Using Manual exposure and spot metering

[sieracki]

Are you shooting digital or film. Your technique will differ depending on the medium. I suggest that in any case you read about the Zone System (in caps on purpose -- this is the holy grail IMO). For film, most people expose for the shadows and develop for the highlights -- this means that you take your important shadow area. meter on it, get an aperture and shutter speed which would be Zone V. If you want to place in Zone III, then you stop down (raise the F number or make the shutter speed faster) by 2 stops. If yoiu are shooting digital like I am then you expose for the highlights. You can start by choosing the most important highlight in the scene (a cloud or the blue sky) -- you can tell this with your meter -- it recommends the least exposure for the brightest portion. or in EV mose, choose the highest EV number for the portion of the scene to base exposure on. Most of the time I can raise highlights to +2.7 or so. So meter on the brightest important part of the scene, read that aperture and shutter speed, then open up 2 and 2/3 stops. Things are a little more complex than this but it's a start.

[djgarcia]

To complement what's been said, I feel also important in determining aperture or shutter speed first is your subject matter. Some subjects may be more speed sensitive (e.g. moving objects) so you may want to set speed and vary aperture. If DOF is more important, set aperture then speed. Obviously every situation has its peculiarities.

It's very important when using the Zone System is to understand the dynamic range and behavior of the film (negs & slides behave different!) or sensor. Using the guidelines nicely posted before, a few (or a lot) of tests with contrasty subjects with a wide brightness range will quickly tell you the story.

[djgarcia]

Another excellent reference is White/Zakia/Lorenz's "The New Zone System Manual". The White is for Minor White. It really gives you great theory and practice. Of course the first acknowledgement in the preface is "We are all indebted to Ansel Adams ..." ::

DJ

[owenpga]

I am try to venture out the the normal aperture priority and shutter speed priority modes to learn more about metering. This is probably a basic question for most but when i'm in manual mode using spot metering how do I determine my shutter speed and aperture settings?? Am i deciding what type of dept of field I want first and then metering off of that F stop setting? If so, what should the shutter speed be. Thanks, Owen

[dlashier]

> when i'm in manual mode using spot metering how do I determine my shutter speed and aperture settings?

Sieracki summed it up but here's what I do (I shoot almost exclusively in manual/spot). I generally check at least three areas of the scene, watching the readout on the right side of the viewfinder. First I'll meter a light area (eg white clouds in a scenic) and adjust shutter speed and/or aperture so that it reads out +2, then I'll check a dark area (eg shadows) to see if it's not off the bottom, or preferably -2 to -2.5. If it's too low and shadows are important I may push highlights up to +2.33 or rarely as high as +2.66. The third check is usually on midtones (typically primary subject) somewhere just to make sure that they're in the 0 to +1 range.

It can be helpful at first to meter a number of spots in a typical scene making notes (mental or otherwise), then bracketing the exposure and comparing your notes with what you see in the raw converter.

Also after a while you learn typical "reference points" that can be used as sanity checks or for making a quick exposure determination when required. The one I use most frequently is low sky (about a "hand" above the horizon) metering at +1 although this will obviously vary depending on time of day, atmospheric conditions, and direction of sun.

Just consider the meter readout to be a histogram "on end" with the readout showing where the spot being metered will land on the histo.

- DL

[howard smith]

Once an exposure is determined, f/stop and shutter speed are locked together.  You can detrmine f/stop, and get a shutter speed to match.  Then you can adjust both to get the DoF you want, or a desired shutter speed to stop a moving image or adequate for hand holding the camera.

In the Zone System, the photogrpaher can determine the exposure off of any tone, and expose and process accordingly.  The system has historically been applied to B&W negatives.  The old advice of expose for the shadow and process for the highlights also works for negatives because developement changes have a much smaller effect on shadows.

Exposing for the highlights is normally used with positive film or digital because over exposed highlights usually look bad while more and deeper shadows can be accepted.  Also, color positive films have less latitude in processing techniques without soem adverse color changes.  With digital, once the highlight is gone (clipped), nothing will bring it back, but soem shadow detail can be retrieved, provided the exposure is not "black without detail."

A couple of good references on the Zone System are "Zone VI Workshop" by Fred Picker, and the Ansel Adams books on "The Camera," "The Negative," and "The Print."