Elecraft

Blue Displays and Visual Acuity

Classic

List

Threaded

11 messages Options

ALAN GARD

Blue Displays and Visual Acuity

Hi

I'm really hesitant about challenging such an accepted authority as AC7AC on any topic. But I think he is incorrect when he says "blue light provides the greatest visual acuity."

A simple experiment (which I have seen performed) can confirm this. Project a graded black and white resolution pattern in white light. Cover the projection lens successively with red, green and blue colour-separation filters and see how many of the patterns the eye can resolve in each case. You will be amazed at how few can be counted through the blue filter when compared with the green or, to a lesser extent, the red.

This characteristic of normal human vision is acknowledged in the design of RGB television systems where less bandwidth is allocated to the blue signal. If it's acuity you are looking for, green is your colour, not blue!

73 de Alan G4LWA

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

gdaught6

Re: Blue Displays and Visual Acuity

Alan wrote...

> I'm really hesitant about challenging such an accepted authority as AC7AC on any topic. But I think he is incorrect when he says "blue light provides the greatest visual acuity."

If I recall correctly, the human eye is most sensitive in the yellow-green part of the
spectrum... 565 nanometers is the peak, but that doesn't necessarily mean "greatest
visual acuity" I guess.

73,

George T Daughters, K6GT
CU in the California QSO Party (CQP)
October 3-4, 2009

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

MontyS

Re: Blue Displays and Visual Acuity

Would there be any difference between emitted light and reflected light?
Monty K2DLJ

> If I recall correctly, the human eye is most sensitive in the yellow-green
> part of the
> spectrum... 565 nanometers is the peak, but that doesn't necessarily mean
> "greatest
> visual acuity" I guess.
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

AC7AC

Re: Blue Displays and Visual Acuity

In reply to this post by ALAN GARD

CONTENTS DELETED

The author has deleted this message.

Brendan Minish

Re: Blue Displays and Visual Acuity

In reply to this post by gdaught6

On Wed, 2009-06-17 at 12:24 -0700, [hidden email] wrote:
> Alan wrote...
> If I recall correctly, the human eye is most sensitive in the yellow-green part of the
> spectrum... 565 nanometers is the peak, but that doesn't necessarily mean "greatest
> visual acuity" I guess.

As someone with short sight I find that yellow - green is much clearer
and sharper at a distance than blue or red.

This makes some sense since the refractive index of my glasses (&
Eyeballs) as well as the sensitivity to light is based on the middle of
the the visual spectrum

If you want Blue because it looks pretty, then go for it but it's not
'better'.

73
Brendan EI6IZ

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Steve Ellington

Re: Blue Displays and Visual Acuity

In reply to this post by MontyS

For long periods of exposure, like the front panel of a radio, it seems like
one would prefer a color that is easy on the eyes and not glaring. Green and
orange are bit tiring while soft blue is soothing. Next, we need plenty of
contrast so we can see the numbers. Here's where we have trouble. TenTec is
using blue on the Jupier now. It's soothing but the white numbers make the
display look milky. Black seems too close to blue and doesn't show up well.
The orange display on the K3 is a bit tiring but I can read it from across
the room. My favorites are displays with a black background and bright
colored numbers. Even white looks good.
Steve Ellington
[hidden email]
----- Original Message -----
From: "Monty Shultes" <[hidden email]>
To: "[hidden email]" <[hidden email]>
Sent: Wednesday, June 17, 2009 3:34 PM
Subject: Re: [Elecraft] Blue Displays and Visual Acuity

> Would there be any difference between emitted light and reflected light?
> Monty K2DLJ
>
>> If I recall correctly, the human eye is most sensitive in the
>> yellow-green
>> part of the
>> spectrum... 565 nanometers is the peak, but that doesn't necessarily mean
>> "greatest
>> visual acuity" I guess.
>>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

hank_stamper

Re: Blue Displays and Visual Acuity

In reply to this post by AC7AC

From the artistic side of color theory, I know both red and blue are
low value colors - value being light/dark.

I suspect this is simply because of their proximity to the edges of
the visual spectrum.

73 de Eric, KG6MZS

On Jun 17, 2009, at 12:34 PM, Ron D'Eau Claire wrote:

> Interesting experiment, Alan. I've not tried it but a little
> research backs
> you up! One source (University of Illinois Dept. of Physics) says "
> The
> blue-sensitive cones are the least numerous, and are also spread
> out away
> from the fovea. This is one reason why it is harder to get a sharp
> visual
> impression of something blue than something of other colors."
>
> I find the sort of white light I use for fine work (5800K color
> temp) tiring
> over time and I've read that the blue end of the spectrum offers
> better
> resolution due to the shorter wavelength. In any event 5800K lights
> are
> "bluish" but contain elements of the whole color spectrum just like
> sunlight.
>
> For something other than "white light", you may be right that a
> mixture of
> blue and yellow light (green) actually works better.
>
> There's also possibility a psychological effect about "blueish"
> light (e.g.
> sunlight) that has nothing to do with the physiology of vision. We
> humans
> are conditioned to be alert when bathed in "sunlight". Specialists
> in sleep
> disorders often recommend shifting to redder and dimmer lights as
> we move
> toward bedtime. They claim it greatly increases our ability to
> drift off to
> sleep.
>
> I do know from personal experience that it's hard to see detail in red
> light, having sat in many aircraft cockpits with the red night
> vision lights
> on straining to read a legend on a chart! Same is true for the
> bridge of a
> ship rigged for night.
>
> Whatever the underlying causes, I do find blue light jarring, while
> redder
> light is softer and more relaxing.
>
> I operate to relax. I was waiting for a hard-core contester or DX-
> chaser to
> say he/she wants to be wide awake and "on edge", that's why he
> likes the
> blue light. That would make good sense, but no one did - so far ;-)
>
> Never hesitate to challenge me. A forum like this isn't about
> "being right".
> It's about open discussion and learning.
>
> Tnx!
>
> Ron AC7AC
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of
> [hidden email]
> Sent: Wednesday, June 17, 2009 11:55 AM
> To: Elecraft Mailman
> Subject: [Elecraft] Blue Displays and Visual Acuity
>
>
> Hi
>
> I'm really hesitant about challenging such an accepted authority as
> AC7AC on
> any topic. But I think he is incorrect when he says "blue light
> provides
> the greatest visual acuity."
>
> A simple experiment (which I have seen performed) can confirm
> this. Project
> a graded black and white resolution pattern in white light. Cover the
> projection lens successively with red, green and blue colour-
> separation
> filters and see how many of the patterns the eye can resolve in
> each case.
> You will be amazed at how few can be counted through the blue
> filter when
> compared with the green or, to a lesser extent, the red.
>
> This characteristic of normal human vision is acknowledged in the
> design of
> RGB television systems where less bandwidth is allocated to the blue
> signal. If it's acuity you are looking for, green is your colour,
> not blue!
>
> 73 de Alan G4LWA
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

hf4me

Re: Blue Displays and Visual Acuity

In reply to this post by Brendan Minish

Anybody remember the first CRT computer terminals? They used GREEN
characters. Later amber was prettier, but the green ones were first, maybe
for a reason.

73, de Jim KG0KP

----- Original Message -----
From: "Brendan Minish" <[hidden email]>
To: <[hidden email]>
Cc: <[hidden email]>
Sent: Wednesday, June 17, 2009 2:39 PM
Subject: Re: [Elecraft] Blue Displays and Visual Acuity

> On Wed, 2009-06-17 at 12:24 -0700, [hidden email] wrote:
>> Alan wrote...
>> If I recall correctly, the human eye is most sensitive in the
>> yellow-green part of the
>> spectrum... 565 nanometers is the peak, but that doesn't necessarily mean
>> "greatest
>> visual acuity" I guess.
>
> As someone with short sight I find that yellow - green is much clearer
> and sharper at a distance than blue or red.
>
> This makes some sense since the refractive index of my glasses (&
> Eyeballs) as well as the sensitivity to light is based on the middle of
> the the visual spectrum
>
> If you want Blue because it looks pretty, then go for it but it's not
> 'better'.
>
> 73
> Brendan EI6IZ
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

hf4me

Re: Blue Displays and Visual Acuity

In reply to this post by Steve Ellington

Commodore supposedly chose two tone blue for that very reason for their
Commodore 64 screen, because it was a soothing color combination.

73, de Jim KG0KP

----- Original Message -----
From: "Steve Ellington" <[hidden email]>
To: "Monty Shultes" <[hidden email]>; "[hidden email]"
<[hidden email]>
Sent: Wednesday, June 17, 2009 2:47 PM
Subject: Re: [Elecraft] Blue Displays and Visual Acuity

> For long periods of exposure, like the front panel of a radio, it seems
> like
> one would prefer a color that is easy on the eyes and not glaring. Green
> and
> orange are bit tiring while soft blue is soothing. Next, we need plenty of
> contrast so we can see the numbers. Here's where we have trouble. TenTec
> is
> using blue on the Jupier now. It's soothing but the white numbers make the
> display look milky. Black seems too close to blue and doesn't show up
> well.
> The orange display on the K3 is a bit tiring but I can read it from across
> the room. My favorites are displays with a black background and bright
> colored numbers. Even white looks good.
> Steve Ellington
> [hidden email]
> ----- Original Message -----
> From: "Monty Shultes" <[hidden email]>
> To: "[hidden email]" <[hidden email]>
> Sent: Wednesday, June 17, 2009 3:34 PM
> Subject: Re: [Elecraft] Blue Displays and Visual Acuity
>
>
>> Would there be any difference between emitted light and reflected light?
>> Monty K2DLJ
>>
>>> If I recall correctly, the human eye is most sensitive in the
>>> yellow-green
>>> part of the
>>> spectrum... 565 nanometers is the peak, but that doesn't necessarily
>>> mean
>>> "greatest
>>> visual acuity" I guess.
>>>
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Bill Coleman-2

Re: Blue Displays and Visual Acuity

In reply to this post by ALAN GARD

On Jun 17, 2009, at 2:55 PM, [hidden email] wrote:

> This characteristic of normal human vision is acknowledged in the
> design of RGB television systems where less bandwidth is allocated
> to the blue signal. If it's acuity you are looking for, green is
> your colour, not blue!

The standard luminance equation used for color television is based
directly on the response of the eye. It calls for 11% blue, about 1/3
red, and the rest green.

For reasons that should be obvious from biology, our eyes are far more
capable of distinguishing shades of green than shades of blue or red.

Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email]
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

KM4VX

Re: Blue Displays and Visual Acuity

In reply to this post by gdaught6

I started the thread a few days ago as my first posting on the Elecraft Reflector and didn't appreciate the number of opthamologist hams using Elecraft. Thanks for the many inputs and it appears impractical to try and change the display. Personally, I find either green or orange as a background psychologically unpleasant; neither color has positive connotations. If blue impractcal I would like to see white on black similar to the older Yaesu rigs or an option in the IC 756 PRO III. Some colors are positive and others are negative. The images green and orange bring to mind are not positive (swamp, nausea, dull, boring) I don't foresee making any after-market changes here but hope Elecraft will offer some diplay options in the future. Selecting which display color option is obviously a very personal choice. It would be nice to have a choice.

gdaught6 wrote

Alan wrote...

> I'm really hesitant about challenging such an accepted authority as AC7AC on any topic. But I think he is incorrect when he says "blue light provides the greatest visual acuity."

If I recall correctly, the human eye is most sensitive in the yellow-green part of the
spectrum... 565 nanometers is the peak, but that doesn't necessarily mean "greatest
visual acuity" I guess.

73,

George T Daughters, K6GT
CU in the California QSO Party (CQP)
October 3-4, 2009

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html