cheap telescops, decent EP's

[garethmob]

hey i was thinking last night in work (before any one asks it didnt hurt:P)

would a cheap telescope but largeish one using really decent set of eye peices work?

i understand some really cheap telescopes have built in barlows (not interested in them)

but would that work?

[Capricorn]

Guess that it is a bit like a chain. The system is as strong as it's weakest link.

If the objective is good, mirror or lens, but the eyepiece poor then a good eyepiece will improve it.

If the objective is poor but the eyepiece good then another good eyepiece won't help. It would basically confirm that the weak(est) item is the objective.

A decent eyepiece will not compensate for a poor objective.

[garethmob]

ahh ok i see thanks for the help capricorn

[Capricorn]

Seems that when they sell scopes thay throw in 2 eyepieces, from the various post it seems the 10mm is generally poor and the barlow is also poor.

Hence it is often a case of upgrading the supplied 10mm to a better 10mm, often the same with the barlow. Annoying.

It would appear that the scope is therefore usually decent, the initial eyepieces being the weak bit.

You could design an eyepiece to compensate for some objective faults but it would only work on that one scope and make other scopes significantly worse. To some extent that is how a Mak and SCT perates.

The front plate on a Mak is a compensator for the spherical mirror used as the objective. Means they don't have to make a parabolic mirror.