[Leica] 21 mm Color Skopar - no viewfinder

[geordiepete211 at yahoo.co.uk (Peter Cheyne)]

> Hello, I bought a 21 mm Voigtlaender from Robert Brown in England  
> for about 300 GBP.  I bought online, so I didn't realize it wouldn't  
> come with a viewfinder.
Now hunting for a viewfinder, I find they cost about the same as the  
lens itself, sometimes more.  I've shot a few rolls using the lens  
with is sometimes, but can't get an intuitive hang of quite how wide  
it is.

I don't want to spend the same money as the lens for a finder.  Does  
anyone have any opinion on whether cutting an aperture in a piece of  
card and holding it at a certain distance would be a usable idea?   
Perhaps I'm being too cheap and there is no way around buying a  
viewfinder.  Any ideas?

Peter