PDA

View Full Version : dimming the lamps


TPnTX
07-01-2008, 08:33 AM
If a 20watt lamp is too bright, how do you dim them down?

We set up 5 20watts uplights in a wooded stream bed area. Even after adjust, moving around, grazing the trees etc. It still is too bright(to me and the customer). I place a little much on each lense and bam! there it is. Perfect.

I'm thinking of getting some high temp paint for the lense.

I know there are lenses but I don't recall seeing anything strictly for dimming.

The 10watt lamps aren't rated the same as 20+ lamps

Chris J
07-01-2008, 08:41 AM
A frosted lens will tone it down quite a bit. Colored lenses will also take away from the output significantly. You could also do a combination of the two.

steveparrott
07-01-2008, 08:53 AM
You can get 10W MR-16's (Narrow, Med. and Wide).

As for lenses: A cross or linear patterned optical spread lens cuts brightness by about 20%; a frosted lens by about 46%; a honeycomb louver by about 30%.

You can also reduce brightness further by scruffing the smooth side of any lens with sandpaper.

Terradek
07-01-2008, 09:35 AM
There is a Seconday side dimmer that is available in either 10amp or 20amp capacities. It is installed much like a wall switch and allows you to dim any single run without affecting the other parts of your system.

Gerry De La Vega
AOLP, CLVLT #0404

Az Gardener
07-01-2008, 09:39 AM
F/X has just come out with a dimmer too.

Pro-Scapes
07-01-2008, 09:39 AM
if your going to place a secondary dimmer in try using a lower tap first but color temp will suffer.

We use 10w quite a bit when needed but make sure you run em in the low 11v range as they dont last above about 11.3 or so.

Steves advice on the lenses is the first thing I would try before you go manipulating the fixture. You may need the full output later on.

If they are a larger body fixture there are clips to secure the lenses to the lamps Im sure Gerry at terradek has them as does FOLD

TPnTX
07-01-2008, 10:23 AM
If I understood correctly the 10w Ushio are only rated for 2000hrs or I think.

If you run them outside the 11.3-12.8 wouldn't it be substancially less?

Eden Lights
07-01-2008, 11:30 AM
Dimming is the only way to go if you want to achieve perfection. (Example:90% too bright, 80% a little low, ahh 85% is just right.)

Lite4
07-01-2008, 11:32 AM
Just use the frosted lenses. You are overcomplicating this. It will give you the desired effect you are looking for.

Lite4
07-01-2008, 11:38 AM
Dimming is the only way to go if you want to achieve perfection. (Example:90% too bright, 80% a little low, ahh 85% is just right.)

I would agree with the dimmer if you are lighting a house or other structure where the reflective light levels need to match perfectly, but this is some trees in a stream area. It would be much harder to gauge. I would try the lenses first before going to a dimmer, I like to keep a constant voltage to my bulbs as to not diminish lamp life unless of course you are using a xenon bulb.

JoeyD
07-01-2008, 12:55 PM
go frosted lenses with hex louvers....10W MR16's are not that good and will not last all that long.....Who has mor einfo ont he F/X dimmer? I have seen Jerry's (TerraDek) and have used them.

Eden Lights
07-01-2008, 01:59 PM
I was assuming you already had hexcells installed since they are downlights. I stay away from 10W MR myself lamps due to the short lamp life. For maintenance requirements I like all my lamps to have similar lamp life specs with a similar bell curve of failure rates. Proper lumen levels is a big concern for many people these days so primary dimmers are a easy sale for many reasons.

Eden Lights
07-01-2008, 02:05 PM
I had three clients last month that had two or more estimates and all of the estimates had some form of advanced controls on the primary side. Customers were sold on the advantages, so your either in or out around here it seems.

Pro-Scapes
07-01-2008, 04:56 PM
the advanced controls are definatly setting me apart here. The fade in fade out seems to have a great effect on the lamp life. Few tweaks in upstart and like Eden said you can dial in everything. Lenses are important tho and we use em where needed.

On the 10w mr lamps we too had alot of premie failures until we dropped the voltage but I would agree a lens or combo of lenses probably would of worked fine.

Shoot for 10.9.11.2 if possible on your 10w lamps and you probably wont be disapointed in lamp life.

David Gretzmier
07-01-2008, 06:18 PM
this is easy. step 1 lower voltage to 10.6-11 on the 20 watt. if you don't like the color or is too bright, step 2- ramp voltage back up to 10.8-11.5, go to 10 watt. most of my charts and my experience indicates that 2000 hour bulbs will typically last a minimum of a year, many times a year and a half, at 10.8-11.5. if it is too dim, go back to 20 watt and..Step 3- either sand lens, or use frosted/honeycomb lens. step 4, go the dimmer route. be careful though, some just vary voltage and some vary amps. the ones that vary the amps is the one you want. good luck.

JoeyD
07-01-2008, 06:35 PM
I dont think that taking the voltage below the reccomended is a very good idea. Not worth jeapordizing lamp life for the sake of having less light. Go to a lower wattage if you have too but the best thing to do is to try and make it work by utilizing designer lenses.

sprinkler guy
07-02-2008, 12:21 AM
go frosted lenses with hex louvers....10W MR16's are not that good and will not last all that long.....Who has mor einfo ont he F/X dimmer? I have seen Jerry's (TerraDek) and have used them.


Joey,

The Zane dimmer that TerraDek sells is the same one that FX is endorsing, not selling. Most of the Ewing branches around here now have a 10 amp set up on display.

JoeyD
07-02-2008, 09:16 AM
Thanks Sean.....I didnt know if there was something new out there..........