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Old 24-07-2017, 03:50   #1
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Red Mode / Night Mode on iPad

Maybe I'm a "gumbie" and this is old news to old salts but I've been trying to do this for two years.

I was gonna buy some red cellophane to put over my iPad when I stumbled across a link solving all my problems with a higher tech solution.

On my iPad I went to
Settings, General, Accessability, Display Accommodations, Colour Filters, (turn them on) , Colour Tint - then slide intensity to max.

Voila - red iPad display. But wait, there's more.

Go back one screen and by reducing "White Point" by 100% you can make the display much dimmer than normal dimming.

Further good news,

Go back to Accessibility main screen and scroll to the bottom to select "Accessability Shortcut". Tick (check) the boxes for "Invert Colours", "Colour Filters" and "White Point".

You're done. If you're in Navionics or your preferred app, you can now "Triple Click" the home button to bring up these options quickly.
"Colour Filters" makes it red
"Reduce White Point" makes it super dim
"Invert Colours" switches the white chart background to black. Nice.

Sadly the "Invert Colours" thing only works on my iPad. On my iPhone it's no longer red but that's ok - it's awesome on the iPad!

My wife is laughing at me because I think it's so cool - I had to tell someone who might appreciate it so I finally signed up on this forum! I hope it helps!!
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Old 24-07-2017, 03:59   #2
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Re: Red Mode / Night Mode on iPad

Haven't needed to yet but I will, so thanks. Your post put a smile on my face So thanks for that too.
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Old 24-07-2017, 04:01   #3
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Re: Red Mode / Night Mode on iPad

Nice to know, though I don't own one. Still, maintaining night vision is always a priority.
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Old 24-07-2017, 04:10   #4
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Re: Red Mode / Night Mode on iPad

Welcome to the forum Dave and thanks for the great tip.

I have just given it a try and it seems to works perfectly, removing one of the issues when using an iPad for navigation.
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Old 24-07-2017, 05:10   #5
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Re: Red Mode / Night Mode on iPad

My understanding is that the US military has shifted from red light for night adaptation to dimmable white light. I haven't found credible documentation to support or refute my recall.

There is a lot of material on "the red myth."
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Old 24-07-2017, 05:47   #6
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Re: Red Mode / Night Mode on iPad

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Originally Posted by Auspicious View Post
My understanding is that the US military has shifted from red light for night adaptation to dimmable white light. I haven't found credible documentation to support or refute my recall.
It is a complicated subject. If you want the best night vision and electronic information is of secondary importance, then red illumination is the only option. This is why WW2 planes had red instrument lighting.

If you want a large amount of complex information that can be processed quickly, you cannot do this and maintain the best night vision so dim white light is the best option.

In a military situation (or very advanced boats) the use of night vision equipment often replaces good natural night vision and complicates the colour issue, as the equipment is not suitable for all illumination systems.

Boats can benefit from both modes. There are times when AIS, radar, and chart plotter information is important and it worth sacrificing some night vision. There are other times when the best night vision is vital even if it makes the AIS , radar and chart plotter harder and slower to use. This is where very dim red illumination is best.
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Old 24-07-2017, 06:29   #7
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Red Mode / Night Mode on iPad

Quote:
Originally Posted by Auspicious View Post
My understanding is that the US military has shifted from red light for night adaptation to dimmable white light. I haven't found credible documentation to support or refute my recall.

There is a lot of material on "the red myth."


You are correct, actually it's usually a green light used by the Military, very similar to the color used in hospital scrubs, ever wonder why they are green? Green causes less eye strain I think, or maybe another myth?
Anyway red light is tremendously intensified by night vision glasses, while green is not, so even a tiny red light looks like a bright flood light to goggles, while the green is barely seen. A red light will blind googles. Just like having a spot light shined in your face.

More to it than that, but studies have found that the red does nothing less about washing out the rhodopsin than dim white light, it's the rhodopsin that is the chemical in the eye you use to see at night, and bright light of any color washes it out, its intensity, not color that does it. It's the reason it takes a while to get your night vision back after being exposed to bright lights, cause it takes time to get the rhodopsin back.
Also red light changes the color of things, like pull out a map and look at it under red light and anything red on the map is gone, can't be seen, while under white light colors stay the same. Of course you lose color perception in dim light cause you use the rods in your eye to see in dim light and they only perceive in black and white, the cones are used to see color, but it takes brighter light to use them

It's thought the red myth came from dark rooms, red doesn't expose film, so it must be the color you need to see in the dark right?

Anyway if your older, by all means do not use red light, most of us suffer from presbyopia and red light is shifted to the side of the spectrum that make it impossible for us older guys to focus on, so red lit things like aircraft instruments will not be in focus to us over 40 crowd.

Best thing to do is use white LED's and dim them, no need to buy red LED's

Now if I could just figure out how to keep my Aqua Signal LED's I have in the cockpit from flickering with a high speed dimmer. Some LED's flicker, some do not? My cheap EBay led strips don't, my Aqua Signals do?
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Old 24-07-2017, 06:36   #8
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Re: Red Mode / Night Mode on iPad

A lot of paper maps from many years back were "red light readable" which meant that the red features were printed in magenta so that the red light viewing would not wash out key features.

Sounds like thinking on this topic has advanced quite a bit since then. I still gotta hand it to the OP. Very cool find !
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Old 24-07-2017, 08:25   #9
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Re: Red Mode / Night Mode on iPad

The key to understanding why red light works when white light does not, is understanding this graph.

Basically rods, which are responsible for night vision when things are very dark are insensitive to red light. Therefore, red light does not bleach out the rod receptors.

However, this is only important for very dark conditions when you are fully dark adapted. Many crew never reach this level of dark adaptation. It is worth experiencing this to see what you have been missing, but it difficult to do on many yachts with the normal setup.

Full dark adaptation is not needed most of time, but on occasions such as entering an anchorage on a moonless night it can be worthwhile, so it is worth setting up your boat instruments so you can still get basic information (like depth) with minimal effect on your night vision.
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Old 24-07-2017, 08:27   #10
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Re: Red Mode / Night Mode on iPad

At night when I am alone on watch I can see better if I play the stereo LOUD!


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Old 24-07-2017, 08:49   #11
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Red Mode / Night Mode on iPad

Nolex, trust me, red light does not "work" any better than any other color. There is no color that does. I have years or training and experience in this, the AH-64 was THE night fighter, the Air Force when they formed the first stealth squadron came and studied how we did things in Tx as we had more night experience than anyone.
It's the level of light, not the color of it that matters.

It's also rhodopsin, or visual purple that gives you night vision
https://en.m.wikipedia.org/wiki/Rhodopsin and it is what requires low light levels to night adapt.
Yes the rods are less sensitive to red, so it takes more light for you to see, use a blue green light and you can see with less light level, but rods are most sensitive there, so it's a wash.
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Old 24-07-2017, 08:56   #12
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Re: Red Mode / Night Mode on iPad

Quote:
Originally Posted by Auspicious View Post
My understanding is that the US military has shifted from red light for night adaptation to dimmable white light. I haven't found credible documentation to support or refute my recall.

There is a lot of material on "the red myth."
When I was an enlisted combat engineer in the eighties, red lights were what we used. Night vision devices started to come out en-masse and those did have green scopes, but they were not lights designed to light up the inside of vehicles. They were designed to allow you to see targets.

Later I became an officer and went into tanks and cavalry (No, horses do not have dome lights! Cavalry refers to reconnaissance). In the mid eighties (I think) they started to move to green dome lights for lighting up the inside of vehicles. This was not because it was a better night light. It was because it was less visible to enemy night vision devices. N.B. Good night vision devices, in particular thermal night vision devices, provide amazing detail at distances well over 1,000 meters (1,083 yards).

I should point out that to me, it made no difference whether I was using red or green light. The only thing I noted was that some colours where harder to read than others depending upon the light. Other than that, I could read just fine. A few people did have issues with the light depending upon what colour it was. Try both and see what works best for you.
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Old 24-07-2017, 09:00   #13
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Re: Red Mode / Night Mode on iPad

I went looking for the night flying handbook we came up with that discussed off center viewing and night scanning techniques etc and could not find it, but bumped into this, it seems the FAA has picked up on some of our techniques, I know where they came from as the names are the same, and that would be one heck of a coincidence.
But there is a lot of scanning techniques etc that can really improve your night vision

https://www.faa.gov/regulations_poli...a/hfh_ch13.pdf
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Old 24-07-2017, 09:08   #14
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Re: Red Mode / Night Mode on iPad

Quote:
Originally Posted by noelex 77 View Post
This is why WW2 planes had red instrument lighting.
WWII was a long time ago and science has advanced.

I remember dimmed white lights in LCAC, helicopters, and M1 tanks when I was a US Navy contractor. There was a lot of discussion about the shift from red to dimmed white. Science--real science, not opinion--won the day. I was told the USAF went the same way but can't say so of my own knowledge.

Yes, the eye is less responsive to red light than to white. By the time red light is bright enough to see by you have the same night vision accommodation problems. Dimmed white is the standard on my boats.

Quote:
Originally Posted by noelex 77 View Post
There are times when AIS, radar, and chart plotter information is important and it worth sacrificing some night vision.
This is where MFDs really pay off. Separate displays mean more aggregate light. Dim the backlight for your MFD all the way down and you have access to everything, overlaid, in one display.

Quote:
Originally Posted by a64pilot View Post
Best thing to do is use white LED's and dim them, no need to buy red LED's
That is certainly my conclusion based on the research. The challenge is finding good quality dimmable white products. Lots of red, although often you have to cycle through bright white and bright red to get to dim red which is frustrating.

One more crew member turns to look at me coming up the companionway in response to a call and blinds me with a bright red head lamp and its going over the side. I may or may not remove the head lamp from said crew in the process.

Light discipline is important.
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Old 24-07-2017, 09:10   #15
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Re: Red Mode / Night Mode on iPad

[QUOTE=a64pilot]
The peak absorption of the retina is at the green wavelength. Therefore you see green "easier and faster " hence less fatigue.
Whén you get older you nailed you shift into presbyopia. But that is not the reason to see the red colour more difficult. The reason behind presbyopia is an altering of the crystalline lens and is the beginning stage of a cataract. Since a cataract in becoming opaque absorbs colours differently you have found your explanation.
LED's need a certain threshold voltage to work. The type of dimmer and the load on the dimmer are crucial. It is not a good idea to use a resistance type as fir the good old people incandescent lamps
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