Hi Ian, this is definitely a great idea. This is an objective metric which is very relevant for this application.
I'm using a hx4700 and agree that readability is weak unless in full sunlight. So I'm looking to buy a new device and readability is definitely the most important metric. Just a couple of suggestions if you make the effort and post the results on a Wiki page: 1. describe the model as complete as possible. Some devices come with different display types. Also say if it has the bare display or an anti glare foil on it. 2. I find the definition of the Test Positions hard to remember. I suggest you use the angel between sunlight and light coming from the display: Position A is 180° Position B is 135° Position C is 90° Position D is 45° Position E is 0° Ronald Am 20.06.2011 14:37, schrieb Ian: > Hi All > > I bought an hx4700 a while back because it was reportedly one of the > best of its generation with regards to sunlight readability. But quit > frankly once I had it installed and wired I discovered its readability > during flight is still not adequate. I previously flew with a low cost > GPS and then a Palm V mounted in the cockpit which also had their > display limitations so I have experienced this before. The information > provided by XCsoar is so useful, I would never fly without the hx4700. > It is just sad that sometimes when I scan the panel I miss some of the > details on the PDA. > > Now I am considering upgrading to the Dell Streak, and actively looking > for alternatives, because the Dell is reported to have significantly > better sunlight readability than the hx4700. But when I read the > reports, it is obvious that sunlight readability is very subjective. > What looks good in the shop and during a casual walk outside does not > always cut it when you mount the device is in a glider cockpit and go > flying. > > So I figure we should design a means of evaluating sunlight readability > so we can compare our experiences in a semi-scientific manner. I took my > hx4700 out into the sun yesterday and danced around with it a while and > came up with the following: > > > PROCEDURE FOR EVALUATING SUNLIGHT READABILITY OF A PDA DEVICE FOR > GLIDING PURPOSES: > > 1) Requirements: > > - PDA, PNA, Tablet Computer, smart cell phone or other device to test, > with enough battery charge. > > - XCSoar software, loaded with terrain maps and turn points, or > alternate mapping software, like Google maps. > > - An outdoor location with direct, bright sunlight. > > - Gliding sunglasses and optionally a gliding hat or peaked cap. > > > 2) Preparation: > > - Start up a XCsoar on the device, demo mode may prove useful if it is > not located in an area covered by your maps and connected to a GPS. > (Otherwise use alternate mapping software like Google Maps). Make sure > you have some coloured features, like terrain markings, as well as some > text details, like turn point or street labels, clearly visible on the > screen. > > - Ensure that the PDA backlight is on full brightness and will maintain > that setting for several minutes during the evaluation. > > - Put on your sunglasses and optionally your hat. > > > 3) Test Positions: > > Take the device out into the sun and assess it in the following 5 > positions. In each position the device should be held at arms length, > with the screen pointing directly back at your eyes. > > Position A: Sun shining over your shoulder such that the shadow of your > head falls just to one side of the device and the device is in full > sunlight. If it has a reflective screen, the reflection of the sun > should shine on your neck or chin, just below your eyes. > > Position E: Hold the device up in front of the sun so the shadow of the > device blocks the sun from shining directly into your eyes. Be careful > not to look directly into the sun. Wearing a gliding hat or peaked cap > allows you to shade your eyes from the sun with the brim of your hat > while you are positioning the device. > > Position C: Rotate your arms in an ark to a point midway between point 1 > and point 5. Hold the device at right angles to the sun so that it > shines across the screen and small adjustments would put in in either > shade or sunlight. > > Position B: Rotate your arms in the ark to a point midway between > Position A and Position C. There should be direct sunlight falling on > the screen. > > Position D: Rotate your arms in the ark to a point midway between > Position C and Position E. The screen should be in shadow. > > Note I have described the positions in an order which easiest to > understand. Once you know what you are doing it is very easy to go > through them in alphabetic (ie positional) order. > > > 4) Test Procedure: > > Line up the device in the required position and then tilt it slightly to > minimize the effects of reflections etc. Move it up to 15 degrees left > or right and/or up or down while maintaining the relative positions of > the sun, your eyes and the device until you have the best visibility. > > Hold the position and look away at some details on the horizon for > several seconds. Then glance back at the device for 2 seconds. Read some > black text details, like turn point labels (or street names) on the map, > and then look at colour features like terrain shading. Assign a score > from 5 down to 1 for the visibility of the details. The score should be > similar to the 5 to 1 score one uses to report on a radio test > transmission, ie: > > 5: Clearly visible > 4: Some distortion, but still clearly visible. > 3: Significant distortion, but still visible. > 2. Lots of distortion, barely visible. > 1. Total distortion, information not discernible. > > Separate scores should be assigned for black text and colour features. > > Finally make a note how high the sun is above the horizon. This will > give others an indication of how bright the conditions were during your > assessment. > > > To test the above I tried it with the following devices: > > - My HP Compaq hx4700. > > - A college's htc Desire smart phone. (Google shows that this phone came > out with two models of screen, AMOLED and SLCD. There is no definitive > way to determine which is installed. The original packing does not state > AMOLED, which suggests it is SLCD but the test results indicate otherwise). > > - My well used Nokia 6110 Navigator cell phone. > > - My Casio black and white digital watch. (Top of the line for a plastic > digital watch, but still not an exotic watch). > > > I logged these results: > > Colour visibility > Position A B C D E > hx4700 5 4 2 2 1 > htc Desire 1 4 3 3 2 > Nokia 6110 nav 1 3 2 2 2 > > Black/white visibility > Position A B C D E > hx4700 5 4 2 2 1 > htc Desire 1 4 3 3 2 > Nokia 6110 nav 4 3 2 2 2 > Casio digital watch 5 5 5 5 5 > > > This was in sunny but winter weather in Cape Town with the sun about 35 > to 40 deg above the horizon. > > The most interesting comparison is Position A, with the sun shining > directly onto the screen. My hx4700 reads 5, but the htc is a 1. My > Nokia goes black and white. > > In position B both the hx4700 and the htc are clearly visible. > > The "shade" positions, C, D and E test the strength of the back > lighting. The htc is better than the others. > > Clearly the limitation of the hx4700 is the strength of the back light > when it is contrasted with a very bright sky as a background. > > As a comparison I tested my Casio black and white digital watch. It > scored "5" in every position for black text (but obviously no colour > scores). Interestingly when the face was in shadow it was just as > legible as in sunlight - but it looked different, as if the white > background has the ability to reflect ambient light even when in shadow. > > I would appreciate it if others could attempt the above test with > different devices. Please give feedback on the devices you test as well > as comments and suggestions on the test procedure. It would be very good > if people could test multiple devices and give feedback on them so that > the relative sunlight readability of different devices can be accessed. > > If others see the usefulness in this idea, I am happy to post it up on a > wiki somewhere. We can keep a log of test results on the same wiki. > > Thanks > > Ian > > > ------------------------------------------------------------------------------ > EditLive Enterprise is the world's most technically advanced content > authoring tool. 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