[Leica] Measuring exposure lag (a long post)

[leicar at q.com (Aram Langhans)]

> * I cheated when I timed the exposure lag of my Oly E-500 several years 
> ago.
> I simply photographed the face of a 1/100 second electric timer. An
> assistant started the timer. When I saw the hand start to move, I clicked
> the shutter. The exposure lag (reaction time plus shutter lag) varied
> between .35 and .45 seconds. Certainly not instantaneous. In this time a
> baseball thrown by a mediocre pitcher would have traveled about 3/4 of the
> distance from the pitcher's mound to home plate. Three examples of this
> measurement of exposure lag are:*
>
> *
  I have used the ruler drop for 35 years as a teacher not so much to 
measure reaction time but to show how to design an experiment to account for 
variables and use statistics to analyze the data.  A great method and I am 
sure it works (I trust gravity).  However, the question is: exactly what is 
it showing you about the initial question.  Does it really predict the 
actual reaction when taking a photo.  You mentioned the pitcher throwing a 
baseball.  I have taken many photos of my nephew when he played baseball. 
Of course, so  have many other photographers.  How could this be if the ball 
is already to the plate?  Of course, a photographer anticipates.  They take 
their past experience and press the shutter to get the shot they want.  No 
one just reacts, because if they do they will miss the photo no matter how 
fast the camera is (shutter lag).  Even if it was instantaneous.  HBC had to 
anticipate the decisive moment.  W/o anticipation, there would be no 
decisive moment.  So, the whole system must be considered, as you do in your 
test.  The skill is in anticipating the decisive moment, not reacting to it. 
In your example, to catch the pitch, you must hit the shutter 0.4 seconds 
before you see the pitch.

Aram