This is a very good point made by Badvok. Do you have a response?

I got as far away as I could in my office, about 20 feet and it was still a checkerboard.

As to this test, i'm using a 17" display at 1280×1024. At upto 3 feet, i can see that the image is not a flat colour, though i wouldn't go as far as to say that at 3 feet i can see the individual pixels! If the image was moving, then i doubt it would be noticable, but may look poorer than a flat colour moving image in an "undecernable" way. At 3 feet i can still see jagged edges around the edge of the image, and interestingly, where there are small portions of the image visible (i have a dock at the bottom of my screen with icons that overlay my browser) between other images, the fact it is a checkerboard is more noticable than in the centre of the screen where there is no other reference for my eyes.

Once i move back to a 4 foot viewing distance, the image does look totally flat, with no apparent checkerboard at all.

One person on your previous page noted that the viewing distances in your graphs were the point, not at which a single pixel was visible, but as which you could discern the difference between 1 pixel and 2 pixels. This would make for another potential test. For example, the guy who found that single white pixels on a black background were visible from further away than single black pixels on a white background would have been better off having an image with a few spots on a contrasting background, some spots of 1 pixel, some spots of 2 pixels (both horizontal and vertical groups for completeness) and testing at which point he could no longer differentiate between the two.

Anyway, thanks for your work and information, i'm feeling much more confident about my choice of HDTV now!

You don't 'see' with your eyes, you 'see' with your brain. The eye is simply an optical interface. The only time the eye's resolution would limit the amount of detail you percieve (or 'see') would be if you kept your eyes fixed on one point of the screen – a highly unlikely scenario with actual pictures.

Have you noticed that although the main area of this pattern blurs and goes grey as you increase your distance you can still perceive the edge as jaggy?

When I changed to 1024×768, the pixels looked HUGE…. 80" on that resolution. So with only 1.7x the pixels, the view distance increased by over 2.25x. I have no idea what that means from a technical standpoint, but I find it interesting anyway.

On another note, although this test is useless as a visual acuity test for my analog CRT, it was very useful for calibrating the moire setting, moire of course being the red-green-blue stripey pattern. I now have have a pretty darn homogenous gray, but that still doesn't help me with the acuity test.

Using the checkboard, the visual acuity checkboard should be around 75 cm, wich is about 2,5 feet.

First of all, love your blog! I just found it while researching all this HD stuff for a client.

He wants a 46" Flat Panel HDTV to double as a display for his laptop to show PP shows, charts and graphs etc. in his conference room. I am trying to find out exactly what to recommend to him and have not found anything on this subject that seems to answer my questions. Can you point me in the right direction?

Yet yours gives an excellent explanation of how/why the visual acuity works. (For the record, I'm using an old Apple Studio Display, 15" 1024×768, and the distance is just about two feet for me.)

But, I do want to say that your disclaimer that it doesn't work on analog LCDs is incorrect. It doesn't work on UNTUNED analog LCDs. But, if you're an insane stickler for perfection like myself, and spent half an hour manually calibrating the display, it works fine.