Notes on using the Canon A620, A630, A640, and A650 IS digital cameras for hang gliding and more
June 19 2008 edition
steve at aeroexperiments.org
This article gives some general strategies on using a digital camera in flight, including while hang gliding. This article also gives some notes on the specific features of the Canon A620, A630, A640, and A650 IS digital cameras.
The Canon PowerShot A620 is a great camera for hand-held use in flight. For hang gliding, the camera fits well
into a small pocket like the elastic drogue chute pocket on a Wills Wing Z-5
harness. (Of course, I attach the camera to a leash attached to my harness, so I can let it dangle whenever I need both hands--a thin bungee cord is best, because the pilot will still have full range of motion even if the camera or cord gets caught on the control frame somehow.) The shape of the camera body
and layout of the controls is extremely well suited to one-handed
operation. The 4 AA batteries give long
battery life and are readily available anywhere. The flip-out screen is invaluable for
self-portraits. The viewfinder is essential for anyone who flies with polarized sunglasses, which make it sometimes inconvenient to view the LCD screen. The 4x zoom is
useful. Once the exposure and focus are
pre-metered by pushing the shutter button halfway down, the response to the
shutter button is almost instantaneous and the recovery time before the next
picture can be taken is very short. If
the shutter button is kept halfway depressed, multiple shots can be triggered
off very rapidly. The “burst” setting
works well too.
One important feature of the Canon A620 is that the saved settings of the "C" mode are recalled whenever the C-mode is re-entered. For example if the user is in "C" mode and makes changes to the settings and then wishes to restore the original settings, as long as he has not used the "save" function, all he has to do is flip the dial out of the "C" mode and then back to the "C" mode. The "saved" settings will be instantly restored. This is very convenient for in-flight use, and many cameras lack this feature.
I primarily use my A620 in “C” mode, set up to emulate “P”
mode. I program the “C” mode so that the
manual focus is locked at infinity. The manual focus lock is easy to turn off in flight by operating the camera controls. To turn it back on, all I have to do is flip
the mode dial into any other mode, and then back to the “C” mode, and I’ll have
all my original settings back, including the manual focus lock. Pre-setting the manual focus reduces the
camera’s response time in any situation where the user has not already
pre-metered the focus by pressing the shutter button down halfway and holding
it there. Pre-setting the manual focus also
prevents the camera from accidentally focusing on some nearby object like a flying
wire, wing strut, etc.
I often set up the "P" mode to be identical to the "C" mode, but without the manual focus lock. Now, flipping the mode dial between "P" and "C" modes is an easy way to turn the manual focus lock on and off.
Here is another way I sometimes set up the camera--I'll set the "P" mode up with "-1/3" exposure compensation and I'll set the "C" mode up with "-1" or stronger exposure compensation. Now flipping the mode dial between "C" and "P" is an easy way to change the exposure compensation. The "-1/3" setting is good for general use, darkening the sky just enough to help make cumulus clouds stand out better. The "-1" or stronger setting is good for shooting down at birds or gliders flying over dark forested landscapes, where the dark landscape would normally cause the camera to brighten the picture too much and wash out the item of interest.
One caution about the "manual focus" feature-- even for very distant objects, I found the focus to be sharper when I used autofocus, or when I set the manual focus slightly short of infinity, than when I set the manual focus to infinity. In other words the scale of distances on the LCD screen is not completely accurate and the sharpest pictures of distant objects are not obtained simply by setting the manual focus to infinity.
One drawback with the A620 is that the “auto” ISO setting is
not useable for any situation where high shutter speeds are needed. The “auto” ISO setting always selects an
unreasonably low ISO value, resulting in slow shutter speeds. For hang gliding and other similar
applications, the exposure time should be kept near 1/1000 sec or shorter, to
minimize blur. This will require
manually setting the ISO. In changing light
conditions the ISO may need to be re-set in flight. ISO 200 works well in most situations but the
ISO will need to be higher for shooting down against a dark landscape shadowed
by clouds, and the ISO may need to be lower for shooting toward brightest part
of the sky on a sunny day.
Another drawback with the A620 and the other cameras in the
PowerShot series is that they are relatively fragile. A modest blow on the extended lens will jam
the mechanism. Also, the cameras are
prone to getting dust inside the lens which can end up being the limiting factor in the useful life of the camera, unless you buy an extended warranty. Also, the cameras cannot be triggered remotely.
The Canon PowerShot A630 is an even better camera than the
A620 for hand-held use while hang gliding.
The biggest improvement is the introduction of a “HI” auto ISO setting
that does generally yield exposure times of
1/1000 second or faster. This is
perfect for nearly all in-flight applications and eliminates the need to
manually change the ISO in flight as the light conditions change, which is a
great improvement over the A620. Some
other improvements: the resolution is slightly higher, and the fold-out screen
is larger. The only slight drawback with
the A630 as compared to the A620 is that since the SD card is now located under
the battery door , it is no longer feasible to change SD cards while hang
gliding or in other similar situations, as the batteries would fall out and be
I haven't used the A640 but the Canon literature suggests it suffers from the same problem as the A650 (see below), to a lesser extent. The Canon literature cites the following shooting rates: A630 1.8 frames/sec, A640 1.5 frames/sec, A650 1.2 frames/sec. A fast shooting rate is very nice for in-flight applications and many other applications, therefore the A630 may be a better choice than the A640 for these applications.
Canon A650 IS
The A650 is roughly the same size and shape as the A620 and
A630, but slightly heavier. The optical zoom has now been increased to 6x, and image stabilization has been added, all of which is very helpful for taking photos
of birds, other gliders, etc.
One disappointment with
the A650 is that the shooting rate for multiple shots is significantly lower
than the A620 or A630, so that the A650 lacks the responsive, quick feel of the
earlier cameras. This is true both when
using the “burst” mode, and when manually triggering off shots in rapid
succession while keeping the shutter button halfway depressed to keep the focus
and exposure locked. In a controlled
test in “burst” mode, the A650 only took 11 shots while the A620 took 18 in the
same time period. In this test the A650's image stabilizer was turned off, and the A650 was set to "Superfine, M2" which yielded a slightly fewer pixels than the A620's setting of "Superfine, L". There is virtually no
“lag” in response to the initial shot with either camera--especially when the
exposure and focus are pre-metered--but the “recovery time” before the camera
is ready to take the next shot is much longer with the A650 than with the A620
and A630. This is a major disadvantage for use of the
camera while hang gliding, or while photographing birds or other moving
objects, etc. See the notes on the shooting rates as cited in the Canon literature given in the "Canon A640" section of this article.
In spite of this lower shooting rate, the Canon A650 is my current camera of choice for hand-held in-flight photography.
I also have recently had great results using the Canon A650 for in-flight movies, with the camera mounted to the keel of my hang glider. The A630, A640, and A650 all have a "long play" video mode that yields a 1 hour movie at 640 resolution and 30 fps. A 4G card is required, which actually would hold about 70 minutes of movie footage, but the camera is programmed to always stop after 60 minutes. I purchased a "Bower" brand wide-angle lens that gives a mild fisheye effect when the "macro" stage is removed. A Canon barrel extension was also required. I've gotten some really great movies with this set-up, mounted on the keel of my hang glider behind the trailing edge of the wing, so that the camera sees some sky above the wing and and also sees a wide field of view around the pilot. However a camera with the capability for remote on/off would perhaps be more optimal for this application. On long flights the movie is always over long before its time to land!
For instructions on how to program the Canon A650 IS to automatically take a shot every 20 seconds, see these links:
For some photos taken with the A620 and A630 while hang gliding etc, see the section of www.aeroexperiments.org entitled “Photo gallery--other aviation-related" -- all photos taken on or after January 2006 and not credited to other people were taken with the A620 or A630.