Photo Image out of focus

[Jeff Weitz <weitz@PIPELINE.COM>]

Hi Everyone,

 

A parent of one of my students sent me the following question:

 

At Lower School graduation, I took a great photo of a friend of mine and his
son.  But it's somewhat out of focus.  I want to print it, but in focus.  My
intuition tells me that all the various light rays hit the film -- but not
quite in the right place.  So it seems to me that all the data for a good
print must be there on the emulsion.  And if I could only bend the light
rays in the printing process (whether before or after it goes through the
negative, I'm not sure), it should be possible to correct the error and make
the print come out in focus.  (After all, they fixed the Hubble telescope,
right?)

I responded as follows:

 

My first thought is that you are seeking an analog solution to a digital
problem.  You're probably right that all the necessary data is there, just
not in the right place.  And your photography friends may also be right that
there are no photographic techniques available at the developer to move
those data around.  The easy fluidity of data is a digital reality, not an
analog one or we would have had it sooner, I imagine.

Is anyone on this list a knowledgeable photographer who can resolve this question one way or the other.  I'm not sufficiently aware of the optics of the development process to answer directly.  Is there an optical solution to the focus problem?

 

Thanks for any help you can give.

 

Jeff Weitz

Physics Teacher

Horace Mann School

Riverdale, New York