megido
Well-known
I recently shot a portrait session with the said lens wide open and close up on a F body. While assesing the contacts, I noticed some quite obvious barrel distortion. (I usually use the Nikkor stopped down and at distance). Is this to be expected for this lens wide open and at minimum focus? For the same session I also used a Leica M and collapsible summicron (which I am very familiar with at wide open and close range) and the difference regarding distortion, or lack of is quite pronounced.
Erik van Straten
Mentor
Yes, mine has some barrel distortion too. It seems that the f/1.8 version is free of it.
Nikkormat FTn, Nikkor-H-Auto 50mm f/2, 400-2TMY.
Erik.
Nikkormat FTn, Nikkor-H-Auto 50mm f/2, 400-2TMY.
Erik.
megido
Well-known
Thanks Erik as always. Quite unflattering for portraits! Whereas the collapsible summicron has always looked totally free of distortion to my eye.
megido
Well-known
Erik, I forgot to ask, do you see distortion at most apertures?
Erik van Straten
Mentor
Usually distortion does not disappear by stopping down, but sometimes it changes when the distance changes.
Erik.
Nikkor Hc 50 f2 barrel distortion
Sharpening up the corners by stopping the lens down can make the distortion *seem* more obvious, but the amount of distortion is unchanged by the aperture setting.
What does change the amount of distortion is a change in the effective focal length of the lens. The designated focal length of a lens is determined at infinity, but in reality the effective focal length increases the further you move the optics of the lens away from the film plane by focusing closer (there are exceptions but this is true for most lenses). This change in effective focal length is why frame lines in a Leica are set for the mfd of the camera and you get more image outside the frame line at infinity.
As the optics of the lens are moved forward away from the film plane and effective focal length increases, distortion tends to increase. The difference in increase of effective focal length between the mfd of a screw mount Leica lens (1m) and the mfd of an SLR lens (0.45m?) is not insignificant.
Sharpening up the corners by stopping the lens down can make the distortion *seem* more obvious, but the amount of distortion is unchanged by the aperture setting.
What does change the amount of distortion is a change in the effective focal length of the lens. The designated focal length of a lens is determined at infinity, but in reality the effective focal length increases the further you move the optics of the lens away from the film plane by focusing closer (there are exceptions but this is true for most lenses). This change in effective focal length is why frame lines in a Leica are set for the mfd of the camera and you get more image outside the frame line at infinity.
As the optics of the lens are moved forward away from the film plane and effective focal length increases, distortion tends to increase. The difference in increase of effective focal length between the mfd of a screw mount Leica lens (1m) and the mfd of an SLR lens (0.45m?) is not insignificant.
Robert Lai
Well-known
The 50mm 1.8 AI definitely has barrel distortion when up close. Only at infinity is it distortion free. I got rid of my Nikon primes below 55mm, due to this distortion issue. (Exception is the 28mm 2.8 AIS).
The worst offender is the 35mm 1.4 AIS. Up close it barrel distorts severely. Women used to tell me to get lost with that lens. They recognized that "it makes me look fat".
Another bad actor is the 50mm 1.2. Another "fat female" lens.
The worst offender is the 35mm 1.4 AIS. Up close it barrel distorts severely. Women used to tell me to get lost with that lens. They recognized that "it makes me look fat".
Another bad actor is the 50mm 1.2. Another "fat female" lens.
mod2001
Old school modernist
My AIS (SN 41xxxx) is absolutely fine in this regards. I shoot a lot of architecture (means straight lines) and can't see any serious issue with barrel distortion(means I never saw it in my photos and corrected it), independent of the distance. And the females love the (half body) portraits with it, no complains here so far.
Anyhow, will take a closer eye on it in future.
Yogi