Author Topic: EEVblog #224 red green blindness problem  (Read 13713 times)

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Offline manolis

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EEVblog #224 red green blindness problem
« on: December 03, 2011, 10:29:21 am »
Hi,
I just wanted to give some, maybe unexpected, feedback on the 3rd part of the power supply series. It is nearly impossible to distinguish the traces on the oscilloscope, for someone with a red green color blindness. (both lines look like the same yellow greenish color) Am I the only one having this problem? If not I would like to suggest using maybe yellow and blue for future multichannel oscilloscope action.

So long
Manolis
 

Offline EEVblog

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Re: EEVblog #224 red green blindness problem
« Reply #1 on: December 03, 2011, 12:18:04 pm »
I don't think you can change the colours. They are matched to the front panel and probe colour coding.

Dave.
 

Offline ablacon64

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Re: EEVblog #224 red green blindness problem
« Reply #2 on: December 03, 2011, 02:50:59 pm »
Maybe this is something the manufacturer should be informed about.
 

Offline IanB

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Re: EEVblog #224 red green blindness problem
« Reply #3 on: December 03, 2011, 05:31:49 pm »
This is an aspect of user interface design that is often overlooked. Typically there should be some other visual cue in addition to colour, such as varying line style or shaped markers/labels on the traces.
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Offline EEVblog

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Re: EEVblog #224 red green blindness problem
« Reply #4 on: December 03, 2011, 05:45:58 pm »
Does everyone go colour blind the same way?
Stupid question??
Sorry, I know absolutely nothing about it.

Dave.
 

Offline Chet T16

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Re: EEVblog #224 red green blindness problem
« Reply #5 on: December 03, 2011, 06:07:28 pm »
There's a couple of different types, there's an android app that simulates them using the camera

 https://market.android.com/details?id=com.SeewaldSolutions.ColorBlindnessSimulator
« Last Edit: December 03, 2011, 06:09:20 pm by Chet T16 »
Chet
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Offline IanB

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Re: EEVblog #224 red green blindness problem
« Reply #6 on: December 03, 2011, 06:11:33 pm »
http://www.colblindor.com/2010/03/16/red-green-color-blindness/

Red-green colour blindness is inherited and present from birth. About 8% of men and 0.5% of women suffer from some kind of red-green vision deficiency.
« Last Edit: December 03, 2011, 06:14:16 pm by IanB »
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Offline benemorius

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Re: EEVblog #224 red green blindness problem
« Reply #7 on: December 03, 2011, 07:04:53 pm »
With some 4% of the population being affected, it may indeed be worth taking in to consideration. It's the most common type of color blindness, but I had no idea the rate was so high.

The suggestion of using the yellow and blue channels for a 2 channel setup seems ideal since that would also allow the full sampling rate compared cutting it in half while using channels 1 and 2.
« Last Edit: December 03, 2011, 07:23:54 pm by benemorius »
 

Offline mobbarley

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Re: EEVblog #224 red green blindness problem
« Reply #8 on: December 03, 2011, 07:18:33 pm »
8% is pretty large! I only suffer from what is probably computer screen induced myopia.  I hate computers
 

Offline ejeffrey

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Re: EEVblog #224 red green blindness problem
« Reply #9 on: December 03, 2011, 09:05:05 pm »
Red-green color blindness is by far the most common, and I think it would be worthwhile for scope manufacturers to select default colors that would be visible to those people.  I don't know how hard this is -- it may be difficult to find 4 colors that are highly distinguishable under a range of lighting and viewing conditions both on the screen and the probes.

In any case, I really think there should be a provision to change the on-screen colors for anyone that can't distinguish the defaults easily.  If not matching the probes is a problem it is a simple enough matter of using some colored stickers.
 

Offline vk6zgo

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Re: EEVblog #224 red green blindness problem
« Reply #10 on: December 03, 2011, 11:28:46 pm »
You are no worse off than a person with an analog Oscilloscope,where you can get any colour you like,providing it's green! ;D (or blue on some 'scopes)

VK6ZGO
 

Offline saturation

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Re: EEVblog #224 red green blindness problem
« Reply #11 on: December 04, 2011, 12:14:39 am »
Most new generation DSO have options to reset the colors, unlike an analog scope.  On the Rigol 1052e series for example, one of the 'skins' maybe one you can see better to distinguish multiple traces on a scope.  The default colors should be viewable: yellow, blue and purple for ch 1, 2, and math respectively which I estimate can be seen by even the worse variant, the protanope.

Normal is upper left, you should see a green tinged 2 in a red-pinkish background of dots.

Best Wishes,

 Saturation
 

Offline Mechatrommer

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Re: EEVblog #224 red green blindness problem
« Reply #12 on: December 04, 2011, 01:12:38 am »
i guess the why yellow-blue mystery has been answered. thanks to OP for highlighting this up.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline aargee

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Re: EEVblog #224 red green blindness problem
« Reply #13 on: December 04, 2011, 06:03:55 pm »
It used to be (still is??) that colour blindness ruled you out of a job in electronics/electrical work.

I remember doing this as a basic test with Telecom in the early 80's.

- Rob.
Not easy, not hard, just need to be incentivised.
 

Offline BravoV

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Re: EEVblog #224 red green blindness problem
« Reply #14 on: December 04, 2011, 06:51:13 pm »
It used to be (still is??) that colour blindness ruled you out of a job in electronics/electrical work.

I remember doing this as a basic test with Telecom in the early 80's.

- Rob.

Pretty confident still applies to bomb squad, you know, those cables at the bomb timer ... <snip>... BANG ! ;D

Offline ejeffrey

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Re: EEVblog #224 red green blindness problem
« Reply #15 on: December 04, 2011, 08:31:21 pm »
It used to be (still is??) that colour blindness ruled you out of a job in electronics/electrical work.

I remember doing this as a basic test with Telecom in the early 80's.

- Rob.

I know several people who work in electronics and are color blind.  It isn't that serous of a problem most of the time.  I can see it being a bigger issue if you are a field technician for the phone company working on bundles of hundreds of color coded twisted pairs.  For your a desk worker doing electronics design and whatnot it is fairly easy to work around.
 

Offline Zero999

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Re: EEVblog #224 red green blindness problem
« Reply #16 on: December 05, 2011, 05:37:54 am »
http://www.colblindor.com/2010/03/16/red-green-color-blindness/

Red-green colour blindness is inherited and present from birth. About 8% of men and 0.5% of women suffer from some kind of red-green vision deficiency.

One thing that most people miss is there's a huge range of different levels of colour blindness. On the one extreme some people have no cones at all which means they have no colour perception at all and generally poor vision, then there are those who only have one colour cones, say green who have normal visual acuity but no colour vision to those who have a two colour cones and those with slight colour deficiency.

I have deuteranomaly which is not red-green colour blindness in the way most people probably perceive it. I have the full complement of red, green and blue cones so can distinguish between different colours quite well most of the time - reading resistor colour codes or distinguishing between different colour wires has never been a problem for me. It's just the peak response of my green colour cells is slightly shifted towards the red end of the spectrum which can make identifying different shades of green, yellow, orange and brown difficult under some lighting conditions. If I look at a rainbow, the green to red part will be appear closer together than it should and the green-violet further apart than the should. This means that although y ability to distinguish between shades in the red-gree may not be so good, I may be better in green-blue end of the spectrum than someone with normal colour vision.
 

Offline slateraptor

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Re: EEVblog #224 red green blindness problem
« Reply #17 on: December 05, 2011, 06:55:22 am »


Oh, crap. So just went into hypochondriac mode. :o
 

Offline IanB

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Re: EEVblog #224 red green blindness problem
« Reply #18 on: December 05, 2011, 08:46:32 am »
Oh, crap. So just went into hypochondriac mode. :o

Why did you just post a picture of a plain grey card?  ;)
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Offline Wartex

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Re: EEVblog #224 red green blindness problem
« Reply #19 on: December 05, 2011, 09:30:56 am »
It used to be (still is??) that colour blindness ruled you out of a job in electronics/electrical work.

I remember doing this as a basic test with Telecom in the early 80's.

- Rob.

I know several people who work in electronics and are color blind.  It isn't that serous of a problem most of the time.  I can see it being a bigger issue if you are a field technician for the phone company working on bundles of hundreds of color coded twisted pairs.  For your a desk worker doing electronics design and whatnot it is fairly easy to work around.

IANAL but labour laws prohibit colorblind in working in industries where work/products affect safety of others. You wouldn't want a PLC wiring harness made by a colorblind person to be used in a power plant or something.
 

Offline Zero999

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Re: EEVblog #224 red green blindness problem
« Reply #20 on: December 06, 2011, 05:42:59 am »
You wouldn't want a PLC wiring harness made by a colorblind person to be used in a power plant or something.
I would have no problem with that whatsoever.

If the wireman's colourbliness caused a problem, it's the engineer's fault for designing the panel so cable colours are important for electrical safey.

Where I work we use wire and terminal numbers, colours are only used in accordance with the electrical code. Even if the technician is not colourblind, it's bad to rely on colour because the lighting may distort colours anyway; this is especially true in locations lit by mercury or HID lighting.
 

Online ciccio

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Re: EEVblog #224 red green blindness problem
« Reply #21 on: December 06, 2011, 07:35:41 am »
With age going up I developed a slight form of colorblindness, that the ophthalmologist declared "futile and of no conseguences" and treated me as a fool because I was passing his (her) tests, so I had measurable problem..
My problem is that, if I don't have a strong lightning and sometimes a small magnification, I have problems in reading resistor color codes. Every strip is gray!!! Same problems with ICs that are laser marked: brown on gray is not OK.
A simple lighted magnifier et voilà: everything is ok.
The experts above can give me some indications?
Thanks and best regards
Ciccio

Strenua Nos Exercet Inertia
 

Offline IanB

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Re: EEVblog #224 red green blindness problem
« Reply #22 on: December 06, 2011, 08:17:21 am »
With age going up I developed a slight form of colorblindness, that the ophthalmologist declared "futile and of no conseguences" and treated me as a fool because I was passing his (her) tests, so I had measurable problem..
My problem is that, if I don't have a strong lightning and sometimes a small magnification, I have problems in reading resistor color codes. Every strip is gray!!! Same problems with ICs that are laser marked: brown on gray is not OK.
A simple lighted magnifier et voilà: everything is ok.
The experts above can give me some indications?
Thanks and best regards

Make sure you have good quality lighting--incandescent preferably. Fluorescent and LED lighting can be really bad for colour rendition. Switching out incan bulbs for CFLs can easily make you think your eyesight is failing.

You might like to get a colour chart like the ones used for monitor or printer calibration and look at it under different lighting sources. Pick the lights that do the best job of making all the colours look different and identifiable.
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Offline benemorius

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Re: EEVblog #224 red green blindness problem
« Reply #23 on: December 06, 2011, 09:35:26 am »
CRI is what's important with regard to colors and lighting. It's not a perfect rating system, and marketing departments do try to cheat as you'd expect, but it's the best thing you have to go by short of actually trying the lights out. A light source with a higher CRI emits a more complete spectrum of light and allows better color rendition. For a perfect CRI of 100, you do pretty much have to go with incandescent lights. Their CRI is 100 by definition. However, if you hate yellow light as much as I do then that isn't much of an option. Ain't no such thing as a 6500k incandescent light.

Fluorescent lighting phosphors have been improving and you can find lights with a CRI in the 90s now, which is very good. You can easily get them with a CRI below 60 if you aren't paying attention though, so it's important to check the specifications. The worst (and often the most common) fluorescent lights out there will actually have gaps in their emission spectrum where they emit no light of a given frequency at all. As IanB pointed out, those can drive even someone with normal vision crazy.

Checking the light source yourself with a color chart sounds like an excellent idea when it's that important. You end up collecting the same data that CRI testing was meant to collect, but you're doing it yourself with your own two eyes, and you're checking a much more complete spectrum than the handful of samples dictated by testing procedures.
 

Offline vk6zgo

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Re: EEVblog #224 red green blindness problem
« Reply #24 on: December 06, 2011, 12:09:37 pm »
With age going up I developed a slight form of colorblindness, that the ophthalmologist declared "futile and of no conseguences" and treated me as a fool because I was passing his (her) tests, so I had measurable problem..
My problem is that, if I don't have a strong lightning and sometimes a small magnification, I have problems in reading resistor color codes. Every strip is gray!!! Same problems with ICs that are laser marked: brown on gray is not OK.
A simple lighted magnifier et voilà: everything is ok.
The experts above can give me some indications?
Thanks and best regards
Have you tried looking at some OLD resistors to see if the problem is as pronounced?

What I have noticed is that modern resistors have paint where,brown,orange & red are not very much different.
I thought it was my eyes until I looked at some oldies in my junkbox--all the colours were distinctly different.
It costs more to use better paint,so the bean counters found a cheap cruddy source & went with it.

The first time I saw laser marked ICs,I thought that they had overheated & burnt the white paint! ;)


VK6ZGO
 


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