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Photography Question 

Odelia
 

How to detemine how long to expose?


I'm working on a photography assignment in which I am photographing flowers on a black backgroung with side lighting. I was advised to use Kodak T-Max 100 but now I am not sure how long to expose. I am planning on using F16 or 22. If it helps any the camera I am using is a Vivitar 2800N. I really need the answer to this question as soon as posiible. Thanks.


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November 25, 2004

 

BetterPhoto Member
  Hi Odelia-
T-Max is great film and I am not familiar with your camera. In commercial photography we always use a Polaroid for testing to determine exposure or the LCD on a digital camera, but it doesnt sound like you have either. Are you using strobe lights, window light, or hot lights? That make a big difference on how you meter to determine exposure. If you are using window light, my best suggestion is to point your camera at the scene and fill you viewfinders metering area with 1/3 flower, 1/3 stem, 1/3 black background. Hypothetically, lets say that gives you a setting of 1/4 second at f/16, take your first shot, then bracket around that. f/11 1/2 @ 1/4, f/16 1/2 @ 1/4, the maybe f/11 and f/22 @ 1/4 also. That way you have covered your bases.


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November 25, 2004

 

Bob Cammarata
 
 
  Pride of Parenthood 2
Pride of Parenthood 2
Nikkor 35 mm, Provia 100, black poster-board background, outdoors on a cloudy day.

Bob Cammarata

 
 
I am curious, as to your decision to shoot at f-16 to f-22.
In a studio setting, where you have complete control over lighting and subject placement, why not shoot with a wider aperture...like f-5.6 or f-8.
These mid-range settings will optimize the sharpness potential of your lens.
As long as your subjects lie within the focus plane, your depth of field will be within acceptable parameters using these wider settings.

As to metering...if the flowers have color, get in close and meter off the brightest part of the petals. This will give you a good starting point from which to bracket 1/2 stop both ways.
A white flower has to be metered differently or it will under-expose.
Meter off the brightest part, then open
a full stop and bracket from there.
As Charlie mentioned, the intensity of your lighting will determine which of the bracketed exposures you will like best.

The enclosed example was metered off the yellow petals in diffused light...(outdoors on a cloudy day), and required an exposure setting of 1/8 second at f-8.

Hope this helps.


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November 25, 2004

 
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