Author Topic: 100ED and simlar scopes - grab&go eyepieces that balance well  (Read 78 times)

Tsar Daniels

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100ED and simlar scopes - grab&go eyepieces that balance well
« on: December 24, 2017, 08:54:24 PM »
Dear Cloudynights folks, this really is a longish post about OTA equilibrium and eyepieces of different dimensions.  Enter from owners of comparable longer-focus refractors is particularly appreciated!

I recently purchased a used SW 100ED refractor I put on a Unistar Deluxe alt-az mount as my grab&go setup.  It came with two eyepieces - a 5mm SW kit eyepiece along with a classic 26mm plossl.  I already have some decent eyepieces (normally utilized in my 8" SCT) that, together with a 2x barlow, can create the majority of the magnifications / FOVs / exit pupils I want.  However these eyepieces vary in height and heft in the "hand grenade" 35MM Panoptic (overall big and thick), to "turkey leg" 14mm Delos (moderate weight but Tall / top thick), to 11mm Delite along with other smaller eyepieces.  While this has been working great in my 8" SCT (w/ counterweight), the alt-az mounted 100ED tends to get out of balance fairly easy when the eyepiece get swapped for another one that is significantly different in weight (I'm sure 100ED being f9 is not helping this either

My thought of a grab and go is something that will require minimal quantity of effort fumbling with gear and allow me best concentrate on celebrating during the tiny windows of opportunity we get here in Pacific Northwest during the "bad" season.  The target is to discover a mixture of several (three or four) "grab and go" eyepieces that, together with a barlow lens, provides an adequate assortment of views rather than require the scope to be re-balanced at any given point during the observing session.
While I have a 22Nag T4 along with other 2" wide angle eyepieces, for the reason mentioned above, as well as to avoid larger exit pupils that will scoop up all the Western Washington light contamination, I decided my grab&go eyepieces will be 1.25" only.  To maximize the true field a 24mm Panoptic is going to be obtained as a lowest power EP.  From there on however, I have been contemplating two different paths:

1) Insert a 10mm "Tall" eyepiece to my 14mm Delos
I already have a 14mm Delos that provides a pleasant 1.12 deg FOV at 64x (1.56millimeter exit pupil) in this scope.  While this would be a excellent general low power eyepiece, I would also have to put in a 10mm for 90x (1.11 exit student) - either a Delos or a Pentax XW.  Both could then be barlowed into 129x and 180x respectively, covering the whole range with just three EPs plus a barlow.  Sounds really nice, but the top-heavy Delos eyepieces become much more so when inserted using a barlow.  Also Delos 14 and 10 every weigh 14.4oz.  Insert the 5oz Ultima 2x barlow andthat becomes a 19.5oz - significantly heavier compared to 8.2oz Pan 24 I mean to use for low power.  Sounds a little iffy but if that difference is significant enough to require rebalancing I cannot tell, because I haven't purchased the 24mm Panoptic as of yet.  After I have it I can check it out, I figure.

- OR -

2) Use the 11mm Delite, add 18.2 Delite or 16T5 Nagler
I already have a 11mm Delite which yields .76 deg FOV at moderate 81x (1.22millimeter exit pupil).  I may also get something nearer to 2mm exit pupil, such as a 18mm Delite or 16mm T5 Nagler for general low electricity, then 2x barlow the two for med-high and high power views.  This arrangement would ensure that all the eyepieces are very similar in weight and size, so would be great for equilibrium.  The disadvantage would be the rather narrow TFOV of this barlowed 11mm Delite at 164x forcing me to nudge the scope more frequently during planetary observing.Are there additional excellent eyepiece options I might be leaving out?  Fantastic clarity across generous FOV at higher magnifications is a priority, provided that the scope is on a manual alt-az mount.
. .
What eyepiece combinations do you guys use with your longer focus refractors offering a fantastic range of subjects / magnifications while keeping the scope well balanced throughout?

Delos users, do you have problems keeping scope equilibrium when moving in the top-heavy Delos eyepieces (especially the shorter focal length ones) to considerably lighter / stouter ones such as 24mm Panoptic or even Delite?