[Leica] Re: LUG Digest, Vol 30, Issue 26

[mark_wilkins at yahoo.com (Mark R. Wilkins)]

On Jun 11, 2005, at 5:15 PM, lug-request@leica-users.org wrote:

>
> Over exposure = death when it comes to quality black and white  
> image making.
> And all "pulling" is is over exposing with a smug attitude.

Obviously your photography speaks for itself, so far be it from me to  
argue that you should try anything differently from what you're  
doing, but pulling can be more useful, done right, than you're making  
out.

Increasing exposure just increases shadow detail.  Reducing  
development time (within reasonable limits, which I'll get to in a  
second) reduces the density of the highlights on the negative, which  
prevents the hottest highlights from hitting the film's maximum  
density -- this increases detail in the highlights as well.

Really, the reason that increasing exposure and reducing development  
("pulling") can eventually cause image problems is that there's a  
time scale to the diffusion of the chemistry through the developer  
and the film's emulsion that depends on temperature only -- and  
reducing development time means there's less time for chemistry to  
diffuse effectively and thus there can be problems with uneven  
development or difficulties with repeatability of the process from  
roll to roll.

To some extent, lowering the temperature of development and keeping  
the development time and degree of agitation the same can help  
overcome this, but that only helps to a point.

"Overexposure" may be a huge problem, but overexposure means exposing  
too much for the specifics of how the film is developed, not exposing  
more than the rated ISO speed of the film (which is what "pulling"  
and "pushing" use as a baseline.)

Ansel Adams' wrote about how to exploit "pushing" and "pulling"  
pretty extensively in "The Negative," if you'd like a more detailed  
explanation of how it works in practice.  However, I don't believe he  
uses those terms -- he just talks about the techniques.

-- Mark