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Originally Posted by brecklundin
Actually, to be honest you are not exactly correct here. Think back to your biochem courses as well as neuro phys courses...you will have learned that the eyes are typically the primary source of creating vitamin D because we are almost always covered in clothes blocking the skins ability to also convert sunlight into vitamin-D. Do a bit of research if need be.
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Vitamin D synthesis starts with a substance that is in the epidermal layer of the skin, which reacts with the ultraviolet light rays of the sun.
Quote:
Originally Posted by brecklundin
Now about your fear of overheating...you have got to be kidding? I supposed in 100F weather sure but that is out of the safe range and even an 8F day would be fine given the tolerances of a hardware being well over what is listed. And I believe the K1 is from 32F to 93F so a 75F day as we had today represents no threat to melt a reader no matter how black. Remember the device is actually powered down most of the time and only powers up when changing something on the screen. There is some power to the buttons and other input components to allow response to events, but the CPU is powered way down and is generating very little heat same for the graphic subsystem.
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Quote:
Originally Posted by Sam I Am
I'm interested in more opinions on the black leather case being heated in direct sunlight while on a sun holiday. Over the course of four hours or more by the pool.
Will the device overheat?
Will it be too hot to hold?
Thoughts?
I haven't decided what colour to order yet.
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I don't know the answer, but have this single incidence of overheating of a dark blue Sony PRS-505 where I measured the heat with an infrared thermometer.
Ambient temperature: 100 F/38 C.
Sony published high operating range: 95 F/35 C.
1. Read for two hours in the shade - no problems, cool to the touch.
2. As a test of screen fade, placed Sony 505 face up in the sun for 10 minutes.
3. Sony 505 was quite hot to the touch; letters faded; rear (all dark blue metal) measured 135 F/57 C. Front/screen measured 130 F/54.5 C.
4. Let unit cool down in the shade. At 115 F/46 C, there was no more fading of letters. (This lack of fade might have occurred at a temp higher than 115, I wasn't checking.)
Would a white casing have fared the same or similar? I don't know, although I expect it would be at least a little cooler from the physics of color absorbtion/reflection. I've never had the Sony in full sun before or since. Maybe I'll do more testing.
To Sam I Am's direct question about being in a black case for four hours by the pool, I'd say it will heat up, from my first experience with screen fade. I had my Sony in a black case for about 30 minutes, I think in the shade, at an ambient temperature of about 75 F/24 C, and it was quite hot to the touch and caused the eInk to fade. I would suggest taking it out of the black case, maybe draping a white towel or magazine over it.
Not that this has any relevance, but I've ordered the graphite K3. Not with any good reasoning. Llike Harry T., I didn't notice any contrast improvement due to the dark frame (compared to white), despite expecting some. But glad of my choice now that I read brecklundin's experience with white.