

The most I've tried with my LX (7mm Burgess EP) is around 285x. Mostly I stick to half that mag as a maximum. I have tried the 7mm many times, not once has the seeing been good enough to achieve any better result than at 140x (14mm EP)

jjjnettie (Jeanette) · #4 05-09-2007, 08:45 PM

I went mad one night during a moment of exceptional seeing and double barlowed my 4mm ep and pointed the scope at Saturn. Those rings at 1250x are pretty special.

Jarrod · #5 05-09-2007, 08:52 PM

Quote:

Originally Posted by jjjnettie

I went mad one night during a moment of exceptional seeing and double barlowed my 4mm ep and pointed the scope at Saturn. Those rings at 1250x are pretty special.

when you say you 'double barlowed' a 4mm eyepiece, do you mean you used 2 barlow lenses, one ontop of the other with a 4mm eyepice at the end?!?
i didnt know that can be done!

jjjnettie (Jeanette) · #6 05-09-2007, 09:01 PM

That's right Jarrod.

monoxide · #7 06-09-2007, 12:42 AM

oh god, now hes gonna go buy a box of barlows lol

§AB · #8 06-09-2007, 09:16 AM

most I've tried was 330x on the moon with my 4.5" reflector, the result wasn't half bad actually.

bojan · #9 06-09-2007, 09:25 AM

Once I tried Saturn with 4mm Ortho and one Barlow.. but pushed to 3~4x (to do it you just have to extend your eyepiece as far from barlow as you can with additional adapters) , it was ~1500.. but seeing was bad and vibrations of the whole thing were magnified accordingly.. so I was not impressed too much.

erick (Eric) · #10 06-09-2007, 10:20 AM

Quote:

Originally Posted by bojan

.....to do it you just have to extend your eyepiece as far from barlow as you can with additional adapters....

A general question if I may, since I know the answer is dependent on a lot of things - how far from the barlow lens? cm? inches? feet? I've been fiddling around with cm-type extension and I've been thinking to stick a foot long tube on the barlow and see what happens!

ving (David) · #11 06-09-2007, 10:56 AM

hmm... 1200mmx4x2 plus 6mm ep equivalent... imaging

bojan · #12 06-09-2007, 11:01 AM

Erick, you can go as far as it is practical. I think I used ~250mm extension, and obviously the magnification you will be getting will depend on the barlow focal length.
Of course, this will result in barlow going in (closer to the primary) a bit more (but not much... Actually in the extreme case, when the barlow external focal point coincides with the focal point of the mirror, the effective focal length of this system will be infinite. This is also a case of Galilean telescope optical system.. he used the negative lens as an eyepiece.

chris lewis · #13 08-09-2007, 07:59 AM

Have used 450x on the moon with my Orion ED100 - image held up well but starting to get a bit dim. Thats 112x per inch - well over the theoretical limit !

Jarrod · #14 11-09-2007, 07:14 PM

1500x!!! i thought i went over the top when i tried 750x!!!

Quote:

Originally Posted by monoxide

oh god, now hes gonna go buy a box of barlows lol

what makes you think i would do that?

although i have no intention of buying a box of barlows, i would like to know how to calculate the magnification that results from double (or triple, or quadruple) barlowing.

using a 6mm eyepiece on the 12" dob i wish i had, with a f/lenth of 1500mm, i would get 250x. a 2x barlow would make it 500x. would the 2nd barlow (a 3x barlow, say) multiply the mag' agian, so 1500x, OR do the two barlows go together to become a 5x barlow, so give a mag' of 1250x?

jarrod

monoxide · #15 11-09-2007, 08:24 PM

if you disregard the eyepiece and think of each (2x) barlow as doubling the focal length of the scope it makes a bit more sense

no barlow = 1500mm
first barlow = 3000mm
second = 6000mm

then you can work out the magnification it would give you

i've had some nice views of saturn at 500x through my 12"

absolutely incredible when you get those moments of really good seeing
its not often you get a chance to do it though

Jarrod · #16 11-09-2007, 08:43 PM

Quote:

Originally Posted by monoxide

if you disregard the eyepiece and think of each (2x) barlow as doubling the focal length of the scope it makes a bit more sense

no barlow = 1500mm
first barlow = 3000mm
second = 6000mm

then you can work out the magnification it would give you

i've had some nice views of saturn at 500x through my 12"

absolutely incredible when you get those moments of really good seeing
its not often you get a chance to do it though

thanks, it makes alot more sense when multiplying the focal length rather then the magnification

.

§AB · #17 17-09-2007, 02:44 PM

someone should try stacking 10 TV 5x Powermates with a 2.5mm Vixen LV....

mickoking · #18 17-09-2007, 06:52 PM

I am too gutless to try really high magnifications :-)

ballaratdragons (Ken) · #19 17-09-2007, 07:00 PM

Quote:

Originally Posted by jjjnettie

I went mad one night during a moment of exceptional seeing and double barlowed my 4mm ep and pointed the scope at Saturn. Those rings at 1250x are pretty special.

Davo Pretorius and I did the same thing at Camp once!!! 2 Barlows really brings Saturns rings up BIG!!!!

I can't say it was a crystal clear view, but it suprised us that we could see the rings at all

We were looking at Saturn when it was only about 5 degrees above the horizon across a dam!!!

1958van (Peter) · #20 15-10-2007, 09:54 PM

I can't imagine more than about 750x given you need to look through so much atmosphere, especially at low elevations. My highest with a usable picture was 570x looking at Jupiter, an Orion 3.8ED in my 180 Mewlon (FL 2160mm) and it has a very good mirror. Peter

----------------------
Mewlon 180 on a GP-DX and Televue Genesis on a TV alt/az mount. Fav EPs, 24.5 Meade SWA and 19 Pano, got a set of Siebert planetary EPs (5.4, 7, 10, 12.5 and 15). Celestron 15x70 binos.