I may have lost a few people after the first lesson as I really did not explain myself properly. I do hope that future lessons are more to the point. Let me first go through some of the reasons for the first lesson on exposure.
- Getting you to dive into your camera settings to change how the camera meters for a scene. I know a few people had difficultly with this. No big deal and nothing a quick glance to your owners manual would not fix.
- I also wanted to show how the different types of metering affected the overall exposure for a photo. If you looked at the fstop and shutter-speed for each of your shots you may see a big difference. To the camera though, each shot would have been “proper” exposure.
But before we go lets take a look at some metering modes you will come across with cameras. Note that your camera may not support all metering modes. Check your manual. The square in the images below respresent your sensor
- Evaluative (Canon), Matix (Nikon) – Basically takes the entire scene and with some magic algorithms (which differ between the companies) calculates an average for the scene. Takes into account dark areas and very bright areas of the entire scene. In most cameras using auto-mode, this is the metering modes the camera uses and works fine for most photos taken in very good light. However, due to the complex algorithms employed by the camera in this metering mode, the results can be difficult to predict.
- Center-Weighted Metering – A mode of metering where the camera adjusts its calculation in a weighted manner where the center portion receives 70-80% preference, while the edges receive only 20-30% preference. Some of you who have been in photography for many many years may know that Center-Weighted metering was the old-standard cameras used. Replaced today with Evaluative or Matrix metering. If your camera supports center-weighted metering make some comparisons of it to evaluative metering. Test during the day with a blue-sky and white clouds. You may be surprised with the results.
- Partial Metering- Meters a small part of the around the center scene (9-14% depending on camera). Can be very useful for photographing subjects that overly backlit. Your subject will be metered properly, however your background will be overexposed. Using evaluative metering would most likely resulted in the subject being underexposed (if you are having a hard time understanding why please ask for some help).
- Spot-Metering-Unless you have a newer camera or a professional camera you may not have spot-metering. Nikon cameras usually have spot-metering however and until recently Canon did not support spot-metering on their entry-level or mid-range dSLR’s. As the name suggests, spot-metering meters off of a very specific spot in the scene (2-4% or the scene). This allows the photographer to get a meter reading from a very specific part of the scene. A very useful mode in certain situations.
Now that you have a somewhat basic understanding of each of the metering modes, you may be wondering what is the camera doing or rather trying to do when it meters? I will explore this in the next update. If you want to jump ahead a little google the following:
- 18% gray
- Incident vs Reflected Light metering
- Exposure compensation (remember the tip I sent out in the winter to set exposure compensation to +2 when shooting a scene with lots of bright snow. The same can be said when shooting a photo at the beach as well).
Also for practice when taking a photo learn to look at what the camera is setting for fstop and shutter-speed. Move the viewfinder betwen light and dark areas and watch how it changes. Read your manual to find out what exposure-lock is and the button that needs to be pressed to activate it. Exposure-lock is a very useful feature of a camera and one you should become very familiar with.
Also if you have any questions please ask, either by email or using the comments section of this site.
