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Thread: Photography 101

  1. #1
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    Photography 101

    Photography 101

    So what is photography? Well, the word comes from two Greek words, photos (light) and graphe (drawing), which basically translates photography to "painting with light". So basically what you do when you take a picture is capture the paint strokes that the light has made. There are two ways of controlling this, and I'll talk about it next.

    The two ways we have of controlling what we capture is either by adjusting the aperture, which changes the amount of light that hits the image sensor if you shoot digitally, and the film if you shoot analog. I am assuming you use a digital camera, so I'll use image sensor from now, but just put in film (see what I did there?) if you shoot analog. The other way is by adjusting the shutter speed, which controls the time the light hits the image sensor.


    Aperture
    The aperture is basically a ring of fans that sit in your lens, and the contract and expand, depending on what setting you have. It is also known as F-stop, and is represented by number, from f/1.2 which is a big opening, and f/32 which is a really small opening. The hard part here is remembering that small numbers makes a large opening, and the large numbers make a small opening. One way to try and remember this is to think of it as a fraction. I.e. 1/1.2 is bigger than 1/32. They are divided into whole steps, with smaller steps in-between, but I'll only list the whole steps. They are: 1.4 - 2 - 2.8 - 4 - 5.6 - 8 - 11 - 16 - 22 - 32

    Techincally speaking, the F-stop is the ratio between focal lenght and the size of the iris opening, which is what the ring of fans are called. And for those of you that want to know how to calculate the F-stop sequence, the formula is: The square root of 2, which is 1,4, and you multiply it with the previous aperture. So if you used F-stop 1.4 and want to know what the next stop is, you multiply it with 1,4, which gives us 1,96 that we round up to 2. Try it. You'll see that it adds up all the way up.

    Visual display of various aperture settings

    What aperture also controls is depth of field. The bigger F-stop you use, the more depth of field you get. For example, using aperture 1.4 on a portrait would lead to out of focus starting at the eye that's furthest from the camera, while using aperture 11 on the same shot would cause everything behind your model to be in focus.

    Small aperture

    Large aperture

    Shutter Speed
    Shutter speed is used to control how long the light hits the image sensor. If you use a fast shutter speed, little light is allowed in, and if you use a slow shutter speed, more light is allowed in. The shutter speed is also divided into steps, which are a bit more logical than the aperture steps. They are as follows (only whole steps): 1 sec - 1/2 sec - 1/4 - 1/8 - 1/15 - 1/30 - 1/60 - 1/125 - 1/250 - 1/500 - 1/1000 and so on and so forth. The system is the same if you go the other way, which gives you 1 sec - 2 sec - 4 sec and so on.
    A fast shutter speed (1/125 or faster) allows you to freeze motion, and a slower speed, such as 1/60 might give you a little motion blur.

    Long shutter

    Quick shutter

    Now, aperture and shutter speed work together to control how much light hits the image sensor. And one can control the other. If you have an image that is correctly exposed at aperture f/1.4 and the shutter speed is 1/60, but you want more of the background in focus, you increase your aperture to, say 4. Now you need to adjust your shutter speed the same amount of steps. Looking back on the aperture scale, you see that when you go from f/1.4 to f/4, it's 3 steps, which means you need to adjust your shutter speed 3 steps, which would give us a shutter speed of 1/8. The same holds true for shutter speed. Say you have your shutter speed at 1/60 and aperture at f/2.8, but you need to freeze an action scene while maintaining a small depth of field. You change your shutter speed to, say 1/250. Now you need to adjust your aperture accordingly. Going from 1/60 to 1/250, we see that it's 2 steps, so you would end up with an aperture of f/1.4
    As you can see, there are several combinations that gives you a correct exposure. Which one you choose to use depends on what you want to express.

    And then you have ISO, which basically is how sensitive your image sensor is to light. The higher the ISO, the darker the environment can be before you have to adjust your shutter speed or aperture, but the drawback is that high ISO increases noise in your photos. Different cameras produce noise at different ISO settings, so you need to experiment in order to know where your camera starts showing too much noise.

    That's all for this time. Feel free to ask any questions, and I'll try to answer them as best I can.
    Last edited by Clone3d; 01-17-2013 at 08:59 AM.
    Please, call meg Johnny.


    Photography 101!

    My photography site

    Quote Originally Posted by NinaCovington
    Hahahahaha! Yes!!!!! You are awesome, Clone!!!!

  2. #2
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    Light, Exposure & White Balance



    White Balance

    Light, no matter what kind, has a temperature, which is measured in Kelvin (K). What this means is that different light has different temperatures, and because of this, different colour, which we need to compensate for when photographing. The higher the temperature, the bluer the light is, and the lower the temperature is, the more it shifts towards a red and yellow tint. Your eye corrects for this automatically, which is why you don't see the colour tint. The camera, however, does not, which is why we need to set our white balance. What the white balance does is adjust the “film” in order to compensate for the shift in colour. Most cameras have settings for Daylight (5200K), Shade (7000K), Cloudy (6000K), Tungsten (3200K), White Fluorescent Light (4000K), Flash, Auto White Balance (awb) and custom. Auto white balance gets you in the ballpark area of where you need to be, while the more specific ones gets you even closer, while custom gets you exactly what you need, if you set it up properly. Things you will notice in the images below, is the color of the white wall (Yes, it is white). There are two images where it resembles white, and I used tungsten and custom in those. The reason the tungsten one is almost correctly showing the white is because I have tungsten lighting.

    How white balance affects your photo


    I suggest playing with your camera by changing the white balance and see what looks right. Remember, your eyes adjust automatically, while your camera doesn't.



    Exposure

    Exposure is the combination of aperture and shutter speed. As I mentioned in my previous instalment, there are several combinations of shutter speed and aperture that gives you the same exposure. In order to understand exposure, we first need to understand histograms. This sounds harder than it is, so here we go:

    What a histogram looks like

    This is what a histogram looks like. What it is, is a representation of where the light is in your photo. The far left is black, and the far right is white. What it tell us is where the light in the image is, and whether or not it's over or underexposed. If it's overexposed it clips on the far right side, like this:

    Overexposed image
    Histogram of overexposed image

    If it's underexposed, it will clip on the far left side, like this:

    Underexposed image
    Histogram of underexposed image

    Correctly exposed, it will be in between the two extremes, with the curve reaching all the way down before it hits either edge, like this:

    Correctly exposed image
    Histogram of correctly exposed image


    Now, how do you know if your image will be under or overexposed before you take it? Well, the camera manufacturers have been so kind as to add a visual aid for this, and it basically looks like this:

    Exposure indicator

    What this tells us is that when the needle is in the centre, the image should be correctly exposed. If it's on the right side, it's overexposed and if it's on the left side it's underexposed. However, it's not really that simple. Some times you need to adjust your exposure. Say you take a picture where you had the needle in the centre and it turned out a bit dark. Then you need to adjust your exposure by either setting a larger aperture or a slower shutter speed. You can see how this affects your exposure by keeping an eye on the needle.

    Now, that picture shows it on the back of the camera, but most cameras also display it in the viewfinder, so no matter if you prefer to shoot via the live-view or use the viewfinder, it will be there to help you.

    That's all for now, and as usual, requests and questions are welcome!
    Last edited by Clone3d; 12-08-2010 at 10:33 AM.
    Please, call meg Johnny.


    Photography 101!

    My photography site

    Quote Originally Posted by NinaCovington
    Hahahahaha! Yes!!!!! You are awesome, Clone!!!!

  3. #3
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    right on thanks Clone3d when my head isn't throbbing I will sit down and check it out
    elevating to new levels of knowledge (that's the plan at least )

  4. #4
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    are these settings typical in most cameras or only the more higher end ones
    I am not using anything fancy and am not sure what all it can do I will have to dig up the book for it
    elevating to new levels of knowledge (that's the plan at least )

  5. #5
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    Haven't looked at compact cameras in a while, but I know that some of them have settings for shutter speed, aperture and ISO. But reading your manual is actually a decent idea
    Please, call meg Johnny.


    Photography 101!

    My photography site

    Quote Originally Posted by NinaCovington
    Hahahahaha! Yes!!!!! You are awesome, Clone!!!!

  6. #6
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    So what kind of qualities would you look for in a good camera?

  7. #7
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    Quote Originally Posted by eweshi View Post
    So what kind of qualities would you look for in a good camera?
    In a digital camera, speed is a big thing to watch, good glass since you need a good lens, low light abilities is very nice to have. Then Changable lenses is a nicety, you get this on SLR's for the most part.
    For me, happiness is learning new things.

  8. #8
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    This is a fantastic thread! Thank you! I'll definitely be adding this one to my personal bookmark list for when I need it, or need to share it!

    Thanks for helping to improve 3D Buzz!

  9. #9
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    You're welcome Jason

    I'd like to add to what Kuanbyr said. In addition to that, you want a camera that is comfortable to hold. If the camera is to big for your hands, or to small, it might become uncomfortable after a while. And if you are on a budget and have to choose between a cheap SLR camera or a cheap lens, buy the cheap SLR and spend a little extra on the lens.
    Please, call meg Johnny.


    Photography 101!

    My photography site

    Quote Originally Posted by NinaCovington
    Hahahahaha! Yes!!!!! You are awesome, Clone!!!!

  10. #10
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    Anything special you guys want me to write? Compositions, light use, color? Or something else? I have a plan for what the next installment will be, but I'm willing to listen to you guys, if there's anything special you want.
    Please, call meg Johnny.


    Photography 101!

    My photography site

    Quote Originally Posted by NinaCovington
    Hahahahaha! Yes!!!!! You are awesome, Clone!!!!

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