109 – Exposure, Part II: One Plus One

Free photographic lessons - Lesson 109: Exposure Part Two

Wow, that previous one was a tough one, wasn’t it?  Well, as said, luckily, things get easier from here.  In this lesson, we’ll look back at lesson 106 and find some balance:

How to master exposure in photography part 2, one plus one.

You now know you have two ways to control your camera’s exposure.  Your shutter and your aperture.  Now we will put those two together to see how they integrate.  We are now at the stage where you’ve learned the letter “a” for aperture and you have learned the letter “t” for time, and now we’re going to put them together to make your first word: “at”.  We can read!

Right, analogy time again.  The following numbers are in no way shape or form anything to do with the real world of photography, but it will help you understand how things work.

Two numbers added together equals the number 9.  What are those two numbers?

It could be 1+8.  It could be 4+5.  It could be 7+2.

What the numbers are does not matter, as long as the answer is nine.

So it is with any given photograph.  Your camera will read the light and tell you what it needs to expose the situation correctly.  Except, it won’t give you ‘9’, it will give a reading in your viewfinder to tell you if you are over exposed, under exposed, or spot on!  What you need to do is adjust your aperture and your shutter speed to get your exposure to correlate with your reading.  How you do this is up to you!  This is where the art of photography comes in: there is no singular right way to do anything – as long as you get the shot you wanted, you did it right!

Take a look at this – This is the Old Jewish Cemetery in Prague, a remarkable place that makes one contemplate your place in the world.
On the left we have an overexposed image, way too bright, looks garish.
On the right the image is under exposed, it looks dull and murky
And in the middle is the Goldilocks exposure: just right.

Old Jewish Cemetery Prague

But back to our arithmetic example again.  It cannot be 7+4.  That gives us 11, and not 9. By parable, if your shutter is too slow and your aperture is too wide, you will over expose your photo.  And it cannot be 3+3 either, that is 6. If your opening is too small and your shutter too fast, you will underexpose your photo, and it will be too dark.  You need to get the exact amount of light into your camera to get the perfect exposure.

You see how the two are working together?  Balancing your aperture and shutter speed will give you the same exposure, but in different ways.  Go try it out, see how you can get the same exposure using different aperture and shutter settings.  Consult your camera manual for where to take the readings, and where and how to set your shutter and aperture.

A few hypothetical examples:  If you want to freeze motion, set up a fast shutter speed (lesson 107), and compensate with the aperture.  If you want to get creative with your depth of field (lesson 203), set your aperture and compensate with your shutter. This is why “what settings should I use?” is a nonsensical statement.  Every situation is different, and depends on the light conditions, your intended effect, and your equipment.  No use for me to say “oh yeah, I shot that at f/1.8” when all you have is a kit lens which only comes in at f/5.6.

Now, a real world example:  You are shooting a wedding at a church, and there isn’t that much light around. From the shutter speed lesson you know you cannot shoot hand held lower than 1/60 of a second.  So you set your aperture to 1/60, and you are under exposed.  Thus you widen your aperture, but you’ve maxed out the aperture as well, it can’t go any bigger.

What now?  Now is the time we bring in the 3rd element of our exposure see-saw, and that is ISO.  Now we have a third 3 element to consider.

Next up, Lesson 110:  Your Third Control – ISO.

cover model:  Ah, my fave, Raven Rose.


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on January 21 • by

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