Author Topic: Questions about barlow lenses - design, # of elements, barrel size, price vs ima  (Read 97 times)


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Hey all, another newbie here,

I'm looking to add another barlow lens to my collection with the goal of getting the highest magnification feasable from my 8" f5 reflector when using an ES 82° 6.7. That's roughly 150x and I already have "shorty" type 2x barlow for a hearty 300x. I'd really like to get Jupiter and its moons as big as possible, pushing 50x-60x per aperature inch when conditions are good, or either a 2.5x (375x) or 3x (450x).

I bought the 2x (meade) when I bought the telescope without much knowledge about the mechanics of barlows or eyeieces because it was cheap and now that I'm purchasing nicer eyepieces I'd like to get the most out of them. It's actually nice enough and serves it's purpose, and there's 3x version I could pick up, but there are obviously many other options at various price points.

Would it be worth the additional cost to buy a better quality barlow? How do you determine the image quality of a barlow lens when looking at its specs? There are 2 element designs all the way up the 5 element designs, all those lens must serve some purpose. Also, would using a 2" lens with 1.25" eyepiece affect the image at all or would the end result be the same as a 1.25" lens?

What do you fine folks think would be best for me and my equipment? I'm not in much of hurry to make a purchase, since there haven't been many clear nights lately, so I could hunt for used ones for awhile if that's best.