"Who killed infinity focus"

"One of the traditional hallmarks of a high-quality manual-focus lens was that the focus ring would stop precisely at the ∞ mark. This allowed photographers to set their lenses quickly so that everything past a known distance would be in focus. Photographers could do this on the run without looking at their lenses or doing hyper-focal calculations and adjustments."

Either me or author of this article don't quite understand 'infinity focus'...
 
"In optics and photography, infinity focus is the state where a lens or other optical system forms an image of an object an infinite distance away. This corresponds to the point of focus for parallel rays. The image is formed at the focal point of the lens.

In a simple, two lens system such as a refractor telescope, The object at infinity forms an image at the Focal Point of the objective lens, which is subsequently magnified by the eyepiece. The magnification is equal to the focal length of the objective lens divided by the focal length of the eyepiece. [1]"
wikipedia
 
An infinity focus stop only needs to be within the depth of focus of the largest aperture, as a matter of practical lens design.
 
brbo said:
"One of the traditional hallmarks of a high-quality manual-focus lens was that the focus ring would stop precisely at the ∞ mark. This allowed photographers to set their lenses quickly so that everything past a known distance would be in focus. Photographers could do this on the run without looking at their lenses or doing hyper-focal calculations and adjustments."

Either me or author of this article don't quite understand 'infinity focus'...
Click to expand...

Wow, :rolleyes: Thanks for saving my time from reading this nonsense.

My high-quality AF Canon L lenses wouldn't stop at infinity, but I feel it without looking at it.
And hyper-focal calculations has nothing to do with stop at infinity, but DoF, which you must look at.
This is the picture from B&H.
http://www.bhphotovideo.com/c/product/457680-USA/Canon_1257B002AA_Normal_EF_50mm_f_1_2L.html

457680.jpg


And most of consumer grade DSLR(SLR) lenses do stop at infinity.

B&H dropped the plank so low with this one.
 
Mostly twaddle. Then again, 1970s Vivitar "solid cats" focus "beyond" infinity to allow for thermal expansion: it can matter with very long focal lengths. Overall, with modern lenses, I can't help feeling "Serve you right for using autofocus".

Cheers,

R.
 
I don't quite get the point of the article, probably I'm so mean, lol.
Are there anyone killing infinity focus? Has it been killed yet?
 
Well, there's no point in attempting to focus at infinity, because with the inverse-square law by the time light from infinity reaches your camera there's very little left with which to make an exposure. :)

~Joe
 
brbo said:
"One of the traditional hallmarks of a high-quality manual-focus lens was that the focus ring would stop precisely at the ∞ mark. This allowed photographers to set their lenses quickly so that everything past a known distance would be in focus. Photographers could do this on the run without looking at their lenses or doing hyper-focal calculations and adjustments."

Either me or author of this article don't quite understand 'infinity focus'...
Click to expand...

Add me to the list of doubters, please. This intro makes you suspect what follows.

Regards, David
 
Well they did not make their point very well, and they did not mention that you actually give half of your DOF away if you focus to infinity (instead of the hyperfocal distance).

But then, focusing to infiinity via hardstop is really the only thing to do if it's really dark and you cannot see the scale anymore.

This used to annoy me greatly when trying to do night shots with my Canon EOS gear (all of which has been sold in the meantime)... it would be too dark for the AF to find its mark, and I would not be able to focus manually either. Very frustrating. And yes, it did serve me right for using AF.
 
I'm more concerned about the other distance marks and aperture marks. If a lens doesn't have these, like many entry level lenses, then you have to measure the distance to the focal point, and consult a chart or app in you smart phone. Assuming you can do both. Old way gave you an aperture setting at approximately the DoF you want in seconds.
 
Roger Hicks said:
Mostly twaddle. Then again, 1970s Vivitar "solid cats" focus "beyond" infinity to allow for thermal expansion: it can matter with very long focal lengths. Overall, with modern lenses, I can't help feeling "Serve you right for using autofocus".

Cheers,

R.
Click to expand...

I use modern autofocus lenses half the time. Does that mean it serves me half right or half serves me right? :D
 
Ko.Fe. said:
Wow, :rolleyes: Thanks for saving my time from reading this nonsense.

My high-quality AF Canon L lenses wouldn't stop at infinity, but I feel it without looking at it.
And hyper-focal calculations has nothing to do with stop at infinity, but DoF, which you must look at.
This is the picture from B&H.
http://www.bhphotovideo.com/c/product/457680-USA/Canon_1257B002AA_Normal_EF_50mm_f_1_2L.html

457680.jpg


And most of consumer grade DSLR(SLR) lenses do stop at infinity.

B&H dropped the plank so low with this one.
Click to expand...

I used to have some Canon glass (including this one), and hitting infinity was always a pain. Not much of an issue in practice on a DSLR because I never shot manual (as I couldn't really gauge it without a split prism or a rangefinder).
 
I sent a Nikon AI lens in for cleaning a couple of years ago and it came back focusing past infinity at the infinity setting. I called to complain, and the (Nikon authorized and trained) repair service put on the (Nikon trained) technician who explained that some AF systems won't give a green dot unless you go past the point of focus and back, which you can't at infinity if it stops there. He said the official word from Nikon was to set them to go past infinity for that reason, mainly, he thought, to keep people from complaining that they couldn't focus at infinity. :)

He did set mine back to the way it was after I asked. My complaint was that I focus by scale quite often, and it didn't work to be setting seven feet and getting fifteen. He warned me, however, to specify what I wanted on future repairs, so it would come back right.
 
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