4mm eyepiece

[wookie1965]

I have been looking for a decent 4mm eyepiece and can get a TS UMA 4mm 82°  for £50 are these any good and is it a fair price please.

[Ricochet]

It is the same as the OVL Nirvana, which FLO sell for £85, so £50 is a good price. The reviews I've seen for the 4mm have all been good so I think it would be worth going for if you need a 4mm. 

[Don Pensack]

Excellent for deep sky:

Great for planetaries, globulars, double stars.

Not great on the Moon (a bit too much internal scattered light), and edge of field astigmatism is more noticeable on the Moon because it fills the field.

And there is residual chromatic aberration.

However, the sharpness and astigmatism is f/ratio dependent.  At f/5, it's so-so.  At f/10, it's excellent.  So it might be very good for the Wookie with all those long f/ratio scopes!