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Posted By: Rewired Mercury or Metal Halide - 03/03/06 02:28 AM
Hey All!
I have a little job coming up for the G/F's mom whereby I am going to install a light in her yard to light up some gardens and a pond.. Nothing fancy, just a general floodlight.. Problem is I do not want it to look too bad colour wise... High pressure sodium is definately out, but I cannot seem to decide if light from a clear mercury lamp would be better for lighting a garden or not, only because mercury produces more green and blue light and would tend to enhance the garden more than light from a metal halide lamp would.. I have read somewhere that mercury light is supposed to be better, but I was just wondering if anyone here would like to share their thoughts.. What would you suggest??

A.D
Posted By: bot540 Re: Mercury or Metal Halide - 03/03/06 03:27 AM
Metal Halide would be the way to go. When lighting a garden you also must consider that most plants are photo-period sensative. Meaning that they bloom when the days get shorter as a survival mechanism. The shorter days signal winter is coming. Illuminating a garden past sun down will stress most plants and cause some to never bloom.
Posted By: gfretwell Re: Mercury or Metal Halide - 03/03/06 04:46 AM
Talk her into something nicer. Nothing looks worse than trying to get attractive light from some "stallag 17" flood light.
Use post lights or some low voltage solution that keeps the light closer to the ground and the light source out of your line of sight.
Posted By: Trumpy Re: Mercury or Metal Halide - 03/03/06 07:00 AM
I'm with bot540 here.
Metal-Halide is designed to bring out the colours in thier surroundings.
What's more, you can get specialised lamps that will accentuate blues and greens.
IMHO, Metal-Halide gives a better class of light for a start.
Posted By: distributor x Re: Mercury or Metal Halide - 03/03/06 02:18 PM
When comparing MH and MV lamps, a MH lamp of equivalent wattage to a MV lamp has a lumen output that is 40% higher than the MV lamp (much more efficient).


Vapor Mercury lamps have long life, but are not as energy efficient as metal halide, producing only 35-58 lumens per watt. Their limited blue-green light spectrum has a lower CRI than metal halide (mrsning thst it will be much easier using MH to see the colours of the plants at night)

one more thing MVR is not mercury vapour, it is GE's MultiVapor (MH).
Posted By: Rewired Re: Mercury or Metal Halide - 03/03/06 11:32 PM
Hey!
Thank you for the input! I will be going Metal Halide for sure! I will be looking for a lamp that Trumpy mentioned that can enhance blues and greens as well, if I can get it and its the right price I will get it , if not I will try a standard Metal Halide..
Its actually an old streetlight thats going up as high as I can get it.. there is going to be some othher uplighting under the trees as well, this is just so she can light the place up if need be without the garden looking way off colour while doing so!
Thank you again for the information!!

A.D
Posted By: iwire Re: Mercury or Metal Halide - 03/05/06 12:58 PM
Rewired

Quote
Its actually an old streetlight thats going up as high as I can get it

If you already have the fixture the lamp type and size is already decided.

The lamp must match the ballast in the fixture.

Bob
Posted By: Rewired Re: Mercury or Metal Halide - 03/05/06 05:11 PM
Iwire:
The old fixture has a bad ballast, so I will be putting in a MH ballast and one of a lower wattage with a lamp to match...
Most likely a 175W metal halide, thats the lowest wattage lamp I think there is thats not "pulse start" and has a mogul socket... I do not want to get into socket reducers, socket extensions, especially if the lamp I use is a "pulse start".. Too high a chance it wont fire the lamp...

A.D
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