Numismatic Photography - LED lighting?
Has anyone had good luck replacing HOT incandescent bulbs with LEDs? We use some MR16 12V single die LED lamps ($30 each) at work for various lighting in our environmental chamber. I was wondering if three goose neck lamps with these bulbs might be a reasonable way to light a stage for numismatic items.
I gather the camera can adjust for white balance given an 18% gray card. The LED lamps in question are rated for equivalent light output to 20 watt halogens.
Any thoughts?
I gather the camera can adjust for white balance given an 18% gray card. The LED lamps in question are rated for equivalent light output to 20 watt halogens.
Any thoughts?
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The author of that book on photography your lovin has a set of quality LED's... but the price is intense for that set up!
3x Halogen Desk lamp
3x Incandesent - which I'll remove the shade from and replace the bulb with a flood light as suggested in The Book.
Option 3 involves a trip to Home Depot and Frys and building some custom LED lights out of bits and pieces. I can go with one of the other two options to get started. But I think I'll try building a custom LED fixture. I was thinking to maybe use some flexi-conduit as the gooseneck, some 2 watt LED MR16 replacements a little plywood base for each lamp - maybe weight it down with one of my Scuba weight belt weights. Power can just be from a 12V power-supply, wall-wart or even a doorbell transformer.
I'm just curious how much LED light is "enough." Is it the equivalent of 3 20 watt halogens? Is it lots more? If I can get way with the MR16 replacements, my little photo experiments are way less likely to burn something (like me) (or my 3-year old) (or my new camera that is expected to arrive tomorrow).
I'm getting that "giddy as little kid at Christmas" feeling. All excited to assembly stuff and start playing this weekend.
The coins looked very washed out... I never even posted a pic in the old thread as they where too harsh.
1. color balance (as Mark mentioned) and;
2. angular size.
An LED emits light only within a narrow band of wavelengths. To produce a visually white light, red, green and blue LED have to be bound together. This is similar to the tri-color elements of a TV screen or camera CCD array. Because the light from a white LED is not really a complete spectrum, getting accurate photographic color can be difficult or impossible, depending on the quality of the LED array.
LEDs are much smaller than other light sources. This results in a very small angular size and produces harsh shadows and accentuated detail. The remedies are to move the LED array much closer to the coin or put a diffuser between the LED array and the coin. Tis is one reason LEDs are good light sources for high magnification photos. (For those who are interested, it is the angular size of the light source, as viewed from the coin, that has the greatest single influence on how the coin looks when photographed.)
<< <i>The two primary problems with using LEDs for lighting coins are:
1. color balance (as Mark mentioned) and;
2. angular size.
An LED emits light only within a narrow band of wavelengths. To produce a visually white light, red, green and blue LED have to be bound together. This is similar to the tri-color elements of a TV screen or camera CCD array. Because the light from a white LED is not really a complete spectrum, getting accurate photographic color can be difficult or impossible, depending on the quality of the LED array.
LEDs are much smaller than other light sources. This results in a very small angular size and produces harsh shadows and accentuated detail. The remedies are to move the LED array much closer to the coin or put a diffuser between the LED array and the coin. Tis is one reason LEDs are good light sources for high magnification photos. (For those who are interested, it is the angular size of the light source, as viewed from the coin, that has the greatest single influence on how the coin looks when photographed.) >>
Bingo.
Very good post, RWB. Dead on.
Although I would argue that the angle of incidence of the light has a greater effect on the way the photo looks than the angular size of the light.
Take care...Mike