Beamshots from the downrange perspective?

I'd like to see pics at various downrange distances, showing how bright it becomes for people at that range, and how looking towards the light appears.

Telescopes & binoculars lose a lot of brightness (proportional to the magnification and also the quality of the optics) so I don't suppose there is a way to take photos showing how bright the target would be when looking through optics, but pics showing the brightness at that range might give a clue.

I really don't think it would show too much. Maybe a little of how bright the spill was around the light. Remember, When going one way only, a light can be seen from very far away. I remember seeing that the Photon II could be seen a mile away under the right conditions, while mine would barely light up the far corner of my garage enough that I could see what was there. [Garage was big enough that before I put in the shelves and the enclosed workshop I could have parked four cars in a 2S 2P arrangement. Just think about back in the day when lighthouses used oil lamps for the beacon, they could still be seen several miles out to sea. All one would see was a point of light, but that was enough.

No no no. How bright it is for the person standing downrange. Can he read a book by the light? Can he see his hand in front of his face? Can he see something 10 yards away from himself by the light?

This would give a clue as to how a person uprange using binoculars might be able to see the target.

Sorry, I misunderstood what you were asking. I was responding to the idea of what a person would see if they were looking towards the light, not what would be illuminated at that range. That might be interesting to see. Would things appear twice as bright as it does at the light source, or four times as bright?

Intriguing idea. I once asked my wife to shine my Hound Dog Super at me from a distance of about 15 yards. I was able to manage a glance at the flashlight. Anything more would have detached a retina. I can tell you that all aspects of color rendition, beam tint, beam profile, etc. are irrelevant when facing the business end of the device.

I, too, would like to see some properly exposed photographs taken from that perspective.

A drone cam would be handy. Or set lit light on table, walk x number of paces at a time with a book, hold book at arms length, snap pix if you want to record it permanently, otherwise put a hashmark on a page of the book for each set of paces and when you cannot read the book (or whatever other target you are striving for) talley up the hash marks and there-ya-go...

lumen aeternum said:

I'd like to see pics at various downrange distances, showing how bright it becomes for people at that range, and how looking towards the light appears.

Telescopes & binoculars lose a lot of brightness (proportional to the magnification and also the quality of the optics) so I don't suppose there is a way to take photos showing how bright the target would be when looking through optics, but pics showing the brightness at that range might give a clue.

Click to expand...

I *think* that there are too many variables to be able to take representative pictures. Camera settings, f stop and time, film speed, etc, can make huge differences. Also, is the observer's eye, night adjusted? Is the scene already illuminated? And if so, at what level, 5 lumens, 650 lumens?

Certainly, someone smarter than me can do calculations maybe even logarithmic calcs to demonstrate what one may expect to see.

For example, a person with dark adjusted eyes, may be able to see fairly well with one to three lumens. But in full daylight, an additional 1-3 lumens would not be noticeable. Flashlight beam distances are calculated to give an increase of 0.25 lumens to the target. That is purported to be moon-light. Now cut that distance in half, and you'll have 4 times as much light.

It's been stated that lumens must be doubled for the human eye to be able to distinguish the difference.

You might experiment with a light that you have, with a known cd, and pace off 100 yards or so, and see how much more you can see with it on, vs with it off. Then pace off 50 yards, and note the difference. Consider doing the same experiment at different times of the evening/night, or with different ambient lighting conditions.

Have fun!