"Zone VI," Weekly Photography Assignment for 8 - 14 March 2010

[keithsnell]

As we sometimes do, I'm going to base this week's assignment on questions that were asked during a previous assignment.  Towards the end of the Zone VII assignment, several people asked questions about how to use the manual exposure mode for their cameras.  Based on those questions, I thought it might be helpful to take the time to cover manual exposure in more depth.  So, I needed to pick a topic that would have you use manual exposure again.  This week's topic is "Zone VI."  For ease of reference, I'll provide the Zone System diagram and description of the zones again.

                                          Zone I        Black without any texture
                                          Zone II       Black with slight suggestion of tonality
                                          Zone III      Darkest areas that still retains visible detail
                                          Zone IV      Average shadows in landscapes/portraits
                                          Zone V       Middle Gray - 18% gray card
                                          Zone VI      Average Caucasian skin
                                          Zone VII     Lightest areas that retain visible detail
                                          Zone VIII    White areas with slightly visible textures
                                          Zone IX      Glaring white surfaces - Highlights
                                          Zone X       A light source (maximum white)

As you can see, Zone VI is defined (in our modified zone system) as one stop above "mid-tone,"  or +1 EV on your camera's manual exposure scale.  Simply spot meter on a subject that you want to render in Zone VI, and set your shutter speed and aperture so that your exposure scale displays the reading as +1 EV on the scale. Having trouble finding something in Zone VI?  How about "average caucasian skin?"  One benefit of this exercise is to get you to consciously think about the tonality (brightness) of skin tones reproduced in your images.

This is also a fun opportunity to experiment with "guessing" the tonality of colors and seeing how close you get.  I challenge you to find colors that you perceive as belonging in Zone VI, and then photograph those colors at +1EV to see if you were right.  (Yellow, or any of the pastel colors might be good colors to try.)  Again, this experiment should be able to help you "nail" the exposure of challenging colors in the future.  Not everything in life is "average tone" or Zone V, and as a good photographer you should be able to modify your camera's exposure settings when needed to capture the scene properly.

Since most of the questions about using manual exposure came from individuals that use Canon dSLRs, I'll base the rest of my discussion on setting manual exposure in the Canon system.  The first step is to put your camera's mode dial in the "M" or manual position.  Once you have placed the camera in this mode, setting the exposure is up to you.  For this assignment you will need to choose a shutter speed and aperture combination that results in an exposure reading of +1 EV on the exposure scale.  For "rebel" type Canon dSLRs, you adjust the shutter speed with the "main dial" (the wheel by your index finger when it is resting on the shutter release button), and you adjust the aperture by holding down the Av+/- button on the back of your camera by your right thumb and rolling the main dial.  As you change the shutter speed and aperture, watch the exposure scale in your viewfinder so that you can set it properly at +1 EV.  Your exposure will be indicated by an "exposure level mark" underneath the scale that will move as you adjust your shutter speed and aperture.  Adjust your shutter speed/aperture combination so that the exposure level mark is underneath the "1" on the plus side of the scale.  (Note that for Nikon cameras, the scale is reversed, and "+" is actually on the left side of the scale.  This is because with Nikon cameras, we have historically moved the controls to the left to increase exposure, and so Nikon reversed their scale to keep the directions consistent.)

Semi-Pro and Pro level Canon cameras have an added "Quick Control Dial" on the back of the camera that is used to adjust the aperture.  To enable the Quick Control Dial you must set the camera's on/off switch to the "Quick Control Dial" setting above the "on" position.

I talked earlier about using "spot metering" to take a meter reading of your subject.  This might have been confusing for readers that have Canon dSLRs from the Rebel (or 3-digit model number) series, since these cameras don't have a "spot" metering mode, but a "partial area" mode instead.  The difference between "partial area" and spot is that the partial area covers a much larger area of the viewfinder/scene than spot metering.  The "partial area" metered in this mode corresponds to approximately 10% of the viewfinder at the center of the frame.  (Roughly equivalent to a circular area contained within the vertical AF sensor locations in your viewfinder.)  Using "partial area" often requires you to zoom into an area of your frame to take your meter measurements, and the zoom back out to compose the scene.  Use the button on the top panel of your camera to select the partial area metering mode.  Readers that have semi-pro "d" (or 2-digit model number) series Canon dSLRs (such as the 50d), or pro "D" (or single digit model number) series Canon dSLRs should have a spot metering mode available as one of their options.  This metering mode covers approximately 3.8% of the viewfinder at center, and is indicated by the center circle in your viewfinder.

A notable difference with Nikon's implementation of spot metering is that the Nikon spot metering area is always tied to your selected focus point.  As you move your selected AF point, you are also moving the area that will be metered when in spot metering mode.  Spot metering for Nikon cameras covers about 2.5% of the viewfinder centered on the selected focus point.

If you have any questions about how to use the manual exposure mode on your camera, please ask questions and give me the opportunity to clarify this assignment.
 
The assignment for the week of 8 - 14 March 2010 is to use manual metering mode and spot/partial area metering to properly expose a subject with a "Zone VI" exposure.  Please upload your images to the "Zone VI" album in the weekly assignments category of the Gallery no-later-than midnight Mountain Time (GMT -07:00) on Sunday, 14 March 2010.

I'll look forward to seeing your images!  (Especially the "fun" images where you attempt to properly capture a Zone VI color.)

Keith

[Michele]

Hi Keith, I'm not sure that the flash does register for the meter reading.  Check out my site for 8 pictures.  After playing around I got somewhat the same light colors as seen.  But are they too light?  I wish I had an actual light meter.  Do you think someone can buy that second hand?

[keithsnell]

HI Michele,

I don't think the colors are too light.  If you want to upload one (or more) to this site, I will check the values in Photoshop and tell you whether I think they are in Zone VI. 

What type of flash are you using?  And how is it connected to the camera?  Flash exposure's are a complicated matter; however it definitely pays to learn how to control flash exposures.  We did have a previous assignment on "fill flash," and you might find reviewing that assignment discussion helpful:  http://community.spiritofphotography.com/index.php?topic=416.0

I've found that I can "trust" the meter on my camera, it's just a matter of understanding how the light from the flash plays into the equation.  You can buy 2nd hand meters from ebay, but personally I would chose to invest my photography money elsewhere.  I find I can control my flash exposures well enough with the camera's built-in meter.

Keith

[Michele]

I used an infrared release.  I don't think it measures the light.  I tried these photos at first in a window and the meter was exactly +1 but the photos were way toooooo light.  I did need a flash or I would have a silhouette (Also cool)  So I tried them against the wall.  Better results, but I did not have the meter on +1.

By the way, what do you do in Photoshop that you can check if it's in the range?

[keithsnell]

Hi Michele,

Canon IR release?  With Canon flash?  What model?

I check the luminance range of portions of the image by using the "curves" tool in Photoshop.  The "input" values displayed on the curves dialog (when you click and hold on a part of the image) show the luminance values in RGB.  In our "modified zone system" we consider anything between RGB luminance values of 137 and 188 to be in Zone VI.  

(Anything between about 188 and 240 would be Zone VII, and Zones VIII, IX and X are all compressed into the range between 240 and 255.  I should note that there is not a direct translation between the "linear" space of camera exposures and the "non-linear" RGB spaces, and there are many interpretations that will match different RGB values to the 10 Zones.  The "curves" that camera manufactures use to map the linear sensor output to the "non-linear" RGB gamma 2.2 spaces (like sRGB and AdobeRGB) are constantly evolving, and so the values I'm providing are "approximations" that provide a reasonable match with the majority of cameras/software on the market.   The zones in our "modified" zone system are a synthesis of scientific analysis (mathematically mapping linear values to RGB) and rational adjustments to match the "perceptions" that Ansel Adams defined in his description of the Zone System.)

I've looked at the luminance values in the image you posted, and yes, the luminance values in the green dress fall into Zone VI.

Hope this helps.  

Keith

[Michele]

Hi Keith, do all the colors have to hit within the range?  What if the majority of the photo is within the range and then you have dark hair?

[keithsnell]

HI Michele,

No, not everything within the image will be in Zone VI.  The point of the exercise is to become familiar with what tones in real life are "Zone VI" or brighter than mid-tones.  Our camera exposure meters have a tendency to expose everything as mid-tone, so sometimes we need to recognize that adjustment is needed, either in camera or in the final rendering (on the computer or in print).

It actually takes quite a bit of experience to be able to consistently identify what colors should be exposed lighter than mid-tone.  Meters are getting better and better, and unfortunately that lures many photographers into the trap of believing that they can always rely on the meter for the correct exposure.  It is useful to recognize that sometimes your camera won't get the exposure right without intervention from you, the photographer. Recognizing when these corrections might be needed is a skill that is developed over time.

Keith

[Michele]

Of course, I used that as a real contrast to illustrate a point, but what if it's more subtle.  I did the assignment, and as I check throughout the photos, some parts of the same color range are within and some are lighter.  Like skin.  My dancer's face is lighter than her shoulders.  Although, I don't see such a huge difference.

Thank you again.

[keithsnell]

True, many parts of the image will fall outside of Zone VI. 

It is useful to learn to "see" and estimate the brightness of different tonalities.  Zone VI is an important area of tonality, and being familiar with the tones that should fall within that range will help us create better images.

The key to the exercise is to pick an area that you believe should be metered at +1 EV, spot meter on that area and take the image, and then evaluate the results on the computer.  The process of evaluating your results and determining how "correct" your metering was will help you be able to effectively meter challenging situations in the future.

Keith

[Michele]

I left them alone but I did check them out using your technique to see if I was in the range.   Some of it is, some of it isn't always within one photo.  I have to finish updating two websites so that's why I finished the assignment a bit earlier.  I read your flash attachment.  Very interesting.  I don't know if you keep all your assignments in archive, but if you have any left (and I don't mean now, of course) I would love to read more.

Also, Easter is coming up, which means a week after that is first communion photos.  I have done these three years in a row but I would love to improve whatever I can with them.  Can I pick your mind for that at some point when things aren't hectic?

And the school two villages over from mine want me to do their student photos.  This is new for me and I want to build a standard or guideline to follow so that all the photos have a consistent look to them.  I will definitely need some help with this project.

Well, that's it for now.  Thank you, Keith, very much.

[keithsnell]

Hi Michele,

Yes, please do ask questions, and I'll try to give some advice for the first communion photos and student photos.  What age are the students you will be photographing for the school photos?

Keith

[Michele]

Primary school.  Kindgergarten to 6th grade.  I was thinking of using the class rooms as backdrops for the class portrait and an actual backdrop for the portraits.  I am not sure.
The first communion begins outside with a marching band as the children follow in two rows behind through the town before arriving at the church.  That is not the problem.  The problem is the uneven lighting in our church.  I will send you a photo to show you what I mean.  Side windows along both walls make the light metering very tricky.  The alter is very dark.  I am allowed to use my flash but nobody else is allowed.  First communions are very important in this part of Switzerland.  Almost as much as a wedding except that there are about 10 brides and 10 grooms to get just right.
Which brings me back to the assignment.  I get the assignment perfectly, but as you see from my photos, the flash does not register.  I did use +1 on the meter at first, that is way too bright.  Might as well have been ghosts.  So I lowered the flash to its minimum and did it again.  Still too strong at +1.  You know that I am not referring to my dinky tiny flash that I attach to the shoe.  I mean a lamp, blitz.  Wait, I will look it up.  Ok. Got it.  It is a strobe in English,not a flash, they use the same word in German but it does attach to the camera, it just does not meter.  My flash that I use outside for fill in light is a real dinky Bower auto focus SFD35 C.  Never seems to work right indoors properly so I only use it outside.  Indoors I use a strobe when I can because the photos look more like natural light. 
On this assignment, though, I knew it had to be softer and lighter than the average photo, but at +1 it never worked.  I took a picture outdoors at +1, so I know how much lighter it should be and it is not ghostly.  So that is why I wanted to know how you spot check the photo after the fact.

Lots again, sorry.

[Michele]

Although, in the church, I can only use a normal flash.   I have a new low light fast lens but it is small.  I have to play with it to see if it will work.

[keithsnell]

Hi Michele,

Thank you for the additional information on your strobe.  From your description, it sounds like you were correct, the camera meter is not registering or taking into account the flash exposure.  The camera has sophisticated circuitry to control the exposure of Canon flashes that are connected to the hot shoe of the camera (or fired remotely via a Canon controller on the hot shoe), however, connecting the remote strobe through the IR remote doesn't provide the information to the camera that it needs in order to control or correctly meter the flash.  Now that you have explained more about your strobe, I understand now that using your strobe and trying to meter at +1EV would have been a nearly impossible task.  I hope that it wasn't too frustrating for you as you struggled to do the assignment.

How do you normally meter (or set your exposure) using the flash?  When I use an off-camera flash, fired with a remote radio trigger, I manually set the flash power to provide the appropriate amount of flash on my subject.  For my remote flashes, I enter the ISO and aperture the camera is set at, and the flash will calculate the effective distance at the selected power setting.  I use the "effective distance" reading as a guide to select the power setting (full power, half power, 1/4 power, etc.) to achieve the proper flash exposure on my subject.  I always take a few test shots to balance ambient and flash.  

I can now also understand why you would want to buy an external flash meter to set the flash exposures.  Given your strobe set up, it sounds like an external flash meter might be useful.  I do find however that I can "calculate" the effective flash range (or required power setting) very reliably if I know the guide number of the flash/strobes.  Does your strobe provide guide numbers or another reference that you can use to calculate the appropriate power setting for a given distance from your subject?

Again, I'm sorry if the assignment was frustrating for you when you tried to use your strobe.  Your images were beautiful, so obviously you were able to overcome the technical difficulties.

I'll post additional thoughts on your school photos in a little bit.

Thanks again for putting such effort into the assignments,

Keith

[Michele]

No.  I cannot input information into the strobe.  I looked at it just now and there is nothing.  But It has many, many levels for increasing or decreasing its power.  If I used a cable instead of the infrared, do you think it would meter the light then?  It is just so much easier with a trigger that I don't trip over.  I am ashamed to say that I take test shots and follow some settings I got off the net for some sort of guide then I just adjust it until I like it as well as with the camera.  That is why I am saying I have been very lucky thus far.  No complaints but I know I can do this better if I knew what to do.  I need to have consistency somehow.  I can't possibly just shoot as many as I do everytime.  Especially if I am going to have a larger quantity to handle.  (Now you're probably wondering why they picked me...  Me too.)  People like what I have given them and word spreads.  I don't turn people down because I need the work and I do get some money out of it, but I always tell them that I am not a professional.  I try really hard to make sure I have many, many photos to chose from (especially for a wedding) but the work is a very time consuming one.  Just one wedding, I took approx. 3000 photos.  I never intrude unless it was for the posed photos and I snap away.  I make a list of every family member and tick them off as I go.  I have another list of shots I feel are absolute musts so that I don't forget anything.  I may be very picky and hard on my results but I get one shot at it.  I feel that every time whether it is important or not to me, it is to the person who asked me to take the photo.  Family photos, pets, whatever.   I love your assignments because I don't feel the need to get it right for anybody else exept for myself and just the desire to learn as much as I can.  I get frustrated when I did not learn something as well as I thought I did.  But in the end, I just love to take photos.  Especially outdoors.   I read and enjoyed your turorials (bedtime reading).  Which is about now.  So I bid you goodnight and thanks for the ear.