[HN Gopher] Find the Odd Disk
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Find the Odd Disk
Author : layer8
Score : 50 points
Date : 2025-04-20 19:17 UTC (3 hours ago)
(HTM) web link (colors2.alessandroroussel.com)
(TXT) w3m dump (colors2.alessandroroussel.com)
| OisinMoran wrote:
| I think this would be more fun if it started out easier, but most
| importantly if it gave you some real world stats at the end, such
| as how you compare to others, or whether you're colorblind etc.
| Freak_NL wrote:
| I found it did start out really easy, getting harder half way.
| You might have some form of colour blindness (or a really bad
| monitor).
| zootboy wrote:
| I wish this had a "I can't tell" option. A few of the really hard
| ones I got right, but I'd say it was more of a lucky guess than a
| genuine ability to discriminate the difference.
| Freak_NL wrote:
| Quite. With the odds being 1 to 3 you'll pick the right one
| when you have to click one at random to proceed, the results
| get skewed.
| Retr0id wrote:
| If you repeat the test a few times, it'll average out.
| lucb1e wrote:
| That's why there's 20 rounds I guess. If you could just
| press "all the same" it wouldn't have to be as many
| isoprophlex wrote:
| 18/20 correct, I think I did well? Interesting how sometimes it's
| more of a feeling than an objective perception.
|
| At the end it says I can play again, because it'll generate more
| data. But for what?
|
| It'd be cool to see some stats, or learn a bit more about what I
| just did...
| tripdout wrote:
| 17 out of 20. Was super easy until #10 and I had to stop and
| think more carefully (which was actually my first mistake), and
| then I got #14 and #15 wrong. The score was about what I
| expected, though - would've been surprised if it was <15 correct.
|
| I wonder how much of this would come down to screen calibration /
| color accuracy? If everything's consistently off in 1 direction I
| guess not much, but I would imagine certain shades might appear
| effectively the same on some cheaper screens?
| layer8 wrote:
| This is from the creator of the ScienceClic YouTube channel [0]:
|
| "As part of the next video, which will be out in a few weeks, l'd
| like to invite you to take part in an experiment about color
| perception. If you don't experience color blindness, l'd greatly
| appreciate it if you could take this test. Feel free to try it as
| many times as you like, think about it as a game!"
|
| [0] https://youtube.com/@scienceclicen
| nkrisc wrote:
| Would be interesting to get some basic analysis of my results.
| From a glance it appeared that the ones I missed (6) tended
| towards red. The low saturation ones and green ones I found to be
| easiest, but was there any actual significance of the
| distribution of my errors? Simply too small a set to say?
| hilbert42 wrote:
| I got the same number wrong but I've passed every Ishihara test
| ever thrown at me. I did this test on a cheap mobile that's not
| calibrated, so it's anyone guess what its gamma and transfer
| curves are like.
|
| One should only take such tests seriously if one's using a
| properly calibrated monitor and it's viewed under ideal viewing
| conditions.
| blueflow wrote:
| How much of the result is vision accuracy and how much is
| dependant of the display?
| hilbert42 wrote:
| As I've mentioned, you can't take this seriously unless you've
| a properly calibrated monitor.
| nuancebydefault wrote:
| What stood out a lot in this exercise is that when looking at,
| versus near a disc, its luminance (or maybe the color as well) is
| perceived as changing. Almost the same i have when staring at not
| too bright stars, they seem to disappear when staring directly on
| them.
|
| And related, I once had an 'eye migrane'. During that half an
| hour, the figures of a clock disappeared the moment i looked at
| them.
| fallinghawks wrote:
| I'm curious how the eye migraine is related. I had one many,
| many years ago. It was a smallish (palm at arm's length) oval
| in the center of my vision that looked like snow on an analog
| TV, accompanied by a feeling of overwhelmed by all the colors
| of the products on the shelves (I was in a grocery). It stuck
| around for about half an hour for me as well.
|
| I've also had eye floaters which cause things to distort and
| can be hard to see through. For about 6 months I had a large
| one in the center of my left eye vision, which was a bit scary
| when I discovered I might not see a car reflected in my wing
| mirror.
| RetroTechie wrote:
| Similar experience. What surprised me: sometimes the odd-one-
| out was really quick/easy to see, and other times it took much
| longer & I thought "at the end, they'll say all disks were the
| same color".
|
| Got 14/20
| fallinghawks wrote:
| 19/20. The first many were very obvious. I missed #14 and I think
| right around there I started to slow down because the differences
| were getting smaller. Looking away and then coming back helped, I
| think. It seemed like if you look at them too long, whichever
| circle you're looking at seems to shift color and it becomes
| really hard to discern the difference.
| Animux wrote:
| Was way easier after deactivating the Android night light.
| Retr0id wrote:
| Interesting. I only got 15/20, and previously considered myself
| "above average" at colour distinction tests but based on other
| replies that's not an especially good score. I'll try again,
| going more carefully.
| Retr0id wrote:
| Ah, yes, 19/20 the second time (only the last one wrong).
|
| The first time I kept my eyes fixed in the same place roughly
| in the middle which clearly wasn't a good idea. On the second
| attempt I glanced between each circle in turn, trying to
| discern the difference over two points in time rather than two
| points in space.
| dvh wrote:
| Your score: 20 out of 20. Mistakes: 0
| two_handfuls wrote:
| Black text on dark grey background, sorry, that's too hard to
| read.
| MisterTea wrote:
| 7/20. I'm also red green colorblind so that likely has something
| to do with it. Could also be the phone screen I'm looking at.
| MisterTea wrote:
| With phone screen on full brightness I was able to get 14/20.
| ilker2495 wrote:
| 17 out of 20. good enough for me. actually, i wonder how many of
| the 17 were just lucky guesses haha! they mention data in the end
| screen, i wonder if it will be made public (so i can see where in
| the bell curve i sit)
| jjmarr wrote:
| 19/20 somehow on my first try. Near the end was just tiny
| differences in saturation or brightness.
| _Algernon_ wrote:
| 17/20
|
| Wonder how big an influence the type and quality of screen has.
| Do OLEDS give an advantage for instance?
| vinnymac wrote:
| 19/20 the neon blue one really messed with my head and kind of
| hurt to look at for some reason, so I am not surprised I got it
| wrong.
| rkagerer wrote:
| My 14/20 went up to 18/20 after I turned up my phone brightness.
| amelius wrote:
| I think it matters what colors you looked at in the previous
| screen. It takes a while for the eyes to adjust.
| yellowapple wrote:
| 13 out of 20 for me. Would've been 14 but I misclicked on one
| early on.
| lucb1e wrote:
| How do I know my screen can display all of these correctly? I
| tried on three different screens, one of which I know is bad, and
| got 16, 16, 18. Is those two mistakes the error margin of the
| screen if my eyes are fine, or much more likely to be the error
| margin of my eyes?
|
| For those reporting scores: please also report device type, like
| LCD/OLED, or which phone model if applicable. Tweakers.net has a
| large database of screen color measurements. As mentioned in e.g.
| https://news.ycombinator.com/item?id=43746400, it can make quite
| a difference
|
| My 18 score was on an Oppo Reno8, the 16 score on the not-known-
| bad screen is some ~2008 display. On the former, Tweakers reports
| an average color error of 3.42 DE2000, 9.58 DEITP, or 2.60 DE2000
| if white is excluded
| theoa wrote:
| Browser > right click on the dot > inspect the RGB numbers
| fuzztester wrote:
| Clever.
| Mogzol wrote:
| The first line on the page says
|
| > Click the disk that's a different color. Use your eyes only!
|
| Inspecting the color is cheating.
| fuzztester wrote:
| Tried it briefly, upto 6. Got all right. Gonna do more later.
|
| Need some interesting optical illusion type of posts on HN!
| fuzztester wrote:
| Escher's creations are cool. Our chemistry teacher introduced
| us to them in school.
|
| https://en.m.wikipedia.org/wiki/M._C._Escher
| lucb1e wrote:
| I was wondering if it got harder or if it's just random:
| function generateColors(difficulty, blacklist) { ...
| let sample = Math.floor(Math.min(Math.max(0,
| 1-Math.pow(1-difficulty, 1.5)), .99)*5); let distance
| = (5 - sample)/5; ... } function
| setupRound(blacklist) { ... const data =
| generateColors(currentRound/totalRounds, blacklist);
| ... }
|
| Plotting that first magic:
| https://lucb1e.com/randomprojects/js/testformula.htm#%24%28%...
| round# difference 0-- 2 5 3-- 5 4
| 6-- 9 3 10--13 2 14--20 1
|
| The "blacklist" parameter prevents that you get the same
| challenge twice. Note also that it submits every answer to the
| server (fine imo, but I think it would be even nicer if this was
| mentioned on the page)
| morning-coffee wrote:
| Not sure what to make of this. Most looked the same and I
| couldn't tell if I was really seeing a difference or not. 12/20.
| (And I am color blind, so not sure if that has a lot to do with
| it or not.)
| havan_agrawal wrote:
| Shouldn't there also be a few "control" challenges sprinkled in
| where all three are the same color and there's no "right" answer?
| If the test is implemented well and/or there is no human bias
| (either from the previous question or from the positioning of the
| circles), then you'd expect to see a uniform distribution of
| answers on the control. If there is bias (e.g. some innate
| preference for the top circle (say)), that should get adjusted
| for in the final analysis.
| smusamashah wrote:
| 14/20. Increased brightness to full, turned off blue light filter
| (aka night light on Android), zoomed in, scrolled the circles up
| and down to dissipate after image from eyes, 19/20.
| fmajid wrote:
| I got 17/20, but then again I have a high-end NEC PA302W hardware
| color-calibrated monitor.
| tkcranny wrote:
| 18/20 on an iPhone - they've have Display P3 wide colour for
| many years.
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