how many stops from black to white. (spotmeter)

Nicole Boenig-McGrade said:

With negative emulsion, expecially B&W, we follow the old rule of thumb: "expose for shadows & process for highlights". To expose for shadows is relatively simple, point the lightmeter at the most important shadow (making sure it's only the shadow you are metering) your meter will read the reflective light as if it were 18% grey (Zone V) and will indicate an aperture/shutter speed combination to suit. ie. 1/4sec f/8)

If you now underexpose by 2 stops (ie. 1/4sec f/16) the exposure for the shadow will move from the middle of the straightline portion of the characteristic curve to the bottom of the straightline portion, where shadows are recorded with full detail.

To process for the highlights:
Changes to development time, temp and agitation have more of an effect on highlight density than midtones and more of an effect on midtones than shadows.
You can reduce density in the highlights by reducing development or increase density by increasing development time. There is a difference to consider though between old technology films (i.e. TriX) and new technology films (i.e. Delta).

If you are taking an incident metering of a caucasian persons face, that reading will give you 18% grey again or Zone V. This will underexpose the persons face by one stop. For caucasian skin tones it's best to overexpose by one stop/expose for Zone VI.

Quinten even if you have the perfect negative with full detail, every consievable tonal range, you'll be limited to the tonal range of the paper you choose.

I hope some of this has made sense. Good luck and good light.
Cheers
Nicole

Click to expand...