Extension ring & portraits

[bluechromis]

If I had a 50 mm lens for 35 mm format and I used an extension ring with that, I a right in assuming that it would act more like a portrait length lens in terms of less facial distortion?

 

[ic-racer]

If you want to call perspective "distortion" then changes in subject to camera distance are the only thing that influences the 'distortion.' So an extension ring would make the 'distortion' more pronounced because you would be forced to be closer to the subject to focus the camera. To get farther away, and have close framing of a subjects face with the 50mm lens, a common technique is to crop the image during enlarging.

 

[Pieter12]

An extension ring will allow you to get/focus closer to your subject. I don't think that will give you a conventional portrait. What you might be thinking of is a teleconverter, which will multiply the focal length of your lens by its factor. So, a 1.4X teleconverter would make a 50mm lens the same as a 70, a mild portrait lens. The aperture of the lens is also affected, making it slower.

 

[neilt3]

Are you sure your not thinking of a tele-converter ?

A 2x tele-converter would effectively make the 50mm lens a 100mm lens .
So you could stand further back and still fill the frame , but with a different perspective .

Using an extension tube on the 50mm lens would just reduce the minimum focus distance to allow close up / macro shots .
So unless you want a close up of an eye or nose , I'm not sure what portrait type shot your planning .

 

[bluechromis]

Are you sure your not thinking of a tele-converter ?

A 2x tele-converter would effectively make the 50mm lens a 100mm lens .
So you could stand further back and still fill the frame , but with a different perspective .

Using an extension tube on the 50mm lens would just reduce the minimum focus distance to allow close up / macro shots .
So unless you want a close up of an eye or nose , I'm not sure what portrait type shot your planning .

Thanks.

 

[John Koehrer]

Using a telephoto lens and an extension tube could allow you to get closer to a subject
but with a 50 you will get the distortion mentioned above.

With a teleconverter you will get a larger image size from the same distance.
IE: If your image at 4-5 ft with the 50 is too small, you may find that 50+ 2XTC gives head & shoulders or a bit less.

 

[Alan Gales]

An extension ring will allow you to get/focus closer to your subject. I don't think that will give you a conventional portrait.

What do you mean by not a conventional portrait?

 

[wiltw]

What do you mean by not a conventional portrait?

Gawd,,,this is what a medical tech working in a COVID testing facility gets to look at all day!!!
No wonder they get sick doing their job!

 

[wiltw]

If you want to call perspective "distortion" then changes in subject to camera distance are the only thing that influences the 'distortion.' So an extension ring would make the 'distortion' more pronounced because you would be forced to be closer to the subject to focus the camera. To get farther away, and have close framing of a subjects face with the 50mm lens, a common technique is to crop the image during enlarging.

^^^

 

[AgX]

If you want to call perspective "distortion" then changes in subject to camera distance are the only thing that influences the 'distortion.'

Or more precise: the ratios between different face-detail to lens distances. The greater these ratios, the greater the distorsion.

 

[wiltw]

Or more precise: the ratios between different face-detail to lens distances. The greater these ratios, the greater the distorsion.

If the face is a FARTHER from a lens, it appears to be less 'distorted' than when the face is really near the lens.
If the face is 10" tall, it appears very 'perspective distorted' (the nose is really large compared to the ears) when the lens is a mere 20" away, the ratio of detail vs distance is 1:2. Move to 120" inches and there is no facial distorion, and the ratio of detail vs distance is 1:12

 

[AgX]

I referred to ratios between longitudinal distances. But yes, one can explain it also, as you did with differences between lateral-distance/longitudinal-distance ratios.

A third explanation would be that the nearer the face to the lens, the more different the scales are by which different face details are reproduced.