On Sun, 02 Dec 2007 11:46:40 +0000, Neil Ellwood <cral.elllwood RemoveThis @btinternet.com>
wrote:
>Dave G wrote:
>
>>
>> The gurus of CHDK found a way to override shutter speeds to now
>> include up to 1/10,000 of a second, so far. Test results show that
>> they may get well over 1/40,000 of a second and more when all is
>> done.
>>
>> The best part? High-speed flash sync's perfectly with at all shutter
>> speeds up to and including the fastest ones implemented. It also
>> allows full use of your widest apertures. No more crippling your
>> camera to only using high shutter speeds with small f-stops.
>>
>Someone has also discovered america - your news is nearly as old.
>
>Exposing film to high speed flash was done fifty years or so ago.
>Reinventing the wheel seems to happen all the time now.
Your level of knowledge is 50 years old and incomplete, as well as your level of
hands-on experience in these matters.
Yes, high-speed flash has been used for these purposes all this time. In a dim
or dark room due to focal-plane shutters having to be used in "Bulb" mode. Or
with the "X-Sync" shutter setting as times moved on to keep up with technology.
In fact xenon-flash was originally invented for just this purpose, high-speed
photography. Its use as a main light source for general photography only a handy
after-thought.
What you fail to realize is that these CHDK-enabled cameras are now able to use
these shutter speeds with or without flash. Only electronic-flash could provide
durations as short as 1/10,000 of a second before while also exposing the whole
frame simultaneously, or by use of special high-speed mechanical shutter designs
confined to the laboratory. Now these shutter speeds can be used in-sync WITH
electronic flash so that no ambient light will interfere with the exposure. In
many readily available and inexpensive P&S cameras.
You really haven't thought this through, have you. This little change now makes
all focal-plane shutters, and all cameras that use them, obsolete (as far as
high-speed photography is concerned).
Even the top of the line D-SLRs being sold this year go no higher than 1/8000
second, and that's by moving a slit over the sensor so that no two areas are
exposed at the same time. Greatly diminishing its usefulness for any real (read:
accurate) high-speed photography.
Here's some of the first test results from one of the alpha-releases of CHDK,
using the camera's on-board flash.
http://chdk.wikia.com/wiki/Samples:_High-Speed_Shutter_%26_Flash-Sync
Notice the available-light quality to these photos. Lights from the environment
reflected in the water-drops. Using any other cameras and any other methods
would have required that those lights be extinguished, or the shapes and
highlights of those drops would have been distorted by the agonizingly slow
focal-plane shutter mechanism in any camera of SLR origins.
High-speed flash sync may now be used with shutter speeds from 1/500 second (the
camera's default) inclusive of all shutter speeds in 1/3-stop increments to
1/10,000 second.
>> Stay informed about: CHDK NEWS: High-Speed Photography Breaks New Records!