Refractor Question

[CanisMajorTom]

What exactly is the difference between a triplet and a doublet? I know the triplet has more lenses but wouldn't that just reduce the amount of light that enters the scope, because my thinking is that every glass surface reflects some light. So the more glass surfaces light has to pass through, the less light will pass through. Yay? Or Nay? Obviously nay but why? :pipethinker:

[Radar]

Hmm :hmm: I really couldn't answer that one mate. Have to wait for some guru's to get in here.

[CanisMajorTom]

Tell them to hurry up please :ahh!:

[AstroTasmania]

This is one case of more lenses is better. As an indication of a 3-element objective, check the price of a apochromatic doublet of a certain size, then check out the price of the same aperture triplet.

Many apo doublets still have some minute residual fringe colour, whereas the triplet is colour free. Their main uses is in photography for optimum quality pin point stars with no out of focus edge at all. If you can afford a triplet and into photography big time, buy one.

Do a Google search on Triplet Apochromatic scopes and see what comes up.

Regards

Shevill

[CanisMajorTom]

I didn't realise you could have an apochromatic doublet? I though apochromatic meant triplet. I will google the meaning of apochromatic.

And here we go-

ap·o·chro·mat·ic (p-kr-mtk)
adj.
Corrected for both chromatic and spherical aberration, as a lens.

Thanks for the reply Shev. :thumbsupmate:

[Radar]

I am actually quite surprised at how clear an image I get from my Skywatcher doublet.

I had forgotten how crisp refractors were. I had been using a MAK as a guidescope. It was a pleasure to start using refractors again.