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Chris Fleming
20-11-2011, 09:49 PM
I'm perpetually tempted to get higher magnification EPS even though I know that unless the seeing is perfect it's pointless. This raises a few interesting questions ...
1. Who actually uses 3, 4 & 5 mm EPs (all the big names make them so they must useful for something?)
2. I have a 12" lightbridge ... whats the highest maginfication I can reasonably expect
3. Any recommendations for a high magnification EP for planets & splitting doubles (I like 82 degree EPs & my highest magnification EP is 9mm). I'm considering a 6.7mm ES or even the new Meade 5.5mm SWA, both can be bought fron the US for $100 to $120)

Any recommendations?

wavelandscott
21-11-2011, 02:45 AM
Think about calculating the magnifiction for a fastish refractor...you will soon see that the 3,4 and 5 mm EPs have a definite use...

Waxing_Gibbous
21-11-2011, 02:54 AM
I use them mostly on short (< f7)FL refractors.
My 3 highest mags are a 5mm Takahashi, a 6.7 ES and a 7.5 Tak.
While the 6.7 is an excellent EP and a bit of a fave for Lunar work, its contrast and sharpness fall slightly, but noticably short of the Taks.
The Taks however have only a 50* FoV and really need, or at least benefit from, a tracking mount.
If I was like 99% of people out there I would recommend the Pentax XWs (70* FoV), but I have problems with their eye position and never got the hang of them. A shame, as when I could get them 'working' the views were nearly flawless - particularly the 7mm.

Poita
21-11-2011, 01:55 PM
I use the 5mm all the time on the 105/650 Lomo refractor, and occasionally on the 10" SCT for planetary when the seeing is up to it. I find the 8-9mm tends to be the weapon of choice in the SCT most nights though, but when the seeing is great, it is a joy to use the 5mm.

brian nordstrom
22-11-2011, 08:48 PM
Hi Chris , :) Your 12 inch on a perfect night get 500x plus , but in reality thats not really possible . Stick to around the 150 - 200x .
To many variables . Seeing , turbulence , clouds , etc , etc. :shrug:
I find on the planets and the moon , my 63mm Zeiss with its 840mm focal length and my 2x Celestron ultima barlow used with my 12.5mm Badder real orthoscopic eyepiece , that gives 133x is about perfect .
That combo shows a perfect image of jupiter , lots of deatail and not to bright .
I can easily top 200x plus, but the seeing wont allow that most nights , so 133x is nice .:thumbsup:
Brian.

doug mc
27-11-2011, 12:07 PM
Depends what you are looking for. The central cratorlet in plato can be seen as a indistinct spot at medium powers, but its shape as a circular crator with rim shadow requires three to four hundred mag with my old eyes. I use eight to ten inch reflectors.

erick
27-11-2011, 01:24 PM
If you can get a response from Sylvian:-

http://www.iceinspace.com.au/forum/showthread.php?t=66161

a 6mm one of these is a cheap way to try. I have a 5mm and a 9mm that I use on the Moon and Jupiter when the seeing is good. (302mm f5 reflector)

Gem
27-11-2011, 11:18 PM
I got a 4.8mm Nagler to use on my old 10" dob... It was good but in hindsight it doesn't get as much use as I would have liked. It needs pretty decent conditions to meet its potential. Since the dob doesn't track, I wanted the FOV of the Nagler to be combined with the high mag for lunar, planetary and double star viewing.
I wish I had of got a 7 or 8mm quality EP instead. Live and learn...

erick
28-11-2011, 02:14 AM
I was using the 5mm earlier this evening on the crescent Moon and Jupiter with good results. 300 magnification. But the air was quite steady.

doug mc
28-11-2011, 02:17 PM
Astronomics in the states is selling these for just under $50.00. Just in case Sylvian has disapeared. I also sent a pm. on sunday, have not seen reply yet. He was good with earlier purchases.

David Niven
29-11-2011, 01:54 AM
I recently bought one of these 6mm tmb and initially, I have my doubt about its performance.
Man, am I wrong!
I used it on Jupiter the other night on my 10" Dob and I am just so happy with what i saw!
Jupiter was crisp at 200x and I have to say, I am happy with it.
This must be one of the most affordable ep around, considering, I paid just $50 for it.