Field of View 135mm lens

[Desert Shooter]

I have just concluded the purchase ,from one of our fellow RFFers, of a LTM Canon 135mm 1:3.5 lens. It looks pristine, and for a very fair price. but surprise, I don't have a 135mm viewfinder. So until I am able to acquire one, I'm planning to use the 90mm frameline on my Bessa R3a as a refrence. But what percent of the 90mm frameline should I allow, 50-60%?

thanks,

 

[Ronald M]

The height of a 90 equals the width of the 135.

66% if that helps

 

[Desert Shooter]

Ronald, thanks. I just discovered that my ltm to M adaptor for 35mm also is 135, and guess what? My M6 now has 135mm britelines and it's about 2/3 of the 90 britlines. So, I can use the lens precisely on the Leica, and guess field of view fairly accurately with the Bessa.