All Forum Comments
Comment by MattMatic posted on FS: K7, FA24-90, DA55-300, Metz 50MZ5 etc at 08/09/2011 - 10:03
More info definitely required
Matt
Comment by MattMatic posted on Which Flash? at 07/09/2011 - 22:25
Cool
Matt
Comment by MattMatic posted on Which Flash? at 07/09/2011 - 18:01
The effective GN also depends on the ISO setting I presume your quoted values are for ISO100.
The higher the ISO, the further the effective flash distance.
So, if you have a GN of 54, with an aperture of f/5.6 at ISO 100 that's 9.6m
But, at ISO200 you can calculate the same as ISO100 at f/4 = 13.5m
Going to ISO400, calculate as ISO100 at f/2.8 = 19.3m
Probably best for the OP to specify the conditions and then we can give more of an idea...
Matt
Comment by MattMatic posted on Which Flash? at 07/09/2011 - 14:38
What distance and ambient light conditions are we talking about? (ie ISO + shutter speed + aperture)
(Because I'm not sure if even the AF-540-FGZ can generate that much light!)
Matt
Comment by MattMatic posted on Which Flash? at 07/09/2011 - 11:40
I work in a laser lab at Johns Hopkins University, and I can say that Frank doesn’t know what he’s talking about. It’s not a specific brand or sensor problem, it’s a simple energy density/flux issue. The materials used in every CCD or CMOS sensor are essentially the same, Silicon. Large lenses focus a significant amount of light onto a fairly small sensor, making a laser that might be safe normally, dangerous once it is focused. None of Frank’s pictures actually show the laser pointing at the camera, and since a laser is a coherent, contained light source, you can only get damage when a laser is pointing at you, or reflected so that is pointing at you.
Simply put, if you’re at a party or show where lasers are shining onto the crowd, you should leave. Only if the power is very low will this ever be safe, but I’m guessing the roadie or DJ operating these lasers doesn’t comprehend the dangers involved, so you can never be sure. If it can damage a sensor, it can probably damage your eye. The people that had their camera’s destroyed in these videos could/should sue to get their camera replaced, and then some.
Matt
Comment by MattMatic posted on Be warned! Lasers can be very bad for your sensor's health!! at 06/09/2011 - 14:16
But what did it do to people's eyes at those concerts??
Seems to be the original thread here - appears those shows were using incorrectly set high power settings which would have damaged retinas too
Matt
Comment by MattMatic posted on Be warned! Lasers can be very bad for your sensor's health!! at 06/09/2011 - 14:05
Never intentionally shine the PinPoint into a person’s eyes, or stare into the laser beam.
Never aim the PinPoint anywhere on any person without notifying them in advance.
Matt
Comment by MattMatic posted on Banish out of focus shots with PinPoint? at 06/09/2011 - 12:13
(The Metz was in "A" mode with the K5 in "M")
Matt
Comment by MattMatic posted on High Speed continuous flash at 05/09/2011 - 17:02
However, the Pentax throttles down to a couple of frames per second with the AF360. Not sure what I'd get from another flash gun like the big Metz... (which can do insanely configurable multiple flashes!)
Matt
Comment by MattMatic posted on High Speed continuous flash at 05/09/2011 - 13:44


Any offers on the other items??
Thanks,
Matt