# 2.5v .5a halogen vs. 2.4v .7a krypton



## Buck91 (Oct 9, 2007)

Well I did a quicky visual test of the output in a 2D army surplus angle head light of these two bulbs. The Krypton is a brinkmann 2D replacement lamp and the halogen is from my PT Solo 2AA headlamp.
halogen: 2.5V 0.5A
krypton: 2.4V 0.7A
As rated on PR base.

They both had approx. the same output with very slightly different hotspot shapes, the halogen having a more notable 'halo' (if I have the terminology correct).

I do have a question, though. Being that the halogen is rated at a lower amperage, should I expect better batt life from this bulb or shorter bulb life? Also, do my 'eyeball' results make sense? I do have photos, just nowhere to upload, so email me if you want to see them.


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## Valolammas (Oct 9, 2007)

Buck91 said:


> They both had approx. the same output with very slightly different hotspot shapes, the halogen having a more notable 'halo' (if I have the terminology correct).



I believe most people here call it spill. Hotspot is pretty self-explanatory, around that is a narrowish corona and then there is the wider spill.



Buck91 said:


> I do have a question, though. Being that the halogen is rated at a lower amperage, should I expect better batt life from this bulb or shorter bulb life? Also, do my 'eyeball' results make sense? I do have photos, just nowhere to upload, so email me if you want to see them.



Everybody loves beamshots, so off to imageshack you go!  (Or any other similar service.)

If you look at numbered lumen ratings, it actually takes a fairly significant difference to be noticeable to the human eye. I believe that's because eyes adapt pretty quickly to different light levels. E.g. "twice as bright" as in, say, 60 lumens vs. 30 lumens, actually looks to most people just a little brighter. I think I read somewhere that most people can barely tell a difference if the brightness levels are within +/- 30% of each other.

So don't worry about it, use whichever you like better. The one that draws 0.5A should give you better battery life and stay bright longer.

It's impossible to say about bulb life if the bulbs don't give any rating. There are bulbs rated for thousands of hours and bulbs rated for only 20 hours with quite a few points in the between, so if it doesn't say, who knows? They will probably both last long enough for you to drop the light.


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## Buck91 (Oct 9, 2007)

Corona was the word I was looking for. Thank you. I guess I'll check out this imageshack; but be warned these are off my cell phone and even though its 2mp it doesn't do dark well.


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## Buck91 (Oct 9, 2007)

Halogen with room light on




Krypton with room light on




Halogen roomlight off




Krypton roomlight off


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## Valolammas (Oct 10, 2007)

Those are pretty good for cellphone camera pics. Doesn't look like there's that much difference, so personally I'd probably use the 2.5V/0.5A one with alkalines and the 2.4V/0.7A one with NiMHs. Though they'll probably both work fine with either.


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## Buck91 (Oct 10, 2007)

Yeah, I threw the .5a in there just because... I wonder how much of a batt life difference there would be between the two running on standard D cell alkies...


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## Bullzeyebill (Oct 10, 2007)

Guys, I say it again, buy a lightmeter, and do some simple bounce tests for comparative purposes. You will learn a lot, and lux info will be good too. Don't need an expensive light meter for comparative purposes. This tool is more important than your next flashlight. Google light meter.

Bill


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## Buck91 (Oct 10, 2007)

I guess for absolute comparative purposes yes, but I'm primarily interested in the functionality. The halogen seems to have slightly better color along with slightly less power comsumption.


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## Valolammas (Oct 11, 2007)

Buck91 said:


> Yeah, I threw the .5a in there just because... I wonder how much of a batt life difference there would be between the two running on standard D cell alkies...



Take a look at the Alkaline Battery Shootout. If you scroll down, you'll find D cell discarge curves at 0.5A and 1.0A rates. There's no 0.7A curve, but there's a whole lot of difference between 0.5 and 1.0 Amps, and it will fall somewhere between them.


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