I am starting a study for quantifying the effects of scopes (get an actual FOV number for 1X zoom for each weapon type), as well as quantifying the effect of a scope on spread. I plan to use this page to "dump" all my findings, exchange with others interested, and a the "reference" for mainspace pages. happypal (talk • contribs) 10:06, August 20, 2012 (UTC)
 The research was interesting, but WAY more straight forward than I thought. There is no real point for this thread actually. Therefore, I am transforming it into a draft for a final "scope" (or other) page.
You may contribute here if you wish, I will move the page once finished, so your contribs will be accounted for.[EDIT:]All info has been moved into the corresponding pages.
 This should bring quite a bit of interesting info, and may warrant a rewrite of "accuracy". I've already rewritten accuracy twice myself, and (IMO), while I got the info through, I think it was a disaster both times :/ happypal (talk • contribs) 11:16, August 21, 2012 (UTC)
Page
Scopes
Each weapon (sub) category has it's own scope, with different shapes and optics. From a mechanical/stats point of view though, all the scopes share the same stats and effects. A Revolver with a sight2 will gain the same benefits than a Sniper Rifle with a sight2. Any visible difference between the weapons will actually come from the weapon category, and not the scope itself.
The scopes are:
 sightnone (sometimes spelled sight_none)
 sight1 (sometimes spelled sight1_)
 sight2 (sometimes spelled sight2_)
 sight3
 sight4
 sight5
The only exception to this rule is Support Machine Guns: While their names are also sightnone, sight1 and sight2, they have their own stats.
FOV
Base FOV
When standing still, the player has a natural FOV of 85°^{1}. When aiming, each weapon category will have a "Base FOV", which is the FOV the player get from aiming with a scopeless weapon (or would be getting for weapons that always have scopes). These base zooms are:
Weapon  Base FOV  Zoom Equivalent: 

Rocket Launcher  65°  1.30x 
Pistol  62°  1.37x 
SMG  58°  1.46x 
Revolver  56°  1.52x 
Assault Shotgun  60°  1.42x 
Combat Shotgun  54°  1.57x 
Support Machine Gun  48°  1.77x 
Combat Rifle  48°  1.77x 
SemiAutomatic Sniper Rifle  36°  2.36x 
Repeater Sniper Rifle  36°  2.36x 
Note: Sniper Rifles actually have a very powerful "no scope" zoom. Whitting's Elephant Gun has a unique scope with an FOV penalty: it does not represent what a Sniper Rifles' scopeless zoom would look like.
Scope Effect
Given the above "Base FOV", when sighting a weapon, the player will benefit from a percentage based bonus of that base FOV. Keep in mind that the formula uses the Borderlands "inverse opposite" formula:
NewFov = BaseFov / (1  BonusFOVEffect)
The actual bonuses are:


So for example, a sight2 with a sight2 will have an FOV of:
48° / (1  70%) = 28°
This would be equivalent to a zoom of 3.0x.
Weapon Card Zoom
It is not yet clear how borderlands rates the Zooms on its weapon cards. Inside a same weapon family, a bigger multiplier is of course better, but given two weapons with the same scope, the one with the biggest Zoom will actually have the lowest displayed multiplier!
Here Are two table recapitulating the data:
  : Zoom not displayed
 N/A: Scope not available on this weapon
RL  P  SMG  RV  AS  CS  MG  CR  SASR  RSR  

sightnone  N/A              N/A  N/A  N/A 
sight1  1.9x  1.8x  1.7x  1.6x  1.7x  1.5x  2.1x  1.4x  1.0x  1.0x 
sight2  2.7x  2.6x  2.4x  2.3x  2.5x  2.2x  1.4x  2.0x  1.5x  1.5x 
sight3  3.2x  3.1x  2.9x  2.8x  3.0x  2.7x  N/A  2.4x  1.8x  1.8x 
sight3  4.3x  4.1x  3.9x  3.7x  4.0x  3.6x  N/A  3.2x  2.4x  2.4x 
sight5  4.9x  4.6x  4.3x  4.2x  4.5x  4.0x  N/A  3.6x  2.7x  2.7x 
RL  P  SMG  RV  AS  CS  MG  CR  SASR  RSR  

sightnone  N/A  1.4x  1.5x  1.5x  1.4x  1.6x  1.8x  N/A  N/A  N/A 
sight1  1.8x  1.9x  2.1x  2.1x  2.0x  2.2x  3.2x  2.5x  3.3x  3.3x 
sight2  2.2x  2.3x  2.5x  2.6x  2.4x  2.7x  2.5x  3.0x  4.0x  4.0x 
sight3  2.6x  2.7x  2.9x  3.0x  2.8x  3.1x  N/A  3.5x  4.7x  4.7x 
sight4  3.9x  4.1x  4.4x  4.6x  4.3x  4.7x  N/A  5.3x  7.1x  7.1x 
sight5  5.2x  5.5x  5.9x  6.1x  5.7x  6.3x  N/A  7.1x  9.4x  9.4x 
Spread
Base Spread
This information is not actually directly related to scopes, but is interesting none the less.
Each weapon category has a "Base Spread". The weapon's parts (manufacturer material included) will then modify this spread.
Weapon  Spread  Weapon Card Equivalent 

Rocket Launcher  1.0  89.0 
Pistol  2.0  83.3 
SMG  2.0  83.3 
Revolver  1.0  89.0 
Assault Shotgun  7  41.7 
Combat Shotgun  6.5  45.8 
Support Machine Gun  2.4  80.0 
Combat Rifle  1.3  89.2 
SemiAutomatic Sniper Rifle  0.6  95.0 
Repeater Sniper Rifle  0.4  96.7 
Scope Spread
When aimed, all weapons will receive a spread bonus from their scope. This bonus is actually quite a substantial bonus. What is very interesting to note is that this bonus is not stacked additively to the other spread bonuses in other parts: It is applied multiplicative afterwards, as its own stand alone field.
Keep in mind that the formula uses the Borderlands "inverse opposite" formula:
NewSpread = OldSpread / (1  BonusSpread)
The table bellow also shows the resulting spread compared to the the weapon's base. The actual bonuses are:


As can be seen, a high powered scope can have a substantial effect on the spread of a weapon. This will of course make Sniper Rifles that much more accurate, but it should be kept in mind that inaccurate weapons, such as Matadors or Anarchys will benefit just as much (extending their useful range from point blank to a few meters).
Talk
Very interesting. The only thing i see that could be a problem is with FOV. You have not described what FOV is. I am assuming it means Field of View, but without a description i am just guessing. Other less technically minded viewers might also be confused bu this. Just my thoughts. 15:07, August 21, 2012 (UTC)
 TY. FOV is indeed Field of Vision: basically, the angle of view that is displayed on screen. I'll try to explain it in more details.
 An interesting point is that the "85°" seems to also be a built in mechanic: As a PC player with a 95° FOV, the debug console shows that my "default zoom" is still 85°. happypal (talk • contribs) 16:06, August 21, 2012 (UTC)