Reflective vs incident readings: who can say it simply?

<p>Hello again Joseph, <a href="http://www.butkus.org/chinon/flashes_meters/luna-pro_sbc/luna-pro-3.htm">here is a link to a copy of the manual for your meter.</a></p>

<p>Much of the info in the manual will repeat what has already been said. It will really get you on your way to getting the most from your meter. If you have a digital camera with manual controls, it would help you to go out and take some shots with the meter (paying no attention to the cameras meter) and get some practice with the methods outlined here and in the manual.</p>

<p>Happy shooting, looks like you have a real nice set up.</p>

<p>Jason</p>

Mark,

The sun is 93,000,000 miles away. The same sunlight is falling on you and your meter as on the boat 500 feet away. After traveling 93,000,000 miles there isn't going to be much difference over 500 feet. If you are in the shadow of a building, then the incident meter won't work properly. The meter and the subject have to be in the same light.

The photo of the boat and water is grossly underexposed. Foliage usually falls on middle gray. The trees in the background should be middle gray and you should see separation of leaves and trees. When people show me a photo and ask about the exposure, I always say, "What does the negative look like?" You can have a perfectly exposed negative but if the printer analyzer sees too much light it may darken down the print to underexposure. Take a look at the negative with a loupe, magnifying glass or 50mm lens reversed. Is that tree line completely clear on the negative (so it prints as pure black as it did) or can you see definition of leaves and clumps of trees on the negative?

<p>Incident light is light coming at you from the source. Reflected light is light that has bounced at you since it came from the source.</p>

<p>Either method can be used equally well to calculate exposure.</p>

<p>Incident exposure readings are based on the idea that the light itself should be measured in order to hit mid-range in the photo; this way, tones will be captured on out to the lightest light and darkest dark which can be caught by the recording media.</p>

<p>Reflective exposure readings are based on the idea that the tone or texture of the surface is read to be placed in a tone that's like it. To do this accurately, it takes either a little experience in predicting what tone a surface will render, or a standard target like a gray card.</p>

<p>The famous gray card has a reflectance which is very close to green leafy vegetation, human skin and exposed natural wood with rough texture, like bark. A reflected reading off of any of those targets or a gray card is often negligibly close to the answer provided by an incident reading; this is because the midranges observed and the midranges which can be recorded cancel one another out, leaving the value of the observed light behind.</p>

<p>For the massive difference in the OP, I would suggest that you should see a six stop difference if you were swinging a spot meter around; this difference could come from the tone and reflectiveness of the objects measured. It could work out to a range of just about anything. This is why people will aim for the middle tone or a target tone of their choice. Tonal shifting (like the Zone System) is about putting those shifts where you want.</p>

<p>A frequent source of problem solving trouble with meter reading includes mixing up portions of the two methods, refining their use in detail to the loss of overall effect, or human error caused by social power struggles for a "superior" metering method.</p>

<p>That is, I wouldn't recommend combining the two methods as part of solving the problem until you have good strong grasp on what's what with both. By the time you can naturally switch between the two, you will. Still, sometimes I will stick with one kind of metering or another for a while, just as part of getting in a problem solving trend. Familiar enough to stay steady; fresh enough to pay attention.</p>

<p>That's my take. Sunny 16 and guide numbers for flash or meter off of the palm of your hand with TtL when in doubt. Good luck. We will now hear from someone who will provide us with 96 pictures of exposure graduations of standardized targets. I hope Shirley isn't ugly. J.</p>

I have been learning my Sekonic L-358. I chose transparency film for my "training". For me, transparency film makes differences in exposure easier to see. I view bracketed sets of slides on an inexpensive light table.

In general, at subject position, I point the meter to the camera. Sometimes, I point the meter into the sun, and then to the camera, and make a decision.

http://www.flickr.com/photos/mix-plate/collections/72157624646288017/

Initially, I was confused between the differences between my in camera center-weighted meter, Nikon FE, compared to the incident light meter. Then I simply decided to use only the incident light meter.

Try this article -

http://www.lighting-essentials.com/using-a-lightmeter-and-placing-the-photographic-exposure/

Or this one -

http://books.google.com/books?id=r2RNOOGJ8DsC&pg=PA29&lpg=PA29&dq=using+incident+light+meter&source=bl&ots=1Otl2qYAZ6&sig=Yi-cIndqHvt-Rrcx-QkVVk0lO2U&hl=en&ei=hhLuS6HrNITwsgOBrbHNDw&sa=X&oi=book_result&ct=result&resnum=10&ved=0CEMQ6AEwCTgK#v=onepage&q=using%20incident%20light%20meter&f=false

Learning my new meter has changed the way I see light. It's somewhat humbling. But I think it's worth the learning.

Good luck.

<p>The incident meter only measures the light where you are standing. If you and your subject are in a shadow but there's bright sunlight (or artificial light) or a bright sky in another part of your photo, the camera's reflective meter might take that bright sunlight into account depending on what metering pattern you have selected. In a high contrast scene (some bright light, some deep shadows) you have to meter and expose carefully or you may lost detail in either the shadows or the highlights. You might lose some detail even if you are careful. In some cases it's unavoidable.</p>

<p> </p>

<blockquote>

<p>for the film I was using at the coast under covered skies the reflective reading at 1/500 was f/32. But the incident reading was 1/500 at f/8. What should have been the correct exposure and why?</p>

</blockquote>

<p>The correct exposure is up to the photographer. You have choices:</p>

<p>- You can expose for the foreground and overexpose the overcast sky.</p>

<p>- You can expose for the bright sky and profoundly underexpose the foreground.</p>

<p>- You can average them and hope that you have enough details in both the foreground and background to make a good print with some serious work in the darkroom.</p>

<p>- You can use a strobe to lighten foreground details.</p>

<p>- You can use a graduated neutral-density filter to darken the sky.</p>

<blockquote>

<p>The famous gray card has a reflectance which is very close to green leafy vegetation, human skin and exposed natural wood with rough texture, like bark. A reflected reading off of any of those targets or a gray card is often negligibly close to the answer provided by an incident reading; this is because the midranges observed and the midranges which can be recorded cancel one another out, leaving the value of the observed light behind.<br>

...<br>

Sunny 16 and guide numbers for flash or meter off of the palm of your hand with TtL when in doubt. </p>

</blockquote>

<p>All of this is sound information, but it doesn't help the OP with his situation. The "famous" gray card is as powerless as an incident meter to determine the effect of a bright overcast sky in the background of the OP's image. These tools only measure light on the foreground.</p>

<p>As the OP mentioned working under a "covered sky," the Sunny f/16 rule is equally useless. And I don't recall him mentioning working with a strobe, so guide numbers aren't going to do him much good either.</p>

<p>I suppose that the Zone system could have helped him potentially, but it doesn't sound to me as though he has a lot of experience in the wet darkroom.</p>

"<I>These tools only measure light on the foreground.</I>"<P>

Yes, but the same light that is falling on the foreground is falling on the background. I used an incident light meter to measure the light standing on my porch and then walked 50 feet to measure the light falling on my back fence. The incident light reading didn't change. Why should it? <P>

True, light intensity varies inversely as the square of the distance but adding 50 feet, 100 feet or 1000 feet to 93,000,000 miles isn't going to make any perceptible difference.

<p>The problem really is about dealing with a scene with a wide contrast. This by itself is a tough thing to do. In addition to that, gray overcast days often result in blown out skies simply because cloudy skies don't have much detail to record anyway! Whether you used incident or reflected metering (correctly) wouldn't make a difference because the problem is not with the metering but with the big contrast range. <br>

The "best" solution to that problem is by using the maxim "expose for shadows develop for highlights". Sometimes this means just holding your hand over the incident meter lightdome. This results in a longer exposure. The the skies will blow out anyway but the foreground will have more detail. You can then burn in the skies when making prints. Not an ideal solution, is it?<br>

The sunny 16 rule can be easily adopted to deal with cloudy days but it is all guesswork, to make up for the days when you forget your meter at home.</p>