A little DIY project with the huge typhoon approacing

[Akira]

There are lots of attractive photo opportunities for which one needs to work in very or even totally dark conditions, nightscapes, star trails, aurora borealis and fluorescence just to name a few.

One of the problems of such occasions is the difficulty to see the settings of the equipment.  Normal flash lights won't be appropriate here, because they are blindingly bright and you would lose the sight for a while.  The LCDs on the camera will show the camera's and often the lens' settings as well, but they also can be too bright.  Some cameras offer a "dark mode" that turns the display to red.  Cameras of classical film camera design (like Nikon Df or many Fujifilm digitals) can be set without relying on the LCD, but it is difficult to see the scales and indexes on the dials.

Then I came up with the idea of a "dark red flashlight".  Contrary to the modern flashlights boasting of their brightness, this one is trying to go as dim as possible without losing its function.

Here is the process:

1. The main parts: from top right, counter clockwise: a battery holder, a 1.8k ohm resistor, a "high brightness" red LED, a thin momentary switch, a generic ABS plastic case and a CR2032 battery.

Why a "high brightness" LED for a flashlight that needs to be as dim as possible?  Because you can keep the ampere as low as possible!  A brilliant idea for a dim flashlight, isn't it? 

With the 3.0V lithium battery CR2032 and the 1.8k ohm resistor, the LED is driven only at roughly 0.5mA, which should be beneficial for sparing the battery life as well as working in very low temperatures.

2.  I drilled the hole into the bottom part of the plastic case at an angle of approximately 45 degree.  By directing the LED downwards, you can somewhat prevent your eyes from looking at the light source directly.  I need to cut a square hole in the top part of the case in order to accommodate the contacts of the switch.  Both the switch and the LED are glued using the UV-cure glue.

3.  The wiring is done.  I decided to connect the switch, the battery and the LED with long cables.  The battery holder can hold the battery quite tightly, and I found the inserting and removing the battery a bit fiddly.  So, I didn't fix the holder to the case and connect to other parts with long cables so that I can insert/remove the battery more conveniently.

4&5.  The finished thingie.

6.  And this is how the scales and indexes are lit.

[Bent Hjarbo]

Very nice, good inspiration.

[Hugh_3170]

Nice work Akira.

IIRC, modern aircracft instruments are red in night mode.

[PeterN]

Really cool and a smart solution!
Thanks for sharing

[Erik Lund]

Nice one! Should be build into the IR remote controls for the cameras 

[Akira]

Thank you, Bent, Hugh, Peter and Erik!

IIRC, modern aircracft instruments are red in night mode.

That makes sense.  I knew about the dim red "night mode" when the updated firmware for Panasonic G9 added the function.

Nice one! Should be build into the IR remote controls for the cameras 

I also thought about modifying ML-L3 that I still have but couldn't figure out the way to disassemble it.   

[Airy]

Good idea. At the army (1983), we also had red lights for reading maps etc. at night. Standard equipment, and an absolute must. Also valid for astronomers.

[Tristin]

Great idea.  I've long wished bodies incorporated a small red light on the VF hump angled to illuminate lens data.  There was that Pentax that hard lights a handful of years ago, but seems to be it.

[mxbianco]

There is an explanation in human physiology: dark red is the only type of visible light that will not cause the human eye's pupil to shrink (or at least to shrink negligibly), so a very little amount of red light will cause menus to be more visible than if you use another color, the worst being a blue led.

Kudos to Akira for the nice work!

Ciao from Massimo

[Fons Baerken]

Well done Akira

[Akira]

Thank you, Airy, Tristin, Massimo and Fons!

At the army (1983), we also had red lights for reading maps etc. at night. Standard equipment, and an absolute must. Also valid for astronomers.

There is an explanation in human physiology: dark red is the only type of visible light that will not cause the human eye's pupil to shrink (or at least to shrink negligibly), so a very little amount of red light will cause menus to be more visible than if you use another color, the worst being a blue led.

Thank you for the interesting additional info from your real experience and scientific knowledge.

I've long wished bodies incorporated a small red light on the VF hump angled to illuminate lens data.  There was that Pentax that hard lights a handful of years ago, but seems to be it.

Actually my initial idea was to mount the red light onto the hotshoe,  But I changed the concept after realizing that one would need to see the equipment other than the camera body.  Also, you would have to make it brighter if you want to light wider areas at a time.

[Tristin]

Red light is standard night equipment for the military because the beam isn't visible, and the illumination is much harder to see at a distance.  Also the reason I'd like red illumination on my camera, it's nice to not be noticed when shooting at night.

[Akira]

Red light is standard night equipment for the military because the beam isn't visible, and the illumination is much harder to see at a distance.  Also the reason I'd like red illumination on my camera, it's nice to not be noticed when shooting at night.

Well, I have some extra parts for the project and bought plastic hotshoe covers.  I may make one based on the initial idea.  Illuminating focusing scale and aperture index on lens from the hotshoe sounds like a good idea.

[Tristin]

I may make one based on the initial idea.

You are not alone, thanks for the inspiration!  One of those occasions where a 3d printer would be handy.  This would be especially handy shooting manual with Z bodies as I can no longer see my selected aperture.  As things currently stand, I have to whip out my phone to illuminate my lens in order to change aperture sometimes.     OT, but the day someone makes an FTZ with aperture register is the day my wallet shrinks.

[armando_m]

red light is required during the astronomy nights, if someone uses white light they get a quick reminder to turn it off

led lamps use pulses vs dc current to save battery, but that will require a bit of circuitry perhaps not worth the effort given the elegant simplicity of your lamp