Flux
10-17-2006, 02:28 AM
Many of the following have come from my observation playing a full-time sniper in BF2 and BF2142 Demo. These are some general tips, ideas, and techniques.
revised on 10/27/06
Now that I've played retail for several weeks straight, I have some new things to add. Although I think this page might get a bit too bloated. Next time I'll come back with pictures and kill some paragraphs.
added the following sections
long range and short range headshots
bullet drop
unlocks
swaying
Now that snipers are given aiming sway when zoomed in, we must all adapt to this new system. Despite having stabilizers, it's still very useful to know how to aim properly with sway.
With a target at 150 meters away (whatever unit of measurement your gun tells you below your crosshair), your target will be roughly ten pixels tall, depending on your resolution. This is a very easy distance to snipe at, even with swaying. It's done in about two steps: lining up your target horizontally, then letting the sway move your crosshair into your target.
Assuming your target is standing still (not that common) you line up your target horizontally, by zeroing the center crosshair mark with your target. Be very exact with the horizontal aim (it's actually more important than vertical in most cases).
Notice that at any time your swaying is very mechanical and predictable. It will go up a certain distance, then down a certain distance, at a near-linear speed. Use this to your advantage when lining up the vertical, by predicting where the sway will go. Thus, if the sway is going up, line up your crosshair below your target. If the sway is going down, line it up above your target.
Sway going up - Aim low
Sway going down - Aim high
Landing the shot by clicking is now just a matter of timing. As your crosshair enters the target, open fire.
headshots in general
As a sniper you're often going to be outnumbered and when you find yourself taking fire, most likley you will die. Hence, concealment is extremely important in your survival as a recon sniper.
Part of this is being able to take a kill without anyone knowing where you are. When you hit someone in the body, they usually run for cover and make shooting them a second time a much more difficult task. Not only that, they will get a general sense of where your shot came from, and come looking for you even if they get killed.
It is almost always preferable to make a headshot than a body or leg shot. The moment you kill a player with a single bullet, they will have almost no idea where you shot them from. Their teammates might, but you will then have one less person to worry about.
If there is a medic, headshot him too. Be ruthless. :mad:
In general, prone players facing you (ie aiming at you) are easy to shoot in the face, especially if you are level with them on terrain. On the Titan, it's much easier to get headshots like you would in other FPS games.
Again as a general rule, try not to head-shot running players if you can. It might very cool and rewarding, but you give away your position and you will most likely miss (unless they are very close to you). If you must take the shot somehow (person is running to an empty walker for example), a body shot just might kill the person if he is already damaged.
A much better choice is to wait until they are prone, crouched, or standing when fighting your teammates, and then give them a bullet in the head.
long distance headshots
A fun game to play in Counterstrike is Shots for Headshots. :) Every time someone makes a headshot, you take a shot of whatever alcohol you've got around you. Prepare to remain sober in BF2142...
Not only is it more difficult to land a headshot, most of the time you won't even know you did (assuming you are still a beginner, but even advanced players cannot confirm all the time that a kill is an absolute result of a headshot).
Using Sidi Power Plant as an example, you are sniping from Warehouse (the roof of the north building) to Reactor Core. The shooting distance is usually about 100-200 meters here, depending on if you are sniping the bridge, the containers, or the core itself. At these distances, you can score headshots by aiming roughly two or three pixels above their heads. The best, and most unscrupulous way to practice this is by shooting people who have just spawned. Not only are they standing (and sometimes not moving at all), they have full health so it's easier for you to confirm a one-hit-kill.
bullet drop
Again, I shall refer you to an old BF2 thread dealing with bullet drop (http://www.totalbf2.com/forums/showthread.php?t=35977).
From my experience BF2142 is exactly the same, though it won't begin to effect your aiming much until you begin aiming beyond 200-250 meters, which takes you to the realm of lone-wolf sniping ranges (dare I say... "real" sniping range).
On Suez Canal Titan mode, if you launch into one of those very high perches that have no stepladders to get to, you can see just one other perch barely under the fog. That's roughly 320 meters. When you try sniping someone that far, you will definitely experience bullet drop. People who are laying prone will be difficult to land a shot on unless you aim higher than they are on-screen.
On Sidi Power Plant (yes we are all sick of this map :)) from the PAC side there is a large fortress just outside of the first base you can capture. From that fortress window to the Reactor Core is roughly the same distance. To hit people in Reactor Core you're going to need to aim several pixels higher than the person is located.
I'm giving you these examples because there's no real good way to judge how much you should compensate for bullet-drop except for practicing for it. Finding maps and locations where you can practice for it is invaluable. For example, in BF2 on Wake 2000, the artillery island is a great place for practicing bullet-drop sniping against people coming to either ends of the island.
In general, at large distances it's better to aim high than it is to aim low, since aiming too high might at least give you a chance at headshots.
hitting people in gun platforms
Please do this at a safe distance. It's very embarassing to be killed by a railgun or even AA when you are trying to snipe it. Believe me.. it's happened so many times.
The gun platforms are invulnerable to your rifle when it is facing directly towards you, or away from you, so wait until it reveals its side. The entrance (right) side of the gun platform is ideal for you to open fire into. I've found it easier to hit infantry inside gun platforms (and headshot them occaisionally) by hitting them when the platform is at a diagonal to you (facing you, but at an angle with the entrance also facing you).
hitting people in vehicles
This is a lot of fun to do, even if you don't have armor piercing like the M95 does in BF2. The only vehicles this has worked on so far have been the buggy and the transport helicopter.
Killing the driver and the gunner in a buggy is a lot of fun, and quite easy to do in fact. Their heads are placed exactly in the head chasis. The driver will be the easiest to kill if he is driving directly towards you. If you have enough time to get out of the way, pop a round into his face and hop/spring out of collision distance. They will get a nasty surprise.
Another way is to wait for people to get in their car, and fire as soon as they are seated. It is nasty, cruel, and deliciously fun.
I don't recommend hitting people in choppers while it is flying, however sometimes people will try and sit in the gunner's seat of a parked chopper and use the MG. The first and second gunner will be seated towards the back of the plane (directly above the MG) and they will be exposed to fire when you are looking at it from the front. This is an easy kill, and you should always take it if possible.
sniper roles
As squad leader - Your main priority as squad leader is to stay alive so that others can spawn on you. Using voice communication is priceless here, because you can inform your teammates very quickly of your strategy and upcoming threats. In general as a sniper squad leader, you will have to fore-go going for high numbers of infantry kills.
Instead, the most useful way to use Recon that I have found is to severely soften up an entire base of infantry, while letting your teammates do the clean-up work. It's easier to spread damage by giving each infantry one sniper round, rather than chase a headless chicken running from your sniper fire.
Since you're responsible for getting your team from point A to point B, I find it easier to drive, and pick up my teammates to drop them off at enemy bases.
As sharpshooter - The highest priority targets for you are going to be infantry running towards a parked walker or APC or tank. These heavy vehicles are infantry magnet, and you will see them flocking towards it. In these circumstances, having another sniper with you to hit that infantry a second time before he reaches the vehicle is ideal. Having engineers damage the vehicle before the infantry can reach it is also good.
As your engineers blow up vehicles, you will see infantry try and escape. They will be hurt by the explosion (even just by a little bit) and will die to single sniper rounds. Take advantage of that opportunity and finish off all infantry if you can.
As a Lurker - Being a lurker is great for sniper practice, but you don't get a lot of action and not a lot of points either. This is not so much a role, but describes a sniper who would rather "lone-wolf" it and hit infantry from a distance, where-ever they may be. There are a few things you can do, though, that can make you effective.
You can harass an entire base, and get them to come looking for you. If they are doing this with armor, so much the better since their armor isn't used to attack the rest of your team.
You can stay at an empty base until the opponent is trying to capture it with infantry. At this point, you can pick them off pretty easily. To do this, you must know the map and the entrances to the base, and be hiding at the opposite end where infantry will try to prone and conceal themselves.
As a Sniper Hunter - This requires that you at least know the popular sniper nests and concealment locations. Be on the look-out for high perches (cranes were popular in BF2, but only for newbie snipers) and rock nooks where infantry could hide. Listen for sniper rounds carefully (the sound should be very familiar to you now), then try to locate the sniper visually. Untrained sniper players will pop off round after round, giving away their location easily. And lastly.. look for horizons on hills. Even though they provide cover for the sniper, their head must at least pop up very obtusely against the background and will be easy pickings for you.
Obviously once you spot the sniper, and his attention isn't directed towards you, you can call him out for your teammates, snipe him (if one hit doesn't kill him and he is still prone, give him another bullet with his name on it), or you can sneak up and knife (for snipers in close vincinity).
sniper vs sniper
Here we assume that a sniper is actively trying to kill you. Your reaction depends on the distance of engagement.
As soon as you get hit with a sniper round (your health will be around 5-30% unless it's a Zeller, in which case you would be dead without heavy armor), stop aiming and get out of your scope, stand up from prone, and run around some corners.
Immediately, try and figure out how far the sniper is, and what general direction. Sound is key here, remembering where the sniper round came from and how distant it is. Also, your damage indicator helps but don't let it confuse you when you turn around. Remember: the indicator indicates damage you took at the time you took it, not what direction you are now facing.
If the sniper is very close to you (pistol range), I would actually try to knife him. Your odds of survival is low if he pulls out a pistol, but it's fun :) However, if you actually want to stay alive, you can do one of two things: If he isn't moving around much, hit him once with a sniper round and finish with the pistol. If you can't do this, you'll have to resort to using your pistol. If for some reason the engagement is lasting too long, it's never a bad idea to run around a corner, gain some distance, then flank him and shoot him at fifty meters.
If the sniper is in medium range (roughly 100m to 150m), you know that they probably have limited visibility of you. The best thing to do will be to withdraw from your current position while running, and listen for additional sniper rounds coming your way. If the round hits your surrounding environment, if can give you a good idea of how the bullet traveled to get to you, which lets you at least have an idea of the direction he's coming from.
At longer distances (200m to 350m fog), simply relocate. The sound of a sniper rifle in BF2142 will be quite muted at such distances, so if you didn't catch it, get to a good hiding spot and begin scanning for obvious sniper nests first, then the horizons, then the shadow areas, and then enemy bases.
It helps to be always paranoid. Getting caught under the scope of another sniper should be the last thing to happen to you if you are good, so it means you got lazy and didn't scan for other snipers thoroughly enough.
unlocks
anti-personel mines
Also known as claymores, these things are your best friend other than your rifle. You can be devastating with these, and people will hate you for it because they think you're cheap. I say tough luck :p
The first and best way to use these are to cover your ***. Be extremely paranoid of people coming from behind you at all times, even in the most remote locations. Always always always cover your back with at least a claymore.
When you are sniping at a high location and you know you're going to be there for a while, always set claymores to all possible entrances. If there's only one entrance, place both claymores at seperate places in the same entrance so when they come back again to look for you, they will find insult to injury.
The second way to use claymores is similar to the first, but not limited to. Place claymores at chokepoints and obvious enemy entrances. Titan vents, corridors, core rooms are all legitimate. Belgrade has many nooks and crannies that have high infantry traffic, so feel free to put them there.
A third use for claymores is to place them around flags or silos you are capturing. Anyone foolish enough to either come attack you, knife you, or reclaim the flag will be blown up. At which point you come back to life and place more claymores in case they come back for it.
Finally, when you are caught in snag and are being fired at from left to right, hopping around like a mad-man placing playmores all over the place will get you more kills than you have deaths. This is very cheap, frowned upon, but life's not fair. I have saved a flag for my team from a full enemy squad doing this.
There are many many more uses for the claymore, but I'll leave it up to your imagination as this page is getting way too bloated. There's also claymore placement to think about (facing, concealment, etc).
4x scope
This is a powerful unlock that will improve your sharpshooting, reduce the effects of swaying, and will roughly double your effective fighting distance. Perhaps the most important unlock if you are in love with sniping as I am.
When zoomed in, scroll up or down to change your zoom level. Note that even on 100% distance drawing in your graphics settings, some things will disappear at long ranges. With this unlock, you can make those things re-appear again by zooming closer and closer towards it.
Also note two other things: when you're zoomed in, you see a lot less of your surroundings. It's easy to miss enemies running around, so try and not stay full-zoomed all of the time. Also, as you zoom closer to a target the swaying becomes smaller relative to the target. This helps you make those key headshots a lot easier.
stabilizer
A complete waste in my opinion. You don't need it when you have either 1) skills or 2) 4x scope (the previous unlock on the tree!). Also, it takes up one extra slot which is better used for RDX and claymores. It's silly how this unlock is not passive.
Use it by holding down shift when zoomed in.
Zeller-H Sniper Rifle
IMO, the Zeller is not worth it due to these aspects:
1) Scope is too bright and it's hard to see infantry. The contrast is too low. Scope is smaller than all other sniper rifles.
2) Sound is too loud and a dead give-away.
3) Extra damage not worth it because other sniper rifles can also kill with one hit on headshots, which are strategically more important.
4) Almost nobody uses light armor except other snipers, who you should kill with headshots.
5) Magazine is too small (three shots only)
6) Reload time is awful
The only upside is that you can shoot and blow up RDXs.
I won't write further on this, but I'll direct you to a fine post (http://www.totalbf2142.com/forums/showthread.php?t=6007) made by "death god" (or whatever the chinese translation is :)).
RDX
Not technically a sniper-tree unlock but a fine unlock coupled with claymores. Be aware that you can blow up claymores and other RDXs with your own RDX to remove other people's traps. Also, this is your only defense (other than railgun) against armored vehicles.
active camoflage
I won't say too much on this as there's additional threads out there on this popular unlock. Not too great for snipers unfortunately. Yes, you can get to sniping locations with it, but there are often many other ways to do the same thing (helicopter, APC pods, Titan pods). It might be romantic to think about stealthing yourself after making a shot, but either you are too far away to be seen anyways, or you are too close and the AC buzzing sound can easily be heard.
spawn beacon
Something dotswarlock wanted to add, and I think this fits here and is worthy to mention:
You can use a squad beacon at strategic locations to no longer be pressured into staying alive (not to mention using it yourself). However keep two things in mind: no one can spawn on you as long as the beacon is active (which might be a bonus if you don't want squad mates giving away your position) and pods landing on a beacon are a dead give away so don't put it at your sniping spot.
stamina boosts and running
I really think of these as investments. These are particularly invaluable especially getting around by yourself when sniping. If I were to start a new soldier, I would place my unlocks here instead of using them on the stabilizer and the Zeller-H. That's how good these are :)
odds and ends
Some stuff I did't cover, but I'm sure other people can fill in quite nicely.
Don't forget your pistol. During close-range combat you're usually able to hit your foe once with a sniper round, and finish him off with the pistol.
The knife is your friend. Getting dogtags is immensely rewarding, especially against people with superior firepower (I find knifing snipers to be not much of a rush now...).
Knowing the map. This is a big topic, but in general having detailed knowledge of sniper locations, your own sniper locations, and the best and fastest routes to rail guns / anti-air guns (as an infantry sniper, they are your only hope vs armor).
"Sniping" with tanks, rail guns. You can hit Titan turrets and enemy helicopters with the hover tank very easily, and hit enemy walkers, APCs and infantry with the rail gun from a base or two away. With tanks, there is serious bullet drop and travel time.. just be aware.
Sniping from the Titan is a lot of fun, but not very productive. By the time your shields are down so you can sit outside sniping, time is better spent inside the titan defending your control stations.
closing
The recon kit is a very diverse kit, and playing as a sniper is very rewarding if you can be an effective asset to your team.
Feel free to add any ideas and additional tips to this thread and share your thoughts on what I've laid out.
Ah my in-game name is mFlux if you ever want to go hunting with me. Or hunt me down :D
revised on 10/27/06
Now that I've played retail for several weeks straight, I have some new things to add. Although I think this page might get a bit too bloated. Next time I'll come back with pictures and kill some paragraphs.
added the following sections
long range and short range headshots
bullet drop
unlocks
swaying
Now that snipers are given aiming sway when zoomed in, we must all adapt to this new system. Despite having stabilizers, it's still very useful to know how to aim properly with sway.
With a target at 150 meters away (whatever unit of measurement your gun tells you below your crosshair), your target will be roughly ten pixels tall, depending on your resolution. This is a very easy distance to snipe at, even with swaying. It's done in about two steps: lining up your target horizontally, then letting the sway move your crosshair into your target.
Assuming your target is standing still (not that common) you line up your target horizontally, by zeroing the center crosshair mark with your target. Be very exact with the horizontal aim (it's actually more important than vertical in most cases).
Notice that at any time your swaying is very mechanical and predictable. It will go up a certain distance, then down a certain distance, at a near-linear speed. Use this to your advantage when lining up the vertical, by predicting where the sway will go. Thus, if the sway is going up, line up your crosshair below your target. If the sway is going down, line it up above your target.
Sway going up - Aim low
Sway going down - Aim high
Landing the shot by clicking is now just a matter of timing. As your crosshair enters the target, open fire.
headshots in general
As a sniper you're often going to be outnumbered and when you find yourself taking fire, most likley you will die. Hence, concealment is extremely important in your survival as a recon sniper.
Part of this is being able to take a kill without anyone knowing where you are. When you hit someone in the body, they usually run for cover and make shooting them a second time a much more difficult task. Not only that, they will get a general sense of where your shot came from, and come looking for you even if they get killed.
It is almost always preferable to make a headshot than a body or leg shot. The moment you kill a player with a single bullet, they will have almost no idea where you shot them from. Their teammates might, but you will then have one less person to worry about.
If there is a medic, headshot him too. Be ruthless. :mad:
In general, prone players facing you (ie aiming at you) are easy to shoot in the face, especially if you are level with them on terrain. On the Titan, it's much easier to get headshots like you would in other FPS games.
Again as a general rule, try not to head-shot running players if you can. It might very cool and rewarding, but you give away your position and you will most likely miss (unless they are very close to you). If you must take the shot somehow (person is running to an empty walker for example), a body shot just might kill the person if he is already damaged.
A much better choice is to wait until they are prone, crouched, or standing when fighting your teammates, and then give them a bullet in the head.
long distance headshots
A fun game to play in Counterstrike is Shots for Headshots. :) Every time someone makes a headshot, you take a shot of whatever alcohol you've got around you. Prepare to remain sober in BF2142...
Not only is it more difficult to land a headshot, most of the time you won't even know you did (assuming you are still a beginner, but even advanced players cannot confirm all the time that a kill is an absolute result of a headshot).
Using Sidi Power Plant as an example, you are sniping from Warehouse (the roof of the north building) to Reactor Core. The shooting distance is usually about 100-200 meters here, depending on if you are sniping the bridge, the containers, or the core itself. At these distances, you can score headshots by aiming roughly two or three pixels above their heads. The best, and most unscrupulous way to practice this is by shooting people who have just spawned. Not only are they standing (and sometimes not moving at all), they have full health so it's easier for you to confirm a one-hit-kill.
bullet drop
Again, I shall refer you to an old BF2 thread dealing with bullet drop (http://www.totalbf2.com/forums/showthread.php?t=35977).
From my experience BF2142 is exactly the same, though it won't begin to effect your aiming much until you begin aiming beyond 200-250 meters, which takes you to the realm of lone-wolf sniping ranges (dare I say... "real" sniping range).
On Suez Canal Titan mode, if you launch into one of those very high perches that have no stepladders to get to, you can see just one other perch barely under the fog. That's roughly 320 meters. When you try sniping someone that far, you will definitely experience bullet drop. People who are laying prone will be difficult to land a shot on unless you aim higher than they are on-screen.
On Sidi Power Plant (yes we are all sick of this map :)) from the PAC side there is a large fortress just outside of the first base you can capture. From that fortress window to the Reactor Core is roughly the same distance. To hit people in Reactor Core you're going to need to aim several pixels higher than the person is located.
I'm giving you these examples because there's no real good way to judge how much you should compensate for bullet-drop except for practicing for it. Finding maps and locations where you can practice for it is invaluable. For example, in BF2 on Wake 2000, the artillery island is a great place for practicing bullet-drop sniping against people coming to either ends of the island.
In general, at large distances it's better to aim high than it is to aim low, since aiming too high might at least give you a chance at headshots.
hitting people in gun platforms
Please do this at a safe distance. It's very embarassing to be killed by a railgun or even AA when you are trying to snipe it. Believe me.. it's happened so many times.
The gun platforms are invulnerable to your rifle when it is facing directly towards you, or away from you, so wait until it reveals its side. The entrance (right) side of the gun platform is ideal for you to open fire into. I've found it easier to hit infantry inside gun platforms (and headshot them occaisionally) by hitting them when the platform is at a diagonal to you (facing you, but at an angle with the entrance also facing you).
hitting people in vehicles
This is a lot of fun to do, even if you don't have armor piercing like the M95 does in BF2. The only vehicles this has worked on so far have been the buggy and the transport helicopter.
Killing the driver and the gunner in a buggy is a lot of fun, and quite easy to do in fact. Their heads are placed exactly in the head chasis. The driver will be the easiest to kill if he is driving directly towards you. If you have enough time to get out of the way, pop a round into his face and hop/spring out of collision distance. They will get a nasty surprise.
Another way is to wait for people to get in their car, and fire as soon as they are seated. It is nasty, cruel, and deliciously fun.
I don't recommend hitting people in choppers while it is flying, however sometimes people will try and sit in the gunner's seat of a parked chopper and use the MG. The first and second gunner will be seated towards the back of the plane (directly above the MG) and they will be exposed to fire when you are looking at it from the front. This is an easy kill, and you should always take it if possible.
sniper roles
As squad leader - Your main priority as squad leader is to stay alive so that others can spawn on you. Using voice communication is priceless here, because you can inform your teammates very quickly of your strategy and upcoming threats. In general as a sniper squad leader, you will have to fore-go going for high numbers of infantry kills.
Instead, the most useful way to use Recon that I have found is to severely soften up an entire base of infantry, while letting your teammates do the clean-up work. It's easier to spread damage by giving each infantry one sniper round, rather than chase a headless chicken running from your sniper fire.
Since you're responsible for getting your team from point A to point B, I find it easier to drive, and pick up my teammates to drop them off at enemy bases.
As sharpshooter - The highest priority targets for you are going to be infantry running towards a parked walker or APC or tank. These heavy vehicles are infantry magnet, and you will see them flocking towards it. In these circumstances, having another sniper with you to hit that infantry a second time before he reaches the vehicle is ideal. Having engineers damage the vehicle before the infantry can reach it is also good.
As your engineers blow up vehicles, you will see infantry try and escape. They will be hurt by the explosion (even just by a little bit) and will die to single sniper rounds. Take advantage of that opportunity and finish off all infantry if you can.
As a Lurker - Being a lurker is great for sniper practice, but you don't get a lot of action and not a lot of points either. This is not so much a role, but describes a sniper who would rather "lone-wolf" it and hit infantry from a distance, where-ever they may be. There are a few things you can do, though, that can make you effective.
You can harass an entire base, and get them to come looking for you. If they are doing this with armor, so much the better since their armor isn't used to attack the rest of your team.
You can stay at an empty base until the opponent is trying to capture it with infantry. At this point, you can pick them off pretty easily. To do this, you must know the map and the entrances to the base, and be hiding at the opposite end where infantry will try to prone and conceal themselves.
As a Sniper Hunter - This requires that you at least know the popular sniper nests and concealment locations. Be on the look-out for high perches (cranes were popular in BF2, but only for newbie snipers) and rock nooks where infantry could hide. Listen for sniper rounds carefully (the sound should be very familiar to you now), then try to locate the sniper visually. Untrained sniper players will pop off round after round, giving away their location easily. And lastly.. look for horizons on hills. Even though they provide cover for the sniper, their head must at least pop up very obtusely against the background and will be easy pickings for you.
Obviously once you spot the sniper, and his attention isn't directed towards you, you can call him out for your teammates, snipe him (if one hit doesn't kill him and he is still prone, give him another bullet with his name on it), or you can sneak up and knife (for snipers in close vincinity).
sniper vs sniper
Here we assume that a sniper is actively trying to kill you. Your reaction depends on the distance of engagement.
As soon as you get hit with a sniper round (your health will be around 5-30% unless it's a Zeller, in which case you would be dead without heavy armor), stop aiming and get out of your scope, stand up from prone, and run around some corners.
Immediately, try and figure out how far the sniper is, and what general direction. Sound is key here, remembering where the sniper round came from and how distant it is. Also, your damage indicator helps but don't let it confuse you when you turn around. Remember: the indicator indicates damage you took at the time you took it, not what direction you are now facing.
If the sniper is very close to you (pistol range), I would actually try to knife him. Your odds of survival is low if he pulls out a pistol, but it's fun :) However, if you actually want to stay alive, you can do one of two things: If he isn't moving around much, hit him once with a sniper round and finish with the pistol. If you can't do this, you'll have to resort to using your pistol. If for some reason the engagement is lasting too long, it's never a bad idea to run around a corner, gain some distance, then flank him and shoot him at fifty meters.
If the sniper is in medium range (roughly 100m to 150m), you know that they probably have limited visibility of you. The best thing to do will be to withdraw from your current position while running, and listen for additional sniper rounds coming your way. If the round hits your surrounding environment, if can give you a good idea of how the bullet traveled to get to you, which lets you at least have an idea of the direction he's coming from.
At longer distances (200m to 350m fog), simply relocate. The sound of a sniper rifle in BF2142 will be quite muted at such distances, so if you didn't catch it, get to a good hiding spot and begin scanning for obvious sniper nests first, then the horizons, then the shadow areas, and then enemy bases.
It helps to be always paranoid. Getting caught under the scope of another sniper should be the last thing to happen to you if you are good, so it means you got lazy and didn't scan for other snipers thoroughly enough.
unlocks
anti-personel mines
Also known as claymores, these things are your best friend other than your rifle. You can be devastating with these, and people will hate you for it because they think you're cheap. I say tough luck :p
The first and best way to use these are to cover your ***. Be extremely paranoid of people coming from behind you at all times, even in the most remote locations. Always always always cover your back with at least a claymore.
When you are sniping at a high location and you know you're going to be there for a while, always set claymores to all possible entrances. If there's only one entrance, place both claymores at seperate places in the same entrance so when they come back again to look for you, they will find insult to injury.
The second way to use claymores is similar to the first, but not limited to. Place claymores at chokepoints and obvious enemy entrances. Titan vents, corridors, core rooms are all legitimate. Belgrade has many nooks and crannies that have high infantry traffic, so feel free to put them there.
A third use for claymores is to place them around flags or silos you are capturing. Anyone foolish enough to either come attack you, knife you, or reclaim the flag will be blown up. At which point you come back to life and place more claymores in case they come back for it.
Finally, when you are caught in snag and are being fired at from left to right, hopping around like a mad-man placing playmores all over the place will get you more kills than you have deaths. This is very cheap, frowned upon, but life's not fair. I have saved a flag for my team from a full enemy squad doing this.
There are many many more uses for the claymore, but I'll leave it up to your imagination as this page is getting way too bloated. There's also claymore placement to think about (facing, concealment, etc).
4x scope
This is a powerful unlock that will improve your sharpshooting, reduce the effects of swaying, and will roughly double your effective fighting distance. Perhaps the most important unlock if you are in love with sniping as I am.
When zoomed in, scroll up or down to change your zoom level. Note that even on 100% distance drawing in your graphics settings, some things will disappear at long ranges. With this unlock, you can make those things re-appear again by zooming closer and closer towards it.
Also note two other things: when you're zoomed in, you see a lot less of your surroundings. It's easy to miss enemies running around, so try and not stay full-zoomed all of the time. Also, as you zoom closer to a target the swaying becomes smaller relative to the target. This helps you make those key headshots a lot easier.
stabilizer
A complete waste in my opinion. You don't need it when you have either 1) skills or 2) 4x scope (the previous unlock on the tree!). Also, it takes up one extra slot which is better used for RDX and claymores. It's silly how this unlock is not passive.
Use it by holding down shift when zoomed in.
Zeller-H Sniper Rifle
IMO, the Zeller is not worth it due to these aspects:
1) Scope is too bright and it's hard to see infantry. The contrast is too low. Scope is smaller than all other sniper rifles.
2) Sound is too loud and a dead give-away.
3) Extra damage not worth it because other sniper rifles can also kill with one hit on headshots, which are strategically more important.
4) Almost nobody uses light armor except other snipers, who you should kill with headshots.
5) Magazine is too small (three shots only)
6) Reload time is awful
The only upside is that you can shoot and blow up RDXs.
I won't write further on this, but I'll direct you to a fine post (http://www.totalbf2142.com/forums/showthread.php?t=6007) made by "death god" (or whatever the chinese translation is :)).
RDX
Not technically a sniper-tree unlock but a fine unlock coupled with claymores. Be aware that you can blow up claymores and other RDXs with your own RDX to remove other people's traps. Also, this is your only defense (other than railgun) against armored vehicles.
active camoflage
I won't say too much on this as there's additional threads out there on this popular unlock. Not too great for snipers unfortunately. Yes, you can get to sniping locations with it, but there are often many other ways to do the same thing (helicopter, APC pods, Titan pods). It might be romantic to think about stealthing yourself after making a shot, but either you are too far away to be seen anyways, or you are too close and the AC buzzing sound can easily be heard.
spawn beacon
Something dotswarlock wanted to add, and I think this fits here and is worthy to mention:
You can use a squad beacon at strategic locations to no longer be pressured into staying alive (not to mention using it yourself). However keep two things in mind: no one can spawn on you as long as the beacon is active (which might be a bonus if you don't want squad mates giving away your position) and pods landing on a beacon are a dead give away so don't put it at your sniping spot.
stamina boosts and running
I really think of these as investments. These are particularly invaluable especially getting around by yourself when sniping. If I were to start a new soldier, I would place my unlocks here instead of using them on the stabilizer and the Zeller-H. That's how good these are :)
odds and ends
Some stuff I did't cover, but I'm sure other people can fill in quite nicely.
Don't forget your pistol. During close-range combat you're usually able to hit your foe once with a sniper round, and finish him off with the pistol.
The knife is your friend. Getting dogtags is immensely rewarding, especially against people with superior firepower (I find knifing snipers to be not much of a rush now...).
Knowing the map. This is a big topic, but in general having detailed knowledge of sniper locations, your own sniper locations, and the best and fastest routes to rail guns / anti-air guns (as an infantry sniper, they are your only hope vs armor).
"Sniping" with tanks, rail guns. You can hit Titan turrets and enemy helicopters with the hover tank very easily, and hit enemy walkers, APCs and infantry with the rail gun from a base or two away. With tanks, there is serious bullet drop and travel time.. just be aware.
Sniping from the Titan is a lot of fun, but not very productive. By the time your shields are down so you can sit outside sniping, time is better spent inside the titan defending your control stations.
closing
The recon kit is a very diverse kit, and playing as a sniper is very rewarding if you can be an effective asset to your team.
Feel free to add any ideas and additional tips to this thread and share your thoughts on what I've laid out.
Ah my in-game name is mFlux if you ever want to go hunting with me. Or hunt me down :D