Ive just recently bought a toyo quick slide and graphic 23 to be used on my toyo monorail.(for a great price, $175 for for slide and back!) The graphic back is 6x9. I plan on purchasing a graflex lens, 90, or 101, or 135. My questrion is will I need to shoot with a recessed lens board? I know that I have to use one w ith a schneider 90mm f8, but will I need to with the graflex lens, if so up to w hat focal length?