How can you tell?...

[estwing]

the difference between ep's performance under light polluted skies?....shouldn't this be done under Dark skies to achieve the right results....just a thought...

[ronin]

To me an eyepiece just performs.

If I find one more comfortable under LP conditions then great, but I suspect that "performance" is the wrong description. Comfort may be relevant, and that may be a case of the coating used and the wavelengths they pass.

[gooseholla]

Wouldn't it give an indication though? If one performs better than another in LP skies surely it will give a better view under dark skies? Also I think it is a good test because let's face it, they are being tested under the conditions most of us will be using them most of the time.

John

[John]

Depends on which performance characteristics you are examining I guess. I think light scatter, astigmatism, distortion and false colour can be checked under less than optimal conditions. Light transmission and subtle contrast variation are more easily seen when the conditions are good.

I've compared some eyepieces where there were no differences unless the conditions were really good. As there was a very large price difference between them in this case I had to consider where the occasional slight extra performance was worth the additional £'s.

They also say that large aperture scopes emphasise differences in eyepiece performance more. Next time FLO loan me some eyepieces I'll have to ask for a 20" dob to test them more thoroughly !

You always need to think whether the seeing conditions are either creating or contributing to effects you are seeing though, I agree.

[Roy Challen]

I don't think it matters too much, if you normally observe under light polluted skies then that is what your comparison is subject to. If you post your findings on here or elsewhere, then your conditions should be mentioned.

[jetstream]

Light pollution is the great eyepiece equalizer IMHO. There are differences in performance seen under any conditions but dark transparent skies make some eyepieces come alive. The difference can be startling on some objects. Of course this is just my 2 cents...