Jerry,
What I mean by opening up - and this is clear from Schneider's MTF charts - is that the Digitar performs extremely well at f5.6-f16, whereas most LF lenses seem to b e optimized for stopped-down performance. My own subjective tests on film showed the best resolution at f8-f11. At these apertures - again looking at Schneider's charts - you will be hard-pressed to find film that will not limit the lens' performance. From the charts it is clear that the Digitar's MTF performance even at f22 is significantly better than the 110 SSXL, at the cost of coverage. I try to open up to f16 when I can with this lens, but rarely go to f11 as I often need more DOF. I originally purchased my Digitar for 6x9 cm, where it really hits a sweet spot - plenty of movements, incredibly sharp, probably outperforming any 35mm lens. The resolving power probably drops a bit outside the specified 150mm image circle, but it still very good in the corners of a 6x17. I notice no color fringing, possibly a slight resolution drop when examined with a 22x loupe.
That said, at f32 all these lenses probably perform equally. The SSXL design is fantastic when it comes to coverage and resolution accross the IC - I use the 150 SSXL on 8x10 - but unless you need the image circle it might be a slight overkill.
When I use more significant front tilt with the Digitar - camera close to the ground shooting 6x17, like the last flower shot in the "bull dust" collection
http://www.8x10.se/imagelib/2004-M088-003-P-600px.jpg
then I have to watch out for dark corners and possibly compensate by dropping the front or use rear tilt. So if I would buy a 120 lens for 6x17 today I would probably look at the Symmar L. Maybe the SSXL. If I already had an 80 SSXL with CF then I would stretch my budget to the 110 SSXL.
Reply With Quote
Bookmarks