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Photography Math Is Hard, Okay?

2020-03-04 6 min read Photography Teknikal_Domain Unable to load comment count

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So you remember the posts about my cards or my cubes, right? And now the pictures weren’t exactly perfect? Well, I just finished running the numbers. And this will be fun.

So as with many things in life, photography has one of those aspects where there can be many different ways to accomplish the same end goal. in this case, we’re talking about lighting. How do you get a shot to be lit such that it’s acceptable and presentable? Well, there’s a few ways:

  • Add more light to the scene naturally (turn on more lights)
  • Use the flash
  • Increase camera ISO
  • Decrease shutter speed
  • Open up the aperture (I’ll get back to this one)
  • Use a better lens

I had always tried the first or third methods first, resorting to the second and fourth as a last resort. Anyways, let’s dive overly in-depth to a specific concept that likely doesn’t need as much as explaining as I’m giving it, shall we?

Natural light

Arguably either one of the easiest, or hardest methods: just turn on more lights. I mean, let’s face it, more lights is the definition of adding light. There’s only one issue, at least in my case: there are no other lights that I can turn on, meaning that I’m left with other methods.

There is one downside here, which also comes out with the flash: temperature.

Use the Flash

I mean, the camera has a flash, right? Why not just turn that on and let it add it’s own light into the scene?

Great idea, in theory. And for many people, this is fine. For me though, I tend to end up taking photos of reflective objects. What this means is that a bright light source right next to the lens will result in almost all of that light being reflected back into the lens and causing some extremely bright spots.

I can help control this a little with changing the flash power level which my particular camera can adjust, but there’s the other issue that it can’t: light temperature.

Light Temperature

I’m not talking temperature temperature. I’m talking about color temperature. When photographers talk about temperature, namely how “warm” or “cool” a light is, we’re referring to how yellow or blue that particular light source is. usually used to describe the particular variation of white we’re dealing with, is it more yellow tinted, blue tinted, or somewhat neutral? For most people, “warm” is yellow and “cool” is blue, but if you’ve ever bought white bulbs at your local hardware store with a Kelvin (K) rating, the higher the temperature, the “warmer” the temperature, the more blue tinted the light is… backwards, I know.

The problem with this is that the camera flash is an almost perfect white, maybe with a hint of blue. All the lights in my house are yellower colors, meaning that the two would mix and.. it wouldn’t look right.

Increase the ISO

ISO (Yes, the International Organization for Standardization) ratings are a holdover from film, where the ISO number of the film, also called the “film speed”, was a way to quantitatively represent the sensitivity of the film: the higher the ISO, the more sensitive it was, but this also meant that the larger the film grains were, therefore the more noisier it’d look.

Well in the digital realm, it’s…. basically the same thing. A digital camera’s ISO relates identically to film ISO — the higher it is, the more sensitive the sensor is to light, but the noisier the final image will be.

I mean heck, this is literally the sensitivity number, so turn it up, right? Not quite.

The default ISO for the camera in automatic mode is 400.. and I can crank that up to 1600, H0.3,H0.7, and H1.0. These work out to rough approximates of 2000, 2500, 3200.

Well remember when I said it makes the image noisier? Yeah, at those levels it’s almost useless. Anything above 1000 in this camera is pushing it.

So while ISO works up to a point, past some levels, especially when you want to capture details, you’ll need to find some other method of increasing the exposure.

Decrease Shutter Speed

Also another pretty big no-brainer for most photography: if the shutter stays open longer, more light can get it, right?

And yes this is true, but there is one downside: With my current arrangement, anything slower than 1/30th of a second will show some blur from hand shake. So how far does the camera think it needs to slow it down? 1/5th. I cannot hold my hands physically in the exact same position for that long, and the result is a blurry mess on the edges of any object.

Open the Aperture

I mean yeah, if I don’t literally close the lens as much I’ll let more light in, there’s just… two issues.

One: the aperture can only open so wide, and this gets smaller the more I zoom in.

Two: the amount of light that is actually let in by opening the aperture is actually not that significant. it can make a difference, sure, but the main reason you play with aperture is depth of field, not for light.

Use a Better Lens

Why yes, of course, spend more money!

But seriously, a lens with a wider aperture, or meant for more low-level shooting would obviously help as they let more light in. Not much to really explain there.

My Solution

Well I have a few ways of figuring it out:

First, I happen to have a Nikon speedlight handy.. you know, one of these things:

Nikon SB-900 Speedlight

it mounts to the camera replacing it’s flash with… a much bigger flash:

Speedlight mounted on a Nikon D80 camera

This one is much more capable of being configured and tweaked. And with it I can, of all things, turn down the flash intensity, put a diffuser on the front of it to spread out the light, and it adds to the scene without creating a huge contrast between warm and cool. Also, since it’s toned down, and the actual light source it farther away from the lens, a lot less light gets bounced directly back into the camera.

If I don’t want to grab that giant heavy thing, or for some reason I can’t use it, I can grab a different lens. it’s not as wide angle as my default one, and it’s not a zoom lens, but it can also capture more light, meaning that I can use some of the other covered-above methods without needing a flash — only just a little touch up in post.

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