Finder cutoff with 500cm too much hassel

[Kellmeister]

Hi,
I'm on the verge of purchasing a 500 series but I'm at a crossroads. I have concerns about the finder cutoff that seems to be a problem when using long lenses and the 500cm. I plan on purchasing some tubes and a 250mm.

What are your experiences when using long lenses with the 500cm? Is the finder cutoff something you get used too? Or should I save my pennies for the 501cm?

 

[tarashnat]

Here is the link to a French page with ex&les of the vignetting in the finder. http://perso.club-internet.fr/cesarigd/photo2f.htm

Taras