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View Full Version : Rodenstock 135mm f/5.6 Apo-Sironar-S (close up distortion?)



ryanmills
26-Feb-2014, 11:03
Thinking about picking up a Rodenstock 135mm f/5.6 Apo-Sironar-S, the size fits 90% of my portrait work, however I know its not ideal for a close up headshots. I have rails for days to focus. I know its kind of subjective but I have read conflicting reports. I know using it backed up its got very little distortion however does distance effect this type of lens. So if I get it focused right up close for a headshot will I start to see distortion?

BradS
26-Feb-2014, 11:46
I think you maybe conflating distortion with perspective. Distortion is a property of a lens. Perspective is entirely determined by the position of the lens relative to the subject. I would expect the Sironar-S to be very nearly free of barrel and pincushion distortion. But any lens, doesn't matter the focal length, is going to give the same perspective when use in the same camera position. I think this maybe what you're concerned about????

I think the bigger concern with the Sironar-S when used for portraiture would have to be the clinical sharpness. It really is not kind to anything less than perfect skin.

I personally find the 135mm focal length quite useful but, prefer the lowly Graflex 135mm Optar (wollensak raptar) or 135mm Xenar for portrait work on 4x5.

IanG
26-Feb-2014, 12:20
I agree with Brad. I use Sirinars and Symmars but Tessar (& type0 lenses are better for portraits. Triplets like the Geronars 150mm & 210 are even better :D

Ian

Bob Salomon
26-Feb-2014, 13:19
What you have to consider, especially with head and shoulder portraits with 45 with a lens as short as a 135mm is not distortion or perspective. It is an optical effect called foreshortening. This means that objects closer to the lens will reproduce proportionally larger then objects further from the lens. With short lenses like a 135mm this would mean large noses, foreheads and chins. To eliminate or reduce this effect you would either have to move further away, thus no more H&S shot or use a longer lens to flatten the image and reduce or eliminate the foreshortening.

A second consideration is depth of field. If you focus on the bridge of the nose and want sharpness only from the tip of the nose to the base of the ear the DOF with a 135mm may be too great.

The 135mm Apo Sironars S has virtually no distortion. At an image ratio of 0.05x the maximum distortion at 37.5 is 0.15%.

ryanmills
26-Feb-2014, 14:52
Thanks, foreshortening as Bob said is what I was worried about but i think i was using the wrong term. This is to replace a 127mm ektar that has seized up after a cleaning only a year ago. I'm mostly looking for that perfect detail at a full body distance that I can use indoors as well. The debate was if I keep the 210mm symmar. I plan to replace it at some point with a 240mm sironar but right now its just too much to spend.

BradS
26-Feb-2014, 22:01
keep in mind that "foreshortening" as described by Bob has nothing to do with the focal length of the lens and everything to do with the distance from lens to subject. The "effect" is completely independent of focal length. Think about a 135mm lens on a 35mm camera....nobody worries about "foreshortening" with a 135mm lens on a 35mm camera...now, put a 135mm lens on your 4x5 camera and place it at the same distace from the subject...you will get the same image...only more of it since the film is much bigger.

A large camera to subject distance makes the subject look flat and, rather boring. Moving closer gives the subject more depth or presense...it makes the subject more intimate.

When planning a portrait, think in terms of subject distance and then figure out what focal length is needed to achieve the desired magnification (which equates to image size). I like to place the camera about one to two meters from the subject - depending uppon how intimate I want the result to feel....again, closer for more intimate and farther for colder more flat portraits.