Hi Fred, I thought for quite awhile about what to do about vision-impaired users of the P3. I couldn't think of any way that a blind or severely visually-impaired person would be able to get any significant benefit from a panadapter so I finally decided not to attempt to make it usable by the blind.
However color blindness is another story. Many of Elecraft's customers are older males and, like me, have some degree of color blindness. I have tried to take that into account in the color scheme used in the P3. The following information comes from the Color_blindness page on Wikipedia. There are three types of cones (color receptors) in the retina that have peaks in different parts of the spectrum: blue, green and red. (The so-called "red" peak is actually more like orange/yellow.) The three spectral responses overlap considerably. The eye measures the response of each type of cone and interpolates to figure out what the actual color must be. "Color blind" does not necessarily mean "blind to colors" but rather an inability to perceive differences between some of the colors that others can distinguish. There are many types of color blindness, but the most common (affecting about 9% of adult males) are the so-called "red-green" hereditary (genetic) photoreceptor disorders, all of which make it difficult to discriminate reds, yellows and greens from one another. There are other types of color blindness that make it difficult to distinguish between blue and yellow, but they are less common. I have tried to make the default colors accommodate people with red-green color blindness. That means making sure that markings and their backgrounds never both come from the red-green end of the spectrum. It also means avoiding small objects and thin lines with such colors (even with a blue background) because many color-blind people can see the problem colors much better if the object has some "mass" to it. It helps that this is the kind of color blindness that I have, so if it looks good to me it should look good to others with red-green color blindness. In addition, to accommodate people with other types of color blindness including those with monochromacy (total color blindness) the lines and text on the spectrum display are all bright colors with a dark background so they should look good in greyscale. The waterfall display is more difficult since the different colors are used to indicate different signal strengths, but weak signals are represented by dark colors so there is still some ability to discern variations in signal strength. Fortunately colors are trivial to change in firmware, so if we get it wrong at first it is easy to change later. Alan N1AL On Mon, 2010-04-19 at 14:51 -0700, Fred Jensen wrote: > Al Lorona wrote: > > > That is really pretty, but my prevailing thought was that perhaps > > it's just too much eye candy-- which really doesn't make interpreting > > the data any easier. The spectrum readout-- arguably the most > > important area of the screen-- is difficult to concentrate on with > > the distraction of the other detail (color, shading, texture, 3D > > effects, text, labels, buttons, controls) of the skin. > > How much of the P3 display information will I miss? I have no color vision. > > 73, > > Fred K6DGW > - Northern California Contest Club > - CU in the 2010 Cal QSO Party 2-3 Oct 2010 > - www.cqp.org ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html

