Just curious as to what other members have in the way of short focal length eyepieces. I was always of the understanding that the Dawe's limit of Useful magnification ran to about 60X per inch of aperture. I've heard some here say that they have eyepieces that are 3mm. Does any company make anything shorter in focal length?
The shortest focal length eyepiece I ever used is 4mm. Every one of those small focal length eps has a very small exit (field stop) which is difficult to use as one needs to get the eye so close to even be able to see into it.
I noticed that Televue used to offer a 4mm plossl. My guess would be that the field stop on the exit would be very small indeed.
On very short focal length telescopes I can see the possibility of using down to perhaps 2mm if the diameter of the diameter of the field stop was reasonable, however I'm not interested in purchasing an expensive eyepiece if the exit diameter is so tiny that one has to cram his eyeball right up against the eyepiece.
I did see that TV offers their Ethos down to 3.7mm, however that field stop is 7mm (not too big).
Does anyone have experience with an eyepiece similar to that?
Is it comfortable to use?
P.S. I may be confusing field stop (FS) with exit pupil (EP) however on the TV website they don't list EP just FS
Edited by woodsman, 10 May 2021 - 11:05 AM.