Old AI Nikkor 400mm f/3.5 ED-IF question

[patriciomurphy]

<p>Hi! Perhaps someone is able to help me on this one.<br>

The 400mm f/3.5 has a "pre-setable focusing ring for rapid refocusing to a specific distance and full-aperture" (taken from http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/telephotos/400mm1.htm). However, I can't quite get to understand how should it work. Perhaps mine is broken, or I just don't get what it's supposed to do.<br>

Can someone enlighten me? How should this thing work?<br>

Thanks!<br>

Pat<br /> </p>

[carl_becker2]

<p>I have a 500mm f4 P which has the same silver lock thumb screw. I have had it set wrong and just changed it to give full focus travel. loosen it and play with it to see what happens. It may be a limit set but I don't remember as I was in the field when I changed it. It's not something I am concerned about using but you may find it handy.</p>

[Michael R Freeman]

<p>The <em>"pre-setable focusing ring for rapid refocusing to a specific distance and full-aperture"</em> is basically a click stop on the focusing ring to allow you to rapidly return to a fixed focus distance from any other position of the focus ring. I think it was a feature primarily intended for sports photographers. For example, the photographer could focus on first base, set the preset ring click stop to that distance, and then focus on the pitcher. Pitcher throws, batter swings and connects, and the photographer can immediately swing the lens to first base, twist the focus ring until it clicks into place, and he should be focused and ready for a play at first.</p>

<p>Focus to a specific distance. Say 10m for this test. If you look to the front edge of the focus ring, you'll see a white dot (roughly halfway between the 6m and 7m markings). There is a small ring immediately ahead of the focus ring with a locking screw. Unlock the screw, and rotate the ring until the lock screw lines up with the white dot. You might feel a slight click as the ring rotates into position and the dot and screw align. Tighten down the lock screw. Now focus the lens to infinity, and then back to 10m without looking at the focus scale. When the lens is focused at 10m, you should feel a light "click stop" at the preset distance.</p>

<p>My AI 400/3.5 IF-ED is "experienced", and the click is very light on mine. It's probably quite worn, and isn't really useful to me.</p>

[rodeo_joe1]

<p>Same thing is fitted to the 400mm f/5.6 IF-ED lens. Never seen the point of it myself and use mine as an infinity stop, since the lens focuses way beyond infinity - presumably for when you're caught in an alternative universe where infinity is much further away.</p>

[rjm photo]

<p>I also use the one on my AIS version of 400mm F3.5 for an infinity stop. I'll focus on the moon and set the lens stop....with the realization that infinity may change with changes in temperature.</p>

 

[alex_lofquist]

<p>I find the detent quite useful when there is a spot where most of the action is likely to occur, but do not wish to be locked into that focus. Examples are birds' nests and feeders, fish jumping up waterfalls (especially if there is a bear waiting with its mouth open), street scenes with the expectation of seeing celebrities exiting a taxi, and others too numerous to mention. </p>

[patriciomurphy]

<p>Thanks everybody!<br>

I get it. I was sort expecting (don't ask me why, since now that I think about it, it doesn't make too much sense...) this thing to work like some sort of focus limiter, so I completely missed it, and actually thought that click I felt while I focused was something going wrong with the lens! :P<br>

I'll be photographing birds this weekend, so I may now see if I find it useful.<br>

Thanks again!<br>

Pat</p>

[Albins images]

<p><strong>Patricio</strong> wrote: "I was sort expecting (don't ask me why, since now that I think about it, it doesn't make too much sense...) this thing to work like some sort of focus limiter, so I completely missed it"..</p>

<p>[<em>shame emoticon</em>:] I have to admit that until now, I did exactly the same thing.. Never used the feature, obviously! Photo.net is a great learning community!</p>

[Albins images]

<p>In addition: I have my lens only for about 10 years, so that must be it..</p>

[patriciomurphy]

<p>LOL! I also never felt the need, but now that I get the point I think of a couple of times when I could have used it...</p>