View Full Version : I really need help choosing the best lens

Ron Spencer
6-Jun-2011, 04:31
Hi everyone,

I really hope someone can help me. I will be shooting stills in my home studio and want incredible sharpness and fine details in my images. I have just about everything I need except a lens and shutter. My idea is to shoot with an H20 Phase One digital back on a Sinar P2 4x5 camera and plan to shoot the entire 4x5 area (or most of the area) with about 12 to 15 stitched shots with the Phase One H20. I have all the elements now, but I really need help with choosing a lens. I want to get the sharpest lens that I can. I know they now make digital lenses that have smaller image circles, so the line pairs per mm are tighter to match up better with the digital sensors (among other things). Do I really need a digital lens? Are there any high end 4x5 APO lenses that could deliver 50 line pairs or more? I would like to get a lens that would be equivalent to about 70 to 100mm lens in the 35mm world. Can anyone help? I know really nothing at all about large format. The lenses especially confuse the hell out of me. Do you have any links to websites that would have the information that I'm looking for?

Thanks to all for any help that you may be able to give.


Bob Salomon
6-Jun-2011, 04:44

6-Jun-2011, 06:12
At the necessary small apertures, all good modern lenses will deliver 50 lines/mm.

If you want to stitch by using rear shifts, rises, and falls to move the back around while leaving the lens in place (which will make seamless shifts easy without needing to distort the images in software), then you'll need a lens with sufficient coverage for the combined stitched format. That will leave out the Digaron and other digital-specific lenses for view cameras. They are designed in short enough focal lengths to provide the full desired image without stitching.

If you want to cover the full 4x5 format so that you can stitch to the edges of that format, then you'll need lenses with at least 160mm of coverage. A lens of focal length a little longer than normal will not present any issue with that requirement. You might not really need a lens of the equivalent of 70-100, by the way. With large-format, people generally find they don't need focal lengths at the extremes to achieve their objectives. Many use a 100mm on a small camera in a studio to increase working distance, which would not be a problem even with a normal lens for 4x5 at 150mm. Were I you, I would consider something in the 210mm range, which is the equivalent in field of view of perhaps a 60mm lens on a 35mm camera. These lenses should provide a sufficiently straight-on illumination of the sensor to avoid significant vignetting over the 4x5 frame, even if you use movements.

Probably the sharpest lenses on the market right now are the Rodenstock Sironar-S lenses, but any of the modern plasmats in that focal range will exceed 50 lines/mm. The older Sironar-N was also (fairly) marketed as an APO lens, and there are lenses of equal quality from Schneider. Of course, your technique will also have to exceed that limit, which means managing the focus plane and using the appropriate aperture. But you knew that already.

Rick "answering the requirements presented" Denney