Sunday, November 27, 2016

Guide to Exposure: Aperture, Shutter, ISO, Light

My brother Joel and his wife Lindsey own a small business specializing in salt water aquariums. (Coral Cove LLC). Typically the fish store is very dark with special lighting over the aquariums. Often Joel asks photography advice. Whether it be asking what type of aperture provides the depth of field he is looking for, how to make the shutter speed faster or slower, explaining the use of ISO and what exactly "grain" is, and overall that photography is just a big light game. Oh yes, and my favorite one was when he asked about white balancing... which is not white like he thought, but actually 18% gray. You see? He did not know this, many people do not know all these things. However, this is exactly why I enjoy helping others.

Want To Learn Some Things? Remember I use a Nikon D90 currently, but this is still the useful for all cameras. I am going to teach you a few things starting with the basics of digital camera operation. I want to help as much as possible to help people become better photographers and separate themselves from just snapping a picture.

Exposure is basically the amount of light reaching the sensor. GOOD and CORRECT exposure consists of four main factors which are ISO (sensitivity to light), Aperture (lens opening, also called f/stop), Shutter Speed (how long the sensor is exposed to the light aka the long click), and last but not least... Light (how much light is in the scene).

This all has to do with light!
E = I x T is known as Exposure = Intensity x Time       Aperture x Shutter

See isn't this easy? It all fits together and makes perfect sense! Now lets talk about scales and mess your easy thinking up! Haha just kidding, it's easy peasy. Just be sure to study and memorize the scales. If you dedicate yourself to that then you will be a much better photographer I promise. Lets work on ISO, Shutter, and Aperture scales now...

The ISO scale for the D90 runs from Low to High. I just about always use the lowest ISO possible. Remember, the higher the ISO the more light sensitive (grainy/noisy). The lower the ISO the less light sensitive (clear/clean). ISO are as follows:
Low (100), 200, 400, 800, 1600, 3200, High (6400)

Aperture (f/stop) is the physical opening of the lens. The more open (f/5.6) the aperture the more shallow the depth of field (blur) in the image. The more closed down (f/22) the aperture, the more full the depth of field (sharp) in the image. Stops double or halve the exposure... for example: f/5.6 is twice as large as f/8 ( + one stop) and F/22 is one half the size of F/16 (- one stop)... Full f/stops are as follows:
1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64, 90

Shutter Speeds are the amount of time that the sensor is exposed to light. You know, the length of the click! Stops double or halve exposures on this camera setting also! 1/60 is twice as much exposure as 1/125 (+1stop)1/500 is one half as much exposure as 1/250 (- 1 stop)Your Camera will have 1/3 and 1/2 stop shutter adjustments. The numbers indicated are actually fractions, for example: 60 is 1/60th of a second and 30" is 30 actual seconds. Bulb setting is a manual setting where YOU hold the shutter as long as you want. Full Shutter Speed Scale are as follows:
30”, 15”, 8”, 4”, 2”, 1”, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000, 2000, 4000, 8000

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