15091 Views Previous 1 2 3 Next 40 Replies Latest reply: Feb 2, 2009 10:37 PM by Peter Jason Go to original post
After getting a new MB and being disappointed with the screen, I spent quite a bit of time learning about LCD screen technology. I learned one thing that might be relevant to this thread...
Twisted nematic (TN) LCD panels -- the cheapest and most common type -- only support 6 bits per channel rather than the full 8 bits required for 24 bit color. That is, they can only directly display 64 levels of brightness rather than 256. Instead, they "emulate" the full range of shades using one of two techniques: (a) dithering, in which alternate pixels use varying shades to create the illusion of an intermediate shade, or (b) frame rate control, in which pixels are rapidly switched between shades to create an intermediate shade.
I'm fairly certain, given the poor viewing angle, that the new MB uses a TN panel. If the panel uses frame rate control, some people may be able to see it and perceive it as "flickering". Hence, eye strain and headache.
For a good description of different LCD panel technologies, see this page:
Hmmmm. Thanks for the info.
Here is an interesting read as well: http://arstechnica.com/news.ars/post/20080326-apple-quietly-settles-lawsuit-over -dithered-laptop-displays.html
Maybe some day Apple will get with the program on their displays. But I'm not going to wait, I have work to do. Already jumped ship.
....."or (b) frame rate control, in which pixels are rapidly switched between shades to create an intermediate shade."
I think this, plus maybe the LED's, equate to eye strain and headache.
A while back I had the original 20 inch aluminum iMac. I could not get to liking the display so I bought an S-IPS (8 bit) display and attached it as a second display. I would almost always use the S-IPS for everything, and got very used to it. Just for kicks, a few weeks later I tried to use the iMac's display for web browsing. I could actually visually see the rapid switching between the shades, it actually looked like the screen was vibrating! Some people get used to this and do not notice, I suppose. But after using the S-IPS (8 bit) I could very much see this "vibrating" and it was very irritating, and it did give me eye strain and a headache.
Man, I hear you. I bought a new MacBook to replace my 3-year-old Thinkpad X41 tablet. At first I couldn't figure out why the fancy new MacBook screen seemed so much harder to read than the old screen. It turns out that the X41s have an S-IPS panel! Once you've seen it, you can never go back...
By the way, I found that using one of the alternative color setting files (e.g. JCDiplay) made a big difference. It improves the contrast and cuts down on the overly-intense blue-y-ness of the LEDs.
An update on my situation:
I contacted the Apple Care line and the guy I talked to was of little help - I had to direct him to these forums just to substantiate my case. So I asked what my options were regarding a refund, and he passed me on to a sales person who told me in no uncertain terms that since my MacBook was customised (expanded harddrive), and since my problems were apparently 'subjective' that I had no recourse to a refund.
I was considering taking them to the "small-claims" court, as under New Zealand consumer law it's a pretty simple clear-cut case, but I first decided to get my eyes tested.
Turns out that my eyes were actually the problem after all: something about the new screens was making my previously unsymptomatic (and undiagnosed) 'astigmatism' become symptomatic. Basically, I could see fine, but my eye muscles were (unconsciously) straining to pull things into focus, and this triggers tension headaches.
So it won't help those people who were noticing flickering, but if it's just headaches and eye strain, consider getting an eye test.
I have astigmatism, but only found eye strain apparent on new Macbook, but not the new Pro, which I have been using for a couple of months - I couldn't use the new Macbook for 20 mins without experiencing problems - the fact is that the new Macbook screen is the only laptop screen that I have ever noticed this problem on - ever.
i had exactly the same problem, but because my apple vendor is quite far i gave it another chance and another and another and finaly after about 3 weeks of headaches its ok, no more problems what so ever ... i think its LED backlit, cause i tried my friends older 15 and 17 inch MBPs with same results (before my eyes finaly adjusted)
I've been looking for topics like this since long time for the reason I'm going to explain later. So, no answers to your questions but just my dramatical experienceand some other questions.
I started using PCs (128k Mac) in 1984 for about 1 or 2 hours/day. In 1986 I was diagnosed as affected (sorry for my English, I'm Italian) from Sistemic Lupus Eritematosus and went on cortison therapy immediately. I had a normal life until 1992 when I staretd feeling strange. In the following years this feeling became more evident: chronic fatigue. My memory became a disaster and I also began suffering from lack odf concentration. Since then, things had only stabilized. I think mentioning this was necessary because it makes non sense speaking of physical problems probably, JUST PROBABLY, related to "something out of your body" like monitors. Here I come to the real matter: in 1996 (with chronic fatigue syndrome in act, I repeat) I started feeling strange sensations to into my head, such as little electricty going around my brain when I wa in front of a CRT. Throughout the years I began suffering also fronneon lights, cellular phones and anything might emit energy. Since then I'm sleeping worst and worst and worst every day and LCD monitor gave even higher problems than a good CRT with a protective screen applied.That's why I started searching for answers about the comfort of the LED LCDs. If I had positive answers I might buy a Unybody but this thread makes me think. There is an important thing I must say: I do not believe monitor are the only cause of our problems. They're just a part of the whole matter. Let me tell you why. In 1998 it was found my intestine i suffering from a problem very similar tio the coeliac disease but it was also found that the cause was not gluten,. What then? Just hypothesis on this: cortison, alcoholics, a diet which was not compatible with cortison and other immune system soppressors taken everyday. Subsequently the stomach, the liver and the intestine became suffering. How can I believe the proble of the monitors comes form my intestine's disease? First: I've been reading on the net that the first cause of electric waves intolerance is intestinal flora problems. In fact taking lots of intestinal flora supplemts makes my life easier. Why? because intestinal flora has thousands of actions such as production of B group vitamins, short chain fatty acids (Omega 3 and 6) which are very important for our brain. I then started taking also those supplements but while B group vitamins are not the panacea everybody talk about because they might overstimulate your neurons (except for B1 and B2) I followed I diet richi of supplemnts of fatty acids and rely on vegetables only for vitamins. Second: in yera 2K I did a very strict duet: italian "pasta" suche as "spaghetti" or similar with olive oil and only chicken meat with olive oil and green salad or colyflowers with olive oil and apple vinegar. In a month I became another person. I felt like a normal person should feel. No more monitor problems! Unfortunatelythat diet a so strict I got a sort of anorexia after 2 months and I had to stop. As today I absolutely need to stay away from anything might excite my neurons, such as coffee, tea, chocolate, B vitamins and many other thongs tha can stilulate the nervous system. Could all this be the consequence of my intestines sickness that brings my brain to be poor of important substances such as short chai gfatty acids? It might be. What's happening now? I'm not feeling well brìecause sometimes I eat food which stimulates neurons and find after a while that is in that category of foodsm such as red pepper!
Let me then get to the end: I have no scientific proves but just a good experience in this matter to say that problems in our body or bad lifestyle (for example: drinking lot of coffe and making little or nothing of physical activity) together with the waves emitted from whatever you might prefer (neon bulbs, LED, CRTs, ecc ecc) brings those problems which, as in all other types of sickness, are different in each of us. Try this: get away from your PC if you have problems; take a couple of pills of Omega 3 and some magnesium (read on the ne of the benefits of magnesium on the brain and problems that can come after deficiency of it); have a one hour swimming pool or fast walking out of the roads of the city (I prefer swwiming, also for you). Then go back to the PC and tell me if you still experience the same problems. Maybe yes, maybe no, maybe alittle better. But one thing I'm sure is true: foods tha stilulate the nervous system, bad thoughts and bad sleeping are the real cause of this problem. Also: do you regularly have excercises for your neck's muscle's after a pC session? Check on the net for it. However, I repeat, you might experience and feel it.
One more thing: can't remember who stated that the LED is not the problem he has at the eyes. You cannot say that because your brain can perceive (bad) things your mind doesn't and reflect it bad to your eyes. There's only a solution to get rid of your problems: get away form the cause of it, no matter what are your opinions on taht cause. Unfortunately we are sorrounded of electric waves and I need computer for my job. At least untile I do not decide to change to farm working.
I am so glad I found this topic. I also suffer from chronic migraines. The PWM used to control CCFL back lighting in regular LCD displays does the same thing to me. I was planning on buying a new MacBook Pro and the 24" LED Display but I think I will wait now and see if it affects others before I get them.
Thanks for the heads up.