| Author | Thread |
|
|
04/03/2004 01:17:45 AM · #1 |
Have anyone experimented with those new ultra-bright LEDs as photo-lights? These LEDs are used in some tiny key-chain flashlights which last forever on a small watch battery and are so bright that one can see the light from 5 miles. I've seen several bigger flash-lights with 3 or 5 LEDs and even saw a site advertising street lanterns with 40+ LEDs - they work fault-free for 1000000+++ hours and consume much less electricity. As far as I know they come in red, green, yellow, blue and white (combined of two luminophores - yellow and blue).
I realize that the spectrum of LEDs is very narrow and it might be hard to obtain proper color reproduction, but can we not try at least RGB matrix and build a color profile for it?
It could be built as bright as a flashlight and might be a cheaper solution than a flashlight! I just realized that I need one and Minolta 3600 which I need for my camera is CAD400 + tax... Not that I am greedy but I would never pay for it as much as for the camera.
Any thoughts? Any results?
|
|
|
|
04/03/2004 01:35:58 AM · #2 |
| I have a 7 LED flashlight I've experimented with; it's very bright, and works, but I can't say I've succeeded in making a good photo with it yet. It's too bright for painting with light, and I'm not sure what else to really do with it. |
|
|
|
04/03/2004 01:48:48 AM · #3 |
Not even close to a good example. I used a blue led flashlight and a silhouette of myself cut out of paper. |
|
|
|
04/03/2004 02:15:04 AM · #4 |
This one was taken with a combination of LED and a flashlight.
//www.pbase.com/image/8487493
 |
|
|
|
04/03/2004 06:09:22 AM · #5 |
There are interesting possibilities here; there are companies making (expensive) LED lighting for areas where a tailored color balance is desired, e.g. high end store displays. A bank of red, green, and blue LEDS can be adjusted to provide any type of light color by adjusting the relative brightness of the three colors.
Sooner or later, this type of light source will probably start turning up as a photo light source. Initially, it will be expensive, but would give all the benefits of "hot lights' without much of the hot. Plus the ability to adjust color.
|
|
|
|
04/03/2004 07:04:32 AM · #6 |
Originally posted by kirbic:
snip....this type of light source will probably start turning up as a photo light source. Initially, it will be expensive, but would give all the benefits of "hot lights' without much of the hot. Plus the ability to adjust color. |
The way I see it... the real advantage is bulb life. You invest your money in one of these nice photo light set-ups only to have the bulbs start changing color temp on you from the minute you start using them and then they only have the life span of what seems like a few hours. Not to mention they always seem to go at the most inopportune time and then you have to wait for the unit to cool or risk burning your fingers trying to replace a bulb. PITA if you ask me. |
|
|
|
04/03/2004 08:51:40 AM · #7 |
I remember seeing a do it yourself LED macro ring somewhere. See if I can find it again
|
|
|
|
04/03/2004 09:21:36 AM · #8 |
I was thinking of an LED macro ring myself, I would be interested in searching for it. if you find the link post it as I need some much better macro lighting for my indoor shots
James
|
|
|
|
04/03/2004 09:27:35 AM · #9 |
here is one link I found
led macro ring light
James
|
|
|
|
04/03/2004 09:55:31 AM · #10 |
Thanks for the hints!
I am not sure why LED photo lights should be expensive as I can not understand why convention lights are. Technically and technologically these are very simple devices and noone should dare to claim that they all have some "photo" quality or calibration or life span - those are main complaints and there is no comparisons with ordinary bulbs sold at HomeHardware published so that photographers could appreciate the difference in price.
I am thinking of building the LED light myself and again - this is a very simple task and parts price is low. My concern is about spectrum of such lights. Although it is relatively easy to calibrate the composite light to certain temperature, the wavelengths ot the channels might be very different from those used in CCD filters. That it why the LED light might create very non-linear response from the scene when it is captured by the CCD. Any other kind of light has very wide spectrum - hot spiral, electric discharge of a xenon bulb, magnesium flame, even fluorescent tubes - those are designed to emulate the daylight. In case of LEDs the spectrum of every channel will be extremely narrow.
Thoughts?
I am seriously considering LEDs to build shoe-mounted light (instead of the flash!). I've got all needed ciquitry for voltage stabilization at hand... Just need to get some LEDs!
James, thank you for the link!
|
|
|
|
04/03/2004 10:20:34 AM · #11 |
Dibutil,
I think the reason that some of these LEDs are more expensive is the intensity rating.
I believe that it's just a "test & sort" (binning) operation, the components that test better are sold as rated for higher power.
I don't think there is a major problem with the frequency response. The LEDs will have a narrow output, true, but the filters have very broad pass-bands, so there really should be no significant color shift. I have no direct experience, just hypothesizing based on what I know of the theory.
I actually have the Nikon Macro ring Light for my trusty ol' Coolpix 995, and it does work nicely for very close-in macro work, but is pretty much useless beyond about 20cm or so. Even close in, there isn't really enough light to achieve best resutls, i.e. shoot with small aperture.
I prefer a macro flash set-up, it doesn't provide extra light for focusing, but I don't find this a problem. What I want is plenty of light in a quick flash to stop subject motion & reduce effect of shake (in other words enable hand-held shots at higher magnification).
I don't own either of the Canon flash units intended for macro work, I use an old Sunpak 544 with reflectors. Works great, plenty of light, variable diffusion & direction, just more hassle to use. I probably will move up to a 550EX this year and adapt that to macro.
|
|
|
|
04/03/2004 07:39:06 PM · #12 |
Well, actually I did not mean specifically macro. I need all-purpose portable light which would replace the hot-shoe unit.
Just checked the price on those ultra-bright LEDs - it's 1.80CAD for red and green and 3.50CAD for blue and white. One produces about 0.2Wt of light power wich is quite a lot compared to bulbs. I am not sure though how to calculate the conventional power equivalent. Some of the LEDs are also rated in micro cnadels (the brightest is about a hundred - if I understood the marking correctly - the salesman did not have a clue).
|
|
|
|
04/04/2004 12:36:39 AM · #13 |
|
|
|
05/22/2006 10:42:28 AM · #14 |
I have been using Ultra White LED Ring Lights for the last two years. They give great results for closeup work.The images are completely shadowless.Color Temp.is 5200 K. Result needs no color correction of the image.They work on 12 volt adapters or 12 volt battery.
Message edited by author 2006-05-22 12:10:48. |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/07/2025 01:57:17 PM EDT.
