Infinity autofocusing

[suk_jung_choo]

<p> I mounted my 20mm AF ED autofocus lens to my D4, set the camera to A and pointed towards the landscape in front. When I pressed the shutter it would not click. It seemed like the camera could not focus lock on to infinity. But I don't recall having had this problem before. Focusing something closer than infinity was not a problem. I then mounted my 35mm AF nikon lens onto the camera and the same thing happened. Is it the lens or is it the camera setting? I'm pretty sure this is a new problem but maybe I'm mistaken. Any help would be appreciated. Thanks. </p>

[CvhKaar]

<p>There is a setting in your camera that allows you to set "Focus Priority" or release priority. this is probably set to "Focus Priority. If you want to be able to release when nothing is in focus , you need to set it to "release Priority". </p>

<p>I do not have a D4 manual available so you will need to look that up in your user manual to know wgat that setting is called on a D4</p>

[suk_jung_choo]

<p>Thank you for your quick reply. I'll be back to let you know if I have the problem fixed. It's funny because I just don't know if it is a problem that maybe always existed but never noticed until now. </p>

[CvhKaar]

<p>I think its on the settings a1 & a2 ?<br>

<a href="http://www.outthereimages.com/images/D4_Setup_Guide.pdf">http://www.outthereimages.com/images/D4_Setup_Guide.pdf</a></p>

<p>btw did you ever visit this ?<br /> <a href="http://nps.nikonimaging.com/technical_solutions/d4_tips/">http://nps.nikonimaging.com/technical_solutions/d4_tips/</a></p>

[mike_halliwell]

<p>What AF choices have you made? AF-S, AF-C, Spot, etc etc? </p>

<p>Have you accidentally moved the selected focus-spot into plain featureless sky with nothing for the AF to grab onto?</p>

[suk_jung_choo]

<p>C.P.M van het Kaar, you are the man! You nailed it. Thank you so much. In the setting a2 it was placed on focus when it should have been on release. That's all I know. So, when I changed the setting to release it worked just perfectly and when I switched back to focus I had the same problems again. So there you have it. That was the problem. I would also like to thank Mike for taking trouble to reply. What a great site! </p>

[frank_skomial]

<p>After you changed into release priority, you gave up assurance of getting sharp in-focus pictures everty time you take the picture.<br>

Now you take a picture regardles if is is in focus or not.</p>

<p>Seek for another reason why your camera cannot focus properly on the landscape ?<br>

What prevents if from sure focusing ?</p>

 

[ShunCheung]

<p>Ok, now your D4 can capture an image with that lens, but is it in perfect focus?</p>

<p>I would suggest putting your D4 on a tripod and use live view to manually fine tune the focus on some landscape subject. Make sure that lens can focus to infinity. Take AF out of the equation during this process.</p>

<p>If that 20mm cannot focus to infinity, it may need some adjustment or repair.</p>

[michael_darnton2]

<p>I don't know the specific cameras involved, but when I sent a Nikon AI lens in for cleaning at an authorized repair service, it came back so that it would focus beyond infinity. This didn't work for me because I scale focus a lot, and it was pretty far off. When I talked with the tech, he told me that there are a few Nikon AF bodies that require the lens to focus beyond infinity to grab AF at infinity, so the word from upstairs was to set them all to go slightly beyond infinity. He was happy to set mine back to the way it originally was, and told me just to note that I wanted them unchanged when I sent them in. I gathered that it's actually less work for him to leave them as they were, so he wasn't unhappy with that, but he told me that getting the first one back to the way it was was a bit of a job.</p>

<p>Perhaps you have a lens that zeroes out right on the spot at infinity, but a camera that doesn't like that.</p>

[Michael R Freeman]

<blockquote>

<p><em>"he told me that there are a few Nikon AF bodies that require the lens to focus beyond infinity to grab AF at infinity, so..."</em></p>

</blockquote>

<p>This is unrelated to the OP's problem, but that makes me chuckle. Unless it is a long telephoto ED lens where it is normal for the infinity symbol itself to go past the index, that's a pretty silly reason to set the focus stop on a *manual focus* lens to anything other than proper infinity focus. First, a Nikon autofocus body fitted with a manual focus lens does not need to "grab AF" at infinity, and secondly an autofocus body fitted with a manual focus lens is always release priority ... at any distance. :-)</p>

[michael_darnton2]

<p>It may or may not be silly, but it was Nikons "silly" not his own. The tech said it obviously wasn't necessary, but that some people do like to see that green light go on, even at infinity.</p>

<p>It's probably either that, or field an endless number of calls from clueless geeky people who believe their camera is broken because it "won't focus to infinity".</p>

[Michael R Freeman]

<blockquote>

<p><em>"...but it was Nikons "silly" not his own."</em></p>

</blockquote>

<p>Actually, it was this particular authorized repair service's "silly", not Nikon. The lens in question did after all, along with millions of other manual focus AI/AIS lenses, originally come from Japan set to a focus stop limit at actual infinity, not "slightly beyond".</p>

<p>As I meant to imply, somewhat amusing "logic" on their part (lots of autofocus AF-D primes also do not focus "slightly beyond" infinity). :)</p>

[suk_jung_choo]

<p>I am not a camera expert so I will just describe things as I am seeing from a simple user point of view. The D4 a2 AF-S priority selection has two options; release and focus priority. When shooting subjects closer to infinity, no issues arise with either settings. When shooting landscape, the focus priority seemed to push the camera beyond the infinity focusing mark (the lens tested were 20mm AF 2.8F and 35mm AF, the cheaper version). Therefore, the shutter would fire only occasionally after focus searching. When set at release priority focusing stopped at the middle of the infinity symbol. Hyper magnifying the landscape shots taken under both settings, honestly showed no detectable differences (I mean comparing the images that were shot after the correct focus confirmation). If you are really a perfectionist, then I guess you will have to go with the focus priority setting or shoot manually, if it is possible to really focus beyond infinity with the naked eye. For me however, I think release priority works just fine. </p>

[CvhKaar]

<p>Glad i could help you,<br>

just happy to see you can figure out how to use your camera, without debating all subjects that were not included in your initial question.. :-)</p>

[Michael R Freeman]

<blockquote>

<p><em>"... without debating all subjects that were not included in your initial question."</em></p>

</blockquote>

<p>Where's the fun in that? ;-) >:)</p>