It's important to test yourself, to take yourself out of your comfort zone and shoot pictures of things you don’t often tackle. It’s how you keep yourself fresh and also how you learn new skills. With that in mind, I spent last Saturday at RIAT.  How many of you enjoy heading out to an airshow to capture some fast jets or the old war birds in flight? Judging by the number of people at RIAT with cameras, it’s quite a high percentage. And if you’ve not been to an airshow since you were a little child, I highly recommend it as a great day out. Take the camera, take a packed lunch, go with some friends and have a ball.

I’ve been to airshows in the past and taken pictures with some reasonable success, however this weekend I went to RIAT, the Royal International Air Tattoo at RAF Fairford and although I had access to a variety of cameras, I choose to take the EOS 7D. Certainly part of my thinking was that it is a lighter camera and with a slipped disc I wanted to minimise weight where possible, but the main reason was the focusing system. The EOS 7D features a very advanced AF system. While it may not be, in outright terms, as quick as an EOS-1D Mark IV, it has something the MkIV misses - Zone AF. I’ve talked a bit about the AF system on the EOS 7D before, but as a quick recap, there are five different modes you can use: Single Point AF, Spot AF, Auto Point Selection, AF point Expansion and Zone AF. Of these, for moving subjects Zone AF and AF point Expansion are the most interesting as they give you large focus areas to place over your subject to maximise your chance of getting it in focus.

For the most part, I spent the day using Zone AF. Now I’ve used Zone in the past and had mixed results. I’ve found with a contrasty background, the AF system can jump to that because there is no priority to the AF points used within the zone - they simply go where they think there is the most contrast. However, Saturday at RIAT was a lovely day - some cloud, some sun and some perfect clear blue skies. If you have a contrasty background, then switching to AF Point expansion gives you a more precise area to focus with and is less likely to grab the background, but still has a larger area than a single point for you to track fast moving subjects with. Zone AF basically gives you five focus zones to select from - each zone is made up of several AF points and they will focu

s where they find contrast. Simply placing a zone over your subject, in this case and airplane, gives you freedom of composition (with five zones it’s very quick to shift between them) as well as freedom within the zone. It makes for a very intuitive system that’s fast an accurate. There is one other reason the EOS 7D is so capable for airshows - 8fps shooting speed. Now I’m not one for shooting bursts, though I know some others are. Personally I find my best shots are the one off shots where I’ve picked a moment at the time rather than snatching a still from a sequence of 20. However, there are times when taking a 3 or 4 shot burst is useful at an airshow and gives you a higher chance of grabbing the picture. Having 8fps to play with means you’ll take those 3 or 4 shots in a shorted time so you have a more compact sequence in terms of picture elements within the scene. So, is the EOS 7D the best airshow camera out there? I think it might be up there with the best of them, in fact, next time I go to a show it will remain my camera of choice even if weight is no longer an issue!

All images © David Newton 2010. All rights reserved, no image may be copied or used without the copyright owner's permission. Please contact David Newton if you wish to use these images. 

Canon have just posted a new firmware for the EOS 7D that sorts out a couple of little issues that have cropped up with the camera.

The new version is 1.2.1 and should be used by any EOS 7D user to make sure your camera is working as well as it can be. 

The firmware has four main improvements:

1. Extends the timing at which the high temperature warning indicator is displayed and the timing of automatic shut down of the camera due to a rise in internal temperature during Live View or EOS Movie functions.

2. Optimizes program shift when the ISO setting of the camera is set to AUTO.

3. Corrects a misspelling in the French-language menu.

4. Corrects a phenomenon in which vertical magenta-colored banding appears in still images taken in movie-shooting mode.
(This only occurs when in Manual exposure mode and when the ISO speed is set to "H". Note that this phenomenon only affects units with Firmware Version 1.2.0)

 ...To give some background to the first two....

When shooting movies or using Live View, the sensor in the camera gets hot. It's an electrical system and just light a lightbulb, one of the by-products is heat. If it gets too hot, it can damage the sensor. However, the cameras feature a very conservative thermo-regulation sensor to shut down the sensor when the temperature passes a certain point. It's affected by external temperatures, so you're really most likely to see it in hot countries where you're filming for a long period of time. This firmware relaxes that very conservative figure allowing you to film for longer before the warning light appears and the camera shuts down. However, it will still be within the conservative figures set by Canon so there will be no risk of sensor damage.

Program shift is for users that shoot in Program (P) mode. In P mode you can still have some control over the shutter speed and aperture by using the Main command dial (behind the shutter button) to change the settings. v.1.2.1 adjusts the program line used for this when you also make use of Auto ISO. 

 The update can be downloaded from here. Please be sure to use a fully charged battery and DON'T, WHATEVER YOU DO touch any buttons or dials on the camera during the update. Well, not unless you want an expensive paperweight! 

Spot AF eh? Sounds like a great idea doesn't it? You know, use a smaller area of the AF sensor for more precise focusing?

Yes, we like the sound of that. Trouble is, it's not the answer to all your prayers and it's certainly not the  best AF mode to use on the EOS 7D by default. In fact, use it and you'll probably find it's not as good as you thought - unless of course you use it wisely. And that means only in situations when it's appropriate. 

The reality is that spot AF is good in bright light on fairly static subjects when you want to focus 'through' obstacles, or when shooting portraits and you want precise focus on the eyes. In all other situations, it's a bad idea to use it - it is slower to track and harder to keep the point on the exact spot you want to focus on. More than that, in low light, it takes longer to focus as well due to the smaller area of the AF sensor being active and therefore less low light sensitivity. 

In short, use it with static subjects, in good light, or when shooting portraits. For all other situations, look elsewhere in the four other AF selection modes for focusing nirvana. 

There are similar restrictions with the other AF modes too, especially Zone AF and AF Point expansion. But I'll save those for future posts. For now I just wanted to get Spot AF off my chest as I've had several emails about it recently.