Dot Physics

Kindle vs. iPad in the Sun

There is this commercial that has been coming on lately showing some people reading the Kindle at the beach. Why is this a selling point? It has to do with the way the Kindle works compared to something like the iPad. I would take a picture, but I have neither of these devices. Instead, I will make a diagram.

i-f50b1b10640178f1b370c6c0baae2247-2010-08-12_untitled_1.jpg

Maybe you can’t tell from my diagram, but I am using the black rays to represent light reflected from the Kindle and red rays to represent light produced from the iPad. And that is the key. The Kindle does not have a light source, it is very similar to a piece of paper. The iPad is kind of like a flashlight in that it is a light source.

So now, you are in the bright sunlight. For the kindle, the brighter the external light source, the more light is reflected. This is good. Your eyes adjust to bright light to not let as much light in. The result is that you can see the Kindle just fine in the sunlight. The iPad only produces a finite amount of light. The brighter it is outside, the less you can see it. First, your eyes are adjusting to just looking at brighter things (so that doesn’t help). Also, there is more light reflecting off the surface of the iPad making it harder to see the image below the glass (this is just like looking through dark windows.)

In the opposite case – in a dark room, clearly the Kindle is at a disadvantage. You need some external light to view it and read in bed. This is actually better for your eyes (so I am told), but it might disturb anyone else in your bed that wants to go to sleep.

In the end, I have neither of these devices. I still read dead-tree books. Oh, and I doubt I would ever take even a book to the beach. It’s not that I don’t want to relax, I would just rather play or dig a big hole.

Comments

  1. #1 Benton Jackson
    August 12, 2010

    Dead tree books don’t have backlights either. They have a little more contrast than a kindle, and use even less power. But a Kindle holds way more books per cubic inch, and you can read it with one hand without a holder.

    Oh- and you can always turn the light on to read the Kindle, but you can’t turn the sun off to read the iPad.

  2. #2 http://jcmartz.myopenid.com
    August 12, 2010

    The link you provided in the text is broken. The correct link shoulb be looking through dark windows.

  3. #3 Rhett Allain
    August 12, 2010

    Thanks – it was a link typo. I fixed it.

  4. #4 ds
    August 12, 2010

    Amazon investors are scared of the iPad, The iPad has had a major impact on the price of shares of Amazon in recent months, as investor sentiment for Amazon has been waning ever since the iPad was released – http://tinyurl.com/35aw49r

  5. #5 Mike Moxcey
    August 13, 2010

    That’s why I’m still waiting for a smartphone that uses e-Ink technology. I cannot use my cell phone in the full sun. I can dial numbers and call people on it but I cannot read the menus or the lists of phone numbers.

    It seems to me there is a profitable (not the same as largest) market for actually usable outdoor cell phones.

  6. #6 AMW
    August 13, 2010

    Any thoughts on the upcoming Mirasol screens from Qualcomm? Having color capabilities in a reflective screen seems like a game-changer.

  7. #7 iPad News
    August 29, 2010

    For the iPad there are some Anti Reflection folio for the display. It works perfect. Only some colour brilliance fade away. But you can look at the display with direct sun lightning. and the fell of touch is better too.
    Best regards

  8. #8 Steve
    September 20, 2010

    My brother was being an idiot about this. He was going with a lot of other idiots on the web saying the reason was because of the glare. NOT true.

    The reason is the type of LCD they use in the devices. The kindle uses and oldschool reflective LCD — almost like the ones you find in cheap watches and the old Game Boys. This type of LCD looks grey-greenish when the unit is off (or even when it’s on provided the LCD screen isn’t all black).

    The iPad uses a back-lit LCD screen. These things look black when the unit is off. They’re the choice for notebooks and similar devices because they give better colour and contrast.

    You don’t need backlighting to see whats on a reflective display because the light reflects off the back of the lcd. However, because it doesn’t produce light of its own, you won’t see it at all in the dark.

    On the other hand, you can’t see back-lit lcds in intense light (such as sunlight) in the same sense that you can hardly distinguish the shine of a flashlight in an open field under the sun. The sunlight is just so much brighter and yes — your eyes are adjusting to the brighter light.

    Some devices like video cameras have reflective – backlit screens. You can use them outdoors without the backlighting or indoors with the backlighting on to provide visibility. Again, just look at the colour of the screen when the unit is off to quickly see whether it’s a reflective screen or a non-reflective one.

    The whole light-reflecting-off-the-glossy-screen is not the main reason why you can’t clearly see the iPad under the sun. Try it with any notebook and see for yourself. Then try shining a flashlight at the ground with the sun out.

  9. #9 Chris Quan
    October 14, 2010

    Here is how to use the iPad as e-reader under direct sunlight.

    1) Use white text on black background mode
    2) Use maximum brightness
    3) Use polarized sunglasses.
    4) Move it around a little for better result.

    Below is example.

    http://www.youtube.com/watch?v=NksXmYdji1A

  10. #10 Vic
    November 5, 2010

    I’m currently reading a book in the sun on my iPad next to my girlfriend reading a good old fashioned dead tree book. She has to wear dark glasses, and I do not – one small advantage of having a screen with lower contrast I guess!

  11. #11 Cctv install
    March 31, 2011

    I am thinking of getting my wife a kindle to read on holiday in Turkey, which I am hoping will be sunny. I had a look at the screen in the shop and it does look totally different to an ipads. Also part of the reason she wants a kindle is because she thinks its lighter than a book to hold as she has arthritis.