Why does the incandescent ML25IT 3c put out more lumens than the 3D?

greenpondmike

Flashlight Enthusiast
Joined
Dec 7, 2017
Messages
1,313
Location
South
I know what yall are thinking--that I probably used a pr type bulb in the 3d maglite, but no, I installed the new bipin bulb in it. The 3c really is brighter than the 3d and the ml25it 3c is listed as 63 lumens while the new 3d is listed as 45. Looks like the numbers are correct, but why? Am I missing something or does the 3c have less resistance because of the design? Doesn't both flashlights use the same bipin bulb?
 
Last edited:
Also the 3d with a kpr103 radio shack bulb seems almost as bright and the hotspot will reduce down farther, but that ain't what I mean because all things equal it seems almost as bright--although when the hotspot is reduced down smaller it's brighter as it should be I reckon. I tried the krypton bulb first though and then put it in the tailcap. The bipin with the bigger hotspot is fine in the trailer, but outside at 30yds it has a doughnut hole that I can't adjust out. When I installed the bipin adapter I pushed it all the way down into the socket. Hope that was right. Maybe this ought to be two different threads since I'm all over the place on this one.

Now to be more specific the bipin xenon is a little brighter and whiter, but not enough to justify the way higher cost and with its gigantic hotspot and doughnut hole at longer range makes it useless to me.
I think the newer 3d flashlight's reflectors are designed in a way that works with the bipin.
 
Last edited:
Well, I'm also trying to seek some answers from folks here that have been through all this. I really don't want to deal with that bipin socket any time soon. The 3d now has a radio shack krypton pr based bulb in it and I'm satisfied with it. I like beamshots also, but without a xenon bulb the 3d would be at a slight disadvantage compaired to the ml25it 3c. That mama jama will put out dude.
 
The reflector of the ML25 is designed around the idea of a combination of spill and throw to achieve an output that seems to defy the lumen spec in dark places. Put it in a place with light pollution and you'll probably see 3D is able to compete against the free lumens a wee bit better.

The incan 3D in its day accomplished a same goal yet the beam itself had a narrow spot vs the ML25 that has a better blend of spot and spill than the older Maglites.
 
Yes, the 2 and 3d maglites I have all seem to have a tighter beam and even the 2d brinkmann legend also. They can throw further than my eyes can focus on a small area. The ML25IT has a fuller beam and spill. I can just plumb see way better with it than I can a small bright hotspot and a weaker spill. I guess my eyesight ain't as good as it used to be because that is what I used to like. Time to start wearing glasses I reckon.
 
The ML25 was/is another hidden gem by Maglite like the classic 160 something lumen LED lights are. If you haven't tried one of those GPM try a 2D LED. The latest one was 213 lumens. It smokes the LED ML25. Right now eBay is the place with the best prices. For whatever reason most places that have them are now asking $50+ for those when a year ago they were $35 or less.
 
Last edited:
I have one. It had a luxon(sp?) rebel led in it when I bought it. I later sold it to my brother in law and he wore the switch out first and then he let it sit up and the batteries leaked badly. I finally got what was left of it back and drilled the batteries out and got a lot of the crud out of it.

Well, I figured since the switch went out first it was a honest warranty claim, so I called them and they said that the switch assembly was one piece and they would send me one after I paid the....... "shipping".

Either before or after ordering I think I remember looking up in the sky and saying (maybe not an exact quote) that it would be nice if they sent me the new updated one. Well, they did! It has a high and a low and man is it bright just to be under 250 led lumens. The xpe was supposed to be a real good thrower. Someone (not me) even called it a spotlight which I'm sure they were exaggerating because they found it useless while night fishing in a boat--too bright. My only experience with it is what you (bykfixer) gave us when you bought the (I think) 3d version of it and then shared it on this forum.

I tried to clean up what was left of old assembly and I have still have some of the pieces left including the rebel led and driver. Don't know if it is any good or not though.

I believe the 168 lumen one you were referring to bykfixer has an xpe in it and the newer version has an xpg or xpg2 if memory serves me right.
 
Last edited:
I know what yall are thinking--that I probably used a pr type bulb in the 3d maglite, but no, I installed the new bipin bulb in it. The 3c really is brighter than the 3d and the ml25it 3c is listed as 63 lumens while the new 3d is listed as 45. Looks like the numbers are correct, but why? Am I missing something or does the 3c have less resistance because of the design? Doesn't both flashlights use the same bipin bulb?
Do we know situation of batteries? I know D cell won't fit inside C barrel but is there any way to swap batteries then check brightness?
Did you swap bulbs then check for brightness?
Also size of head diameter (1.5" vs 2") may fool you.
 
Thanks for answering fivemega. It's not only me--it's what maglite listed themselves about the 3d and the ml25it 3c. These figures are probably five years old when they listed the lumens with their incandescent lights which they don't seem to now. The ML25IT 3c was listed as 63 lumens and the 3d was listed as 45 and when I tested them it looks like it is true. In my first post concerning that I was wondering if the difference is in the switches because they are both different. I believe the push button switch (3d) has more internal resistance than the twist switch does and maybe that is how they got 18 more lumens out of the ml25it. I mean with all things the same--same bipin bulbs and same output of the batteries. The d cell batteries don't put out any less or more than the c cell ones, but I believe the d cells last longer.
 
Thanks for answering fivemega. It's not only me--it's what maglite listed themselves about the 3d and the ml25it 3c. These figures are probably five years old when they listed the lumens with their incandescent lights which they don't seem to now. The ML25IT 3c was listed as 63 lumens and the 3d was listed as 45 and when I tested them it looks like it is true. In my first post concerning that I was wondering if the difference is in the switches because they are both different. I believe the push button switch (3d) has more internal resistance than the twist switch does and maybe that is how they got 18 more lumens out of the ml25it. I mean with all things the same--same bipin bulbs and same output of the batteries. The d cell batteries don't put out any less or more than the c cell ones, but I believe the d cells last longer.
Xenon will be brighter than krypton, is the short answer.

1000005389.jpg
1000005391.jpg


The longer answer would be that you could buy a couple brand new 3 cell Maglite branded Xenons and run them..the replacement bulbs come in different flavors, 3 cell, 4 cell, 5-6 cell, that kinda thing.
 
Last edited:
Both flashlights I were referring to were xenon when maglite (not me) listed them as 45 and 63 lumens. That's the specifications if you bought either flashlight new five years ago. I say five years because nothing has changed between then and now except that they don't list the specs for the ml25it 3c anymore.

I DID buy a maglite bipin bulb and socket for the 3d since it was older and had the pr bulb.

In my comparison I compared both flashlights with XENON BIPIN BULBS and it seems that the specs as maglite listed them ARE correct.

So I'm confident that the push button switch is the source of 18 less lumens on the 3d and that is why some folks modify these switches when they build a mag85 or a ROP.

So I believe the internal resistance of all unmodified maglite push button switches can rob you of significant lumens at base level stock form and if the flashlight is modified and not the switch the significance of lost lumens could be waaaay higher.

So, without putting an ohm meter to the switches I believe the famed push button switch (really the big mag plastic assembly inside) is the culprit and it is the steel spring inside that cushions the bulb that is mainly the source.

Years ago I watched a video on modifying the switch and the tailcap on a maglite. All that was done in essence was reroute the current that flows through the smaller spring in the switch and the larger spring in the tailcap. This is done by bypassing the current flow through both springs and rerouting it through two small and ultra flexible thin copper straps that you solder between two different points per spring.

Just think about how many more stock lumens you can get out of a maglite by doing this mod to the spring in the tailcap alone. You might be able to pick up 5--20 more lumens without more battery power or higher output bulbs. To mod both springs all you need is a little patience, a good solder gun, some good flux core solder and two thin, small ultra flexible copper straps.
 
Last edited:
I "guess" the answer to my second post on this thread is that maglite uses a slightly different reflector on their newer bipin xenon flashlights than they did on the pr bulb based ones, so the results are probably different when you install a bipin bulb and socket into an older maglite vs buying a new maglite with the bulb already installed.

The new maglite should adjust down very well.
 
To sum up the last two missing posts dc38 showed me I was assuming the NEW 3d maglite had a xenon bulb, but it was really a krypton instead so THAT was why there was a difference in lumens for the most part. I was trying to find lumens in the modern description of the 3d and completely overlooked that it had a krypton bulb in it.

My fault and I admit to posting in ignorance. Thank you dc38 for showing me and for sharing that other thread with me on how chickendrumstick went through the same thing I did concerning replacing a krypton bulb with a xenon bipin bulb.
 
I bought a 1980 2D with a stuck battery for cheap and when I did get the battery out I cleaned every conductive part well, put in a glass lens and new kyrpton bulb. Compared to another 2D it looked a bit brighter. So I took apart the other one, cleaned it and it was as bright as the one that had the stuck battery.

Sometimes, even though it looks clean it's not. I've had several non working antique flashlights that didn't look dirty go to working when I cleaned the things like the spring and other parts of the conduction path.
 
Back
Top