High Pressure Mercury Lamps

[Down with Umbrella]

You can even under drive or over drive lamps moderately for a short time without an ill effect. I ran an 80w fluorescent merc on a 70W son ballast for a few days with no noticeable effects.
I assume you do know that a 175W hid lamp of any type will be enormously bright as a desk light, though?!!

The bulb in question is rated @ 100W. If what you say is true I could probably under drive it with an 80W ballast. The EYE Moon Pulse Mercury lamp.

Also on that website there are some antique 40w incandescent lightbulbs I might pick up as well. Those might be more appropriate for a desk light and achieve the same effect.

 

[trencheel303]

If you are going to do that also look on ebay. I picked up some repro vintage carbon filament style bulbs from ebay (shipped from Malaysia) for about $2 a piece roughly. Might work out better for you.

Use caution when underdriving hid lamps. It's not really recommended as the lamps are designed to operate within their specific parameters. You might find the arc tube clouds up or they otherwise diminish in performance if you do it over a long period. Or they might not, but it'd be a shame to under drive a hid especially a good brand. Just get a proper rated bulb (even 50 is pretty bright, clear mercs at 50W have over 2000 lumens and they are a relatively inefficient light source!!) and you'll have no worries, and use less power.

The two "fancy" bulbs were the ebay repros. Beats paying fortunes for an actual carbon filament lamp which you'd then be too afraid to use lol.

And yeah, doesn't get much more steampunk than those

 

[Cyparagon]

You don't want to use a mercury lamp as a desk light. Reds show up as brown/grey, and people look like cadavers.

 

[Down with Umbrella]

Those antique bulbs will be better for my project. I'll see what's on eBay. It's a good thing I've seen them cheap and with tungsten filaments. I am however still interested in Mercury lamps. Might have an application for something in the basement.

 

[trencheel303]

You don't want to use a mercury lamp as a desk light. Reds show up as brown/grey, and people look like cadavers.

He could use a fluorescent coated one. I don't know about the Americas but here we can even get deluxe coated ones with a yellow phosphor that have a warmer tone. I've never seen one in person but I know they exist.

Here is a listing for one of the Edison type bulbs I got. They claim 3000 hour life, which is quite good if it's true.

http://www.ebay.co.uk/itm/Edison-Vi...8&pid=100005&rk=4&rkt=6&sd=271621320487&rt=nc

 

[Down with Umbrella]

Well, goodness gracious. I got up close and personal with one of these bulbs today when I had to do field weld right next to one. All I could see was the ballast that read "400W HID". I flipped my hood down and stared for a moment. Cool to see the inner workings.
These particular ones might be phosphorus coated because I didn't NOTICE strange shades of color around the light.
In fact I've seen these quite often I just never really paid much attention to them because they're usually on and very bright to look at.


Thanks for the links to those antique style blubs. It's nice to see them cheap.

 

[Sigurthr]

Shot this one myself: this is my 100W unphosphored lamp.

E-PM1 Full Spectrum Camera; ISO200 F/22 1/4000sec

 

[Blarg King]

Starting to take an interest in these high pressure mercury lamps (and high pressure sodium). Considering starting my own hydroponics garden and these are one of the primary sources of light for growing plants.

 

[trencheel303]

Nice, sig.

The thing I really like about these clear merc lamps is how there's no phosphor to diffuse the arc, and as mercury arcs dance and flicker a lot the shadows they create shimmer and scintillate. It's pretty cool to watch.

@blarg, low pressure sodium has no colour rendering but is way cooler than HPS, IMO. #justsaying

 

[Blarg King]

Oh I do so love LPS, but 1 wavelength doesn't make plants grow XD

Bit sad here really. There were bridges in the city here that still had LPS lights, but the went through and replace them all with LED.

 

[trencheel303]

I've been busy. Remember those clear EYE lamps I posted on the previous page? Well here in the UK clear mercs are very very difficult to come by, we don't use them and haven't done for decades, if ever really except in the early days (where we'd have been more likely to use LPS or fluorescent) so they're like gold dust. Well another collector traded me ONE of those for all of this:

There's 6 mercs there and one is a self-ballasted as well. Two are clapped out with blackened arc tubes (this was a request) and the little 50W in the middle is a new GE which is a totally lush lamp.

I also bought some Philips HPLs (cheapese unfortunately) the "4" range apparently being designed to virtually eliminate early failures, but they don't tally up very favourably at all after the 24,000 hour mark, which is where Philips say 50% of failures will occur. So no Lifeguard by any means, then...

^^50W HPL4 and a dim 80W merc ----------------- ^^50W HPL4 and the 80W HPL4 ----------------------- ^^50W HPL4 and the "ordinary" HPL-N 125W

The slightly disappointing thing about these is, they have the potential to be really nice modern lamps, but in typical Chinese fashion they look like sh!t. The HPL4 logo on the top of both of them is like a wonky halo and the cap on the small one isn't even connected to the glass straight. The small one is a "deluxe" type with a colour temperature of 3400K.

Now, the real daddy of the collection will be, when it arrives, the 100W Lifeguard lamp I bought off the US ebay a few days ago. It's a 100W BT shape with .. wait for it .. a /C phosphor!! And by the looks of it, it's NOT A Philips Westinghouse, which we all know stands for crapola. AFAIK they stopped even using /C before Philips took over, and I can't see any Philips branding.

I've become a bit of a merc fanatic lately, it's probably fighting for the favourite spot over SOX. It's quite unusual as well in that I don't normally like anything with a colour temperature "higher" than about 3500K but I just can't get enough of the light from a clear merc, it's just lush.

The following picture of course exaggerates the differences between DX and clear mercs, but I like how artistic it turned out. I was running those two (250 and 400W) in series off a large SON ballast for a bit, as I'd never powered them up before. I do need 250W gear though as that lamp is a UK made Thorn and has a really nice output, probably better when it's not having the shit overdriven out of it!

 

[Sigurthr]

I typically run one phosphored HPHg and one unphosphored concurrently in my study, as I like the blend of color temp the two yield. I also have overhead shop lighting of two T8 5800k fluoros for working under. The down side is that the parallax created by the lamps being so far apart can cause off color bars in photos when objects cast shadows, such as in your photo.

I picked up two of the antique style tungsten bulbs for use in the overhead lamp in the bedroom, as my wife has complained for ages about the two 6200k compact fluoros I had in there being too bright. And while I agreed that they were indeed too bright, it is REALLY hard getting used to the 2600k color temp of the tungstens. Incidentally, she complains the room looks too yellow now, haha, but at least the brightness levels are appropriate. I wish I could find >5500k <400lm fluoro/led bulbs locally, but all we have here are 3600k fluoros which don't even last 6mo of use or obscenely overpriced 4000k LEDs. In general, high temperature, low lumen sources seem to be rare.

On the subject of comfort lighting, I find it odd how counterintuitive personal preferences can be. I find that for myself, monochromatic or narrow-band lighting, regardless of the color rendition index or color temp is far more pleasing than black-body radiation curves under 5000k or so. I.e. a LPS lamp with terrible CRI and low color temp is infinitely easier on my eyes than the damned 2800k tungstens. Those antique bulbs's only saving grace is their surface luminance is low due to the extra long uncoiled filaments.

 

[trencheel303]

I wonder what's causing this? My MB/U lamp has an unmistakable red band in its emission spectrum... wtf?!

I'm sure there is a perfectly rational explanation, but I'm not sure what it is! I can't see it being fluorescence from the carpet or walls, but it could be possible I suppose? You can clearly see some amount of red does show up, particularly on the shoe. Weird!

 

[Sigurthr]

There's a natural Hg red band emission, it's usually just too weak compared to the green, blue, violet, and UV lines. Running at a certain pressures enhances or diminishes various emission bands.

 

[starlight]

How the heck do I photography HPS lights? I get the scrolling lines in the camera screen and lines in the pictures when taken. My MH light is doesn't happen.

400w HPS

400w HPS

400w MH running at 275w

Adjustable digital ballast

 

[trencheel303]

Try setting your camera's shutter speed native to the frequency the lamp is running at. Although if you're using an electronic ballast god knows what that is.

Thanks for the clarification, sig. Someone on LG also explained it and said that you get a small amount of red from the electrodes themselves and from the interaction of electrons and ions as well! The red does seem quite strong on my lamp giving the red converse a definite burgundy/blood red tint. I also never knew the violet line was actually 405nm - that's cool!

http://www.lighting-gallery.net/gallery/displayimage.php?album=lastcom&cat=11976&pos=0&pid=106421