Handheld Exposure Meter

Discussion in 'Medium Format' started by danac, Aug 17, 2021.

  1. No. Completely wrong.
    For any subject. Reflectance values, and means therof, are what can and will skew reflected (!) light metering.
    But incident will give the correct reading, whether your subject is grey, pitch black, or bright as snow.
     
    Last edited: Oct 4, 2021
  2. I agree, but stated it differently. IMO, you are measuring the light falling on the subject, while assuming the reflectance of the subject is about 18#%. In your response, you do the reverse, assume the reflectance is 18% and measure the light falling on the subject. The glass is half empty or half full.

    Ultimately, a spot meter is better able to deal with problematic lighting and subject material, provided you have the knowledge and experience how to use it. Modern cameras with "smart" matrix metering, dynamic range hovering around 16 stops, and fast bracketed exposures, may render the art of measuring light moot.
     
  3. To quote the redoutable Mr. Spock: "Fascinating." The goal here is to make as perfect an exposure as possible with pre-visualization as opposed to wasteful bracketing. After all, my camera can only expose fifteen images per roll of 120 film. If there is a steep learning curve, so be it. I'm willing and ready. Given the methods stated here, I wish there was more time to practice (being brand new to medium format). It will be interesting to borrow my friend's Sekonic L-608. Thursday Deb and I leave for Zion and Bryce Canyon National Parks. We have photographed these parks several times in the past. For insurance I will backup every important image with my venerable Canon A-1. Deb and I were married in Zion NP exactly forty years ago on the day we will be there.
     
  4. I use the L-408 when on film, mostly incident. The spot metering is useful sometimes e.g. shooting against the sun. I wish it had a light for the display (smart phones resolved this though).

    Review of Sekonic Multimaster L-408
     
  5. No. Not all. Incident light metering measures light, and assumes nothing about the subject.
    Not half full. Not half empty. No glass at all.
     
  6. Again, not at all. Spot meters are only usefull if you want to meter reflected light over a small angle, of a bit of the scene you cannot meter in isolation otherwise.
    Using one, or any other reflected light meter, you need to judge how the reflectance value of that bit measured biased the reading, and adjust accordingly.
    If anything, that complicates metering problematic lighting.

    Matrix metering has achieved a level of obscurity that makes it nigh impossible to know what it is doing. So it indeed is good if and only if you know you can trust it to do what you want. Whether it does that or not you can only know after the fact. So not a problem for those who do not mind a trial and error aporoach.
    You really need to master the art of light metering if you want to be in control.
     
  7. Congrats on your anniversary :)

    I'm an old incident guy, but I do recognize it's limitations.
    Incident is easy to use, for me. As I remember, it worked fine 99.9+% of the time.

    But as was said, incident does not account for subject dynamic range (DR)/brightness of the scene.
    That is when you have to use your brain to compensate, or a spot meter to determine the dynamic range/brightness and then your brain to determine how to shoot the scene. The sunlit tops of the canyon or the shadowed bottom of the canyon?
    This is more important for slide film which has a narrower DR than negative film.

    Where incident does not work, is when you are in completely different lighting that the subject.
    Example shooting from a deep shade out into bright sunlight, or the reverse.
    In that case, having something like the convertible Sekonic meters would be nice. I could use incident most of the time, with the ability to use spot for those conditions where incident does not work. Right now I have TWO meters, incident and spot, which is a hassle to deal with.

    Although to effectively "previsualize," I would have to go with a spot meter, and use it as in the zone system.
    But the setup work for that was a hassle that I did not want to deal with.
    You have to shoot a grey card and scale, at different exposures, to determine the dynamic range of the film.
    Then determine what different objects meter as, and how to adjust the exposure to move them to a particular point in the grey scale. And what effect that has on the entire scene.
    That was way more work than I wanted to do.
    But then, I was shooting cheap 35mm film, not EXPENSIVE and hard to handle 11x14 sheet film.

    This is presuming color film where you don't adjust the development process. It can get more complicated for B&W where you can adjust development.
    Read a GOOD book on the zone system, and you will see what I mean.
     
  8. Trust, but verify! "Trust" in matrix metering is one part, but it is very easy to verify the results. Matrix metering relies on artificial intelligence, which is fortunate since the real thing has become hard to find.

    An incident meter measures light impinging on the subject. While it could be expressed in lumens or some other absolute vale, the exposure value, given in shutter speed and f/stop for a given ISO rating, assumes the subject has a reflectance value of about 18%
     
  9. As good as matrix metering may be, as @Ed_Ingold said, you need to verify it, not blindly trust it.
    I've learned the hard way (subject over/under exposure), that there are situations that the matrix meter on my Nikon D7200 simply cannot handle properly, and I have to deal with in other ways.

    But back to the subject, handheld meters.
    I've not yet seen a matrix handheld meter.
     
  10. No, it does not.
    It 'assumes' that something having a reflectance value of x must be rendered as something having a reflectance value of x, without caring one bit what value x might be.
    That's why with one and the same reading, snow will be white, pitch will be black, and something having a reflectance value of 18% will appear as such in the recorded image.
     
  11. ;)This fascinating thread reminds me of the saying: "For every PhD, there is an equal and opposite PhD."
     
  12. Once upon a time there were photography books which explained how things work. Now we have the internet, where everyone is an expert and hardly anyone bothers to read and understand. Sheesh!

    An incident light reading and a reflected reading of an 18% grey card should give the same exposure if the light is uniformly distributed. If my term "assumes" implies an anthropomorphic assignation of a machine, try reading again in context.
     
    Last edited: Oct 4, 2021
  13. Good self-assessment, Ed.

    So let's teach a bit. Photography 1.0.1

    Let's keep talking about 'assumptions', Ed.
    When you point a reflected light meter at something, it measures a certain amount of light. What it assumes is, that if it is a lot of light, the exposure of film or sensor must be less, that if it is not much, the exposure must be more, and that if it is something in between, the exposure must be that too.
    Because, Ed, it 'assumes' that the subject is one and the same, that all that is different is the amount of light. So a black subject is assumed to be a dimly lit grey subject, so an overly rich exposure is suggested. A white subject is assumed to be an overlit grey subject that requires a more conservative exposure. And a grey subject is assumed to be a grey subject in moderate light, so an inbetween exposure is suggested. The result of assuming that the subject is an 18%, grey subject is that all exposures produce a middle grey.
    Take away that 'assumption', do not bias exposure suggestions with such an assumption, and the white subject will be rendered white, the black will be rendered as a black subject, etc. That's what you get using incident light metering. No (! take note) assumptions about subject reflectance values.

    Now for an assignment, explain the difference in your own words, Ed.
     
  14. For all the outgassing, it's uncertain how many here use a meter of any sort regularly. Hands up for those who do!
     
  15. If/when I shoot film, which has been rare, I use my incident meter.

    If I am trying to figure out a lighting issue, I will use the incident meter to measure how much light is hitting a particular spot, and from which direction.
    I did that on my high school football field, to figure out night exposure issues. Inside the 10yd line -1 stop. At the corners -2 stops. :eek:
    Facts beats guessing.
    For graduation, I use my incident meter. The synthetic graduation gowns reflect sooo much light, that they confuse the Nikon matrix meter, and totally underexpose the faces. What is more important, the gown or the faces?

    The handheld meter is simply a tool that gets used when I need it.
     
    Last edited: Oct 4, 2021
  16. AJG

    AJG

    Since I shoot with studio flash most of the time for commercial work, I use my Sekonic L 718 flash meter (98% in incident mode) a lot. Chimping the screen on the back of a DSLR just doesn't do it for me, but YMMV.
     
  17. Okay - slight change of pace. I was going to borrow an L-608 but there isn't time to learn it's use. So I will take my friend's Luna-Pro and the variable angle spot attachment. I put the correct batteries in it and zeroed the meter. My question to those who have used this set up is: how good is the spot meter attachment?
     
    Last edited: Oct 5, 2021
  18. If you don't have time to shoot and process a roll of film, do a sanity check, to see that the meter is in the ball park.
    Broad daylight, the sunny 16 rule (or sunny 11 if you are further north).
    ISO = 100, f/16, 1/125 sec.
     
  19. Both the big 1 degree see-through attachment and the small 15 and 7.5 degree thingy are good.
    More modern meters are more convenient.
     
  20. I see others have found what I have experienced. When taking group photos, being consistent is better than being right-on. You spend a lot less time adjusting and editing when you can work in blocks. While you don't absolutely need a meter when setting up a digital camera, you can get it done more quickly with than without. Time is money (customer annoyance, and used heartbeats). Setting up for large goups, I walk around the stage to profile coverage of the flash units (triggered with my aging Sekonic 508 in incident mode), and make the necessary adjustments.

    The L-508 has a variable spot meter, 1 to 5 degrees. I don't recall using anything less than the tighest setting. The variable feature was dropped in subsequent models. I found the spot mode useful for landscapes with an Hasselblad, The hard part is knowing what to measure and how to apply that measurement.
     
    Last edited: Oct 5, 2021

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