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View Full Version here: : The relationship b/n Scope and Eyepiece.


Mike21
30-07-2009, 01:32 PM
I'm guessing there needs to be a certain balance between expenditure on scope and expenditure on eyepieces; like the relationship between amplifiers and speakers. If one out performs the other by too big of a margin, you're wasting your money. Skywatcher doesn't appear to be bothered by the relationship. I've seen plastic bodied 1.25" Barlows sold with 200mm reflectors on an HEQ5. A couple of thousand dollars of rig and a plastic eyepiece?? By the same token, it'd be silly to put a $400 EP on a $200 scope - wouldn't it?

Do any of you more experienced boffins have a rule of thumb as to the relationship between scope and eyepiece?

Mike.

erick
30-07-2009, 01:38 PM
:D:D:D:D:D:D:D:D:D :ashamed::ashamed:

Scope - USD15; Barlow/diagonal/eyepiece - USD680 :screwy:

Mike21
30-07-2009, 01:44 PM
You're good for a laugh Eric! Who needs to be putting their "Don't look at the Sun" sticker back in it's rightful position?

erick
30-07-2009, 02:05 PM
I didn't read the instructions before I stuck it on :doh:

h0ughy
30-07-2009, 02:15 PM
mmm i can see a point at which it will snap....LOL

Mike21
30-07-2009, 02:26 PM
We've diverged. Since it was you that made me think about better EP's on a different thread; do you have a rule of thumb? Could I get more out of my $1700 Megrez 110 if I spend more on EP's? Luke at Andrews convinced me to purchase 18mm and 5mm planetary eyepieces (generic) and claims they were in the same ballpark as WO EP's, but not up to Baaders' standard. He's believable too because he said that the 3mm EP (in the same series) was not getting the same rave reviews. Does a $400 EP blow you back in your chair or does the law of diminishing returns set in; and if so roughly where?

Tough one to answer I know.

Ta, Mike.

dannat
30-07-2009, 04:46 PM
Mike - i reckon you also need to weigh up what you want them for..those planetary ep's are made by the factory who produces the WO ep's being essentially the same. Luke is right the 3mm gets bad reviews cf the 6mm & 12mm etc. In the short f/l ep's like 6mm i reckon i notice less difference in ep's - as you are usually centering on a planet or something small/dim - and so only using the middle bit of glass. I have bought some s/hand orthos for this at $60 - sharp in middle but narrow fov.(overall gives 80-90% of exp ep so i don't care)
When you get the longer f/l ep's(20mm-35mm) i reckon the difference is way more noticeable - you want a more expensive wide field to take a lot of stuff in & see the edge of the field. I see the difference as being big - like 40-50% difference in the cheaper ep. So i would spend more at the bigger end..
but it is a personal decision - also depends a lot on how much do re me you have to spend

Mike21
30-07-2009, 07:10 PM
Thanks Dan,

This is one field that I poorly understand. I thought and still believe that the super short EP's (3mm say) were really pushing the envelope of sensible refraction and therefore good ones would be pricey; like low f-type apo refractors. Conversely, I thought that long EP's (say 20-40mm) did not bend the light as savagely and were therefore easier to make and therefore less pricey; like high f-type long achromats. You've corrected me and given me something to think about.

Thanks.