View Full Version here: : Read it all and still confused
15-11-2006, 12:44 PM
Done all my research into which EP to buy but still confused. Too much choice. I need something clarified please. To view DSO's it is recommended 100x-150x, yet when I use my 17mm EP (120x) I can't see any detail of galaxies, just little blobs. Just how much magnification is needed to make out structure ? Help me spend around $300 on a quality EP. Any recommendations.
Using C8 Advanced
15-11-2006, 12:57 PM
It probably depends on where you are observing from. With an 8" scope in light polluted suburbia, you will only detect traces of the brightest galaxies. In a dark sky site however, it will amaze you. At any rate, galaxies generally aren't great targets if you want to see details, they are just too faint and tenuous. That being said, any good eyepiece will help you, and if you can spring for a 2" model and your scope can take it, so much the better. I am quite partial to the Vixen LV and LVW series myself, but thats purely a personal choice.
15-11-2006, 01:05 PM
I find the 2mm exit pupil rule spot on for me when it comes to faint fuzzies. Anything under 1.5mm exit pupil is too little light IME, except for brighter objects. (exit pupil = EP focal length / telescope f-ratio) But they are called faint fuzzies for a reason. In an 8" scope most galaxies will be faint wisps and/or puffs of light. You need dark skies, dark adapted eyes, and some practice to see structure. Couple of the best ones in the night sky atm are NGC 253 and NGC 1365. In an 8", you can see mottling on the disk for the former and the barred spiral arms of the latter.
One DSO EP for f/10 (I assume) for around $300? I'd go for an LVW 22 or 17mm. (and I'd eventually get both.) But if you already have a good 17mm Plossl, do not expect miracles from a more expensive EP. Most of the gain from a more expensive EP will be in a well corrected larger FOV not in detail seen.
15-11-2006, 06:27 PM
From my in-town light polluted back yard I can just see Centaurus A with direct vision through an 8'' sct.
15-11-2006, 08:20 PM
Shane is right Evan .. from my backyard my eastern view covers a very dark piece of sky ,ngc 253 a couple weeks back
(trees had only just let me get a peek) was stunning to look at from home
lots of structure .Couple weeks on I had another look last night
the object now has moved more west over the glow from town (10 000)
and I could just make it out, 13mm nagler both times , and last night was
probably one of the clearest I've seen ,but the views were
completely differant .
15-11-2006, 10:06 PM
I alternate mostly between the standard Meade 26mm (76x) and 13mm Baader hyperion (153x) a lot of the time with my 8 inch LX90 any more magnification and detail doesn't seem to improve. On very rare occasions I barlow the 13mm and get better detail on planetary.
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