AMBIENT ??OVEREXPOSURE TECHNIQUE

I REALIZE THAT THERE ARE PROBABLY AS MANY METERING TECHNIQUES AS THERE ARE BOOKS WRITTEN TO DESCRIBE THEM. I HAVE JUST PURCHASED THE "WEDDING PHOTOGRAPHER'S HANDBOOK" BY ROBERT & SHEILA HURTH. THEY DESCRIBE THEIR METHOD FOR METERING AMBIENT LIGHT AS FOLLOWS: TAKE A AMBIENT READING OF THE STRONGEST LIGHT FALLING ON THE SUBJECT AND THEN OVEREXPOSE THAT READING BY ONE STOP (F8 @125-----to F8 1/60). NO MENTION OF FILM RATING?? CAN SOMEONE COMMENT ON THIS TECHNIQUE. I NORMALLY RATE 400 ISO @ 320, TAKE AN AMBIENT READING AND SHOOT WHAT THE METER READS.

I to have read this book and puzzled over this coment. After reading the entire book, I decided that they over expose every negative by one stop just for insurance against under exposed negatives. Color print film does have a good deal of exposure lattitude and can easily handle the extra stop of exposure. I usually tend toward the over exposure side especially when I am using strobes.

This is probably an attempt to give the film as much exposure as it will tolerate without blocking (i.e. burning out) the highlights.

 

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Since meters are typically calibrated to 18% gray which is Zone V, you can probably open up three stops to "place" the brichtest part of the imabe on Zone VIII without blocking. You should experiment to see how it works for you.

 

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I expose B/W film in this manner and have wonderful negatives with full shadow detail.

The overexposure technical can only be used with negatives.

With Black & White Film the number of gray scale will depend of the film developpment. If you want further informations, read the exellent book fronm Ansel Adams "the Zone System". It describes all the interaction between exposure-film and grey scale with time developpment and so on.

With colour film, I have just remarq that the temperature colour was a bit warmer.

 

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Salah Benacer