Film Exposure Guide

I realized that I needed to write a new article about exposure considerations for different film types when talking to a young photographer the other day.  I will frame up how I think about exposures for negative films (color and black and white) and transparencies in hopes that this helps you.

I think most photographers struggle when working outside in the many different and ever-changing lighting conditions ranging from bright sun to nighttime.

When thinking about the dynamic range of the contrast of our scene, there is little to worry about, assuming you make the proper exposure.  Meaning that your film will handle the contrast of your scene, you just need to worry about yourself and your metering technique.  A little knowledge goes a long way to making great prints.  After readying and applying the techniques I have in this article you should be able to make beautiful prints from just about any lighting scene.

When working in the sun we worry about reflectance as it relates to our main subject (architecture, person, etc).  It can make things look very flat and unflattering.  A white object on a black background is about 4 to 5 stops, which is not a problem even for transparency.  The issue that gets people in trouble is when your subject is in strong light and you have other areas in deep shade, the potential reflectance back to your camera can be quite large and cause all sorts of bad results.  The other factor that you have to consider is the nature and angle of your lighting.  I encourage everyone, to include myself to study and understand light better to include the quality, color, and its behavioral characteristics.  A full working knowledge of lighting will go much farther in helping you create winning prints that a new camera could ever do.

If the sun is behind you this will produce a very low-contrast scene because all of the subjects because your scene is receiving the same light making your subject look very flat and unflattering.  When the light source (sun, etc.) is in front of the camera this creates a potentially nasty issue of narrow shadows.  When you have side lighting the shadows are much wider causing your meter to record the reflectance of your main subject AND the shadows.  Don’t fret, it will be okay!

Just know that there is about a three-stop difference between the sun and open shade.  Open shade is when direct sunlight is blocked, but the open sky is still available.  This was standard literature on film boxes.

In practice there are many times when there is less than a three-stop difference between the sun and open shade because the light is bouncing around.  The sun and clouds are very tricky, so you have to watch them and be aware. What if there are more clouds today versus yesterday?  You guessed it, white clouds bounce more light than no clouds at all.  This is when you start getting into trouble with transparency film because you are adding a couple more stops of light and pushing the outer limits of its ability to hold detail.

We know that meters work from the logic of middle grey (zone v).  If you have ever photographed snow or a woman in a white or black dress and it looks “grey” then you understand the problem perfectly.

You don’t need to worry about the technical details, just how to properly meter your scene and produce the tones and print that you want.

Transparency film is known to have a high middle disposition, in other words the proper exposure for the middle tone is not in the middle! It is actually on the higher side causing the age old problem of your middle values being to the right and then your highlights may be blown out.  This is why people are afraid of transparency film.  In general, transparency film has a reduced ability to record higher values than negative films, but are known for their shadows.  Digital cameras, at least the ones I have seen also tend to share the same challenge with transparency films.  On the up side if you have ever looked at a properly exposed chrome on a light table then you understand the quest.  I would rather look at my large format chromes on a light table than my best print.

I will give you a tip that I learned the hard way.  I came from a black and white negative film background so I metered my scenes for transparency in the same way.  Big mistake!  I always use my spot meter for negative films (I will discuss below) but for transparency I use my incident mode (little white dome).  Spot metering reads the reflected value off your subject in a very specific spot, no pun intended.  By using the incident mode on your meter you get the natural light falling onto your subject which yields a much more accurate reading for transparency film.  This is why I always use a hand-held meter for transparency film, even if the camera I am using has an internal meter.  The only exception is my Hasselblad prism also includes an incident meter in addition to two reflective modes.

If you insist on spot metering for transparency films, then meter for your highlights which is the direct opposite of negative film.  If you meter your white snow or the white fence on zone v (middle value) or maybe a little higher, you should be very close to a proper exposure.  I just use the incident mode and get accurate results about 99% of the time.

I avoid high contrast sunny scenes as a general rule with transparencies.  I absolutely avoid this scenario with Velvia 50 and even Velvia 100.  If you absolutely must use a transparency film in this scenario I would generally recommend Provia.

Since I am talking about transparency films, you should know if you are doing long exposures (sunrise/sunsets, etc) then you will likely have color shift issues with Velvia because of reciprocity failure.  Velvia 50 is the worst, with Velvia 100 being better and Provia being the best performer in this category.  With Velvia 50 you start getting reciprocity failure at 4 seconds and for Velvia 100 at 2 minutes.  Provia is even longer at 4 minutes.  You may want to read my article on selecting a Fuji transparency film for landscape photography.

You won’t end up with those jaw-dropping HDR looking colors of Velvia 50, but you will have a great chrome, almost all of the time.  I routinely rate my Velvia 50 at 32-40 and Velvia 100 at either 100 or 125.  If your scene is sunny with Velvia rate it near box value and if it is shady lower your EI to 32 for Velvia 50 or 100  for Velvia 100.  Just refer to the reciprocity charts at Fuji and be aware of this before cranking off a bunch of exposures on your once in a lifetime trip.

Negative films, either black and white or color C-41 are also “off center” but in the opposite direction of transparency films.  The shadows are more of a challenge for negative films and its ability to read into the higher values (bright areas).  I always use spot metering for negative films.

I spot meter the shadows of my scene where I still want detail in my print and then adjust for -2 stops.  I just dial in -2 stops on my exposure meter.  However, if you have a situation where you main subject is white, like snow, then I would typically dial in +1 to +2 stops of exposure come placing the snow on zone vii or so.  It also depends on the sun and clouds so that is why some people bracket to make sure they get the shot.

For black and white film, and in particular with larger formats (120 and sheet film) I tend to expose a little more than the meter says for the best tonality.  For 35mm, I do just the opposite to cut down on grain and enlargement challenges.  As I have mentioned in other articles, If you have not conducted densitometer tests of your films and process then just rate your Tri-X at about half the box speed (EI 200) and develop a little less than the manufacturer suggestion and you just saved yourself many hours of testing and will get the bulk of the benefit from the testing process.  Feel free to send donations to my PayPal account at any time!  Just remember with Tri-X or any black and white film (120 or sheet film) don’t underexpose or develop too long and all should be good.  By doing this, and metering as I suggested (-2 stops for shadow detail) you will get adequate shadow details and also get up to about 4 stops above middle for your highlights resulting in a very long tonal scale and those beautiful prints that we all want.  This logic also applies to color negative films as well.

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