• 03-11-2005, 01:41 PM
    wwinn
    Why Nott Compact Fluorescent or HMI Lighting?
    Hi:

    I've been a photographer for a long time, and grew up with Speedotrons and the like for product photography. I have recently had the opportunity to work with compact fluorescent and HMI Continuous lighting. I find them highly effective, and very easy to use. I was wondering why these lights are not highly recommended in this forum. To see what I m talking about, visit the following pages:

    http://sell-it-on-the-net.com/online..._lite_kits.htm

    http://sell-it-on-the-net.com/online..._lite_kits.htm

    These lights really work for me, and I was wondering what your cons are.

    Thanks in advance for your replys.
  • 03-11-2005, 02:52 PM
    Asylum Steve
    Simple...
    First of all, thanks for the input, wwinn...

    Off hand, I can't recall anyone here ever mentioning that HMI lights were bad or difficult to work with. If you can find any threads like that in the forum archives, please point it out to us and maybe we can figure out the reasoning.

    However, if these types of light kits haven't been, as you say, highly recommended by folks here, (my guess would be) it's for the simple reason that the vast majority of forum posters are amateurs on shoe-string budgets.

    HMI lights are still a relatively new technology to the average photographer, but as the price comes down, I'm sure many will see them as a great alternative to hot and flash lights, especially (as you mention) for studio product photography.

    As for people shooting, for the time being, I'm going to stick with my monolights. There is simply much more power for the money.

    BTW, anytime you want to post examples of shots taken with the HMIs, feel free to do so, so we can evaluate them too...
  • 03-11-2005, 03:56 PM
    SmartWombat
    Re: Simple...
    First thing I thought about with discharge lamps is the flicker.
    But it says "flicker free" lamps. I guess that means the frequency is so high you won't notice.

    They were installing high frequency ballast units at work during the refurbushment. But those were only 1kHz, which means a 1/1000 second flicker.
    They'd have to use a frequency that put the flixker out of the shutter range that you'd normally use in a studio, and for me those new luminaires at work would do the job.

    Apparently mains frequency (50Hz Europe, 60Hz USA) is slow enough that your brain can see the flicker, even if you don't consciously percieve it. What happens is your eyes tend to move during the dark period and stop during the light period. Leads to eye strain and headches if you're susceptible.
    Hot filament lamps don't ahve the brightness change and your eye moves more freely.

    I suspect it's similar with monitors, which is why I put the refresh rate up as high as I can.

    Interesting visual trick, btw. When your eyes are moving, flicking from point to point, you don't percieve the motion, I guess you'd get motion sickness? So some researchers looked at the eye movement by computer, and while the eye was in motion changed the text on the screen in an area that you weren't looking at. Surprise, people didn't notice that it changed.
    Neuropsychology of vision gets interesting sometimes :D