Hi all,
For a change, here I come with a tip instead of a question.
Short:
You can use a red laser pointer (those made for presentations) to
help AF in low light conditions, at distances where the AF-light pattern
from the camera doesn't work anymore.
How: Point the laser light to the exact point where you want to make
focus. Place your active focusing point on it and activate AF.
Restrictions: The subject should be reflective. The color is also
important. Blue & black colors will absorb most of the red light of the
laser.
This worked with an EOS50E + 20-135is
A bit longer:
Since I received this laser pointer I've been playing arround with it. I
did some 'light painting' of some friends in the dark but it was only
till lately that I casually tried it to aid the AF. The first try was
indoors, and at short distances. I used it with the left focusing point
because the AF-light of the 50E is shadowed to the left by the lens. It
worked! and AF was pretty quick as well. I suppose the red light of the
laser is about the same frecuency that the AF-aid light of the camera.
The sensors are somehow optimized for it.
The ultimate test was last saturday. I was walking through the "Jardin
de Tulleries" in Paris when I spotted this sculpture framed and
backlighted by a fair wheel long behind it. I was at least 10mt behind
it. It was *really* difficult to focus on it. AF wouldn't and even
manually, thanks to the backlight, I couldn't see when the statue was
sharp. Then I recalled the trick of the laser (that was causually in my
pocket) and I tried what I described before... Presto. AF in no time.
After that I did some more test with equally good results. Back in the
hotel, I tried with absolutelly NO light in the room: it worked as well.
I conclude that if the surface can reflect a scattered light from the
laser, AF will work. (Notice that a mirror will reflect the laser
light, but will be of no help for AF. The laser point should be visible.
If any of you happen to have a laser pointer, I'd like to hear if you
can reproduce those results with other camera/lens combinations.
Enjoy! (even in dim light)
Gerard.
*
****
*******
***********************************************************
* For list instructions, including unsubscribe, see:
* http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************
