How do you determine exposure for backlighting

[Claire Senft]

What methods are you using to determine exposure and SBR, to establish a developing time, with conditions of backlighting?

I find this to be a troublesome situation.

 

[Ornello]

What methods are you using to determine exposure and SBR, to establish a developing time, with conditions of backlighting?

I find this to be a troublesome situation.

Meter using the incident method for the shadow area. Expose and develop normally. That's all there is to it.

 

[KenS]

What methods are you using to determine exposure and SBR, to establish a developing time, with conditions of backlighting?

Claire,

When working, I used to do a lot of macro work with small sealed glass bottles or test tubes with bacterial or fungal cultures on their specific growth media.
I would meter with the incident hand-held meter pointing twards the polarized light source. Correct exposure was usually 1.5 stops (plus bellows extension, plus 1 and 1/3 for the on-lens polarizer) open from the light meter reading.

In about 20 years, I rarely found this technique to fail.

Ken

 

[Jeremy]

When working, I used to do a lot of macro work with small sealed glass bottles or test tubes with bacterial or fungal cultures on their specific growth media.
I would meter with the incident hand-held meter pointing twards the polarized light source. Correct exposure was usually 1.5 stops (plus bellows extension, plus 1 and 1/3 for the on-lens polarizer) open from the light meter reading.

In about 20 years, I rarely found this technique to fail.

Ken

Thanks Ken, I'll try this out. I have always wondered a quantified manner in which to measure backlighting with an incident meter--before it was guesstimation (which was pretty close most of the time, but not all of the time).

 

[Jorge]

Claire, I use the incident method. For the low value I point the dome towards the camera, for the high value I point it towards the light source. I determine the high values by getting closer or further away from the light source. This is how I did the refractory shot. This BTW was a 37 minute shot and I measure the highlight at the frame of the window...I wanted the "glow" from it to be infectios. If I wanted the window more defined I would have gotten closer to the window so that it would have indicated a higher value and the corresponding lower development.....

 

[Claire Senft]

Jorge, that is in line with what I am looking for. With backlight and the meter pointed in the direction the camera is facing, there is little difference betwenn the shielded and unshielded meter dome.

 

[Jorge]

Jorge, that is in line with what I am looking for. With backlight and the meter pointed in the direction the camera is facing, there is little difference betwenn the shielded and unshielded meter dome.

I rarely shield the dome...when I want more detail in the dark parts I just get the dome deeper in the shadows. Of course, when I cannot get close to the subjetc, shielding is the only option.

 

[rogueish]

there is little difference betwenn the shielded and unshielded meter dome.

I thought the dome was the sheild!?
Could you explain this part to me?

 

[Jorge]

I thought the dome was the sheild!?
Could you explain this part to me?

This is something done mainly by those using the BTZS, to meter the "shadows" we sometimes shield the dome with our hand or gray card to simulate the shadows present on a scene.

 

[rbarker]

I usually use some combination of incident and multiple spot reflective readings to determine exposure placement and the correponding development plan. The exact method depends, I think, on the subject and the nature of the backlighting, plus whether supplemental lighting (fill) is possible and/or desireable. "Backlighting" includes a lot of variable situations.

For example, a backlit portrait or model shot would be handled much differently than an image of a translucent object where the light transmitted through the object might determine its luminance value. With the former, I start with a spot reading of the face, and adjust that to place skin tone values; then incident-meter the back light to see what that's going to do with hair, etc. If the difference is too great, I might add a reflector or fill flash to bring up the light level on the subject. For the latter, a spot reflective metering of the translucent area, adjusted to place its tonality might be given precedence.

 

[Max Power]

OT:

Jorge, I just have to tell you that your photograph is stunning, as in jaw-droppingly amazingly gorgeous...and that's on a crappy little computer monitor!

OK, we will now return you to your previously scheduled broadcast

Kent