Bruin
Noktonian
I got this idea from this Leica FAQ page: http://leica.nemeng.com/027b.shtml
It's basically a pentaprism glued onto a double bubble level, which provides the hotshoe foot and perpendicular surfaces to align the prism to. I got a 1-inch square pentaprism from Anchor Optics, but you can find them a little cheaper at Surplus Shed (make sure it has reflecting surfaces). I chose the Jobu Design bubble level because the shell and foot are made of hard-anodized aluminum. Superglue provides a strong bond between the etched prism side and an anodized side of the level.
As is, the finder gives a pretty narrow FOV. I originally wanted to cement a plano-concave lens to the front of the prism to give a wide-angle view. It was a challenge to find the right size and strength surplus lens, and it wasn't completely flat on the plano-side. Twice I tried optical cement to glue it to the prism, but after curing any slight pressure on the lens would begin to compromise the bond
The surfaces are too smooth for the cement to really hold.
With the prism alone, I have to hold it fairly close to my eye to get a decent view, making it more like a right angle finder. If you guys have any ideas on how to attach a negative lens on the front, let me know!
BTW, someone looking at you while you use this WLF will see your single eye staring at him/her. It's kinda creepy...
It's basically a pentaprism glued onto a double bubble level, which provides the hotshoe foot and perpendicular surfaces to align the prism to. I got a 1-inch square pentaprism from Anchor Optics, but you can find them a little cheaper at Surplus Shed (make sure it has reflecting surfaces). I chose the Jobu Design bubble level because the shell and foot are made of hard-anodized aluminum. Superglue provides a strong bond between the etched prism side and an anodized side of the level.
As is, the finder gives a pretty narrow FOV. I originally wanted to cement a plano-concave lens to the front of the prism to give a wide-angle view. It was a challenge to find the right size and strength surplus lens, and it wasn't completely flat on the plano-side. Twice I tried optical cement to glue it to the prism, but after curing any slight pressure on the lens would begin to compromise the bond
The surfaces are too smooth for the cement to really hold.With the prism alone, I have to hold it fairly close to my eye to get a decent view, making it more like a right angle finder. If you guys have any ideas on how to attach a negative lens on the front, let me know!
BTW, someone looking at you while you use this WLF will see your single eye staring at him/her. It's kinda creepy...
Attachments
Bruin
Noktonian
payasam
a.k.a. Mukul Dube
Kevin, bright (no pun here) idea -- but the usefulness of the thing depends on whether or not it is accurate for any of your lenses.
fgianni
Trainee Amateur
Nice idea, can I ask you a couple of questions.
Where did you get the prism?
To which focal lenght does the FOV compare?
Thanks
Where did you get the prism?
To which focal lenght does the FOV compare?
Thanks
Bruin
Noktonian
Thanks for the kind words, guys. I originally wanted to use it with wide angle lenses and scale focusing. The negative lens in front would determine the FOV in 35mm terms - I think the planoconcave lens I have is -34mm FL and approximates a 28mm FOV. Without a lens on the prism, the FOV depends on how close your eye is to the prism. It's like looking through a 1" square tube about 3" long.
Francesco, I got the prism from Anchor Optics (an Edmunds Optics subsidiary). You can also find them at Surplus Shed, where I bought a few lenses to try out.
Francesco, I got the prism from Anchor Optics (an Edmunds Optics subsidiary). You can also find them at Surplus Shed, where I bought a few lenses to try out.
bulevardi
Established
Kevin, that's a brilliant idea.
Certainly when shooting from the ground with a mini tripod all the time, it's very very handy !
I'm ordering my pentaprism and hot shoe bubble level already !
Certainly when shooting from the ground with a mini tripod all the time, it's very very handy !
I'm ordering my pentaprism and hot shoe bubble level already !