Is there a website showing the cross section of a modern autofocus lens and how the autofocus mechanism in a lens works?
anir...@gmail.com
press the camera's button. It must drain a lot of energy from the
battery to do this. I recall the old autofocus lens was a monster
size. Is there a diagram somewhere in the web which shows how this is
accomplished? Is there some kind of a spiral screw along the outer
skin of the lens barrel? I also assume that the bigger the lens, the
more energy needed to move the lens during autofocusing.
Thanks for the info.
Don Stauffer
I have seen such diagrams, but do not have a reference to any right now.
Consider too that it is not unique to autofocus. Remember that when
you do manual focus you only move one ring, you do not have to move
individual elements. Yes, frequently the mechanism employs a coarse
pitch helical groove or "thread". Consider that a small motor could be
geared down to move the focusing ring.
Most lenses are pretty well made these days with high precision and so
very little friction. As a result they do not take a LOT of energy, but
they certainly do take some. As a result, some camera manuals do say
that using manual focus, if available, will lead to longer battery life.
anir...@gmail.com
> On Fri, 29 May 2009 14:18:58 -0700 (PDT), in rec.photo.digital
I finally found a website (all the way from Malaysia) which shows a 3D
slice of a Nikkor autofocus lens
http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/AFNikkor/index.htm
I wonder if there are other websites that show this in more great
details.
According to the 3D section, it looks to me that the motor gear is
located directly under the ring grip where you twist the lens when you
want to change the zoom distance manually. It is neat! I am curious
about this, as I seem to notice that my cheap Nikkor autofocus
70-300mm lens feels rather flimsy on the plastic outer barrel and
wonder where the motor mechanism is located and how it works. Although
it is relatively cheap, I could not afford to send my lens to a
machine saw and cut it into half in lengthwise to find out where the
mechanism is :)
I would love to see more about this autofocus lens info, if someone
has more info or amke reference to websites.
Bob Larter
> On May 30, 9:22 am, m...@mine.net wrote:
>> On Fri, 29 May 2009 14:18:58 -0700 (PDT), in rec.photo.digital
>>
>> anira...@gmail.com wrote:
>>> Just curious to know how the lens barrel is moving up or down when you
>>> press the camera's button. It must drain a lot of energy from the
>>> battery to do this. I recall the old autofocus lens was a monster
>>> size. Is there a diagram somewhere in the web which shows how this is
>>> accomplished? Is there some kind of a spiral screw along the outer
>>> skin of the lens barrel? I also assume that the bigger the lens, the
>>> more energy needed to move the lens during autofocusing.
>>> Thanks for the info.
>> Some discussion of the Nikon SWM lens design may be found here.http://imaging.nikon.com/products/imaging/technology/scene/03/index.htm
>
> I finally found a website (all the way from Malaysia) which shows a 3D
> slice of a Nikkor autofocus lens
> http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/AFNikkor/index.htm
>
> I wonder if there are other websites that show this in more great
> details.
Somebody recently posted the complete service & parts manual that
covered several Canon prime lenses, which had detailed diagrams &
explanations for all this stuff. Maybe someone else here still has the URL.
--
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