Avatar is a superb film. The problem I had was getting a headache and feeling sick. I’m very sensitive to refresh rates and I found that IMAX really wasn’t fast enough for me.

IMAX – Experience, IMAX plus & IMAX – They’re all different and It’s worth knowing the difference.

There are cinemas that may have just upgraded one of their ‘screens’ and installed an IMAX projector. These are called the IMAX Experience.

I found I had a headache that lasted me for three days, I also found out that it’s not just me.  Since writing this post I’ve had many visits from people who have experienced exactly the same thing – (few of whom have left a comment – hint, hint) – it felt as though I had a constant pain in the back left of my head, it was uncomfortable enough for me to take a look on the Internet for whatever info I could find or know that maybe it was just me.

The problem I found for me, was not the actual animation frame rate – it was the display rate of the IMAX projector… I swear… I could see the images flickering badly. It was as though I could watch the images being drawn. This might sound unlikely, but I think a few see what I mean and have had the same experience.

You might develop a headache because you see the screen flickering as you watch it.

This can make some people uncomfortable, like us. And for others…whose brains work more slowly – lol! It’s no problem at all.

For this reason – images that are drawn 24 times a second – are simply not fast enough for those of us who can see the display flicker as we watch.

There could by other reasons you feel sick…

There are actually a few possibilities I’ve learnt about, one of them is that to use Avatar as a prime example. The camera ‘focuses’ on a particular person or image. – The rest of the scene is rendered to be out of focus, ok? It’s supposed to be that way – The trouble is, anyone that’s curoius can’t help but be amazed at the 3D’ness of it all. Wow!

I found myself staring at incidentals in the background. Watching leaves fall in the foreground and everything moving in real 3D! It’s amazing! It reminds me of the day when I first saw Star Wars – Now that’s really SOMETHING!

The problem here is what your brain is trying to do, is to re-focus an image that is drawn to be out of focus.

You see the problem here?

Your eyes can’t possibly bring into focus what is drawn to be out of focus. Can it?

So if your eyes are constantly trying to bring into focus an image that is drawn blured you will get eye strain.This will give you a headache. You’ve probably never experienced this before but at least now you know why.

Avatar was a first in many ways. BUT, in the future, I recommend it would be wiser to choose a different lense type for the rendering of the images, because with such a ludercrous a depth of field, it is essential for the viewer to be able keep focus on the part of the screen that the director intends for them to look at – or risk having a headache for a few days.

Watching IMAX 3D films can be a bit like learning to ride a bicycle, it takes practice – Oh dear I’m going to need lots more trips to the cinema to watch IMAX films – oh no!

But remember there’s IMAX and there’s IMAX – (a much better version) that doesn’t flicker.

So watching IMAX


Let your eyes relax, don’t stress out, just look at the part of the screen that’s in focus (It’s where the director wants you to look anyway).

Tip number #2 – some IMAX display refresh rates are slower than others.

The way 3D works is by sending polarised images to the screen. In the days of the old CRT monitors, a refresh rate of 60Hz wasn’t enough for me. I always needed to set my display to whatever resolution could be displayed at 72Hz – anything less and I could see the screen flickering badly and that in itself would make me feel ill. I do a test (and this really works though people will look at you as a little strange if they catch you doing it) is to look at a display and then hum to myself at a low frequency – as you would if you’re trying to set up a resonant frequency in the bath tub, if you hit exactly the right pitch the sound becomes really amplified – this sets up a vibration in my head at whatever frequency I’m humming at and with old CRT technology I could see the screen with a ‘black bar’ across it as though watching it from a video camera that isn’t using telesync.

I don’t have this problem with LCD displays, I think maybe they stay illuminated a little longer than CRT screens.

It’s the refresh rate it’s as simple as that. If this means changing every IMAX cinema in the world then so be it. Better to change it now than later – before they get sued because people are throwing up or having a fit!

72Hz was fine for me and 72Hz is 24 * 3, doubling the frame rate is still not fast enough. I suggest that IMAX invite people who are sensitive to such things to a preview of their latest technology before they roll it out across the world.

I was going to post this reply after doing a Google for ‘IMAX feeling sick’ but thought I’d make a post of it myself, because what I was experiencing was slightly different to what was happening to others. The majority of people who feel sick after watching an IMAX film are not following the focus of the camera. You should focus your eyes where the camera is focusing, not on areas of the screen that are rendered to be blurred such as incidental objects in the foreground or background.

Your eyes will naturally focus straight ahead of where you are looking, when you look at a true 3D IMAX image that is not the focus of the scene your brain will naturally try to focus on where your eyes are looking – however you will not be able to bring the image into focus because 1. It’s not a real object and 2. It was rendered to look blured by the computer that way as if it’s not in focus you’re not supposed to be looking at it.


Combine the problem of not focusing on where the director problem wants you to focus with having a screen ‘refresh’ issue and you could come out of the cinema feeling very sick indeed. What I suggest to do is this:

For the ‘flickering’ just close your eyes for a few minutes, allow your eyes to relax when open and only look at the part of the image that is in focus and you should be able to fully enjoy the IMAX experience although I highly suspect a higher display refresh rate will help tremendously.

Still this is a stunning technology and there are bound to be a few quirks at the beginning but I sincerely believe that a new era of cinema has just begun – and it’s utterly amazing.

Anyway, cheer up my sick friends – it can only get better from here.

Get well soon.


Should we petition to the makers of IMAX? We need to see all your films in full 3D before they go on general release so that we can verify that they are of a sufficient standard of 3D technology so as to be fit for release to the general public.


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