Interpreting specs: Compare beam profiles of different lights with similar specs?

richbuff

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If two different lights have similar lumen and throw specs, does that mean that the beam profiles (beam width and length, hotspot size) will be similar?

If I have a collection of lights, and I have the specs, and then if a new light is released with throw and lumen specs that are similar to another light already in my collection, can I figure that the beam profiles of both lights will be just as similar as the specs are?

For example, MX25L4CvnT - XPL PDT + DriverVNX2, 5000 lumens and 861 meters throw. I know firsthand what the beam profile looks like.

I do not have the K60vn - XHP70 Dome on, 4814 lumens and 807 meters throw.

Can I figure that the K60vn - XHP70 with dome has a similar beam profile as the light that I already have?

These two lights are very different as far as emitters are concerned, of course. One XHP70 in a single, large reflector, versus four smaller emitters for four XPL emitters. But the lumen and throw specs are similar. Excluding tint, by how much can the beam profiles differ? If lumens and throw are very close to each other, can the hotspot of one be much broader or narrower than the other?


Same questions, another example: TN40vn Spec 4 XHP35 HI + DriverVNX2, TN36UTvn handle and carrier. 8700 lumens, 1414 meters throw; versus

RC40vnT - XML2 PDT + DriverVNX2, 7142 lumens with 1382 meters throw.


Can I assume that the TN40 and the RC40 will have very similar beam profiles, with the first slightly outperforming the other as far as beam profile is concerned?



Excluding tint, what can I not visualize in advance about the beam profile, if I have lumen and throw specs?

Thanks in advance for replies, and sorry about the flood; this is, after all, a flashlight forum. :)
 

MikeB.

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If two different lights have similar lumen and throw specs, does that mean that the beam profiles (beam width and length, hotspot size) will be similar? No, they can be very different.

If I have a collection of lights, and I have the specs, and then if a new light is released with throw and lumen specs that are similar to another light already in my collection, can I figure that the beam profiles of both lights will be just as similar as the specs are? No again.

For example, MX25L4CvnT - XPL PDT + DriverVNX2, 5000 lumens and 861 meters throw. I know firsthand what the beam profile looks like.

I do not have the K60vn - XHP70 Dome on, 4814 lumens and 807 meters throw.

Can I figure that the K60vn - XHP70 with dome has a similar beam profile as the light that I already have?

These two lights are very different as far as emitters are concerned, of course. One XHP70 in a single, large reflector, versus four smaller emitters for four XPL emitters. But the lumen and throw specs are similar. Excluding tint, by how much can the beam profiles differ? If lumens and throw are very close to each other, can the hotspot of one be much broader or narrower than the other? Differences will depend on emitter size, the depth of the reflector, smooth or OP reflector, size of reflector and so on will affect beam profile.


Same questions, another example: TN40vn Spec 4 XHP35 HI + DriverVNX2, TN36UTvn handle and carrier. 8700 lumens, 1414 meters throw; versus

RC40vnT - XML2 PDT + DriverVNX2, 7142 lumens with 1382 meters throw.


Can I assume that the TN40 and the RC40 will have very similar beam profiles, with the first slightly outperforming the other as far as beam profile is concerned?



Excluding tint, what can I not visualize in advance about the beam profile, if I have lumen and throw specs?
There may be some lights that will have similar beam profiles, but there are so many variables that can change the beam, there is really no way to know without comparing side by side.

Thanks in advance for replies, and sorry about the flood; this is, after all, a flashlight forum. :)
 

MikeB.

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I'll also add that some lights have more lumens in their hotspot, and others have more lumens in their spill.

Example, think of 2 lights with say 1000 lumens and 100k lux. The first light might have all lumens in the hotspot with little or no spill, so bigger hotspot. The second light might have brighter spill but very small hotspot with same throw as first light. I'm not sure if this makes sense, but extreme example would be aspheric lense vs reflector light.

Does this help any?
 
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richbuff

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Thanks, MikeB., for your informative replies.

I thought about two lights having same lumens and lux, but with different amounts of size and luminosity of the hotspot and the spill, but I figured that in that case, the throw would be different.

So, for example, the MX25L4CvnT - XPL PDT versus the K60vn - XHP70 Dome on: It could be possible for both lights to have very similar throw and total lumens specs, for same throw, but one light could have a very much less defined smaller hotspot with broad spill, and the other light could have a bigger, sharply defined hotspot with very little spill.

The brightness in the center of the beams would be the same, for same throw specs? So it could not be a possibility that the spills and the hotspots would have the same width and breadth, but with one light having a brighter hotspot, and the other light having brighter spill?

Thanks again!
 

MAD777

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Based on my assortment of flashlights, lumen & lux do not tell the whole story.

The most significant items not included (besides tint) are the:
hot spot size,
total width of the spill,
sharply defined hot spot or blended transition into the spill.

Flashlights with similar lumen/lux specs can look different due to these characteristics.
 

MikeB.

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^^^^^ Yup, that pretty much explains it better then I did.
 

richbuff

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Thanks, MAD777 and MikeB., for explaining that due to emitter differences and/or reflector differences, that beam profiles (spill size and hotspot size) can easily be very different for two different lights that have very similar throw and lumens specs.

So, for example, the MX25L4CvnT - XPL PDT versus the K60vn - XHP70 dome on: Two very different lights with similar throw and lumen specs, but most probably very different beam profiles, as per the reasons you both have stated.

Thanks again! :)
 

MikeB.

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I was eyeing the MX25L4CvnT, but it hasn't been available for a while. I have 2 different K60vn though, but that doesn't help. I do have a 6XPvn, but that is a different light again, but it is close to K60vn specs.
 

richbuff

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I have been eyeing the K60vn for a long time, but I haven't bit, because I have the MX25L4CvnT that is close to K60 specs, but in a smaller size and weight class.

I have seen many killer beamshots of the K60vn, and I see the MX25L4CvnT beam in real life, but not vice versa.

I have noticed that comparative beamshots taken by the same photographer are useful for cross comparison, but beamshots taken by different people are not as reliable for cross comparison.

My guess is that the K60 has a very much less defined hotspot with broad spill, compared to the MX25L4CvnT with its comparatively sharply defined hotspot with its comparatively very little spill. Similar lumen and throw specs, but one light is better suited for use at short range, and the other light is better suited for use at longer range, as per very different beam profiles, as per the two lights having very different emitter/reflector classification.
 

Newlumen

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Totally agree. Tn36utvn xhp 70 shave dome 12,300 lumen.. Rc40vnf 90 cri xhp 70 13,600 lumen.. There is only 1300 lumen different... Rc40vnf is way brighter.... I assume the size of the reflector make different.
 

MAD777

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Totally agree. Tn36utvn xhp 70 shave dome 12,300 lumen.. Rc40vnf 90 cri xhp 70 13,600 lumen.. There is only 1300 lumen different... Rc40vnf is way brighter.... I assume the size of the reflector make different.
Most likely, the hot spot is brighter on the RC40. What are the lux numbers on the two lights?
(I think my TN36UTvn is about 60K lux)
 

MAD777

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Rc40vnf 100k lux
tn36utvn 60k

remember my rc40vnf is 90 cri k4. 5700 k
The human eye interprets hotter hot spot as the "brighter" light, when in fact the one with the most lumens can appear "dimmer" due to a cooler hot spot.

The higher lumen light would of course have more flood. Not necessarily a brighter flood, as it could be a dimmer but wider flood, covering more area.

The human eye cannot be trusted! LOL
 

Impossible lumens

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I would suspect that the MX25L4CvnT would have a more polished looking beam than the K60VN due to the properties of the XHP-70. It must have an OP reflector for a reason. In the vast ocean of flashlights I would say that these two are much more closely comparable than many. I would think that thermal properties would be the biggest thing the K60VN has going for it in this comparison. If you want to run your light for a while on turbo, K60 wins.

Other than that, I would say the MX25L4CVNT is probably a better light with a nicer looking beam. This is speculation though. Like you said, nothing like going out in a pitch black night with one in each hand.
 

richbuff

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Thanks everyone, for your informative and knowledgeable replies.

I have been meditating frequently on this topic, compare beam profiles of different lights with similar specs, before going to sleep nightly.

For example, two lights, both with same head diameter, both with four XPL emitters, both with four reflector wells.

But, one light has four smaller non-overlapping reflector wells, (such as seen in Eagletac lights) and the other light has four large diameter reflector wells, but there is a lot of overlap, such as seen on the TN40.

How will the two beam profiles compare?

My guess is that the first light will have a sharply defined hot spot, with less spill, and the second light will have some more throw in the very center of the beam, with lots of spill.

So, a cylinder of light from the first light, and a cone (point forward) of light for the second light; that is, for the second light, max throw is in the very center of the beam, and more spill with less throw moving from the center of the beam.

Anyone have any input on small non-overlapping multiple reflector wells, versus large but very much overlapping reflector wells, for same number of wells and same head diameter?
 

eekazum

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The non-overlapping reflector light will have less noticeable petals. I also think it will have a more narrower beam profile.

This is turning out to be an interesting thread :)
 

MAD777

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Anyone have any input on small non-overlapping multiple reflector wells, versus large but very much overlapping reflector wells, for same number of wells and same head diameter?

I have 3 such lights in these configurations: 3 reflectors, 4 reflectors and 6 reflectors. The beam is singular and uniform. No evidence of multiple reflectors in shape. The one outstanding feature common to all 3 is a large hot spot. I consider this a plus in most circumstances.
 

hahoo

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I'll also add that some lights have more lumens in their hotspot, and others have more lumens in their spill.

Example, think of 2 lights with say 1000 lumens and 100k lux. The first light might have all lumens in the hotspot with little or no spill, so bigger hotspot. The second light might have brighter spill but very small hotspot with same throw as first light. I'm not sure if this makes sense, but extreme example would be aspheric lense vs reflector light.

Does this help any?

thats actually brilliant, and i have never dissected this situation in this manner:huh:
makes real good sense, even to my lil brain :D
 

brighterthanthesun

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If two different lights have similar lumen and throw specs, does that mean that the beam profiles (beam width and length, hotspot size) will be similar?

If I have a collection of lights, and I have the specs, and then if a new light is released with throw and lumen specs that are similar to another light already in my collection, can I figure that the beam profiles of both lights will be just as similar as the specs are?

For example, MX25L4CvnT - XPL PDT + DriverVNX2, 5000 lumens and 861 meters throw. I know firsthand what the beam profile looks like.

I do not have the K60vn - XHP70 Dome on, 4814 lumens and 807 meters throw.

Can I figure that the K60vn - XHP70 with dome has a similar beam profile as the light that I already have?

These two lights are very different as far as emitters are concerned, of course. One XHP70 in a single, large reflector, versus four smaller emitters for four XPL emitters. But the lumen and throw specs are similar. Excluding tint, by how much can the beam profiles differ? If lumens and throw are very close to each other, can the hotspot of one be much broader or narrower than the other?


Same questions, another example: TN40vn Spec 4 XHP35 HI + DriverVNX2, TN36UTvn handle and carrier. 8700 lumens, 1414 meters throw; versus

RC40vnT - XML2 PDT + DriverVNX2, 7142 lumens with 1382 meters throw.


Can I assume that the TN40 and the RC40 will have very similar beam profiles, with the first slightly outperforming the other as far as beam profile is concerned?



Excluding tint, what can I not visualize in advance about the beam profile, if I have lumen and throw specs?

Thanks in advance for replies, and sorry about the flood; this is, after all, a flashlight forum. :)

Other than meeting some of you guys, the best thing about a CPF get together would be the opportunity to compare so many lights to one another.
 
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