Ken, the APO Ronar is an f/9 lens whereas the Artar is an f/11. More glass and a heavier barrel (brass vs aluminum?) make the Ronar feel about twice as heavy. It's a big lever arm to put at the end of a field camera. I bought the Ronar but quickly bought an Artar to use instead because I didn't want to lug the Ronar around. It's a really big and heavy lens. A few reputable people who have used both say that you'd be hard pressed to notice much of a difference between the two. Resolution is similar, but the Ronar has a bit more contrast...stressing "a bit." I haven't done the comparison. One look at Michael Smith and Paula Chamlee's prints and you won't question the quality of the Artar.