Archive for May, 2009

Auto-ISO and Studio Lighting

Thursday, May 28th, 2009

You have your studio set up. You shoot your grey card. You take a reading with your light meter. “F5.6 at 125 shutter speed at ISO 200”.

Great. You take a second and third reading to make sure. You set your camera to (M)anual mode, you dial in F5.6 and 1/125 second shutter speed. Your ISO is already showing 200. You take a photo, and the picture is overexposed without hope. What went wrong?

If you do a lot of outdoor shooting, you probably have set your ISO to auto, meaning your camera will bump up the ISO if it thinks you will be underexposed at your current settings. Since the camera took its light metering without your studio strobes firing, it thinks it’s too dark, and it has just bumped the ISO to something like 3200, which is not what you want.

When shooting in a studio, make sure to turn off the auto ISO feature, or you will be sorry.


Monday, May 18th, 2009

Bokeh is a term from Japanese that means “blur” or “haze”. When using a lens with a shallow depth of field (e.g. you have it set to F1.8, as opposed to F22), light sources outside of your focus area can get hazy, and may appear as spheres of light. This could be a pleasing effect if intentional.

Here are some examples of pictures showing bokeh, and lack of bokeh.

The first shot shows a picture with a light source that’s out of focus. Since the shot was taken at a small aperture (F22), the light does not seem hazy. (Remember: an aperture with a high number, like F22, means a small opening).

Bokeh_1764Figure 1: No Bokeh

The second shot uses a large aperture (F1.8), so the out of focus light source looks more like globes of light.

Bokeh_1763Figure 2: Same light fixture, but with bokeh

For more on bokeh, check out this article in Wikipedia.

How to Photograph Your Pet

Tuesday, May 12th, 2009

Everyone loves taking snapshots of their beloved pet. In order to get the best snapshot of your pet, or any animal in general, follow these simple rules.

  1. Focus on the eye. When you are focusing on your pet, focus in their eyes. This is especially true when using a large aperture where the rest of their body might be out of focus – the key item you need to capture is their eyes, because that’s the first thing viewers will look at.
  2. Get down to their level. When photographing animals, it’s not very exciting to photograph them from four feet above them. Get down to their level and see the surroundings as they see it. It’s much more dramatic that way.
  3. Don’t corner them. When composing or cropping the shot, make sure they are walking into the picture, and not out of the picture. So if they are walking left to right, make sure they have some empty space on the right side of the picture for them to “virtually” walk into, otherwise it will seem out of sorts.
  4. Crop close. Although this rule can be broken often, especially if you want to capture more of the surroundings or more of the action, a close composition more often than not has more impact.

Here is an example of breaking the rules with an animal. It’s not my pet, but you’ll see that the focus is not on the eyes. The picture was taken slightly higher than the animal. The animal is also trying to walk outside the frame, and has no room in front of him. This gives the picture an unnatural feeling.

Bad Duck

Figure 1: Bad animal picture

Here’s a better picture. The shot was taken closer to the eye level of the bird. The focus was done at the animal’s eye. The animal is walking into the picture, and not out of the frame, giving a more natural feel. The picture was cropped close enough to show the details of the animal, but not so close as to give it a “trapped” feeling.
Good seagullFigure 2: Better image

Are Megapixels Important?

Wednesday, May 6th, 2009

Marketing folks love to promote Megapixels when advertising cameras. Are Megapixels what you should be looking at when you are buying a new camera? Not necessarily.

A Megapixel is a million pixels, or “squares” of colour on your monitor or printed photograph.

It is true that more pixels means you can print and display larger pictures. How many Megapixels do you need? You can print an 8×10 picture with a 4 Megapixel camera without any problems. You may not notice any improvement going to a 6, 8 or 10 Megapixel camera if all you are printing is 8x10s or smaller.

Going to higher Megapixels can also be problematic. If you increase the number of Megapixels without increasing the size of your image sensor (the digital chip that captures the image), then you can actually introduce noise in your picture, making things worse.

Read the reviews for cameras, and don’t buy solely on Megapixels. Check out the cameras sensor size, and it’s sensitivety to light (especially in low light situations).

I’ve used a 3 Megapixel camera that takes better pictures than a 14 Megapixel camera I’ve also tested.

For an excellent site for reviewing cameras, ignore the Megapixels and check out Digital Photography Review.

Aperture, Shutter Speed and ISO

Monday, May 4th, 2009

The aperture is the size of the opening in your lens to allow light onto your sensor or film.The wider the aperature, the more light that comes in at any instant. Aperture is measured in f-stops. A higher number means a smaller opening, which means less light.

The shutter speed is how fast the shutter is open to allow light in. The longer the shutter is open, the more light that comes in over a period of time.

To get the same exposure with a higher f-stop (smaller hole), you need to leave the shutter open longer, thus you will need a slower shutter speed. You want to make sure the shutter speed isn’t too slow, because vibrations in your hand will affect the image. If you need to use a long shutter speed, you will want to use a tripod to stabilize the camera.

ISO is a measurement of film. A higher ISO number means it is more sensitive to light, and you can speed up your shutter speed if you use a higher ISO film. In digital cameras you obviously can’t change the ISO of the film, but digital cameras let you emulate ISO values. A word of warning: higher ISOs increase noise in pictures (or “grain” in film cameras).

Here is a neat utility that let’s you see first hand how aperature, shutter speed and ISO affect the quality of an image.

The Diagonal Method

Sunday, May 3rd, 2009

The Diagonal Method is a method of composition alternate to the popular Rule of Thirds.  Although it is less known than the Rule of Thirds, historically significant photographs, mainstream advertisements and even famous paintings use this technique. Read the article.