Archive for May, 2009

Picture for today:

Going down hill. Taken with 5D and 17-40L.

Till next time…

Picture for today:

Apples at the super market. Taken with 1DsII and 50mm f/1.4.

Till next time…

Link to part1

Last time I stopped at aperture. This post will finish the coverage of the exposure triangle. I ended rather suddenly with aperture so we’ll pick it up from there. There isn’t much else to be said about aperture at least for the purpose of these posts. You might be wondering why aperture is represented as f/ followed by a number. The reason for that is not necessary for a complete novice to understand. But if you’re the kind of person that must know, it’s a ratio of the focal length and the aperture size.

ISO as explained in the first post is the sensitivity of the film or imaging sensor to light. Most cameras lists ISOs in full stop increments (e.g. ISO 100, ISO 200, ISO 400, etc.) but most DSLRs allow increments of 1/3rd of a stop. What is a “stop”? For the purpose of these posts, a full “stop” is equal to twice or 1/2 the amount of light recorded. I will try to minimize the amount of “technical jargon”. Just remember that each time you increase the ISO, say from 100 to 200, you are making the film or sensor twice as sensitive to light. Each time you decrease the ISO, say from 200 to 100, you are making the film or sensor half as sensitive to light. With both digital and film, the higher the ISO rating the more “noise” there will be in the image. For film the “noise” is in the form of film grain and digital is similar to “white noise”.

Interesting fact for those that are technically minded: There are two kinds of noise in digital, luminous and color.

Almost all newcomers to digital photography are obsessed with digital noise and will often sacrifice shutter speed and/or aperture to allow for lower ISOs. That is one of the most retarded monkey brained things you can do (IMO). I routinely shoot at ISO 1600-3200 without reserve. Often shutter speed (which directly relates to handholdability, is that even a word??? Oh well it is now) and/or aperture (e.g. Depth-of-field, DOF) is more important than a little noise. I rather have a noisy image over a blurry or out of focus image any day, unless I’m specifically going for that effect. I’ve even done a photo shoot at ISO 3200! My advice for the new photographers, shoot at whatever ISO will allow you to get the shutter speed and aperture you want to use. Noise can be reduced in post processing and more importantly PROPERLY EXPOSING!

Oh, I realized that I never talked about depth-of-field (DOF). Basically, DOF is the area in which the photo is in or out of focus depending on how the term is used. Again, I’m keeping things as close to layman terms as possible to avoid confusing novices.

There you have it, a basic crash course on exposure. I want to mention one more thing though. When using DSLRs (well cameras in general), you should always shoot in the highest quality setting possible. What’s the point of buying an expensive camera if you’re just going to shoot it at “Small JPEG” setting? Might as well just stick with a cheapo camera phone. Now I understand if you must use a lower quality because you’re out shooting and you run out of memory cards but if you’re doing it just to be able to “I can fit over 1000 pics on a 1GB SD card!” you shouldn’t. By the way, I’m assuming those of you that are reading these posts are using DSLRs or advanced point and shoots which allow for full manual control.

Anyway, if you have questions feel free to leave a comment and I’ll try to answer it.

Till next time…

Picture for today:

Bird Drinking from fountain. Taken with 1DsII and 50mm f/1.4

Till next time…

With the advent of affordable DSLRs, photography is within the reach of the vast majority of people. Cameras like Canon’s Rebel series, Nikon’s D40 and D40x, and Sony’s Alpha A-300 series to name a few are making it easy for complete novices to get their hands on DSLRs and join in the fun and art of photography. Most novices will stay in the “creative auto” modes or “semi-auto” modes such as Aperture Priority or Program mode. To really learn though, it is best to shoot in Manual mode. Understanding exposure is the first step to photography.

For those who are just starting out with photography, I highly recommend the book Understanding Exposure by Bryan Peterson. It will guide you through the whole process and explain in detail the “exposure triangle”. In this post, I will make an attempt to give you a crash course in getting a proper exposure and hopefully move you into Manual mode. Exposure is controlled by three elements: shutter speed, aperture, and ISO. These three elements is what makes up the exposure triangle. Changing one affects the other two.What is shutter speed, aperture, and ISO?

Shutter speed – the length of time the shutter is open. Larger the number the shorter the time and visa versa.

Aperture – the size of the lens opening. This is controlled by the aperture blades “closing down”. Smaller the f/stop the larger the opening and larger the number the smaller the opening. At this point in time, we won’t worry about what an “f-stop” is.

ISO – the sensitivity of the film or imaging sensor to light.

I’m going to assume that you already know what/where your camera’s meter is. If not you should read the manual. Actually, you should read the manual regardless if you’re a complete novice. In most cases, novices who shoot in Aperture Priority, Shutter Priority, or Program mode and won’t do anything with exposure compensation. This means that the camera will attempt to center the meter every single time. Your job as a photographer is to change each of these three elements in order to get a proper exposure based on your camera’s meter (generally it means to center the meter).

A few notes on shutter speed and aperture. Camera shake (the shake from your hands, etc.) can be reduced by following this simple “rule”. The shutter speed should be 2x the focal length that you are shooting at if you’re using a crop camera. If you don’t know what that means it’s ok… just use the formula. What is focal length?? Focal length (at least for this post) is basically the number that is listed on your lens. For example, Canon’s kit lens is the 18-55mm IS and if you’re zoomed all the way out to it’s widest setting the focal length is 18mm. So take that and multiply by 2 (18*2=36) and set your shutter speed to or above that number. In other words, you should use a shutter speed of 40 or 1/40th of a second.

As for aperture, the basic thing to remember is the smaller the number the more “out of focus blur” there is. That’s about it… more to come if I feel like it or if people are really interested in this kind of post.

Till next time…