beam shots on white walls? Must we?

I've only been here a few months and am wondering why everyone posts beam shots on white walls. Whenever I see shots posted in comparison on things outside it always seems to be more definitive as to how they compare. I just looked at some beam shots showing a AA mag from about 18 inches that could be some more powerful light but at a distance. Wouldn't it be more scientific at least to have standard distances and come to think of it, since all cameras see light differently, doesn't that kind of rule out the validity of all beam shot comparisons? At least, when someone posts a shot taken outside of the side of the building or bush across the street, at least we can decide if we see more recorded detail from one comparison to the next. It would seem that only by comparing visible detail do we get a sense of at least brightness differences from one light to the next. The wall beam shot has me baffled and wondering what everyone else sees that I don't. Sure , one can see the shape of the beam and how much spill there is and whether there are funny beam artifacts etc. But beyond that, isn't the camera, which as a rule doesn't do well taking shots at night without ir help? I'll stop now because I don't know if I'm really making a valid point, just that the wall shot is really the last thing I personally would like to see, anyone else? I know walls are convenient, but beyond that?

Most conditions are all different as are cameras, settings, etc as you said. What I find useful is when someone posts a comparison to a light that I am familiar with. I can then make a relative assessment because I have something to compare it to.

I think it is better for the picture takers to edit the shots first to make it reflect the actual beams that you would see in person. It does not matter whether the beam was taken at a distance or as near as 1 m, as long as the beam shot reflects what you are actually going to see in person.

just my 2 cents

If the beam shots are "comparison" shots with more than one light's beam in the same image it allows a direct comparison of relative spread, intensity, smoothness, and shape. This works expecially well if one of the lights in the shot is one I am familiar with.

If the beam shot is a stand-alone shot, it allows me to judge the smoothness of the beam, the beam shape, and relative concentration of the light's output in the center spot and the "spill" or flood portion of the light.

Without standard distances light-to-target, standard distance and settings for the camera, standard reflectivity and color balance of the various wall surfaces (unlikely), and standardized response of the camera to visible light (impossible), most beam shots are suitable only for a rough relative judgement of beam shape and oddities.

Comparison shots are at least of a bit more use as they allow one to mentally compare the light's output to one with some familiarity.

Then again, why do most of us look into the shiny ends of our lights when they are on even though we know we shouldn't? /ubbthreads/images/graemlins/grin.gif

/ubbthreads/images/graemlins/thinking.gif

Along with what has already been said, my neighbors would think I was nuts (not that they already don't) for popping off photos of my flashlights in my backyard late at night to do write-ups.. /ubbthreads/images/graemlins/eek.gif

I would agree with you that a beamshot of a single light isn't very valuable, but, I agree with all the responses so far about comparison shots. Take this beamshot picture, for example...


Comparison between Inretech Super6 and MadMax Minimag


I can glean quite a bit about the lights used from this picture, especially If I'm familiar with one of them.

1. I can know the color of the beams of both lights if I'm told the pic is an accurate representation of what was seen when the beams were photographed. (and this is)
My old MadMax standard was a greeny. My Super6 is white.

2. I can get an idea of how focused the beams are if I'm told the distance to the wall. (or ceiling, in this pic)
These lights were about 9" from the ceiling in this pic, if I remember correctly. The beam, or rather, swath, of the Super6 is much much wider than the beam of the MadMax.

3. I can know the characteristics of the hotspot, and spill etc.
The Super6 has no hotspot, really, and due to the nature of the Super6, the flood of it eliminates seeing the spill of the MadMax in this pic, but this is admittedly an unusual comparison. (because the Super6 is an unusual light)

4. I can know other "extras" about the beam quality, such as artifacts that it may have.
The Super6 has a "spirograph" like pattern around the edges.


I think that beamshots are useful, and find myself asking for them, when a light is described without them.

Beamshots are useful for 2 things:

1. gleaning useful data from a single light beamshot.

2. comparitive data between 2 or more lights.

Since there are too many variables in camera abilities, color and other things aren't always rendered correctly. For those who can afford an expensive camera with all the need abilities, beamshots are more accurate.

If I were to post a beamshot, it would only be a dim idea (pun intended), but, better than none at all.

The white target gives a much better idea of color, than say a tree.

Real world shots are also useful to illustrate things like throw and/or flood, etc.

One way to reduce inaccuracies is to shoot all the photos with the same aperture and shutter speed by manually setting it.

I do prefer shots that compare all the beam shots as a group in one photo though.

And also, let us know what color balance you're using if you're not going to color correct in photoshop.


Joey

Though still far from scientific, I always take two pictures on the same day then post the beamshots next to each other. Same room, same ambient light, same camera and settings, two different lights. Would get clumsy if comparing 20 lights but to post a quick pic along with a written description, it ain't too bad.

Better to have a pic you can ignore than have no pic at all.

I mean, though you can't really tell how bright it truly is and how well it would work indoors, outdoors at longer distances, underwater etc... from these two pics, you can tell than the PrincetonTec Surge is easily way, way brighter than a 2D MagLight. Right?

I agree completely.

Size15s was kind enough to email me some pics of beamshots taken OUTSIDE, and they were waaaaaaaaaay more informational and useful than any other beamshot I've ever seen.

BTW, I never thanked you for the email, Size15! Thanks!!!

In response to cratz2 post...

Not only can we see the PT is MUCH Brighter, we can see how useless the beam from a stock M*g can be! I mean Jeez, look at the blotchy, splotchy, yellow light on the left. You will never catch ANY of my 7 or 8 M*gs putting out THAT bad of a beam!!!

I happen to like white wall shots. My camera doesn't do manual. I just want to see beamshots!!!

In my "urban throw tests" I'm restricted to verbal descriptions. Even if I had elaborate photo equipment I'm not sure how useful it would be. I try to make my comparisons as clear and succinct as possible, and people (Flashaholics) seem to find them useful.

I agree that comparative beam shots of lights illuminating objects at known distances can be helpful.

Brightnorm

cratz2, nice comparison.

most beam shots on walls with similar beams do not show much of anything, maybe comparable brightness but not much else. I know that what I say is heresy, but maybe I just don't get it. Even an indoor shot of something will show at least subjectively how much over all light there is and what the color of light is becasue it will help identify colors. A beam shot on a wall will not even usually tell you what color the wall is. When I use a light it's usually to shine it on something other than a wall, anyone else?

I WOULD do outdoor shots, but I'd likely have problems with my neighbors asking drunken, stupid questions... and I'd hate to have my modded Mag6D impounded for evidence.

As my best camera is a USB webcam, and not portable, I'm stuck with indoor shots. I can however lock the white-balance, so I can do multiple lights without having it change between LED and incandescent lights. I did beamshot pics of 3 lights, a stock Legend LX, a LX w/5w BB750 mod, and a 6D Mag-5w mod. The 5w lights had identical color, but the LX looked positively yellow. Of course, my camera would promptly auto-adjust the white-balance and brightness between shots if I hadn't used the driver options to lock them.

My beamshots were both LX's for comparison, then one each for examination of beam irregularities, the one of the two 5w lights together, and a final shot of that corner of my room in normal light.

The ideal beamshots would all be by one person, with one set of equipment, and one set of settings. (Where's Craig when you need him... /ubbthreads/images/graemlins/smile.gif) Side-on 'smoke' shots would be a plus, especially if there was an obvious scale. (Like a surveying stake, with alternating white and red bands a foot long.)

I may just be an idiot or something. But I MOSTLY shine my lights at walls and ceilings... often two at a time to compare them.

I say keep 'em coming, whether wall, ceiling or something else. Just so we can compare any two lights.

[ QUOTE ]
PlayboyJoeShmoe said:
I may just be an idiot or something. But I MOSTLY shine my lights at walls and ceilings... often two at a time to compare them.

I say keep 'em coming, whether wall, ceiling or something else. Just so we can compare any two lights.

[/ QUOTE ]

I use white wall (or ceiling) tests for measuring total output rather than just "brightness". The indirect light corresponds roughly to lumens, sometimes with surprising accuracy when comparing lights.

I also find beam diameter comparisons useful along with observations of light distribution within and external to the beam's center.

Brightnorm

I admit that I switched in a NOS bulb from about 5 years ago to do that shot. I usually use a replacemend bulb out of the Garrity 2AA + 2D rubber flashlight kit. Much whiter but no better focus.

Still, a stock 2D Mag is pretty embarassingly bad considering how good most non light nuts think they are.

And I've extensively tried to do outdoor shots but they all come out looking like crap. My camera just won't pick up the beams if they're further than about 15 feet.

[/ QUOTE ]...I use white wall (or ceiling) tests for measuring total output rather than just "brightness". The indirect light corresponds roughly to lumens, sometimes with surprising accuracy when comparing lights...

Brightnorm


[/ QUOTE ]

Totally agree, this is the same test I use to guage total light output. (picture yourself in a dark closet with the door closed shining two lights against the ceiling and the wife walks in. Honey what are you doing? /ubbthreads/images/graemlins/grin.gif) Anyways, I once posted some "ceiling" type shots but I didn't think they were as sexy as beamshots against a white wall. I do agree shining at objects at a distance shows real life utility of a flashlight's beam.

CM

[ QUOTE ]
cratz2 said:
Though still far from scientific, I always take two pictures on the same day then post the beamshots next to each other. Same room, same ambient light, same camera and settings, two different lights. Would get clumsy if comparing 20 lights but to post a quick pic along with a written description, it ain't too bad.

Better to have a pic you can ignore than have no pic at all.

I mean, though you can't really tell how bright it truly is and how well it would work indoors, outdoors at longer distances, underwater etc... from these two pics, you can tell than the PrincetonTec Surge is easily way, way brighter than a 2D MagLight. Right?



[/ QUOTE ]

In the case of two or more beamshots it would be nice if they were ALWAYS identified. OK the case above is pretty obvious but they are not always so. /ubbthreads/images/graemlins/icon23.gif