Archived posting to the Leica Users Group, 1998/10/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>>>>>>>>>> >I bought a used, mint Noctilux last week, latest 1.0 version, and ran a >roll of Koday Royal Gold 400 through it this week The subject was 3 feet >from me and all of the pictures of same were blurry. If this was not due >to incorrect focusing in the M6 viewfinder, was this because I am >unaware of the true minimum focusing distance at f 1.0? IOW, what is the >true minimum and maximum depth of field allowance at f 1.0? Thanks!>>>>>> Hi SP, At that distance <<<The subject was 3 feet from me and all of the pictures of same were blurry.>>>>>> the depth of field is about "nada!" :) Like nothing, el zippo! :) <<<<<<<<<<< Per the Depth-of-Field Calculator at http://www.serve.com/ballen/DOF.html the DOF of a 50 mm lens at f/1.0 and 3 feet is 2.969 feet to 3.031 feet, or 0.062 feet, which is about 3/4 of an inch. Fairly miniscule. By comparison, DOF of an 85 mm lens at f/1.4 (and I shoot reguarly with the AF Nikkor version of this lens on an FM2) at 3 feet is 2.985 feet to 3.014 feet, or 0.029 feet, which is about 1/3 of an inch. Even more miniscule. I've not shot with a Noctilux (though I really, really want to!). But I have taken many succesfully focused photos with my 85 mm lens wide open at 3 feet (I've also taken many not focused pictures under those conditions; I've found subject movement a bigger problem than focusing). And the numbers suggest the Nocti should be marginally more forgiving. Larry