# Side mirrors on cars. **URL:** \ **Category:** Factual Questions\ **Created:** [December 25, 2007, 6:23am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192 "2007-12-25T06:23:33Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Anchuldigs](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anchuldigs](https://boards.straightdope.com/u/Anchuldigs)\ **Post date:** [December 25, 2007, 6:23am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/1 "2007-12-25T06:23:33Z")
Why is it that the mirrors are made so that “objects in mirror are closer than they appear”? Wouldn’t it be safer to make them appear to be closer rather than further? ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [December 25, 2007, 6:28am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/2 "2007-12-25T06:28:34Z")
Because it gives you a wider field of view. The driver’s side mirror doesn’t need to be convex because it’s close. ---
**Author:** ![JimOfAllTrades](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@JimOfAllTrades](https://boards.straightdope.com/u/JimOfAllTrades)\ **Post date:** [December 25, 2007, 6:30am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/3 "2007-12-25T06:30:01Z")
Bending the mirror so that you have a wider view also has the effect of making things look a little smaller, and hence a little further away. The thinking is that it’s better to see more of the scene, even if what you see is a little smaller. By magnifying the scene (making things look closer) you would see less of the scene. You can’t have both. ---
**Author:** ![aktep](https://avatars.discourse-cdn.com/v4/letter/a/f0a364/32.png) [@aktep](https://boards.straightdope.com/u/aktep)\ **Post date:** [December 25, 2007, 6:30am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/4 "2007-12-25T06:30:44Z")
The mirror is curved to give you a better field of view. But the curving makes things look further away. > [@http://www.physlink.com/Education/AskExperts/ae449.cfm](#): > > For the passenger side mirror, a planar mirror would not do, since since it is further away from your eye, it would be very limited in the range of vision it provides. So, we need either a huge mirror (not a very good or elegant alternative) or a mirror that can ‘compress’ images to that smaller size. The latter has been chosen, and the convex mirror is the tool that does the job of ‘compression’. Just like the back of a spoon, anything in a convex mirror looks smaller than its actual size. Making them appear closer would give you a “zoomed in” look of barely more than your fender. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [December 25, 2007, 6:31am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/5 "2007-12-25T06:31:47Z")
It is related to field of view. So, no, it won’t be safer for the car you can’t see in the mirror to have been larger (appear closer) if you could see it. Frequently only the passenger side mirror is designed this way, because the extra distance between the driver and the mirror narrows the field of view even more. ---
**Author:** ![Anchuldigs](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anchuldigs](https://boards.straightdope.com/u/Anchuldigs)\ **Post date:** [December 25, 2007, 6:47am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/6 "2007-12-25T06:47:12Z")
Thanks. ---
**Author:** ![Santo\_Rugger](https://avatars.discourse-cdn.com/v4/letter/s/e95f7d/32.png) [@Santo\_Rugger](https://boards.straightdope.com/u/Santo_Rugger)\ **Post date:** [December 25, 2007, 7:05am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/7 "2007-12-25T07:05:53Z")
Just to clarify, when talking about the passenger mirror being farther, the significance is that the angle formed between you, the mirror, and the other car is wider. Therefore, you need a wider field of view to compensate. ---
**Author:** ![Dog80](https://avatars.discourse-cdn.com/v4/letter/d/6bbea6/32.png) [@Dog80](https://boards.straightdope.com/u/Dog80)\ **Post date:** [December 25, 2007, 10:49am UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/8 "2007-12-25T10:49:38Z")
European cars do not have the inscription on the mirrors. Is it a US requirement? ---
**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:** [December 25, 2007, 3:08pm UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/9 "2007-12-25T15:08:54Z")
Yes, it’s US regulations. See here [Stock Images, Royalty-Free Images, Illustrations and Videos - iStock](http://www.istockphoto.com/file_closeup/?id=1822945&refnum=808759) for an example. ---
**Author:** ![chorpler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chorpler/32/2888_2.png) [@chorpler](https://boards.straightdope.com/u/chorpler)\ **Post date:** [December 25, 2007, 4:31pm UTC](https://boards.straightdope.com/t/side-mirrors-on-cars/431192/10 "2007-12-25T16:31:58Z")
[The Master speaks.](http://www.straightdope.com/classics/a941021b.html)