2 May 2005
It is cloudy and breeze today. There will be no observing I have looked up the specifications for my telescope to see what I am getting.
I am not married to Orion or to this particular line of eyepieces. I would consider anything else with similar specifications, equal or better quality, and at about the same price point. I am buying these eyepieces with a view to being able to use them on any future scope(s) I buy so don't want to get something that may limit me later.
| Specifications | |
|---|---|
| Aperture | 107.95mm (4.25") |
| Focal Length | 432mm |
| Focal Ratio | f/4 |
| Theoretical Values | |
| Maximum Magnification | 216x |
| Limiting Magnitude | Mag. 12.7 |
| Resolving Power | 1.2" |
Thinking about eyepieces I have looked in the Orion catalog (because I have it) and picked out their Epic line. Although it is one of their more expensive lines I chose this line because they have a long eye relief (20mm) so they will be good for afocal photography, a fairly wide apparent field of view (55º), and the line is parfocal so there will be minimal refocusing on changing lenses. Keeping in mind that I have binoculars of 7x, 8x and 15x, I have selected the following eyepieces as my likely choices along with a 2x Barlow lens.
| Focal Length | Magnification | Field of View | 2x Barlowed Magnification | 2x Barlowed FOV |
|---|---|---|---|---|
| 18 mm | 24x | 2.29º | 48x | 1.15º |
| 12.3 mm | 35x | 1.57º | 70x | 0.78º |
| 7.5 mm | 58x | 0.95º | 115x | 0.48º |
I am not married to Orion or to this particular line of eyepieces. I would consider anything else with similar specifications, equal or better quality, and at about the same price point. I am buying these eyepieces with a view to being able to use them on any future scope(s) I buy so don't want to get something that may limit me later.
posted by Charlie at 16:04
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