What I learned at EOS Discovery Day that I didn't already know

• Composition
  
  • Try shifting your perspective. For example, climb on top of your car.
• Exposure
  
  • There is a well-known rule-of-thumb that the minimal safe shutter speed is about 1/focal length of the lens you're using. I asked if one should use the true lens focal length or the effective focal length due to the crop factor. Rick Berk, a Canon rep, said that it depends on who you ask. I suppose to be safe, one could use whatever number is lowest.
    
  • For the power switch on the Canon EOS 40D/50D, the middle setting locks camera exposure.
    
  • Typically, one uses evaluative and spot metering the most.
    
  • Each segment on the histogram represents approximately one f-stop.
• Autofocus
  
  • Don't use AI Focus AF. This mode switches between One Shot AF and AI Servo AF depending on the subject's movement. But it's too slow.
    
  • Autofocus fails for low contrast subjects (e.g. sky), low light, back-lit subjects, and textures.
    
  • If two or more AF points light up at the same time, that means they are the same distance from the camera (only occurs in auto AF mode).
    
  • Auto AF point selection mode focuses on the nearest subject. This may or may not be what you want.
    
  • To take a photo of a group, focus 1/3 of the way into the group and use an aperture of f/8-f/11.
    
  • Custom function "AF point selection method" can be set so you can instantly change AF points without first pressing the AF Point Select button.
    
  • Try focusing close to blur the background.
• Flash
  
  • Try both flash and no flash in the same shooting situation.
    
  • Direct flash makes people look fatter, bounce flash makes people look skinnier.
    
  • For sharp action pictures with flash in manual exposure mode:
    
    • Set a fast shutter speed (1/200 or 1/250 sec depending on camera model).
    • Set a medium range aperture (f/5.6, f/8; possibly wider if you need to reach farther away).
      
    • Set a moderate ISO , such as 200 or 400 (higher if you need to reach farther away, lower if you're in an extremely brightly-lit area).
      
    • Ignore the camera's metering scale -- it's telling you that the ambient light will be under-exposed (black background) which is okay.
  • How to avoid red eye
    
    • Move closer to the subject.
      
    • Bounce the flash.
      
    • Increase the level of ambient light
      
    • Have the subjects look away from the camera.
      
    • Move the flash off camera.
  • Usually, TTL does a very good job at exposure.
• White balance
  
  • Auto white balance is a good starting point.
    
  • The fluorescent white balance setting is not very good for CFL style fluorescent bulbs (spiral shape).
• Live View
  
  • Live View is designed to be used on a tripod.
    
  • Live View is very useful for macro photography.
    
  • The best feature of Live View is magnifying your images to 5x or 10x. This allows you to easily check your focus.
• Digital management
  
  • Even if you set your picture style to black-and-white, you can still extract the color from the RAW image (but the JPEG).
    
  • If you forget to download images before you formatted your memory card, you can still recover the images by using data recovery software. Just don't shoot any new images on that card!
    
  • A 4 GB memory card contains about the same amount of information as will fit on a DVD.
    
  • The faithful picture style is good for brochures.
    
  • If you turn on long exposure noise reduction, the processing time is equal to the exposure time, i.e. it wil take twice as long to take the photo.
    
  • Two types of noise: chromic and luminous.
• Miscellaneous
  
  • There is a depth-of-field preview button near lens mount.
    
  • The proper way to do diopter adjustment: Remove the lens from the camera. Turn the diopter adjustment wheel until the etched lines of the AF points are sharp.
    
  • Use a freezer zip lock bag to protect your manual. My manual got wet in a rain storm.
  
  

Canon SD870 IS little-known features

• If you press "display" while in playback mode, you can see a histogram and "blinkies" for overblown highlights.
  
• There is a panning mode for the image stabilizer.
  
• There is a slow synchro flash mode.
  
• Holding the shutter button halfway and pressing the macro/landscape button locks autofocus (AFL).
  
• Holding the shutter button halfway and pressing the ISO button locks exposure (AEL).
  
• You can register the useless print button to a useful function like exposure compensation.
  
• It's possible to set custom white balance. I tried the Expodisc with the camera and it worked! You just have to hold the Expodisc over the lens, which is a bit awkward but not too bad.
  

I didn't realize it but many of the Canon dSLR features (e.g. histogram, AEL, AFL, custom white balance) are built into this little Powershot camera! I just didn't know about these advanced features until I started doing SLR photography.