22 Beamshots, my big lights (MC-E/P7/throwers/aspherical/HID)

[dymonite69]

But what is being actually being measured on the y-axis and under what condition?

 

[saabluster]

HKJ I wonder if you could do me a favor. This was a tremendous amount of work and I understand the difficulties involved. I wonder if you would mind retesting the DEFT vs the Titanium L35. The reason I ask is your lux measurements do not seem to match what I saw in person or what I think I see in the pictures. At a DFW GTG I got to use the L35 next to the DEFT and found the DEFT to be at least equal if not slightly greater in throw as viewed by my eyes. It could be just that particular L35(was windstrings) I suppose. Obviously there are tint and color saturation differences. But looking at the picture in detail does not show the L35 to have three times the lux. Way more light overall yes but I just don't see such a disparity between the two on lux. Here is a snippet of the DEFT and L35 photos.

Now my thought is that the lux test was taken too close factoring in the differing lights and the type of lights involved. I think these extreme throw lights should be tested at a minimum of 10 meters to allow the beam to "mature". Do you think you could redo the test at 10-20 meters? I would really appreciate the additional info.

Pretty please?

 

[HKJ]

Can someone tell me what is being described in this graph?

This is a lux measurement, a higher measurement translates into a longer throw.

HKJ I wonder if you could do me a favor. This was a tremendous amount of work and I understand the difficulties involved. I wonder if you would mind retesting the DEFT vs the Titanium L35. The reason I ask is your lux measurements do not seem to match what I saw in person or what I think I see in the pictures. At a DFW GTG I got to use the L35 next to the DEFT and found the DEFT to be at least equal if not slightly greater in throw as viewed by my eyes. It could be just that particular L35(was windstrings) I suppose. Obviously there are tint and color saturation differences. But looking at the picture in detail does not show the L35 to have three times the lux. Way more light overall yes but I just don't see such a disparity between the two on lux. Here is a snippet of the DEFT and L35 photos.

Now my thought is that the lux test was taken too close factoring in the differing lights and the type of lights involved. I think these extreme throw lights should be tested at a minimum of 10 meters to allow the beam to "mature". Do you think you could redo the test at 10-20 meters? I would really appreciate the additional info.

Pretty please?

I am doing my lux measurements indoors, that will give an advantage to lights with higher output (due to reflections), but I believe that error to be rather small.

To compare I took these two pictures from the review:

Converted them to B&W and only took the center of the beam:

I think the L35 wins here.

Note: The DEFT is running on alkaline batteries, my eneloops are to thick to fit in it.

 

[saabluster]

Note: The DEFT is running on alkaline batteries, my eneloops are to thick to fit in it.

No wonder.:ohgeez:Alkalines cannot sustain the output needed for the LED to be at max power. I tested your light with the eneloop cousins and they fit but only if you align the seams of the batteries to not add to the diameter of the battery unit. Of course even then they can be tight. Try redoing the test with the other recommended cells- the Energizer Ultimate Lithium primaries. Those give the highest output and longest runtime. If you want I will send some to you.

 

[HKJ]

No wonder.:ohgeez:Alkalines cannot sustain the output needed for the LED to be at max power. I tested your light with the eneloop cousins and they fit but only if you align the seams of the batteries to not add to the diameter of the battery unit. Of course even then they can be tight.

I was a bit disappointed that the eneloops could not be used and that I had to use alkaline.

Try redoing the test with the other recommended cells- the Energizer Ultimate Lithium primaries. Those give the highest output and longest runtime. If you want I will send some to you.

I will include the DEFT in my next big light shotout (That will include HID's, SST90 and a few smaller lights) and then use lithium in it.

 

[saabluster]

I am doing my lux measurements indoors, that will give an advantage to lights with higher output (due to reflections), but I believe that error to be rather small.

One thing you could do to improve the accuracy is put a tube painted flat black on the inside over the front of your light meter to cut out any "dirty" light. I still would like to see a longer measurement taken on at least the DEFT and L35 or Microfire. Pleeease.

 

[HKJ]

One thing you could do to improve the accuracy is put a tube painted flat black on the inside over the front of your light meter to cut out any "dirty" light. I still would like to see a longer measurement taken on at least the DEFT and L35 or Microfire. Pleeease.

The black tube is a good idea, but longer distance is a bit difficult, I will try to locate a place. My L35 is damaged and will not be included in more beamshots (I have ordered a new one to replace it).

 

[dymonite69]

This is a lux measurement, a higher measurement translates into a longer throw.

So what are the following graphs showing?

[size=+3]22 Beamshots September 2009[/size]

The first graph shows all lights at maximum brightness

These two graphs show brightness (lux) at 4 meters distance,

 

[HKJ]

So what are the following graphs showing?

The first one is a ceiling bounce to measure the total light output. This is the cheap and unprecise version of a integrating sphere. I uses a small room with white walls and white ceiling and aim the light at the ceiling, then measures the lux reflected to the floor.

Both the green graphs are lux measurements, just with different scale.
For this I aim the light at a wall (For these lights I uses a 4 meter distance), then uses the lux meter to find the brightest spot on the wall.

I always uses scaled values in my graphs to avoid people comparing the measured lux to other lux measurements from other comparisons/review, because this would not be valid.

 

[dymonite69]

I always uses scaled values in my graphs to avoid people comparing the measured lux to other lux measurements from other comparisons/review, because this would not be valid.

HKJ,

Thank you for your patience in explaining the methodology. How do you scale your graphs, is it simply by dividing it by a constant? Which constant?

Do these methods correspond to some kind of industry rating or peculiar to this forum?

Are there are others means of quantifying these effects?

Are there professional labs that can measure the lighting intensity distribution over the entire beam area with high spatial resolution?

 

[HKJ]

Thank you for your patience in explaining the methodology. How do you scale your graphs, is it simply by dividing it by a constant? Which constant?

Yes, the constant is usual selected to give the reviewed light a 100 value, for general comparison it I have no fixed rules.

Do these methods correspond to some kind of industry rating or peculiar to this forum?

These methods are mostly used here. The total output is either measured with a ceiling bounce, a lightbox or a sphere, or best of all (and the only way to get the correct value) a real integrating sphere.
Usual lux (My green graph) is measured at 1 meter, but this have rather big errors for lights with large reflectors. More reviewers has started using longer distance for bigger lights, some calculates these values back to one for, for better comparison to other light. Because I do not make measurements for comparison to other measurements, but only within the same article, I do not bother with these calculations.

Using lux measurements at 1 meter makes it possible to compare the throw of different lights, because it is then possible to calculate the lux value at any distance, but only if the light source is a point source and that spoils it for big reflectors.

Are there are others means of quantifying these effects?

There are more than just lux and lumen to a beam, usual we uses beamshots to show this.

Are there professional labs that can measure the lighting intensity distribution over the entire beam area with high spatial resolution?

You do not even need a professional lab for that, just some patience. Moving a lux meter around and recording the value at different locations would do it. The RAW picture from a DSLR and a white wall, might also be useful for this.

 

[dymonite69]

Using lux measurements at 1 meter makes it possible to compare the throw of different lights, because it is then possible to calculate the lux value at any distance,

HKJ,

Thank you for the technical summary. It will help me understand the other posts a bit better.

BTW some people quote their torch as having a throw of x distance. Are there any conventions e.g lux level, diameter of beam for which this is defined.

 

[HKJ]

BTW some people quote their torch as having a throw of x distance. Are there any conventions e.g lux level, diameter of beam for which this is defined.

There are no fixed rules for throw, it can either be calculated for a specific lux level or how far the tester can see with the light.

The marking on lights might get a bit more standardized in the future, because there is a new ANSI standard for flashlight measurements. The standard is made by flashlight manufacturers and the measurement methods are designed to make the light look good. You can read a bit about it here.
Some differences between the standard and cpf:
Lightoutput: most people can not measure lumens, that is the reason for ceiling bounce and lightbox measurements.
Runtime is to 10%, on cpf we usual test to 50%. The 10% will give a big advantage to unstabilized lights.
Beam Distance is to 0.25 lux, this is a very low level and you will probably not be able to see this far with the light.
On cpf we does not usual check water resistance or how solid the light is, very few people wants to risk destroying their lights (There are exceptions).

 

[Lumenshroom]

Lovin' that MC-E.