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Grimulkan · 03-26-2009, 02:30 PM

Food for thought. I tried this out on my DR with some interesting results. I will post screenshots later, and perhaps the same on a Sony PRS-505, if I can get my hands on one again.

Meanwhile, if anyone feels like trying this out, I've included the test images and the experiments.

Numbered test images:
1) 1-allwhite.jpg - All white image.
2) 2-allblack.jpg - All black image.
3) 3-darktest1.jpg - Lots of white shapes/lines on a black background.
4) 4-lighttest1.jpg - Lots of black shapes/lines on a white background (perfect inversion of 3).
5) 5-text.jpg - Lots of white text on a dark background, what the DR would be used for most of the time.

For the experiments, put all 5 test images into a folder on the DR. For an image sequence of 1->3 (for example), click on image 1 in the content browser and after it loads, click on 3 in the page bar. Then close the image viewer for the next experiment. The "Please wait" ghost may be present in the first image, so ignore that for these tests.

Experiment 1: Image sequence 3->4
This changes from one image to its complete inversion. It looks like there is NO ghosting in this case.
Experiment 2: Image sequence 3->1 and 4->1
This changes from some image to an all-white image. There doesn't seem to be any ghosting here either!
Experiment 3: Image sequence 3->2 and 4->2
This changes from some image to an all-black image.

Woah! Who you gonna call™?

In the sequence 3->2, the ghost shapes are darker than the background, while in sequence 4->2, the ghost shapes are lighter than the background.

My guess is that if there is anything black in the previous image and the same spot is black in the next image, it appears whiter! Anything white in the previous image does not seem to ghost at all (I could be wrong here, I'd need to examine the camera photographs carefully to decide), and anything white in the next image does not ghost either.

So, contrary to popular belief, ghosts aren't white at all

In fact, anything white is immune to haunting! You can also try the sequence 5->3, to see how ghosting could really distract. But 3->5 wouldn't produce noticeable ghosting, so normal text reading is not affected. Also, 5->1->3 will kill all the ghosts.

This is really puzzling, because I was under the impression that black and white are both equally natural states for e-ink "pixels" as they are bi-stable. Why would one color ghost and not the other? Does it have something to do with the particular refresh strategy?

I still don't know if this is a DR controller-specific issue, or a general e-ink thing.

Edit 05/20: This thread is relevant to your interests. Also see a follow up to this post here.

03-26-2009, 02:30 PM	#16
Grimulkan Lord Posts: 177 Karma: 328 Join Date: Feb 2009 Device: Q1 (on way out), PRS505, DR1000S (dead :<), TC1100 (10'' perfection!)	Food for thought. I tried this out on my DR with some interesting results. I will post screenshots later, and perhaps the same on a Sony PRS-505, if I can get my hands on one again. Meanwhile, if anyone feels like trying this out, I've included the test images and the experiments. Numbered test images: 1) 1-allwhite.jpg - All white image. 2) 2-allblack.jpg - All black image. 3) 3-darktest1.jpg - Lots of white shapes/lines on a black background. 4) 4-lighttest1.jpg - Lots of black shapes/lines on a white background (perfect inversion of 3). 5) 5-text.jpg - Lots of white text on a dark background, what the DR would be used for most of the time. For the experiments, put all 5 test images into a folder on the DR. For an image sequence of 1->3 (for example), click on image 1 in the content browser and after it loads, click on 3 in the page bar. Then close the image viewer for the next experiment. The "Please wait" ghost may be present in the first image, so ignore that for these tests. Experiment 1: Image sequence 3->4 This changes from one image to its complete inversion. It looks like there is NO ghosting in this case. Experiment 2: Image sequence 3->1 and 4->1 This changes from some image to an all-white image. There doesn't seem to be any ghosting here either! Experiment 3: Image sequence 3->2 and 4->2 This changes from some image to an all-black image. Woah! Who you gonna call™? In the sequence 3->2, the ghost shapes are darker than the background, while in sequence 4->2, the ghost shapes are lighter than the background. My guess is that if there is anything black in the previous image and the same spot is black in the next image, it appears whiter! Anything white in the previous image does not seem to ghost at all (I could be wrong here, I'd need to examine the camera photographs carefully to decide), and anything white in the next image does not ghost either. So, contrary to popular belief, ghosts aren't white at all In fact, anything white is immune to haunting! You can also try the sequence 5->3, to see how ghosting could really distract. But 3->5 wouldn't produce noticeable ghosting, so normal text reading is not affected. Also, 5->1->3 will kill all the ghosts. This is really puzzling, because I was under the impression that black and white are both equally natural states for e-ink "pixels" as they are bi-stable. Why would one color ghost and not the other? Does it have something to do with the particular refresh strategy? I still don't know if this is a DR controller-specific issue, or a general e-ink thing. Edit 05/20: This thread is relevant to your interests. Also see a follow up to this post here. Attached Thumbnails Last edited by Grimulkan; 05-21-2009 at 08:56 PM.