pixelpixi
Guest
Bryan and Aldie lent me some bulbs, so tonight I did a color comparison as scientifically as I could. I took a two pictures of my tank with each bulb. One pictures with actinics off, then another with actinics on. I put a white piece of plastic in the tank to have a spot that just reflects the color of the lamps. I also placed a clean neutral gray rock near the top of the tank for the same reason.
My camera was set up as follows:
Image Mode: RAW
Lens: Fixed 50mm
Aperture: F1.8
Shutter Speed: 1/200
ISO: 200
I converted the RAW images to jpeg using Aperture. The only changes I made were to set the white balance to 6500 Kelvin and no tint.
A note about the white balance: 6500K is the closest thing there is to a standard white balance used for monitor calibration (it's part of the widely used sRGB color space standard) so it's a good bet for making the images appear on screen as they do in real life. It's close to the color of light that the sun emits, which on a sunny day is split by rayleigh scattering into yellow direct light and a blue sky. Because it's the color of the sunlight, we've evolved to perceive it as white.
Digressions on scattering aside, the line up was as follows:
Iwasaki 6500K - This is the bulb that came with my aquarium and cabinet.
Reeflux 10,000K - Bryan lent me two of these. I took photos of both in case they were different. (due to age, for instance)
Ushio 10,000K - Another 10,000K bulb. This one from Aldie.
Hamilton 14,000K - Another pair of bulbs from Bryan.
The actinic lighting is provided by 2 36" VHO Super Actinic R bulbs.
All bulbs are 250W powered by an IceCap ballast.
Now without further ado, the results!
http://www.rgba.net/bulbs.html
And my interpretation:
Iwasaki 6500K-
The Iwasaki is fairly yellow. No surprise there since it's a 6500K bulb. It's not -that- much more yellow than the Ushio, though. Overall not bad but too yellow.
Ushio 10000K -
Nice crisp white color, especially with the actinics on. It feels like solid daytime light to me.
Hamilton 14000K
Bluer, as expected, but also a whole lot more dim. I kind of like the blue, actually, but I don't like how dim it looks. Notice the white reflector in these images. It's a lot darker than in the others, and that came through in person too.
Reeflux 10,000K
These are the bulbs that really surprised me, and not in a good way. They have a really strong pink tink that's way off the black body radiation curve. To me it looks unnaturally red both in the images and in person. I think some of that might be because they aren't new bulbs, but I'm not sure it's not all of it.
Out of these bulbs the Ushio 10,000K is definitely my favorite. I think I would still prefer a little more blue, but it doesn't seem bad. If anyone else has other spare 250W single ended bulbs, especially in the 10,000 to 15,000 K range, I'd love to borrow them and add them to this test!
My camera was set up as follows:
Image Mode: RAW
Lens: Fixed 50mm
Aperture: F1.8
Shutter Speed: 1/200
ISO: 200
I converted the RAW images to jpeg using Aperture. The only changes I made were to set the white balance to 6500 Kelvin and no tint.
A note about the white balance: 6500K is the closest thing there is to a standard white balance used for monitor calibration (it's part of the widely used sRGB color space standard) so it's a good bet for making the images appear on screen as they do in real life. It's close to the color of light that the sun emits, which on a sunny day is split by rayleigh scattering into yellow direct light and a blue sky. Because it's the color of the sunlight, we've evolved to perceive it as white.
Digressions on scattering aside, the line up was as follows:
Iwasaki 6500K - This is the bulb that came with my aquarium and cabinet.
Reeflux 10,000K - Bryan lent me two of these. I took photos of both in case they were different. (due to age, for instance)
Ushio 10,000K - Another 10,000K bulb. This one from Aldie.
Hamilton 14,000K - Another pair of bulbs from Bryan.
The actinic lighting is provided by 2 36" VHO Super Actinic R bulbs.
All bulbs are 250W powered by an IceCap ballast.
Now without further ado, the results!
http://www.rgba.net/bulbs.html
And my interpretation:
Iwasaki 6500K-
The Iwasaki is fairly yellow. No surprise there since it's a 6500K bulb. It's not -that- much more yellow than the Ushio, though. Overall not bad but too yellow.
Ushio 10000K -
Nice crisp white color, especially with the actinics on. It feels like solid daytime light to me.
Hamilton 14000K
Bluer, as expected, but also a whole lot more dim. I kind of like the blue, actually, but I don't like how dim it looks. Notice the white reflector in these images. It's a lot darker than in the others, and that came through in person too.
Reeflux 10,000K
These are the bulbs that really surprised me, and not in a good way. They have a really strong pink tink that's way off the black body radiation curve. To me it looks unnaturally red both in the images and in person. I think some of that might be because they aren't new bulbs, but I'm not sure it's not all of it.
Out of these bulbs the Ushio 10,000K is definitely my favorite. I think I would still prefer a little more blue, but it doesn't seem bad. If anyone else has other spare 250W single ended bulbs, especially in the 10,000 to 15,000 K range, I'd love to borrow them and add them to this test!
