Loupe Optics

[steve_rasmussen]

Have you noticed how many lousy loupes there are on the market? Ever wonder why a good one is so expensive? Loupes have to correct the same aberrations as a photographic lens does. You just can't do it with two elements (like the cheap loupes use). Most loupes are f/1 to f/2 in speed which really adds to the aberration correction problem. In general, the better loupes have four to six elements. The more elements, the more aberrations can be corrected. The best designs are symmetrical, coated and aspheric. Anastigmatic loupes are corrected for astigmatism and have a flat field. This however is not a guarantee of sharpness because the manufacturer only claims to correct astigmatism, but what about the other aberrations? Flatness of field is not important on visual instruments (loupes). SR

[jim_korczak1]

Thanks for the tip Steve. I shoot negative almost exclusively, so never really thought about loupes. If I do, I will keep a lookout. Any reccomendations?

[steve_rasmussen]

Jim: The sharpest one I've used is the Rodenstock 4x aspheric. It is

coated and probably achromatic, both of which are important. SR

[joel_collins]

I use the <a

href="http://www.pentax.com/accessory.jhtml?accessoryType=LUPES">Penta

x 5.5X loupe</A>. It's a monster, covering about 70% of a 6x7 image.

Seems like it costs about $80, less than half of the price for the

Schneider and Rodenstock loupes. Check it out.

[patrick_drennon]

I got the opportunity to try the Schneider, Rodenstock, and Pentax

loupes side by side and ended up with the Pentax. It isn't better, I

just couldn't tell any difference so it was (for me) easily best

value.

[mayorson_kirk]

try to use the contax 45mm2 planar T* lens for contax G1 or G2 as a loupe and you will find the result satisfy your taste. I am sure!!!