# Fence Visibility: Vertical vs. Horizontal **URL:** \ **Category:** Factual Questions\ **Created:** [July 10, 2024, 6:22pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012 "2024-07-10T18:22:04Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [July 10, 2024, 6:22pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/1 "2024-07-10T18:22:04Z")
I see a new type of fence that has become popular. It has 4-5 inch slats that run horizontally and have a quarter-inch gap between them. This seems to allow a great deal more visibility than a vertically aligned fence with the same size slats and the same quarter-inch gaps. I’m wondering why this is the case. With a vertical fence, if I’m moving fast enough, I can get some view “through” the fence because it’s like a movie projector or persistence of vision or some such. But with the horizontal fence I seem to be able to see “through” the fence much better even when standing still. Why do the horizontal gaps allow for so much better “look through” than same-sized vertical gaps? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 10, 2024, 6:30pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/2 "2024-07-10T18:30:55Z")
For one thing consider the position of your two eyes. You can see the same thing with both of them through a horizontal gap. ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [July 10, 2024, 6:39pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/3 "2024-07-10T18:39:10Z")
I think it has more to do with the thickness of the slats: when you look to the side of vertical slats they overlap at an angle of say 30° or 45°, depending on the distance between the slats and their thickness. Increase the distance between them and the angle you can look through may increase to 60° or more. On a horizontal plane this does not play such a big role, as fences don’t go up or down more than a couple of degrees from the POV of person looking through (depending on how far away you are from the fence, obviously). ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 10, 2024, 6:48pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/4 "2024-07-10T18:48:03Z")
That is undoubtedly so. Even with one eye you can see better through a horizontal gap. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [July 10, 2024, 6:54pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/5 "2024-07-10T18:54:01Z")
It’d be nice if we knew whether the OP was standing face-to-fence, or driving by 100 yards away at 60mph. The perceptual results are gonna be different depending on relative motion, distance, etc. IMO, but semi-informed IMO … Most of what’s interesting on other side is more or less level. So the one horizontal slat-gap that gives you a look at the cows or the house or whatever on the far side provides a much larger part of the _salient_ scene. Consider just standing still outdoors with no fence around looking at the scene in front of you. Your _eyes_ see the dirt near your feet and a lot of sky. But your _brain_ sees (pays attention to really) a scene just a few of degrees tall and 20 or 30 degrees wide. If we did impose a fence in the way, clearly a horizontal gap in a fence would make that visual attention process go better than a fence with a vertical gap of the same size. ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [July 10, 2024, 6:57pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/6 "2024-07-10T18:57:07Z")
In most cases, these are fences 25-30 feet away moving past slowly (walking) or standing still. ---
**Author:** ![YamatoTwinkie](https://avatars.discourse-cdn.com/v4/letter/y/cc9497/32.png) [@YamatoTwinkie](https://boards.straightdope.com/u/YamatoTwinkie)\ **Post date:** [July 10, 2024, 7:07pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/7 "2024-07-10T19:07:33Z")
I think its likely a combination of the fact that human movement is mostly on the horizontal plane, and anything to see behind a fence (i.e, a yard or a single story house )is mostly on the horizontal plane. A horizontal gap provides a constant image when moving left-to-right, and the image it provides is of the entire yard. A vertical gap provides a shuttered image when moving left-to-right that is going to be blocked 95% (4" slat / 4.25" center spacing) of the time when moving slowly or at something equivalent to 5% brightness when moving quickly, and a good portion of what you’re looking at is going to be a vertical slice filled with sky and the fence on the other side. ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [July 10, 2024, 7:10pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/8 "2024-07-10T19:10:28Z")
Are there enough factual replies for me to now say that the horizontal boards will make the fence look fat? ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [July 10, 2024, 7:21pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/9 "2024-07-10T19:21:18Z")
Only if you mean it in a good way. But I kind of like the style of these horizontal fences even though I don’t like the visibility issue. I think they have a nice mid-century modern appeal which is amplified by the greater finishing of the slats, which makes them look fancier. ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [July 10, 2024, 8:09pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/10 "2024-07-10T20:09:05Z")
Agreed, and no fence-shaming here. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 10, 2024, 8:29pm UTC](https://boards.straightdope.com/t/fence-visibility-vertical-vs-horizontal/1004012/11 "2024-07-10T20:29:21Z")
If you’re looking directly perpendicular to a fence, either one should be equally easy to see through. But you’re usually not looking directly perpendicularly, but at some horizontal angle. At enough of a horizontal angle, you can’t see through a vertical-slat fence at all. Correspondingly, at enough of a vertical angle, you couldn’t see through a horizontal-slat fence, either. But it’d need to be an extremely tall fence in order to get that kind of angle.