Photographing moonlight -- the real one, and the flashlights

[hank]

Full moon is coming up. Anybody here who’d want to try comparing various flashlight levels to actual full-moonlight illumination?
Our house is plagued with a horrible new LED streetlight that’s much brighter than the full moon, so I’ll have to find a less illuminated location to try to take pictures.
I’ve always guessed that we get “moonlight” levels that are surprisingly bright because the lights are made in places with no dark skies to use the low level.
So I was wondering — how bright is the full moon light where you are? Compare it to your flashlights?

Reading up, it will take a time exposure:

https://www.google.com/search?q=moonlight+photography+time+aperture

Kodak Recommendation from Trial Exposures Under Difficult Lighting Conditions

Moonlit landscapes: 30 seconds at f/2 at 100

For scenes lit by the unobscured full moon to show full detail in the surroundings, not including the moon in the picture.

Adjusted: ISO 100 film at f/8 is 8 minutes

Another rule of thumb is the Looney 16 Rule, which says the full moon is roughly 250,000 times dimmer than the sun, which works out to 18 stops less light than full sunlight. (2^18 = 262,144) The sunny-16 rule for full sunlight says for ISO 100 film, expose f/16 at 1/125, so adjust this 18-stops.

Adjusted: ISO 100 film at f/8 is 8 min 30 seconds

[djozz]

What a nice subject. I’m in the middle of a city so no moonlight level measurements here but I can do some calculations :

Moonlight brightness will actually be a luxvalue, not a lumenvalue, every flashlight even on turbo if shined from far away enough will produce moonlight level.
Given that full sunlight is said to be about 130.000 lux, if the above Looney 16 Rule is correct moonlight should be about 0.5 lux. Say we want to produce the moonlight level at 1 meter distance from the flashlight, and it must be produced by my current EDC (a Jaxman with Carclo triple with high CRI Nichia leds), a quick throw measurement (throw is 355 lux at 1 meter with output at 88 lumen) and calculation learns that my moonlight level needs to be 0.12 lumen to get real moonlight level at 1 meter. But the ‘moon’ that the bistro driver produces is 0.22 lumen instead, so about 2 times as much, which implies that the required 0.5 lux is not at 1 meter but at 1.35 meter.

My Brinyte B158 aspheric lens thrower (322 kcd, 950 lumen) needs much less light to achieve 0.5 lux at 1 meter (in the hotspot), just 0.00015 lumen is enough

Edit: wikipedia says that moonlight van be typically 0.1 lux, so a bit less than in the calculations above. That will make my EDC on moon setting of 0.22 lumen produce moon level at 3 meter.

[hank]

Thank you djozz!

> What a nice subject

I was pondering coming up with something for us all to do together while, ahem, waiting on other things to happen.

> every flashlight even on turbo if shined from far away enough will produce moonlight level.

Let’s say handholding the flashlight and pointing it at the ground or a handy outdoor white wall, one where you’d see it compared to moonlight and moon shadows — say a meter distance?

Chuckle. I guess a new metric could be, set your flashlight on turbo and start walking until the bright spot matches moonlight and record the distance (grin)

When I played with this last night (following my own advice to back slowly away from the keyboard and find something useful to contribute) I noticed most all the lights I tried are really brighter than last night’s not-yet-full-moonlight.

The Moon today is in a Waxing Gibbous phase. This phase is when the moon is more than 50% illuminated but not yet a Full Moon. The phase lasts round 7 days with the moon becoming more illuminated each day until the Full Moon. … The moon is then visible though most of the night sky setting a few hour before sunrise.

Moon Phase for Today and Tonight

I realize that for anyone south of the Equator the Moon is upside down (or I am), but that won’t affect the brightness.

What, pent up chattiness? Moi?

[hank]

More than one-third of the world’s population can no longer see the Milky Way because of man-made light.

Among those missing out on awe-inspiring Milky Way views: nearly 80 per cent of North Americans and 60 per cent of Europeans.

Rare 'bright nights' mystery solved by Canadian scientists | CBC News

———Full moon is Saturday, July 8th——

[MRsDNF]

@djozz

What a nice subject. I’m in the middle of a city so no moonlight level measurements here but I can do some calculations :

Moonlight brightness will actually be a luxvalue, not a lumenvalue, every flashlight even on turbo if shined from far away enough will produce moonlight level.
Given that full sunlight is said to be about 130.000 lux, if the above Looney 16 Rule is correct moonlight should be about 0.5 lux. Say we want to produce the moonlight level at 1 meter distance from the flashlight, and it must be produced by my current EDC (a Jaxman with Carclo triple with high CRI Nichia leds), a quick throw measurement (throw is 355 lux at 1 meter with output at 88 lumen) and calculation learns that my moonlight level needs to be 0.12 lumen to get real moonlight level at 1 meter. But the ‘moon’ that the bistro driver produces is 0.22 lumen instead, so about 2 times as much, which implies that the required 0.5 lux is not at 1 meter but at 1.35 meter.

My Brinyte B158 aspheric lens thrower (322 kcd, 950 lumen) needs much less light to achieve 0.5 lux at 1 meter (in the hotspot), just 0.00015 lumen is enough

Edit: wikipedia says that moonlight van be typically 0.1 lux, so a bit less than in the calculations above. That will make my EDC on moon setting of 0.22 lumen produce moon level at 3 meter.

:+1:

[hank]

[mattlward]

I like stars, this location is not as dark as I would like but in south eastern IL it is about the best I have…. Shot with a full spectrum modified digital camera. Milky Way!

[hank]

Nice! and is that with tonight’s almost-full Moon in the sky?

[The_Miller]

In, when clear will step in garden to compare

Q8 should come in handy for we can set our own moon level!