Focus ProblemThe early editions of the A40 had trouble focusing when the camera was zoomed to the second last zoom position of 13.4mm. Canon provided an adjustment for this around July 2002.
A40 cameras released since then will have this adjustment included. If the fifth digit of the serial number of your camera is 5 or highter, then the adjustment should already be applied.
Some cameras with a 4 as the fifth digit have also been found to not require the adjustment, so if in doubt go to the Canon site to check your serial number.
Further information can be found under 'Service Notifications' at http://www.powershot.com/powershot2/customer/firmware.html
Problem with focusing in Infinity ModeSeveral people have reported finding it difficult to get a focus in Infinity mode, and almost impossible when zoomed as well. Chuck Martin suggests that ...
"... when in Landscape the lens cannot move away from its setting for the hyperfocal distance, and that this inability to move interferes with the A40's ability to determine that an object at, say, 50 ft is really in focus. Certainly, when you look at the LCD while "focusing" in Landscape it is hard to detect any lens motion. I don't know if the A40 needs to focus back and forth a little bit to find the best focus setting or not, but the behavior in Landscape suggests that it might."
However, not everyone seems to have this problem, so I don't know if this is a fault or a limitiation.
In AUTO modeIt should be possible to take good photos using Auto mode without even trying.
Things that might affect picture quality in Auto mode include:
- using 'small' resolution and 'normal' compression ... I always use 'Large' and 'Superfine'
- Camera-shake in low-light conditions, or when zoomed ... use flash, or tripod, or lean against something.
- Camera unable to focus in low-light conditions ... can be got round by using 'focus lock'
- I find the photos straight from the camera are a little soft, so I often apply a little 'Unsharp Mask' to them as a matter of course.
And I also heard that breathing out, holding it, and shooting between heartbeats can also work - but not for long exposures ... :-)
Using the self timer can also help, by avoiding any slight movement caused by pressing/releasing the shutter.
- In Program mode(P), first of all adjust the exposure compensation (the ± button)[p.75] ... -2 will give a relatively dark photo. And if possible, meter (which happens when you half press the shutter to set the focus) on a light area rather than a dark area. This will also decrease the exposure a little further.
- In Manual mode(M), a smaller aperture[p.69] will give a darker photo.
And if the subject is close enough, switch to macro mode[p.55], and this
will also reduce the intensity of the flash.
There's also an interesting thread on the CANON DIGITAL PHOTOGRAPHY FORUM at <http://photography-on-the.net/forum/viewtopic.php?TopicID=2912>
And an explanation of sorts at <http://www.fujifilmsupport.com/faq/tech/spot/spot.htm>
I really don't know if a slave flash would help, because I assume the A40 flash would still be operating, but if you could borrow one it might be worth a try.
Might be a wild goose chase, but you could try changing some small thing, just in case ...
... like trying a different flash mode - slow synch for example?
... or different picture modes - perhaps snapshot or infinity?
... or changing from AUTO to Program, or from Program to Manual, etc?
Otherwise it's probably a case of waiting for most of the dust to settle, taking more than one photo, or just trying to do without flash whenever possible in that sort of situation ...
Another suggestion I just came across is to use a Negative Ion Generator - used to purify air by precipitating out the particles. Don't know how well it would work - probably not very well if folk keep moving around - and sounds expensive, so maybe not worth buying one - but if dust is a regular problem, and you just happen to know someone that has one ...