Using XeVision's 50w HID aircraft landing lights on rally truck?

[iceagecaver]

I currently run a pair of IPF 170watt H4 off road lights on my beloved truck. While I like these lights, I want to switch to HID for my next rig which I'll be buying in probably 3-4 years. I was thinking about getting 2 50w HIDs facing forward, two offset at 15 degrees, two offset at 45 degrees from front, and two off the sides, from XeVisions line of landing lights, which would total 42,000K lumens. Can anyone tell me if I am going to see an increase in visible light? I really like the idea of small bulb housings. The IPF housing is 8" across. I can't get a candlepower or lumen rating on the IPFs, just '170 watts' I just it hate when these lighting manufacturers use lighting specs (lumens/watts/candlepower) that can't be compared to other companies.

OK, skulking around this forum a bit, I found a lumen rating on an H4 bulb of 1000 lumens, but it is for the 50/65watt version, not the 100/170 watt version. Can I reasonably assume 3500 lumens for my H4 bulbs?

My other concern is with lights that can take the pounding of road travel for tens of thousands of miles? HID seems best for that at its brightness.

 

[TorchBoy]

With eight 50W HIDs (making a total 400W) you may well see an increase in visible light... if it doesn't blind you first. Even with a single pair you might notice an increase.

Generally the higher the wattage of an incandescent bulb the more efficient it is, but sorry, I can't remember the actual figure you want.

 

[-Virgil-]

With eight 50W HIDs (making a total 400W) you may well see an increase in visible light... if it doesn't blind you first.

You might be trying for sarcasm here, but you're (inadvertently?) making a good point. Lumens or candlepower is really pretty far down the list of deciding factors when picking automotive forward illumination devices. How the light is distributed (beam pattern) is more important than how much light there is. A zillion lumens won't help you (and will in fact sabotage your efforts to see what you need & want to see) if those lumens are not distributed appropriately for the task at hand. More is not always better. It's really best to start at the start (defining the illumination tasks) rather than at the end (picking this lamp unit over that lamp unit based on beam flux).

Generally the higher the wattage of an incandescent bulb the more efficient it is

H'mm. I don't agree. First off, the relevant quantity is efficacy (lumens per watt) not efficiency. Secondly, remember that there are tungsten-halogen automotive bulbs with identical nominal ratings ("12v, 55w") and flux ranging from 910 (9003) to 1820 (H2) lumens.

 

[TorchBoy]

You might be trying for sarcasm here, but you're (inadvertently?) making a good point. Lumens or candlepower is really pretty far down the list of deciding factors when picking automotive forward illumination devices.

Yeah. I don't think I'd want a 50W HID pointing straight sideways on each side.

H'mm. I don't agree. First off, the relevant quantity is efficacy (lumens per watt) not efficiency.

"Efficous"? :shrug: Doesn't sound right.

Secondly, remember that there are tungsten-halogen automotive bulbs with identical nominal ratings ("12v, 55w") and flux ranging from 910 (9003) to 1820 (H2) lumens.

Surely comparing a 9003 with an H2 is comparing apples with oranges? The more current a filament has flowing through it the hotter it'll get, which means the more visible light its blackbody radiation will be giving off. I stand by my generalisation.