Lens coverage information http://www.graflex.org/lenses/lens-spec.html
Resolution information http://www.hevanet.com/cperez/testing.html
The particular lens can make a perception difference here.
A very good medium format lens, say on Pentax 67, will hit around 90 lp/mm A mediocre medium format lens, like a Yashica D, will hit around 40 lp/mm
A good LF lens, Super Symmar XL, is up at that 80+ lp/mm range.
A decent LF lens, Fujinon-W 135/5.6 (70s vintage), is around 70 lp/mm.
A mediocre LF lens, like a Wollensak, will be about 35 lp/mm, and really bad corners!
There's so much information on those large (6x7 & 4x5) negs that the minimal enlargement to 11x14 makes little difference when quality lenses are involved on both parts. A mediocre lens on either unit will make a clear difference.
4x5 to 11x14 is only a (roughly) 3x enlargement. 6cm x 7cm to 11x14 is a (roughly) 5x enlargement. So there's not much to compare because the difference isn't being pushed. The film will hold everything the lenses will resolve.
It's not surprising that the difference isn't immediately visible with quality lenses
on both formats. The detail is all there. The tonality difference will show up @ 16x20,
with a good 4x5 lens really shining. But @ 11x14 & up, I suspect you'll find that corners
are more a problem. It's like the difference of an average zoom and that Vivi 90-180
flat field zoom. The image just feels better. A good wide-coverage 4x5 lens gives that.
(Which is why I picked the Fujinon-W 135/5.6. Wide circle, excellent resolution,
modern multi-coating, and relatively cheap @ about $250 shipped. And why I print with
longer lenses in the darkroom--keep those corners from pulling any little bit.)
In many ways, 6x7 is far more practical when prints stay below 16x20. You lose the facility of Zone control on a shot-by-shot basis, but with a good neg you still get an excellent print.
http://www.cicada.com/pub/photo/zs/
The Zone System is nice, but it's a practice all its own. I don't use it because
I don't have the time, patience, or funds to keep testing density curves.
Rather, for me a good neg == a good print.
And (even cheap) 4x5 allows some practical lens movement.
Collin
----------------------------------------------------------------- At 07:17 AM 3/28/03 -0500, you wrote: OK, your saying you cant hardly tell the difference between 67 and 4X5 on an 11X14 print. Maybe your 4X5 lenses aren't up to snuff? 4X5 is 3 time larger than 67 and the difference in sharpness should be clearly visible.
As far as optical printing goes, there are many of the opinion that scanning and digitally printing can exceed what is possible conventionally due to limitations in enlarging lenses, even really good ones. Scanning is more consistent from center to edge than optical printing techniques. ----------------------------------------------------------------- * "Never give up, never surrender!" --- Yes, you should watch Galaxy Quest.
