Your favorite eyepiece for planetary detail
Posted 22 November 2012 - 09:53 PM
Posted 22 November 2012 - 10:37 PM
Posted 22 November 2012 - 10:44 PM
That said, when I'm looking at planets, I find myself reaching for my Brandon 6mm far more often than any other.
Posted 22 November 2012 - 10:51 PM
Posted 22 November 2012 - 11:00 PM
Posted 22 November 2012 - 11:12 PM
Posted 23 November 2012 - 12:33 AM
Posted 23 November 2012 - 12:34 AM
Posted 23 November 2012 - 12:43 AM
They are cool^^
Posted 23 November 2012 - 01:24 AM
5XW, 7XW, 10XW (have 14-40mm but too low for most details I want to see)
5XO - fills the spot where a 5mm SMC would be; also acts as a 'ZAO-II 5mm' (since there isn't one)
6, 7, 9, 12 SMC orthos (have 18 but too low power for details)
ZAO-II set + Zeiss/Baader 2x
25 aspheric micro ep (superb contrast)+ 2x Zeiss Barlow
ZAJ set excluding the 4mm, 8mm
Docter 12.5 84deg AFOV (on 'never sell no matter what' list)
Posted 23 November 2012 - 02:17 AM
If the seeing supports 400x, I need first to be using a telescope that is performs well at 400x and then I will choose the appropriate eyepiece. The 25 inch, that would be the 9mm Nagler, in the 12.5 inch F/6, the 4.8mm... In the 12.5 inch F/6 it would be the 4.8mm Nagler, in the 12.5 inch F/4.06, the 3.5mm...
Posted 23 November 2012 - 05:14 AM
Posted 23 November 2012 - 07:06 AM
Posted 23 November 2012 - 07:29 AM
Posted 23 November 2012 - 09:29 AM
Posted 23 November 2012 - 09:54 AM
Posted 23 November 2012 - 10:03 AM
Posted 23 November 2012 - 10:25 AM
What is your favorite eyepiece for planetary viewing? Right now, I'm using a 10" SCT, but plan to invest in a TV NP101IS
Unfortunately, what will work good in your SCT won't even be a candidate for planetary in the NP101 because of the radically different focal lengths. A 5mm eyepiece in the SCT will get you around 500x and in the NP101 only 100x. So the planetary choices will be quite different.
Magnification and exit pupil should be considerations in the choice, as well as what your local seeing conditions will allow on most evenings, and on rarer evenings. For me, the local seeing usually allows 200x most all the time, and then more rarely 400x. So that is my working range.
I also find that a .75mm exit pupil is a good working max for maintaining good contrast. Not a hard-fast rule but just what my eye tends to like. In the NP101 that exit pupil would be produced by a 4mm eyepiece (135x). In your SCT that exit pupil is produced by a 7.5mm eyepiece (330x). But that magnification is a bit high so if you back it down to 200x then the SCT would be using a 12.5mm eyepiece. Bottom line is that the SCT, due to its larger aperture, will having working planetary eyepieces between 12.5mm to 7.5mm or even 6mm, whereas the NP101 will likely have a working range starting at 4mm then getting smaller, probably down to 2mm on the very rarest evenings under very dark conditions since the view will be dim using 2mm.
If it were me, I would be looking for 3 eyepieces for the SCT, probably 8mm, 10mm, and 12mm. Without getting exotic, an 8mm and 12mm Brandon, then need to find some suitable eyepiece near 10mm, so perhaps an 11mm TV Plossl or the older 10.5mm smoothsided version. Going exotic would opt for the 8-10-12 TMB Supermonocentrics or AP-SPLs since they both come in those focal lengths.
For the NP101 the 2-4 Nagler Zoom gets you the focal length range you need in one eyepiece, so something to consider. Another thing you could do would be to get the 8-10-12 trio for the SCT, then get a 3x Barlow to use those same three with the NP101. This way save some money by using the Barlow to get to the shorter focal lengths that the NP101 needs for productive planetary. Yes, not a purist approach for planetary mandating a Barlow, but it works good enough and IMO a higher class planetary, like the Brandon, when Barlowed will at least be the equal of the 2-4 Zoom in terms of how detailed the image is.
A final consideration is to think about operating ergonomics. The NP101 shines as a rich field telescope with its very short focal ratio. In that role you are likely to be using very wide field eyepieces with some good eye relief. So the switch to a tight eye relief narrow FOV planetary may not "feel" like a great transition. So the better tactic from this standpoint would be to perhaps get some wide fields with good reputations for planetary also and then Barlow them for the NP101. So in the 8-12mm focal length range you could assemble some Pentax XWs or Delos to fit that also.
Lots to consider...most of it driven really by personal preferences.
Posted 23 November 2012 - 10:50 AM
It's great now. I mean it was DIRTY... a film and dirt. blew off the dirt and used 91%Iso with dist H2O. It may become my favorite now. Have to say my 17mm TV smoothie is darn good too.
My award goes to the underdog 12.5 generic Ortho for now.
Posted 23 November 2012 - 10:59 AM
(1) 7mmT6 Nagler, 5mmT6 Nagler, 2" 2x Powermate
which respectively give (magnification, exit pupil):
7T6: (77x, 1.3mm)
5T6: (108x, 0.96mm)
7T6 + 2xPM: (154x, 0.65mm)
5T6 + 2xPM: (216x, 0.46mm)
(2) 4.7mm Ethos; 3.7mm Ethos, 2" 2x Powermate
4.7E: (115x, 0.87mm)
3.7E: (146x, 0.68mm)
4.7E + 2xPM: (230x, 0.46mm)
3.7E + 2xPM: (292x, 0.34mm)
Obviously, the 3.7E + 2xPM pushes the scope a bit over its recommended "true" magnification limit of around 250x, as well as producing an exit pupil problematically small for many people. The 5T6 + 2xPM or 4.7E + 2xPM are at the realistic useful limits most nights, or even just the 3.7E by itself on really mediocre-minus nights.
If the scope is undriven, the 3.7E and 4.7Es keep planets within the FOV luxuriously long, and therefore easier to pick up fine detail from extended uninterrupted study than with the Naglers. For my tastes, in an undriven NP101 a narrower-field EP (e.g. 50deg AFOV) would require annoyingly frequent nudging in the magnification ranges useful for viewing planetary detail.
Posted 23 November 2012 - 12:49 PM
I've been through Baader GO's and University HD Ortho's and a 5mm TMB Supermono in the past but I'm very happy with my current line up and see them being with me for a long time
Posted 23 November 2012 - 04:03 PM
AS80/1200: Carl Zeiss Jena ortho 10mm (Jupiter), TMB Mono 7mm (Mars, Moon)
ED100 f/9: TMB Mono 7mm, Carl Zeiss Jena ortho 6mm, Pentax XO5.1
in past N250/1600: TV Plossl 8mm
Posted 23 November 2012 - 05:12 PM
Posted 23 November 2012 - 06:43 PM
In pairs: 15 or 20mm TV Pls., 15 or 21mm RKE, or 16mm Brandon.
non-tracking Dobs: 10 or 7mm Pentax XW.
for 5" f/12, 8" f/6, and 12.5" f/5.
Posted 23 November 2012 - 08:18 PM