Reflective vs. incidence meter reading??

[markbarendt]

But providing a middle-gray rendering of a metered area is not what incident meters do. They are keyed to the highlights and nothing else - great for transparencies and digital. With negative film, being keyed to the highlights doesn't guarantee anything about shadow detail, which is what you really want to be controlling at exposure time. Incident meters are certainly convenient and quick but for negatives, and having time to meter, cannot beat a spot meter for getting a desired exposure.

And that would also be a no.

You can use incident meters to peg to the main light (point it at the sun) or to open shade (point it away from the sun) or whatever, but they don't discriminate about what tones they see and are most definatel not keyed to the highlights.

Incident and reflective metering are both useful, with experience and understanding both can be very accurate. One is not better than the other.

I wrote a primer on incident metering here (there was a url link here which no longer exists)

 

[baachitraka]

Actually incident reading give 5-stop range.

E.g., EV 12 whose range starts from 9.5 - 14.5.

Transparencies approximately = 5 stops. So, we may need not consider about the extreme ends.

Negative films > 5 stops. We need to consider the extreme ends.


Sorry, my english has gone into drain.

 

[baachitraka]

@Mark: True, it does not know anything about the tonal range. It only measure the light falling on the subject.

If I take the incident reading(dome pointing to camera) on a shade, will it render as middle gray on print?

 

[markbarendt]

An EV is a specific point on a scale, not a range.

The film we are metering for defines the range. When we set the EI/ISO on the meter we are telling the meter the offset from the measured speed point of the film to the light measurement done by the meter. The ISO standard defines one way of finding the speed, there are many others that have been described by various and sundry sources. We can apply all kinds of factors into the EI number for any reason we please.

The 5 stop range thing is an urban legend, a myth, some body's over simplification.

 

[markbarendt]

@Mark: True, it does not know anything about the tonal range. It only measure the light falling on the subject.

If I take the incident reading(dome pointing to camera) on a shade, will it render as middle gray on print?

Only on a transparency.

With negative it's all relative, there is no specific point that can be defined as the absolute middle gray point. This is because print exposure is set in the enlarger, and in the enlarger you can place any tone you please from the film at middle gray on the paper.

Proper metering allows you to set the camera in a way that allows you to get good shadow and highlight detail around middle gray. It gives you a reference point to make your work easier.

If for example you used TMY which has a 14 stop range you could pick an EI that might put your intended middle gray 7 stops above the film's toe. 1 or 7 stops to the toe, it's your choice.

 

[Noble]

They are keyed to the highlights and nothing else - great for transparencies and digital. With negative film, being keyed to the highlights doesn't guarantee anything about shadow detail, which is what you really want to be controlling at exposure time.

This seems very contradictory. If you have a correct exposure for a slide given the greater dynamic range of negative film you should have an even better negative image. It may not be perfect but it most cases I would assume it is 95% of the way there. I have not really gotten into spot metering because I shoot roll film. I can't really start doing N+/-2 developing and stuff like that for a single frame. In real life with roll film how much of a dramatic difference does it make? I shoot TMAX 100 @ ISO 50 and adjust development to keep the highlights from blocking up. Beyond that I just accept what I get.

 

[Diapositivo]

Imagine a Rembrandt portrait with that "Rembrandt lighting", half the face in full light, the other half in shade.

With slide film you place the dome near the cheek in full light pointing it toward the camera. That gives you the incident "expose for the highlights" reading.

With negative films you place the dome near the cheek in shade pointing it toward the camera. That gives you the incident "expose for the shadows" reading.

My €0.02.

 

[Allan Swindles]

Just read the Weston Master V or Euromaster instruction book. IMHO nothing's changed. Diapositivo has summed it up well.

 

[Poisson Du Jour]

And that would also be a no.

You can use incident meters to peg to the main light (point it at the sun) or to open shade (point it away from the sun) or whatever, but they don't discriminate about what tones they see and are most definately not keyed to the highlights.
[...]

Luminance. This is the critical point that has been missing from the discourse. The values of individual tones (or luminance values) that make the scene and how incident/reflective have no way to differentiate those values. The solution is...?

 

[markbarendt]

And that would also be a no.

You can use incident meters to peg to the main light (point it at the sun) or to open shade (point it away from the sun) or whatever, but they don't discriminate about what tones they see and are most definatel not keyed to the highlights.

Luminance. This is the critical point that has been missing from the discourse. The values of individual tones (or luminance values) that make the scene and how incident/reflective have no way to differentiate those values. The solution is...?

The point I'm getting at is that we should endeavor to understand what the meter is seeing and understand how a reading (measured luminance) relates to the film curve we are using.

While the beginnings are understanding normal in the end the solution is individual practice/experimentation.