I was clicking through my followers today and saw a very interesting blog post by Patti D.
Its tied into photography and explains why you look different in picture than what you perceive yourself to look like in the mirror. Interesting read!
Link to Patti D's blog
Monday, May 30, 2011
Ok, time to get into the good stuff.
Metering, is the technique you use to achieve perfect exposure.
The camera reads light intensity as a value between 0-255. 0 being complete darkness, and 255 being complete light/whiteness. By metering, you tell your camera what value is completely in the middle of these two values.
Look at the picture above. If I had "spot metered" the picture as the shadows in the bottom, then the black would be considered the "middle intensity" and the camera would expose so the shadows appeared as the middle intensity (which is a color called 18% grey). The problem comes from that a lot of data: the green grass, sidewalk, sunlight, would all be pushed up to 255 light intensity, and would appear as pure white in the data file. There is no way to recover that data, as it is all read as white. Thus, we need to understand metering.
Theres different ways to meter, superior knowledge, a light meter, a gray card, or using your cameras metering system. I use my camera's built in metering system because it does enough for the type of shots I want. First, lets go over the types of metering:
Evaluative: The camera examines the whole view, and then averages it so that it is neither overexposed and underexposed. This works well in most situations, unless you want to start shooting into the sun, or shooting where theres areas of darkness and brightness in the same picture.
Spot metering: The camera meters for the focus spot you have selected as your focus point (usually center focus)
Partial metering: The camera meters off a larger area (10-15% of the frame) around a selected point.
Center weighted metering: The camera meters 60-80% off the center of the frame, and then feathers out the weight of it towards the edges of the frame.
Average, partial, spot, and center weighted metering on a Canon 5D Mark 2
To be honest, I don't have experience with partial and center weighted. I stick to spot metering.
A few tips my mentor Dan Carter taught me:
What we are usually trying to meter in sunlight is 18% grey. If you dont have a grey card on you, green grass is usually 18% grey. So before you take the picture, point the camera at some grass in the same sunlight as your subject, click the metering button which locks in your exposure, and go back to the subject and take the picture.
Spot metering lets you capture images most other cant. Say you want to shoot the subject with the sun behind her. Usually a big problem with point and shoots, since they average meter and youll end up with a completely black subject, with a light sky. Instead, use spot metering to expose off the person's skin, and then take the picture with the sun outside of the frame. There will be some lens flare and washout of the subject, but this can be fixed in post processing.
For the photo above, I spot metered for the grass halfway between me and the tree in Aperture priority mode. Then I just snapped the picture, added some warmth in post processing, and thats it!
Sunday, May 29, 2011
It is more commonly used in the terms of f-stop number.
The f-stop number is the ratio of the focal length over the aperture diameter.
There common f-stop numbers are: 1.2, 1.4, 1.8, 2, 2.8, 4, 5.6, 8.
For the numbers 1.4, 2, 2.8, 4, 8, there is half as much light passing through the lens in each increasing number.
Setting a low fstop will give you more light, which lets you use a faster shutter speed.
It also narrows the depth of focus, so you can have only a small area in focus, and the background and foreground have a blur.
The quality of the blur is called bokeh. Sometimes bokeh is confused with the blur itself. Bokeh is the aesthetic quality of the blur. Sometimes, due to the lens construction, there can be a blur that has a lot of jagged lines in the background. This usually isnt considered good bokeh. The shapes of light sources in your blurs are determined by the blades in your lens. These blades control the aperture size, and "blink" when a camera takes a picture. Cheaper lenses will use less blades. The Canon 50mm f1.8 uses 5 blades, so when you have light sources in your bokeh, you will see pentagon shaped blurs.
One common mistake of the beginning photographer is that he or she will always shoot at the lowest fstop number to achieve that blur. This fails when shooting either groups of people or a single subject at too close of a distance. When shooting large groups, only the people standing in the same plane as the focused subject will be in focus. When shooting a single subject, only a small sliver of their face will be in focus, such as the vertical plane running through their eyes. Meanwhile, their nose or their ears will be out of focus. Typically, one should close portraits or group portraits at f5.6, as this will widen the depth of focus to capture everyone/everything sharpley
Saturday, May 28, 2011
Understanding how your camera works is critical in setting you apart from the masses of people with just a camera. I can't count the number of times people ask me what certain functions are for on their cameras.
There are basically 4 options on your DSLR:
Shutter speed - the amount of time the sensor is exposed to what the lens sees. This will appear as 1/the number you see per second. Most cameras have a maximum speed of 1/8000s, and a slowest speed of "bulb" or 30 seconds
Aperture or f/stop number- the size of the hole in the lens that will allow light through. This will be expanded upon on a later date.
ISO - A mentor of mine once described ISO as light gathering bees. Select a higher ISO, and you will have more bees that gather more light, but there will also be noise. A lower ISO will gather low light, but have less noise. Therefore, there should be a balance between ISO and shutter speed. If youre finding that your images are blurred because the shutter speed is too long (because the subject you are trying to capture is too dark) then turning up the ISO may help you in this situation.
Exposure - is how bright you want to your picture to be.
With the Auto (Green Box) function on your camera, all of these options are selected for you.
I like to shoot on Av, or Aperture priority mode. My method is as follows.
- Select Av
- Select the Aperture I would like to shoot at. In the picture above, I wanted to get the 4 subjects' torsos in focus, but didnt need anything else to be. I was using a Canon 85mm f1.8 lens.
Since I was 1)pretty far away and 2) wanted to get a sun flare in the picture, I chose the aperture/fstop number 1.8, which I felt would be enough to get them all in focus. This means that when the shutter clicks, the lens aperture will be as wide as it can be. I probably should explain how aperture works as it is a more important fundamental, but will do it in my next post.
- With the Aperture selected, I chose a low enough ISO as to where my shutter speed remained high. ISO 640 gave me a shutter speed of 1/2000s, which was fast enough so that no hand vibration would blur the image.
I then metered off this grass (super important, will cover a later day), and composed it so that the sun was out of the frame, but just by a bit to the top right.
Snap the picture, but thats not all. A bit of post processing work, and thats what I got.
Friday, May 27, 2011
A few friends and I decided to have a flannel themed photoshoot. From the set, here's the big "keeper" of the set.
I'll go through the steps of how it came to look like how it does.
First, the camera body. I'm using a Canon 5D mark 1. Sometimes I see the new 7D's and 5DmkII's and get envious, but as of 5 years ago, the 5DmkI was the top of the line camera. And photos 5 years ago are as good as they are today, so buying better gear isn't always the solution.
The body can only give you so much. From what I've learned, the body has two main functions: Focus, and metering. Anything else you can fix in post processing such as Adobe Lightroom or Adobe Photoshop. If your picture is either 1) out of focus or 2) over/underexposed, theres not much you can do to fix that. Theres only a few other problems a body will solve: card write time, frames per second, and so on, but if you think that by buying a better camera you can take amazing pictures, you are mistaken.
The second important part of your gear is the lens. Theres tons of information on lenses online, but to keep it short, I like to use prime (one focal length) lenses. These lenses dont zoom, but in exchange for the lack of zoom, prime lenses produces sharper pictures. For this picture, I used a Canon 20mm f2.8 lens. Its not a pro series lens, just a plain old prime that ran me about $375 off craigslist.
Another important part is the lighting or the flash, but that wasnt used in this picture.
Thats all for this time, but next time I will go into detail about the metering options, shooting in RAW, and post processing software and techniques I used.