Saturday Evening Post #70 : Exposure by Cat’s Eye.

If you are like me, and let’s hope that is not in too many ways, 🙂 then no doubt you’ll have pondered from the day you first picked up a camera,
“What is Correct Exposure?”

And… haven’t there been any number of ‘friends, family, websites, blogs, books, faceblot pages, and courses to set you on the right road.

Luckily this is not going to add to the incessant chatter.

I think, “What is correct exposure?” is about as useful as asking, ‘What colour should I wear?’ Because of so many variables.

T’would be easy to offer advice, such as, “Oh for my bird shots I use the fastest shutter speed, blah, blah.”

The great New York newspaper, Wegee,  is reputed to have said, “f/8 and be there!”

So let’s go at this another way.  How to you-royal plural-determine correct exposure?

Well in this modern day and age, you point the camera, press the shutter and all is well. (most of the time, with the exceptions of the critical moments, when its wrong!)
No doubt modern camera design is at pains to get it as close for most general picture making as possible.  Else people wouldn’t buy the cameras. So hats of to the manufacturers for their great work.

All sorts of hand-held exposure meters have been used in the past, and each had their adherents. And if you think camera blog discussions get heated and verbose, you’ve never heard the disciples of one sort of meter lampooning the other less informed individuals of lesser choice meters. 🙂
When I started, the choice was pretty simple, English company Sangamo Weston had a Weston Master meter. I confess to owning several during my lifetime, and have just purchased one from ebay, as much for sentimental as much as practical reasons.

As time went on and studio requirements changes, so did my choice and Sekonic meters came (and went)

Note I’m not into, here, whether fast shutter, or large or small aperture are the creative issue.
And don’t start me on the poorly defined “Exposure Triangle”.

Just a lighthearted stroll through the thorny subject of how we determine from the light available, and our photographic intention, what settings might best bring out our intent and feel for the subject.
Simply, how to measure the amount of light off the subject. (Or just for completeness for the Incident Method die-hards, how much is going to strike the subject)

What is the average reflectance of a scene has also bought in its wake, a host of disagreements.

For the record, Kodak scientists in the early 1900s arrived that in bright sunlight about 13.4% And then based their recommended exposure settings for their filums upon that basis.
Not good enough cried Fred Picker and St. Ansel, and they  cajouled Kodak into making their measurements at 18%.
Dah Dah, enter the great Kodak 18%-90% reflectance Card. Kodak Publication No. R-27.  Cat 152 7795.  Which, distinctly says on the outside of the package.
Designed for use with and exposure meter in artificial light. For use with Kodak Ektacolor and Vericolour Films.

Makes me smile when I see the card recommended for use in daylight by some controversial exposure determining system. And also in camera reviews that say—Oh, the manufacturer has set the basic exposure wrongly as it overexposes by 1/3 stop. Sure does. It’s easy to speculate when you don’t grasp the theory.

Then there’s the Sunny Sixteen Rule. Used to be on the leaflet inside each roll of filum.
Set the shutter speed to 1/ISO and aperture to f/16 and in bright daylight you’ll get correct exposure.
And if you’ve never done this, then next time your out in bright sunshine, set the camera to Manual. Dial in 100ISO, set the shutter to 1/125 (closest to 100) dial in an aperture of f/16, and sun over-your-shoulder. Bet is so close  to acceptable as to be scary. 🙂 But who wants to shoot at f/16. Not me.

You could try the Nicéphore Niépce method:  8 hours out the back window of the house. Yep, first recorded exposure ever! And no shadows in the scene. Give you HDR folk something to ponder. 😉 Actually there is more recent research that suggests it might have been several days exposure!   Think about that the next time you choose 1/4000th.

Which brings us to Exposure by a Cat Eye.

Enter: Oscar Gustav Rejlander, the year is 1857, and he is embarking on a rather risque work called, “Two ways of Life”. Here’s a link

To quote from Rodger Cicala over at,

“Rejlander’s photographic career was remarkable. It wasn’t possible to practice “street photography” in those days, so Rejlander would use models to recreate scenes he observed of the poor in Britain at that time, producing haunting photographs that are collected in museums around the world today.
 He was also the first to use a light meter— sort of, anyway. He would bring his cat into the studio: if the cat’s eye’s were like slits he used a short exposure, if more open a long exposure, and if the cat’s pupils were wide open he knew there wasn’t enough light to photograph!”

So there you are.  The next time you struggle with “Should I add or subtract EV for this shot?” Just remember there is a long history of incorrect exposures littering the photographic biosphere.
And take heart, I’m responsible for a good many of them 🙂

Here’s a visiting Black Kite, just back to re-establish its breeding territory I think.
Guess which exposure method I used?  Oh, and to help, I don’t own or have access to a cat;-)


11 thoughts on “Saturday Evening Post #70 : Exposure by Cat’s Eye.

  1. I loved reading this one, David. Especially the story about using a cat for metering. I need to get a cat, then. I will guess, and this is totally for fun: f5.6 ISO640 1/1600 … and it might be slightly overcast. It’s a beautiful photograph!

    Liked by 1 person

    1. Hi Derek, not a bad guess on the settings. I think I just meant, how did I calculate it, but none the less you nailed it close enough.
      Deatails. Bright sun on bird, lowering grey cloud on a squall behind.
      ISO 400, f/6.3 (I drop the aperture on the 500 PF, just cause I’m paranoid), and Shutter Time 1/3200.
      I no longer do Exposure To The Right, (DxO Photolab seems to like a bit more ‘robust’ image to work with, and their Prime covers any noise likely to come up.)
      I explained my logic down in Eleanor’s post, but essentiall, I guess most days. (*and I can always check the lcd to see if I’m off by much).
      Sunny day is ISO 400, Cloudy ISO1600, Overcast-or in Shade 1600
      It is indeed based on Sunny Sixteen rule.
      Just use 10X Iso at f/5.6 on a sunny day. Which gives me 1/4000, as above, and I dropped by 1/3 speed to 1/3200 because of the f/6.3
      Sounds complex, but in reality, for most of the subjects I work with, its more than adequate.
      Bit of a change for me this past few months, as I’m an Aperture Priority dude for everything else. 🙂
      Good work on guessing, I’m impressed.


  2. Ah! First get your cat! Wonder if I can borrow next doors!
    Fascinating reading, David. Is there a right answer – probably not! But there is plenty of discussion!

    Liked by 1 person

    1. G,day, These days, everything goes into Post, and we adjust accordingly. I usually do my best to protect the white detail areas, and let everything else get sorted out with a sweep of a curve. Besides, I like waving round my old Weston V, makes me feel young again. 😉


  3. Somehow I don’t think taking a cat on a birding expedition is such a good idea. I may have to stick with f8 or 9, ISO where it needs to be so I can get a reasonable speed, and hope for the best.

    And indeed, a beautiful shot of the Kite, whatever your settings were.

    Liked by 1 person

    1. Hello Eleanor, I have a few (changable) rules about all this, but one is Sunlight is Best. 🙂
      I generally work with f6.3 on my max aperture f/5.6 lenses, (the 300 with TC and the 500PF), Just adds a touch of bite to the contrast. Not sure it really helps. Then I adjust ISO depending on the light. Bright Sun/hazy 400ISO, overcast 800, and Melbourne at its worst, or bird in shade, ISO 1600, Porridge days. Go home. 🙂


  4. You seem to love all those theories and rules as much as I do, David. Mind you, I’ve never heard of the Exposure by Cat’s Eye but I think I quite like this one, except, as all the lovely people above have already said, it’s not very practical nowadays, even if one does not use a fish-eye lens.
    I like your shot of the Black Hawk and it’s not really the exposure you’ve used that makes me ponder – I always wish for an advice how to compose my in-flight shots. Your positioning of the bird’s head and the outstretched wing reinforces my idea of esthetics for such captures.
    Now I’m going to read all the other outstanding (in both meanings of this word) posts by you.

    Liked by 1 person

    1. Hello Adam,
      Black Kites are the best models. They ‘hang’ in the sky and allow you to get them in the viewfinder. They are also the most inquisitive of raptors, (maybe also Whistling Kites), and super air confident.
      They will swing round overhead, or sweep out and come back again. The toughest part is making sure that however they turn, that the face gets some light. Going away, or banking away or directly coming from the sun direction is always a loss of face light.
      The same sort of thing for Black-shouldered Kites, if you are on the sun over your shoulder position wiht them, then it does give the best light when they swoop about. However they are much more likely to wingflap more, and its not always easy to nail a great pose.
      The funny thing about the instructions for the Kodak 18% card is they state: “…Use a lens opening 1/2 Stop larger than the meter indicates for a frontlighted scene…. PS (If it was being written today, it would be 1/3rd stop). Because they knew that not everybody was going to use St. Ansel’s Zone System. (Which was designed for Black and White anyways)
      A tad more history?
      For awhile during the 1960s and early 1970s the leaflet dropped the 1/2 increase recommendation. Why?
      Because the copy-writer at the time of revision, didn’t see the need for the paragraph, and took it out.

      My guess, is, that is one of the reasons, we see so many people being ‘fooled’ by thinking 18% an average reflectance of a scene.

      In the studio, we always used the white side, and calibrated back. (But you’d have to read the post on Dean Collins, to see why we went that way.L)

      Dang, sorry I should have put all that in a different Sat Eve Post,
      Good luck with the inflights.

      Liked by 1 person

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