Widest view eyepiece for a NexStar 6SE?

[TREJ]

I am looking for some advice regarding an EP that will give me the best wide views of star clusters, galaxies and other DSO’s in my NexStar 6SE. This comes with a 1¼inch star diagonal, and I do not want to replace this with a 2inch at the moment, even if the telescope will accept it, so I am limited to 1¼inch EP’s.

It seems to me that as soon as you go above 25mm in wide view EP’s you are limited to 2inch ones. The best I have found so far is the £96 Baader Hyperion 24mm at 68º AFoV giving a 65.28’FoV at 62mag; even the £145 SW Nirvana 16mm or WO UWAN 16mm at 82º AFoV only gives a 52.28’FoV with 94mag and they are £145/156 respectively.

My supplied EP the Celestron 25mm E-lux gives me a 52’FoV and the Omni 40mm, though not a wide eyepiece, provides 68.75’FoV.

As a newcomer, am I missing something or is it an optical fact that to get a wide view I will have to move up to 2inch EP’s and all the changes that implies. Some thoughts would be appreciated, so over to all the experts out there.

I think I am well covered for lunar and planetary viewing with X-Cel LX 18mm, 12mm and 7mm EP’s and a X-Cel LX 2x barlow.

[michael.h.f.wilkinson]

You need to look at the field stop diameter of the EP, as this limits the true FOV for a given focal length. In a 1.25" barrel this does not get much wider than about 28mm. The Baader Hyperion claims 28.5mm which is really the limit, the Televue Panoptic claims 28mm. You cannot go beyond this, except with bigger barrel diameters, or with a focal reducer. I used a 0.63x focal reducer with my C8, and it worked fine. In combination with a wide field EP such as the Panoptic or Hyperion 24mm you get something like a 1.73 deg true FOV at 39x (roughly). I have since switched to 2" EPs, but for years I was very happy with my reducer.

[E621Keith]

The Hyperion 24 is the max you can go on a C6. It doesn't matter whether the eyepiece is a 2" or a 1.25" because the C6's 1.25" baffle tube is the limiting factor.

[John]

If you want wider views than the 24mm Hyperion and similar can give then the focal reducer route that Michael mentions is probably the best option. I used one in a C8 pretty successfully a few years back.

[E621Keith]

I'm not convince focal reducer will work for the 24 Hyperion, although I haven't tried that myself.

I understand how it can work on a C8 which has a 37mm baffle tube. However, a C6 has a 27mm baffle tube while the Hyperion 24 has a 29mm field stop, so the Hyp 24's field is already limited by the baffle tube diameter, surely adding a focal reducer will just reduce magnification without changing the true field of view.

[michael.h.f.wilkinson]

I have heard people use 2" EPs in a C6 successfully, but if the baffle tube is only 27 mm vignetting must occur. However, the visual system can tolerate quite some vignetting, so maybe it was overlooked.

[Dunkster]

I use a GSO 2" diagonal and 20mm TV Nagler with the 6SE, although it's the only 2" EP I have. The diagonal gives it a nice sturdy feel for holding heavier EPs, and the Nagler... is another story