Nikon D3400 Autofocus - How to Use the Autofocus Options on the Nikon D3400 DSLR Camera

This article is about Nikon FOCUS and in particular D3400 AUTOFOCUS. Now it is worth remembering that this Nikon D3400 DSLR is designed to work on autofocus and the lens, if you bought the kit lens, that is also designed to work on autofocus. Autofocus on a DSLR tends to be quicker and more accurate than the naked eye and so it is recommended - whatever the kind of photography you want to do - to use the autofocus function.

There are a couple of occasions when you might want to use manual. If, for example, you are shooting video and you have somebody who is fairly static, then I would recommend that you first of all use autofocus to ensure that the subject is sharp, and then switch it over to manual. That is just to prevent the possibility of, when the subject moves in or out of the frame or in and out of focus, it stops the camera trying to track. The other time might be if I am shooting landscapes. Now, again, I might well use the cameras autofocus system in order to make sure that I have everything in focus and then switch it off. That is really just to ensure that whilst I am either setting up or composing or while I am actually taking the picture itself which, remember, could be on quite a long shutter speed for 5 perhaps 10 seconds (perhaps more if it is a night-time shot) that the camera will not be distracted by something moving across the frame. It is a safeguard. The camera should not be distracted, but it is to ensure that nothing untoward does happen it is worth sometimes switching over to manual focus.

When you are in manual focus and you are looking through the viewfinder you have an option to help you here, which is called the rangefinder, and if you go into the menu and you go into the SETUP MENU then about halfway down just below BUTTONS you have an option for rangefinder. You also have the option below that to ensure that the MANUAL FOCUS RING is on, which of course is what you want. You switch that on when you are looking through the semi-automatic settings which are A, S and P, and you are looking through the viewfinder. You will see that there is a levels gauge at the bottom and it will move and will help you to discern when the subject that you are looking at is sharp. When it is sharp there will be a little green dot in the bottom left hand of the frame. When you are in MANUAL MODE that gauge is not there. It is an exposure levels gauge but the green dot will still appear when the subject is sharp. You do not get that when you are looking through the back screen and you are on manual. When you are looking through the back screen in MANUAL MODE, the best thing to do is to use the magnifying glass to magnify the image that you are looking at and so work on manually focusing by getting what you are looking at and what you are trying to focus on as large as possible on the back screen and that is fairly easily done through the magnifying glass + to go in and you can use the magnifying - to come back out again.

However in most cases, you will want to use the Nikon D3400 autofocus systems. The Nikon D3400 has two autofocus systems. The system that operates through the viewfinder is called PHASE DETECTION what that means essentially is that the beam that comes in through the lens is split and bounces around the back of the camera onto the sensor and at that point the camera tries to join the two images together again and in doing so it work out the length for the lens. It is very quick it is quite accurate and it is much quicker and far more accurate than the naked eye. For Liveview, it does not have the opportunity to split the beam coming through because the light goes straight through to the back of the camera. So the system used here is called CONTRAST DETECTION. Now actually this is pretty good too, because it gets right down to individual pixels where it can detect a contrast between different shades. However it can also be quite easily confused and that is more often than not when the illustrative light comes on here just to help the camera get a better idea of what it is looking at so that it can focus more accurately.

The Nikon D3400 DSLR camera essentially splits the focusing function, or the D3400 autofocus function, into two. It splits it into FOCUS MODE which essentially allows you to tell the camera whether the subject is static or moving, and then it also splits it into AUTO FOCUS AREA MODE, When you can tell the D3400 which part of the frame, or how much of the frame, the camera should be scanning in order to focus on the subject. That changes depending on whether you are looking through the viewfinder or whether you are looking through the back screen.

So lets take a look at them. Now, in this instance we are looking through the viewfinder. Of course, you can go in to the SHOOTING MENU and find FOCUS MODE and AREA FOCUS MODE on the back screen here, and make the changes accordingly, but that would be very complicated when you are trying to shoot things live, so fortunately they are on the back screen with the i button. So if I just come out of that and press i then I will find them on the bottom line. The very bottom left is the FOCUSING MODE, so if we go into that one you find there are three options outside of manual. The three options are SINGLE SERVO which basically means that when you press the shutter button the camera will focus and it will remain focused until you either take your finger off the shutter button or you completely take the picture by pressing it all the way down. That can be quite useful because if you focus on the subject in the middle of your frame and yet you do not want the subject in the middle then you can move the camera so that the subject is off to one side and take the picture and the subject will still be sharp. The other option is AF-C which is CONTINUOUS. That is for things which are moving around, so again if you press the shutter button halfway down then you focus on the subject and if the subject moves then the focus will try to keep up with the subject and keep the subject in focus before you press the shutter. The third one is called AF - AUTO and that is kind of a mixture between the two. If your subject is static then it will just focus as if it is static and if your subject moves around it will effectively move on to continuous. However I do not recommend that last option because it is the Nikon D3400 making this decision, not you. I think you should make the decision so I would recommend that you either stick to single or continuous when you are looking through the viewfinder because you then have control over how the autofocus is working.

When you are looking through the back view screen there are two choices for this D3400 autofocus. They are SINGLE SERVO and FULL-TIME SERVO. Single servo just focuses when you press the shutter button, and is ideal for static subjects. Full-time servo will try continually to focus. Now this is quite interesting because unlike with looking through the viewfinder, when you have to keep the button pressed down, here it has a little green square on it and whatever is in the square the camera will attempt to keep in focus. That could be quite useful for when you are shooting video, for example, because it will try to keep whatever the subject is in the middle of the screen in focus. However it is quite slow and it does have to search sometimes, so it can be quite distracting. It is not as immediate or quick as you would hope and if you are shooting video then I go back to my original point. If it was me, shoot on single or shoot on manual. But it is not too bad. It does try its best and if you are going to shoot video where frankly the moving in and out does not really matter, then it can be very useful because of course it maintains that subject in focus.

This article is about Nikon FOCUS and in particular D3400 AUTOFOCUS. Now it is worth remembering that this Nikon D3400 DSLR is designed to work on autofocus and the lens, if you bought the kit lens, that is also designed to work on autofocus. Autofocus on a DSLR tends to be quicker and more accurate than the naked eye and so it is recommended - whatever the kind of photography you want to do - to use the autofocus function.

There are a couple of occasions when you might want to use manual. If, for example, you are shooting video and you have somebody who is fairly static, then I would recommend that you first of all use autofocus to ensure that the subject is sharp, and then switch it over to manual. That is just to prevent the possibility of, when the subject moves in or out of the frame or in and out of focus, it stops the camera trying to track. The other time might be if I am shooting landscapes. Now, again, I might well use the cameras autofocus system in order to make sure that I have everything in focus and then switch it off. That is really just to ensure that whilst I am either setting up or composing or while I am actually taking the picture itself which, remember, could be on quite a long shutter speed for 5 perhaps 10 seconds (perhaps more if it is a night-time shot) that the camera will not be distracted by something moving across the frame. It is a safeguard. The camera should not be distracted, but it is to ensure that nothing untoward does happen it is worth sometimes switching over to manual focus.

When you are in manual focus and you are looking through the viewfinder you have an option to help you here, which is called the rangefinder, and if you go into the menu and you go into the SETUP MENU then about halfway down just below BUTTONS you have an option for rangefinder. You also have the option below that to ensure that the MANUAL FOCUS RING is on, which of course is what you want. You switch that on when you are looking through the semi-automatic settings which are A, S and P, and you are looking through the viewfinder. You will see that there is a levels gauge at the bottom and it will move and will help you to discern when the subject that you are looking at is sharp. When it is sharp there will be a little green dot in the bottom left hand of the frame. When you are in MANUAL MODE that gauge is not there. It is an exposure levels gauge but the green dot will still appear when the subject is sharp. You do not get that when you are looking through the back screen and you are on manual. When you are looking through the back screen in MANUAL MODE, the best thing to do is to use the magnifying glass to magnify the image that you are looking at and so work on manually focusing by getting what you are looking at and what you are trying to focus on as large as possible on the back screen and that is fairly easily done through the magnifying glass + to go in and you can use the magnifying - to come back out again.

However in most cases, you will want to use the Nikon D3400 autofocus systems. The Nikon D3400 has two autofocus systems. The system that operates through the viewfinder is called PHASE DETECTION what that means essentially is that the beam that comes in through the lens is split and bounces around the back of the camera onto the sensor and at that point the camera tries to join the two images together again and in doing so it work out the length for the lens. It is very quick it is quite accurate and it is much quicker and far more accurate than the naked eye. For Liveview, it does not have the opportunity to split the beam coming through because the light goes straight through to the back of the camera. So the system used here is called CONTRAST DETECTION. Now actually this is pretty good too, because it gets right down to individual pixels where it can detect a contrast between different shades. However it can also be quite easily confused and that is more often than not when the illustrative light comes on here just to help the camera get a better idea of what it is looking at so that it can focus more accurately.

The Nikon D3400 DSLR camera essentially splits the focusing function, or the D3400 autofocus function, into two. It splits it into FOCUS MODE which essentially allows you to tell the camera whether the subject is static or moving, and then it also splits it into AUTO FOCUS AREA MODE, When you can tell the D3400 which part of the frame, or how much of the frame, the camera should be scanning in order to focus on the subject. That changes depending on whether you are looking through the viewfinder or whether you are looking through the back screen.

So lets take a look at them. Now, in this instance we are looking through the viewfinder. Of course, you can go in to the SHOOTING MENU and find FOCUS MODE and AREA FOCUS MODE on the back screen here, and make the changes accordingly, but that would be very complicated when you are trying to shoot things live, so fortunately they are on the back screen with the i button. So if I just come out of that and press i then I will find them on the bottom line. The very bottom left is the FOCUSING MODE, so if we go into that one you find there are three options outside of manual. The three options are SINGLE SERVO which basically means that when you press the shutter button the camera will focus and it will remain focused until you either take your finger off the shutter button or you completely take the picture by pressing it all the way down. That can be quite useful because if you focus on the subject in the middle of your frame and yet you do not want the subject in the middle then you can move the camera so that the subject is off to one side and take the picture and the subject will still be sharp. The other option is AF-C which is CONTINUOUS. That is for things which are moving around, so again if you press the shutter button halfway down then you focus on the subject and if the subject moves then the focus will try to keep up with the subject and keep the subject in focus before you press the shutter. The third one is called AF - AUTO and that is kind of a mixture between the two. If your subject is static then it will just focus as if it is static and if your subject moves around it will effectively move on to continuous. However I do not recommend that last option because it is the Nikon D3400 making this decision, not you. I think you should make the decision so I would recommend that you either stick to single or continuous when you are looking through the viewfinder because you then have control over how the autofocus is working.

When you are looking through the back view screen there are two choices for this D3400 autofocus. They are SINGLE SERVO and FULL-TIME SERVO. Single servo just focuses when you press the shutter button, and is ideal for static subjects. Full-time servo will try continually to focus. Now this is quite interesting because unlike with looking through the viewfinder, when you have to keep the button pressed down, here it has a little green square on it and whatever is in the square the camera will attempt to keep in focus. That could be quite useful for when you are shooting video, for example, because it will try to keep whatever the subject is in the middle of the screen in focus. However it is quite slow and it does have to search sometimes, so it can be quite distracting. It is not as immediate or quick as you would hope and if you are shooting video then I go back to my original point. If it was me, shoot on single or shoot on manual. But it is not too bad. It does try its best and if you are going to shoot video where frankly the moving in and out does not really matter, then it can be very useful because of course it maintains that subject in focus.