Chuck Lott's Split-Pupil Finders

 Chuck Lott is an amateur astronomer and master finder-maker from Waldport, Oregon. He's the genius behind the classic 35mm film can finder. He also likes to tinker with split-pupil designs. Here are just a few of his various models.

On this one, the reticle is down inside the closed tube, at the focal point of the lens. When you look through the lens, you see the reticle (a red arrow) focused on infinity, so it stays put when you move your head around. When you move your eye up to the top edge of the lens, magic happens: you can see the reticle and you can see beyond the finder to your target -- without any obstacle in the way.
Split pupil effect


Here's a folding model. It's hinged at the bottom and curved to fold down around the curve of a medium-large telescope tube so you're not so likely to bump it while moving the telescope.

Here's one with a foam rubber eye guard and the view through it.


Here's one you look down into. A mirror directs your aim down the length of the telescope tube.


Here's another folder that uses a Fresnel lens.

  Here's looking through the lens at the reticle.

Here's a way-cool shot of the split pupil effect. Chuck shone a laser from the reticle to the edge of the lens, showing how much the light path bends when it goes through the lens. When you look through the lens along the lower line of sight (the nearly horizontal one), the reticle (down low on the left) actually appears to be out there in space directly ahead of you (see photo above).

If you own one of those big Coulter Cannons from the '70s and '80s, this is your finder!

Here's a bright yellow version of the same.

Here's a minimalist design.

Here's another minimalist design.

It folds, too!

How to contact Chuck

If you have questions or comments, Chuck can be reached at the email address to the left. (This is a graphic file to thwart spambots, so you'll have to copy it by hand.)