PRS-650 Screen contrast

[gmw]

Hi All. Not sure if this is a problem or not; whether it's my reader or me; or even whether it's real or imagined. Anyway, to the point I suppose...

It seems to me that the screen on my reader has better contrast after it has been turned on and used for a few pages. More specifically it is as if the background gets whiter when it has been used for a bit.

When I first turn the reader on (with default "original" view settings) the contrast is not too bad if the light is good, but anything less than quite good light seems to give the background a distinctly gray hue. I've tried playing with the contrast and brightness settings for the display, but to be honest none of these seem to effect the background (except for the worse). But after a while (a few pages turns) the contrast seems to improve - but it is hard to tell whether the effect is really the screen or whether my eyes are adjusting, which is why I thought I would post here and see what others had found.

One idea that I had with regard to this is whether the choice of sleep screen has any effect on this sort of thing. For less than good reasons I deleted the pictures that came with the device and it currently shows only a white screen when asleep. I was reading that these screens flicker to black as you change pages to clear previous text and I wondered whether creating a black sleep image might help in anyway.

Is it just me? Is is this a known property of these screens? Any words of wisdom would be appreciated.

[boxcorner]

Can't say I've noticed it myself, but I imagine it takes a finite length of time for eyes and brain to adjust to perceive whiteness (or greyness). Whilst it might be possible to measure some things objectively, I guess others will forever be subjective. I remember reading comments to the effect that some people feel the E Ink Pearl display appears whiter when surrounded by black (eg Sony), rather than grey (eg Kindle). So the contrast of a display with its surroundings may be important. Another point that might be relevant is that luminous intensity of some light sources increases some time after they are first switched on.

[gmw]

Originally Posted by boxcorner

Can't say I've noticed it myself, but I imagine it takes a finite length of time for eyes and brain to adjust to perceive whiteness (or greyness). Whilst it might be possible to measure some things objectively, I guess others will forever be subjective. I remember reading comments to the effect that some people feel the E Ink Pearl display appears whiter when surrounded by black (eg Sony), rather than grey (eg Kindle). So the contrast of a display with its surroundings may be important. Another point that might be relevant is that luminous intensity of some light sources increases some time after they are first switched on.

Thanks for you thoughts on the topic. That last sentence is a very good point, I've definitely noticed that some fluorescent light globes, as they get older, take time to get to full luminance ... although in this case most of my reading is done beneath those little 50W halogen globes and I don't think they suffer the problem.

It could just (or mostly) be an eye adjustment thing I guess. I dislike the font limitations of the 650 but aren't quite game to try the various firmware replacements yet. I find small is too small but medium is too large (there seems no excuse for such pointless restrictions in the Sony firmware). One definite eye-adjustment phenomenon that I have I noticed is that if I have been reading on medium for a length of time and I look up an my main computer screen suddenly everything there seems to be printed much smaller than usual. I think I've got some weird sort of 3D-TV-depth-perception sort of thing going on here.

I'll make an appointment to get my eyes checked soon and hope that that will let me use the small font on the reader more comfortably.

[SeaBookGuy]

I'm just about finished reading a book where the default "small" size I found a bit large, and switched to
XS instead!

[dordale]

I notice that after I first turn on my reader the display isn't as "contrasty". After I turn one page, it seems to go back to normal.

dordale

[Kiwimick]

I thought it was just my eyes adjusting because I also seem to think that the background seems to get whiter after a turn or 2 but it could also be down to the lighting on the tube where I do most of my reading.

Although saying that when it does "whiten" it is amazing and just blows away the 600 screen. Im so glad I upgraded I can see myself keeping this for years

[KenJackson]

Originally Posted by gmw

I find small is too small but medium is too large

I had been thinking that small is too small but medium is larger than it needs to be.

I assumed that more sizes take more space to implement and more menu space to offer, so I thought nothing more of it. I didn't know there were firmware updates available to change it.

[caeebe]

Originally Posted by SeaBookGuy

I'm just about finished reading a book where the default "small" size I found a bit large, and switched to
XS instead!

I find it weird that different books (mostly epubs) seem to have different font sizes. For most books the small is a bit too small and medium is definitely too big. But on a few books I've read the small is way too small and the medium just right. I don't know if this is a time of day issue for me or what. I do wish there was one more size between small and medium though.

[gmw]

Originally Posted by KenJackson

I assumed that more sizes take more space to implement and more menu space to offer, so I thought nothing more of it. I didn't know there were firmware updates available to change it.

From what I can see both PRS+ and EBookApplications have solutions for older models already and are working towards the newer. If I've read some of the forums correctly, some people have adapted these techniques for the later models already. But when you read that some people have also managed to turn their devices into paperweights in these attempts, it does make you a little nervous about trying them.

It's nice to read that a few others seem to have noticed some amount of contrast change. At least, if I'm imagining it, I'm not alone and maybe we can form a support group.

[boxcorner]

Originally Posted by KenJackson

I had been thinking that small is too small but medium is larger than it needs to be.

I assumed that more sizes take more space to implement and more menu space to offer, so I thought nothing more of it. I didn't know there were firmware updates available to change it.

It seems that most users would like a size between S and M. My eyes are both myopic and astigmatic. I find S too small and M just right, without my glasses, but a tad too big with them.