Kobo Touch - Sharpness - Page 2

FJames · 06-07-2012, 10:24 AM

The impression of text crispness on the display is a function of several things:

1. The actual screen resolution, which is 600 x 800 for the Pearl e-ink screen, or about 167 dpi. That's not as high as, say, the iPhone retina display at 326 dpi (2x linear or 4x area density).

2. The contrast ratio between black and white, which is only about 10:1 for a Pearl e-ink screen, compared to a typical backlit LCD display which manages about 500:1 in low ambient light, although it's not quite fair to compare the contrast ratio of a passive screen in high ambient light to a backlit screen in low ambient light. (Forget the high contrast ratios that you see for TVs - they are nothing more than a marketing fantasy.)

3. The font, i.e., the details, the density, whether anti-aliasing is used etc.. Many people have commented for example that the default Kindle font looks sharper than the default Kobo font on the same e-ink display, but it's primarily because it's a heavier font.

4. The screen refresh, just as the other posters have mentioned. The e-ink pixels often don't reset fully from black to white or white to black when re-written, leaving behind a faint ghost image of the previous contents. This builds up over several pages, leaving the impression of lower sharpness due to fainter black text and the faint gray image of past text on the white background. The flash-to-black full reset clears the display and returns it to pristine state.

stokietom · 06-07-2012, 10:55 AM

Quote:

Originally Posted by John F

Maybe your seeing anti-aliasing?

I suggested the screen dump because you may have a legitimate problem that is hard to communicate. A picture is worth a thousand words.

How would be the best way to go for taking a screen shot of it?

Thanks

John F · 06-07-2012, 02:03 PM

Quote:

Originally Posted by stokietom

How would be the best way to go for taking a screen shot of it?

Thanks

I'll let someone with some photography skills answer.

larrymohr · 06-07-2012, 02:39 PM

Quote:

Originally Posted by stokietom

How would be the best way to go for taking a screen shot of it?

Thanks

Do you have access to a scanner?

Just place the Kobo on the scanner bed face down and scan @300DPI and you should get a pretty good image of the text.

Larry Mohr

stokietom · 06-07-2012, 04:58 PM

Quote:

Originally Posted by larrymohr

Do you have access to a scanner?

Just place the Kobo on the scanner bed face down and scan @300DPI and you should get a pretty good image of the text.

Larry Mohr

Before I do that, will that potentially damage the screen or anything?

Cheers

Xennex1170 · 06-07-2012, 05:45 PM

Quote:

Originally Posted by stokietom

Before I do that, will that potentially damage the screen or anything?

Cheers

I suppose just as much as if you were out in direct sunlight for a few minutes.. There should be nothing to affect the workings however since a simple flatbed scan would not actually break any of the infrared lines causing any page changes or such.

I just remembered another property of the e-ink screens.. Seems that since the microcapsules containing the little black and white beads are in a type of suspension, the colder the ambient temperature, the more ghosting you can expect. Not sure what the optimal temperature should be though. :P

stokietom · 06-07-2012, 07:29 PM

I scanned it and you can't see the text clear enough anyway.

stokietom · 06-07-2012, 09:18 PM

I have noticed this is definitely more noticeable under direct light.

Can anyone else confirm this as normal?

Thanks

GoingDown · 06-08-2012, 05:41 AM

I would say you see effects of antialiasing. Can you try to change to different font and see if the problem is still there? Some fonts will get lot more antialiasing than others.

stokietom · 06-08-2012, 08:37 AM

Some fonts do seem to make it more noticeable than others. As said though I'd have to be a fool to assume I was going to get perfect crispness.

What fonts do you guys use? I just tend to notice small things like this much more.

taming · 06-08-2012, 09:09 AM

I use Delima. It gets a kind of rounded look in the medium sized font I tend to like. Seems very clear to me, but as I said earlier, nothing looks terrifically clear when I hold it too close. It looks great at my normal reading distance.

PeterT · 06-08-2012, 09:11 AM

One not too bad font, anyone have other recommendations?

Font preferences for reading

stokietom · 06-08-2012, 10:09 AM

Quote:

Originally Posted by taming

I use Delima. It gets a kind of rounded look in the medium sized font I tend to like. Seems very clear to me, but as I said earlier, nothing looks terrifically clear when I hold it too close. It looks great at my normal reading distance.

So we are no doubt noticing the same thing then.

Do you also find it's more noticeable in direct lighting though?

I will try and find the right font for myself again, cheers!

taming · 06-08-2012, 10:53 AM

I don't think we are noticing the same things. I think my 60 year old eyes make everything blurry up close. I would expect though that an 800x600 eInk screen resolution would not be as good as what I see on my computer or cellphone/tablet screen.

I tend not to sit in direct sunlight. I do notice more ghosting (looks sorta like stripes behind the text) depending on the angle the light is coming from. I have to decide to pay attention to it for it to bother me.

danskmacabre · 06-08-2012, 11:31 AM

I definitely notice artifacts on my KT in bright sunlight whereas in lamplight indoors I generally don't notice any, but it's not at all a problem for me, doesn't detract from the reading experience at all.
I have my page refresh on 6 pages.

I would add I have installed lots of extra fonts and some are a fair bit better than others for clarity.
I have settled on the "Felbridge" font most of the time as it has great clarity and feels "comfortable" to read with.

06-07-2012, 10:24 AM	#16
FJames Addict Posts: 320 Karma: 320941 Join Date: Jun 2011 Location: Canada Device: Kobo Touch & Aura	The impression of text crispness on the display is a function of several things: 1. The actual screen resolution, which is 600 x 800 for the Pearl e-ink screen, or about 167 dpi. That's not as high as, say, the iPhone retina display at 326 dpi (2x linear or 4x area density). 2. The contrast ratio between black and white, which is only about 10:1 for a Pearl e-ink screen, compared to a typical backlit LCD display which manages about 500:1 in low ambient light, although it's not quite fair to compare the contrast ratio of a passive screen in high ambient light to a backlit screen in low ambient light. (Forget the high contrast ratios that you see for TVs - they are nothing more than a marketing fantasy.) 3. The font, i.e., the details, the density, whether anti-aliasing is used etc.. Many people have commented for example that the default Kindle font looks sharper than the default Kobo font on the same e-ink display, but it's primarily because it's a heavier font. 4. The screen refresh, just as the other posters have mentioned. The e-ink pixels often don't reset fully from black to white or white to black when re-written, leaving behind a faint ghost image of the previous contents. This builds up over several pages, leaving the impression of lower sharpness due to fainter black text and the faint gray image of past text on the white background. The flash-to-black full reset clears the display and returns it to pristine state. Last edited by FJames; 06-07-2012 at 10:27 AM.

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06-07-2012, 07:29 PM	#22
stokietom Member Posts: 20 Karma: 10 Join Date: Jun 2012 Device: Kobo Touch	I scanned it and you can't see the text clear enough anyway.

06-07-2012, 09:18 PM	#23
stokietom Member Posts: 20 Karma: 10 Join Date: Jun 2012 Device: Kobo Touch	I have noticed this is definitely more noticeable under direct light. Can anyone else confirm this as normal? Thanks

06-08-2012, 05:41 AM	#24
GoingDown Zealot Posts: 114 Karma: 1274 Join Date: Dec 2010 Location: Finland Device: Kobo Touch	I would say you see effects of antialiasing. Can you try to change to different font and see if the problem is still there? Some fonts will get lot more antialiasing than others.

06-08-2012, 08:37 AM	#25
stokietom Member Posts: 20 Karma: 10 Join Date: Jun 2012 Device: Kobo Touch	Some fonts do seem to make it more noticeable than others. As said though I'd have to be a fool to assume I was going to get perfect crispness. What fonts do you guys use? I just tend to notice small things like this much more.

06-08-2012, 09:09 AM	#26
taming Trying for calm & polite Posts: 4,012 Karma: 9455193 Join Date: May 2010 Location: Mostly in Canada Device: kobo original, WiFI, Touch, Glo, and Aura	I use Delima. It gets a kind of rounded look in the medium sized font I tend to like. Seems very clear to me, but as I said earlier, nothing looks terrifically clear when I hold it too close. It looks great at my normal reading distance.

06-08-2012, 09:11 AM	#27
PeterT Grand Sorcerer Posts: 13,693 Karma: 79983758 Join Date: Nov 2007 Location: Toronto Device: Libra H2O, Libra Colour	One not too bad font, anyone have other recommendations? Font preferences for reading

06-08-2012, 10:53 AM	#29
taming Trying for calm & polite Posts: 4,012 Karma: 9455193 Join Date: May 2010 Location: Mostly in Canada Device: kobo original, WiFI, Touch, Glo, and Aura	I don't think we are noticing the same things. I think my 60 year old eyes make everything blurry up close. I would expect though that an 800x600 eInk screen resolution would not be as good as what I see on my computer or cellphone/tablet screen. I tend not to sit in direct sunlight. I do notice more ghosting (looks sorta like stripes behind the text) depending on the angle the light is coming from. I have to decide to pay attention to it for it to bother me.

06-08-2012, 11:31 AM	#30
danskmacabre Guru Posts: 733 Karma: 3593438 Join Date: Jun 2011 Location: Australia Device: Kobo Glo. Galaxy Tab S 8.4	I definitely notice artifacts on my KT in bright sunlight whereas in lamplight indoors I generally don't notice any, but it's not at all a problem for me, doesn't detract from the reading experience at all. I have my page refresh on 6 pages. I would add I have installed lots of extra fonts and some are a fair bit better than others for clarity. I have settled on the "Felbridge" font most of the time as it has great clarity and feels "comfortable" to read with.