Optics are a device used by vehicle crews to increase the magnification of the enemy being targeted for a more reliable targeting solution. Typically used in specific modes, optics come into play whenever using the sniper scope (gunner position), the commander's binoculars (from commander's cupola) or scope (from wherever the commander might reside).
When operating the Gunner scope (typically activated by using "sniper aim" via pressing shift button), objects are initially seen with the scope set to the minimum zoom setting. To toggle between the minimum and maximum zoom settings, this can be achieved utilising the scrolling mouse wheel, pressing the default "zoom in" key Z or through any other key mapped specifically for this function on a keyboard, mouse or joystick/throttle controller. Any gunner scope will contain a crosshair and a compass, with most tanks having a firing application for their current ammunition, like here:
After Rank V the commander scope is available for most (but not all) tanks and are used by pressing "commander scope sight" hotkey. Unfortunately, this button is not set by default. Zoom controls are identical to the gunner scope. This scope does not have a proper ballistic application and at first is only used for advanced scouting and rangefinding, but on more advanced tanks you can also bind and activate "use commander sight to aim" hotkey to attack while using it ("aim mode" letters will appear on the top-left corner of your screen, signifying that the commander is currently in control) and to also receive an approximation from your gunner in Arcade battles. Commander will remember this and take over the weapons control every time the commander sight is used from that point onward until told otherwise via the same hotkey:
If such function is present on your tank, then if your gunner is knocked out, the commander will quickly take over and fire weapons instead of him. In most cases (but not always), if the tank can fire anti-tank guided missiles and the commander can take over the weapons, then switching to the commander optics aim will also move ATGM controls and line-of-sight directly to the commander optics as opposed to the weapon itself (in AB/RB) or gunner optics (in SB), but only for as long as the player is sitting in the commander optics. This is very important for some tanks, particularly the ones that can fire ATGM from their cannons, as the "gun" camera itself might violently shake and wobble while the tank is moving (therefore, guiding the missile into the ground by accident), while the commander sight does not shake. When commander is incapacitated, the commander sight cannot be used and all advantages gained with it are lost.
It is also possible to use driver sight as well by binding "driver camera" hotkey. This will put you directly into a driver seat, which may or may not be useful to check if the tank is in a proper hull-down position or not. In some rare case when the gunner and commander are completely blinded by the smoke screens and the third-person view does not provide any information at all, this may save the tank by providing it with at least some vision in the immediate vicinity. Be aware, that using it will also disable all tank controls besides those directly related to driving.
When looking at a vehicle in the vehicle garage of War Thunder, vehicles with optics will show their location when looking at the vehicle in X-ray mode. Using the cursor to hover over the optic a pop-up bubble will appear annotating the device as an "optic", some will even have additional information listed in the pop-up bubble. Generally, if the vehicle has more than one set of optics, only one of them will list the zoom levels, field of view and other options and typically this will appear when hovering over the gunner's optics, however, this is not always the case and all optics may have to be checked for more information.
Some vehicles do not contain as much information as others and when the optic pop-up bubble only lists one zoom level, it is assumed that this is the maximum zoom available for the optics on this vehicle as in the Ho-Ri Production Japanese tank destroyer. Sometimes, the pop-up will provide incomplete information or simply change, so testing things personally is still the best option.
Several vehicles may not have a zoom range specified, when it comes to these, it is best to take the vehicle out on a training run and choose a fixed object in which to compare the zoom rate in comparison to other vehicles with known zoom rates. This will provide a general range in which to have a better idea of what the optics are capable of during combat manoeuvres.
Optics themselves can be pivotal in the ability to disable an enemy tank or it can also be an Achilles' heel, especially for super-heavy tanks such as IS-7, in which the viewports where the optics are at providing a very weak point in the armour structure. Although they are extremely hard to target due to their extremely small size, nonetheless they can be hit. Optics are also very easy to hit on particular light SPG and tanks and often have less than 10 mm of RHA protection behind them, making them incredibly easy to attack with ammunition that has a high amount of Explosive mass, causing fatal overpressure damage to a tank in question.
Damage to the optics generally will not affect vehicle or crew gameplay at all, however, the optics will become unusable until they are manually repaired, which can affect certain vehicles (As an example, Warrior cannot launch ATGM if commander's optics were destroyed).
Differences between various optics in game
Optics zoom levels are an important indicator as to what type of tank is being used. Typically brawler tanks meant to be used on the front lines will not have much zoom capabilities beyond X4 as they are meant for up-close fighting and not long-range sniping. Tanks with zoom ranges of +X12 are meant for more reserve positions where they can maximize the zoom capabilities at disabling vehicles from a long distance. Those who are comfortable with the different vehicles and the optics located there can sometimes effectively push the limits of the optics and make the long-range shots with weaker optics or utilise a sniper-tank in close quarters battle.
An important note to remember in arcade mode is that it is easier to fine-tune gun aim with stronger magnification, especially if an enemy tank has only one small weak spot and you are limited on time. Also, the stronger the zoom is, the further apart the shell drop marks become making it slightly less confusing when estimating the shooting angle targeting solution.
Also worth noting, the optics of certain nations and/or vehicles may show vignetting or dark areas around the view area from a scope which limit the amount of area which can be viewed through the scope. As optics developed the vignetting lessened or virtually disappeared allowing for a larger viewing area. The FoV stat mentioned on optics does not take vignette in consideration and merely mirrors the zoom level as a reminder of the default screen resolutions for that exact magnification - the X10 scope will almost always have FoV of 7° stated, even if the last 2° are not visible due to the vignette. The only way to find out the truth is to test drive the tanks yourself.
When the tank has an ability to lock-on and track enemy aircraft with optics (generally mentioned as IRST), but doesn't have a separate camera for this specific purpose, then gunner optics will also have the description of the tracker. This option is not always listed in the pop-up, so manually checking for it is highly recommended past rank VI.
Commander's sight is different from Gunner's sight and might have different zoom and field of view. Generally, it isn't stronger than gunner's sight, but there are exceptions. On older tanks, commander sight can only have normal night vision, while on most modern tanks, the commander might have the thermal sight as well, just like the gunner. Information on available night vision types for each crew member is listed in the NVD/TVD modification itself (in tank "modifications" menu). If commander optics can control and guide the weapons, then the commander himself will have a pop-up telling that he can control the main armament (which isn't always the case).
Commander's binoculars always have about X6 zoom and same lenses across all vehicles.
Work-around methods for improper zoom levels and scopes
Sometimes tanks have extremely powerful X16 zoom while utilizing demolition cannon with low-velocity shells or extremely weak zoom (and very bad lenses at that) while utilizing high-velocity APDS or APFSDS. It makes ballistic marks on scope way too cramped or spaced out for comfortable use and in case of early HEAT, shells may make sniper scope unusable. Some, like rocket tanks, do not have ballistic marks at all and leave you all alone with your muscle memory.
There are some ways to work around these problems:
Zero-in the gun
To work around the problem, you can "zero in" the gun for a chosen shell to a certain distance, so that you can aim at targets directly. Also, some tanks like AMX-50 Foch have abysmal scope quality, but their rangefinder works faster than one of the others, making this method more viable than aiming yourself.
To activate this function, go to Controls->Tank->Miscellaneous->Sight distance control and enable "relative control", then assign buttons for "increase value" and "decrease value". Minimalistic settings look like this:
Now, to pull the gun up (to shoot further by default) use "increase value" and to pull the gun back down use "decrease value" like on this screenshot:
Zeroing only considers your current shell for a set distance. When you shift the shell to one with different velocity, it will be zeroed to a different distance. For example, if you set gun for HE to 450 meters, the APFSDS at these settings might get launched 2,100 meters away. Keep this in mind for APDS tanks or assign the reset button as well.
How to guess how far you need to "adjust" the gun?
In realistic mode, use "rangefinding" (key not assigned by default, can be found in Controls->Tank->Miscellaneous next to sight controls.) to find out the distance towards the hostile tank, or estimate it yourself, then set the gun to that number. Having an actual rangefinder modification and high "rangefinding" crew skill speeds the process up, increases the accuracy and maximum range of estimation.
Low-velocity shell chemical shells (550 m/s and below) have a tendency to have double the falloff past 1,000 m range, in some cases they start falling off even at 800 m range, so even if you do zero-in the gun, the scope may still fail to tell you where the shell is going to actually land.
Try to not set gun adjustment sensitivity too high or too low, or you may end up needing to aim in reverse. Remember, since your gun aims at a distance you set yourself, if someone drives too close to you, you now have to aim below them:
In Arcade mode gunner always tells you the distance towards the target you are pointing the crosshairs at and with no failure at that, which means you can just zero-in the scope to that exact number and your shell will almost always hit the mark, assuming you researched all the accuracy upgrades. Sometimes, it is much easier, than trying to make out the marks on your sight. For example, on X10 scopes the APFSDS scope does not have a reference number for 1.6 km distance, only the big "mark" representing it, which may be confusing to some players.
