laszlonagy wrote:
I would add one more thing to the monitor selection criteria: refresh rate.
I will be buying monitors soon and I decided I will buy a monitor with 120 Hz or higher refresh rate. Better on the eyes on the long run, in my opinion.
Another long post I'm afraid
But here we go!
Eye strain is indeed another important aspect to consider when doing too much computer work.
And there are lots of conflicting parameters...
Panel type, dimming method, brightness, monitor distance, resolution, ..
FLICKERING
But refresh rate is not one of them I think. It determines how often the image is refreshed from the GPU. Refresh rate is important for a smoother gaming experience, not so much for CAD work. It's not the same as the Hz the monitor backlight is 'refreshing' of flickering, which is usually around 200Hz.
That should be fast enough, but it can get problematic with lower brightness. Your screens brightness should be adjusted to the brightness of the room. Ideally, a piece of white paper and white on your monitor should have similar brightness. The difference during the day is quite spectacular. Some monitors have an ambient light sensor and adjust automatically, might be useful. But having your brightness at the right settings is important for your eyes.
Most affordable monitors use PWM for dimming, meaning you get more flickering by reducing brightness. They flicker at the same interval, but stay on for a shorter period, which causes a more noticable flickering.
Some brands (benq, eizo) use different dimming methods to tackle that problem. There is also software (iris) that 'darkens' the colors at GPU level while maintaining full brightness at monitor level.
So when choosing a monitor, make sure you can set it to a low brightness if you sometimes work in a more dim environment - some monitors cannot go low and only the max brightness levels are mentioned in the specs!
And make sure it doesn't use PWM for dimming..
List of flicker-free monitors (updated a year ago...)
http://www.tftcentral.co.uk/articles/flicker_free_database.htm
VIEWING DISTANCE
Windows users need a "100% screen" for AC. This means the ppi should be around 100. Depending on viewing distance and your vision of course.
Some reports say it's better to have a high resolution because that is easier on the eyes. So from that perspective, 4K is better than HD. It's a relative matter, it is based on viewing distance and resolution combined. That comes down to ppi and we're restricted by AC in that regard (mac users are not)
Websites on ergonomics recommend viewing distances of 20-25", but that is probably based on the generally used monitor sizes of 24" max.
In absolute terms it's better to have a bigger viewing distance. In this "old" article the author recommends a VD as large as possible.
http://office-ergo.com/wp-content/uploads/2010/12/Monitor-Viewing-Distance.-Ankrum-D.R..pdf
There are two problems with the usual VD of 20-25 inch
1. single eye: focus distance (accomodation) is not comfortable
"resting point
of accommodation (RPA)" "The RPA averages 30 inches for younger people and gets farther away with age"
2. stereo vision / convergence: short VD makes your eyes squint
"The RPV averages about 45 inches when looking straight ahead and comes in to about 35 inches with a 30-degree downward gaze angle."
Conclusion:
1. A larger viewing distance is better! From 30" on, 35" should be ideal.
My 24" monitor is normally at 26", with the foot at the back of my 80cm/31.5" deep desk. I've just set it 5" farther (secured with two screw clamps) and it feels ok - see picture. The ppi of 94 is still comfortable to read and work in AC. Around 100ppi should still be OK at this VD. But now the 24" size feels even smaller.
2. At this viewing distance, 43" UHD would make sense, although I would have to get a vesa mount to hang the screen level with the backside of my freestanding desk.
The problem is: the choice of 43" screens is limited and they are not optimised for eye strain. The Dell P4317Q for example uses PWM as you can see here:
https://www.youtube.com/watch?v=lYv4gziERoY
LG 43UD79-B uses PWM as well apparently.
So they would have to be combined with Iris software.
The Philips BDM4350uc uses DC and is a better option in that regard.
https://pcmonitors.info/reviews/philips-bdm4350uc/
Unfortunately it has a glossy screen...
For this screen size, I would also need a desk mount. But most desk mount arms are designed to bring the screen nearer, nor farther! And most don't take screens this size..
3. The bigger you go, the more you have to compromise on IQ and 'eye relief features". After looking at a lot of screens, it seems like it's impossible to get all the specs right.
32" 16:9 - lots of choice, affordable, would prefer more vert res though
30" 16:10 - less choice, expensive
43" 16:9 - less choice, affordable, IQ compromises, viewing distance might be problematic on a normal desk
As you see on the picture, 32" 16:9 has less pixels, but is a bit wider than 30" 16:10. The benq monitors with eye relief features and CAD mode might be a good choice in that size.