All the five aberrations are better corrected if you are not using an "extreme" optical design. Extreme wide field means correction with more lenses to correct the field, so this will increase the optical aberration. I want to be optimistic: the light transmission of each optical surface can be 95% so for each single surface it means a light loss of 5%, extreme optimistic: 2%??? it means an eight elements eyepiece=10%-40% of light dispersion, more: each surface gives another problem, the internal reflection=lost of definition on bright images (planets for example), this is why refractors or some reflectors are best for planetary images (not catadipotrics). In terms of magnitude it is easy to say: your main optics-(10%-40% of light grasp)= true main optics aperture. I have some "TV eyepiece" very nice and comfortable, but I belive it is an optical non sense! The maximum Clave' field is 68° on the 2" series, with extreme contrast, definition, optical correction, brightness. Zeiss abbe II has the same optical concept: minimum possible glass. Why is so difficult to find a Clave' or Zeiss abbe II? Why these optics are so expensive? Simply, these are the best!
