[Wavytone]

Alex, the practical limitation with an 8" SCT isn't the eyepiece focal length - it's the aperture out the back of the mirror.

The longest eyepiece I've used on a C8 was a 2" Unitron 60mm Kellner (I know the owner, could probably borrow this beast if you want to try). It has a modest field stop - perhaps 45mm diameter.

But there are a few 2" eyepieces that basically have no field stop - ie the inside diameter of the eyepiece barrel is effectively the field stop, at about 48mm. An example is the TMB Paragon 40mm (you can try mine, next time) and I am sure there is at least 1 Nagler like this.

But the real snag with a C8 is that the aperture of the back at the mirror cell is significantly smaller and it will cause vignetting in a big 2" eyepiece.

I'll have the TMB 40, TMB30, LV50 and NLVW30 for sure next time at Katoomba and could probably arrange the 60mm Kellner if I can find an adapter for it (it has an odd-size barrel). Of these eyepieces, the Vixen LV50 is still my pick on my 180mm Maksutov and I expect you will conclude the same on a C8. I'll bring my my set of LV's as well if you want to try comparing colour/contrast using say the LV25mm vs the RKE28mm, or the LV15 vs RKE15, or LV7 vs RKE8mm (seeing permitting for a C8).