Focusing & Stabilization
When it comes to focusing a lens, there is a simple lens design, if you want to get into the basics of how lenses focus. And that is, you can just move the entire unit of lenses forward and back, and as it moves forward, it's gonna focus closer up, and it moves back, it's gonna move further away. But this is kind of inconvenient because the lens is moving in and out of the lens self right there, and that could be a problem if you're using a filter with it. It can bring dust in, because every time it comes back in, if there's a piece of dust or rain or something like that, it's gonna bring it in to the internal elements. So you can see some video here of lenses that have elements that move forward and back. I don't like these. But, in some cases, they're the only option you have. And so it's preferred not to have this. But there are some lens designs you just can't get around at having. When a lens has internal focusing, it's gonna be better sealed, it's gonna probably last a little bit...
longer than one that has external. But it's probably gonna be bigger and heavier because of that. Many lenses, or at least some lenses, will have a focusing switch, a limit switch, so that you can choose where the camera is going to focus the lens. This is more common on telephoto zoom lenses. And, so, in this particular example, you can choose to focus in the full range, from two meters all the way to infinity. You can flip the switch to two to six meters and just focus on things in the closeup. Very few people ever do this. But sports photographers, knowing that they're not gonna photograph anything that happens really close to them with, a long lens, will set it at six meters to infinity so that the camera searches a smaller range of area. So it'll be quicker in focusing. This is also the type of switch that you may see on a macro lens. And so you may wanna have it in the full range, for closeup to infinity, which is where I would leave things most of the time. But if you know you're focusing on closeup material, you can set it in the close range. Or you could set it just to the distant range. One of the things to look for in any lens, between, say, a basic lens and more of an intermediate lens, is does it have a focusing scale on it. So that when you turn the focusing ring, you will be able to see where the lens is focused at. This is gonna be really handy in many different types of photography. Generally, when you're gonna be on a tripod, you'll be able to focus the lens by hand and know exactly where that lens is set to. Now, as I said before, when you focus near to you, the lens elements move away from the body. And as you focus to infinity, the lens elements move back into the body. And this will be important when we get to the topic of extension tubes. Now something to note is that virtually all lenses can focus beyond infinity. So if you want things in the distance in focus, you can't just rack your lens to the end. Cause it's going beyond infinity, and it does that to accommodate for heat and cold expansion that may change the dynamics in the lens. And so you often need to come back a little bit. But it varies from lens to lens. Some lenses, like these Canon lenses, will have little red marks for people who are shooting infrared photography. Infrared photography has light focusing at a different place than standard light. Most of us don't need that. And it's gonna be that big white line that we're gonna be most interested in. Some lenses will have macro capabilities even though they're not a macro lens themselves. And so, in these cases, they'll have the word MACRO on it, listed on it, which means it can focus up close. But that can really vary from lens to lens. There is a lot of lenses out there that now have image stabilization units built into them. And what they have is essentially is a gyro motor, which monitors your hand holding of the camera. And it adjusts elements within the lens to balance your movement out. Now there are some cameras that have it in the camera. And there are some use into the camera and the lens, and they combine the power of the two of them together to have as much stabilization as possible. Now each camera company has their own name for this technology. Image Stabilization, Vibration Reduction, and so on and so forth. Each company has their own version of this out there. They all work quite well. The newer versions tend to work better than the older versions. If you are using the Canon system, some of their higher-end lenses will have a one, two, and three switch on them. And their normal lenses will just have an on and off. And that's basically position one, which is your normal, handheld movement. Some of the lenses will have a number two position on it. And this will accommodate for panning. And so, as you move the camera from side to side, you don't want the camera correcting for that. And so the camera automatically realizes this and turns off that part of the stabilization. Even if you're turning your camera vertically, it'll understand what direction you're trying to shoot. And it won't try to stabilize what you are actually wanting to move. Finally, there is a third position on some of their most premium lenses. Which will only stabilize the image during the exposure and not when you're looking in the viewfinder. It can be disorientating if you are looking at stabilization in some cases with long lenses, so they allow you to turn that off. Nikon has switches on their lenses as well. Most of their lenses will have a simple On/Off. And it's best to turn it off when you are on a tripod. So be aware of that. Some of the Nikon lenses will have a Normal and Active mode. And the Normal is for standard handheld photography. And Active is when you are shooting and you are on something else that's moving. Like a train, or a car, or plane, or anything that's sort of moving around that has a mechanical movement to it. That's when you would want to put it into the Active setting. And with every system on the market, Imagine Stabilization, Vibration Reduction, or any other manufacture, I have found it best that if your camera is truly stationary, on a tripod, it is best to turn off the stabilization. What happens, if you leave it turned on, is that it starts looking for movement and it might start moving its devices around and getting a bit of blur from that. And, so, if you are rock solid steady on a tripod, that's a good time to turn off stabilization in however your camera does that.
Once you’ve chosen the camera of your dreams, how do you know which lens will maximize your camera’s capabilities? Join camera expert John Greengo as he explains what the best lenses are to add to your camera bag. He’ll explain:
- Which lens is best for specific areas of photography
- The technology behind lenses
- How to use specialty lenses including macro and fisheye
- Tips on operating and maintaining your lenses
John will also talk about lens accessories including hoods, mounts, filters, and teleconverters. By the end of this class, you’ll understand exactly what lens you’ll need to take your best photos!