I've been thinking I want to add a fresnel lens to my focus screen for my 4x5 camera but after reading around the web, I keep seeing conflicting info about this.

My desire is to brighten the screen, the camera and my lens focus fine it is just a little dark. And I don't want to spend a ton of $ for this--it's about convenience not necessity.

Initially, I figured to just find some inexpensive fresnel and put it on the back/out side of the screen, the side facing away from the lens. This, I think, wouldn't change where the image is formed for focus and would, I thought, just increase apparent brightness.

However , after spending this morning reading about this, I am seeing lots of disagreement about the correct way to do this.

I'm a little interested in the theory about this but am much more interested in empirical/practical application.

So, who's got the straight poop on this?

Thanks!
Rob
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