I have a 12.5" f6 dob and am looking for an ep in the 13-15mm range with at least a 60-70° FOV for around $200. I have a 25mm wide field (76x)that works good as a finder. I would like to get close to double that power for the next step. A 15mm would give me 127x, 14 would be 136x, and a 13 would be 147x. I have a 10.5mm Pentax XL on it's way and that gives me 181x. For my higher powers I have a Teton 8 and 7mm which gives me 238 & 272x respectively. I don't really have/use anything above that because the skies here in SE Wisconsin don't ever really get THAT good. I had in mind a Pentax 14mm XL. Anyone have other suggestions??
EP suggestions
Started by spacemanspiff, 04/20/2009 08:16PM
Posted 04/20/2009 08:16PM
| Edited 04/20/2009 08:18PM
Opening Post
Posted 04/20/2009 08:34PM
| Edited 04/20/2009 08:39PM
#1
At f/6 the XL 14 is probably the finest choice reasonably available, given it is out of production but comes up on the 'mart farily often. And it is within your price range ($190 to $210 typically).
The new company Explore Astronomy (forget exact name) has a 100 degree 14mm eyepiece for $400 but that is 2x your desired expenditure; it is also a heavy eyepiece which can influence dob owners.
If you get impatient with waiting for an XL to come up, XWs can occasionally be had for $240 to $250 used. The XW 14 is despised by fast dob owners and deservedly so; mine works well at f/6.5, don't know what the trip point is at which the image starts to deteriorate markedly due to fast focal ratio of the scope. But f/4.5 is deinitely not where you want to be with an XW14. F6 I guess would be OK.
After Pentax you are left with muddy glass makers such as the Meades, Nagler 13s and the like, some of which are expensive and some of which don't do too well in many cases (beware the Radians). The Vixen LVW 13mm "super wide" is probably what I would choose to fit your specs. (don't confuse these with the 1.25 inch Vixens). At 65 degrees it fits your desired spec; prices list at $290 but used should be cheaper and you might do better if you call the vendor (such as Highpoint, Astronomics, or Woodland Hills). I am still of the disposition to prefer Japanese precision glass to Chinese budget glass.
I would suggest XL or XW 5 or 7mms in your arsenal for high power views, with a 12.5 inch dob you really want to get up into the 250-350x range for the occasions that require it. For reference I seldom bother doing Jupiter or Saturn viewing in my 14" if the seeing won't support 230x or higher, unless Joe public is around and really wants to catch a view no matter what. In my 4" I'm maxing out the exit pupil at 188x so that's as high as I go on that one.
Though of narrow field, the RKE 12 and 8mms would be nice to have as planet viewing eyepieces, but they're around 45 degrees.
Good hunting,
Greg N
The new company Explore Astronomy (forget exact name) has a 100 degree 14mm eyepiece for $400 but that is 2x your desired expenditure; it is also a heavy eyepiece which can influence dob owners.
If you get impatient with waiting for an XL to come up, XWs can occasionally be had for $240 to $250 used. The XW 14 is despised by fast dob owners and deservedly so; mine works well at f/6.5, don't know what the trip point is at which the image starts to deteriorate markedly due to fast focal ratio of the scope. But f/4.5 is deinitely not where you want to be with an XW14. F6 I guess would be OK.
After Pentax you are left with muddy glass makers such as the Meades, Nagler 13s and the like, some of which are expensive and some of which don't do too well in many cases (beware the Radians). The Vixen LVW 13mm "super wide" is probably what I would choose to fit your specs. (don't confuse these with the 1.25 inch Vixens). At 65 degrees it fits your desired spec; prices list at $290 but used should be cheaper and you might do better if you call the vendor (such as Highpoint, Astronomics, or Woodland Hills). I am still of the disposition to prefer Japanese precision glass to Chinese budget glass.
I would suggest XL or XW 5 or 7mms in your arsenal for high power views, with a 12.5 inch dob you really want to get up into the 250-350x range for the occasions that require it. For reference I seldom bother doing Jupiter or Saturn viewing in my 14" if the seeing won't support 230x or higher, unless Joe public is around and really wants to catch a view no matter what. In my 4" I'm maxing out the exit pupil at 188x so that's as high as I go on that one.
Though of narrow field, the RKE 12 and 8mms would be nice to have as planet viewing eyepieces, but they're around 45 degrees.
Good hunting,
Greg N
"Scope will get you through times of no money better than money will get you through times of no scope." --Freewheelin' Franklin
Posted 04/21/2009 04:27PM
#2
I have a 25mm wide field (76x)that works good as a finder. I would like to get close to double that power for the next step.
Barlow?
Also, the Siebert Ultras are much better than the Standards. Had you thought about one of his 13mm? He has a petty generous return policy.
Barlow?
Also, the Siebert Ultras are much better than the Standards. Had you thought about one of his 13mm? He has a petty generous return policy.
Funding Member
