Depth of Field
Alright let's talk for a little about depth of field. This isn't a Photography 101 class but we gotta talk about it a little bit in here. And so Depth of Field is of course controlled by your Aperture setting, your Focal Length, and your Shooting Distance. And so what I have is a little bit of a quiz here and for those of you watching the recorded version of this class, you may want to pause the class and really think about things to see if you can come up with the right answer. So here is the way the quiz works is I'm going to give you some information about how a photograph was taken and I want you to imagine what this photograph is gonna look like. So in this first case, we have a 50mm lens, a normal lens, this is all full frame by the way, full frame cameras, 50mm lens set to 1.4. Okay 1.4 is a really shallow Depth of Field set for one meter away. Now is one meter close or far? That's pretty close, which means we're gonna get shallow Depth of Field with a 1.4, a meter away, that me...
ans we're probably gonna get shallow Depth of Field and a 50mm lens, well that's kinda the middle. So we have two things kinda pushing us to shallow Depth of Field, so I would bet this photo is gonna be shallow Depth of Field. And indeed yes, we do get very shallow Depth of Field. And so if you look at the settings, as you get better and better about photography, you'll be able to tell. Okay the same 50mm lens, the same 1. but now we're focused at five meters away, much further away where we tend to get more focus, we're probably gonna have something that has much more in focus in this photograph. And we do. It's not all totally in focus but it doesn't have that shallow Depth of Field as the first image. Alright, 2.0, still pretty wide opening, 85mm lens, they tend to have fairly shallow Depth of Field. Is three meters close or far away? It's kind of close so I'm gonna guess we're gonna get fairly shallow Depth of Field. Our subject is in focus, our background is indeed quite out of focus in this case. Alright a 50mm lens, six meters away. I'm thinking we're gonna have more Depth of Field here, more things are in focus. And this is the type of thing that an experienced photographer gets very good at is knowing how much Depth of Field they want in a particular photograph because they're trying to make a particular statement or to tell a particular story. A 300mm lens is gonna have shallow Depth of Field. A 2.8 Aperture, generally pretty shallow Depth of Field. Now 10 meters may seem like a long way's away but with a 300mm lens, it's pretty close. So we're gonna get a very shallow Depth of Field in this particular case. Keeping that same 2.8 but with a Wide-angle lens which tends to have a lot of things in focus, focused very far away, we're gonna have a lot of Depth of Field in this case. Now alright, moving on to f/4. We'll start with 100mm focused up quite close at a meter, you can guess there's gonna be very shallow Depth of Field in a picture like this. And it has to do with that 100mm lens and focusing up close. A 35 tends to have a lot in focus. Three meters is moderately far away and in this case, we're starting to get more and more Depth of Field as we're stopping this Aperture down. Now alright, we got a pretty long lens but we're focused a pretty long way's away and so it's gonna be hard to get shallow Depth of Field when something is 50 meters away from us. Alright, 300mm lens but focused more than 100 meters away, that means we're probably still gonna have everything in focus because we're focused so far away from the camera. And so one of the points I want to make as we go through this is one of the most important things and I think it is the most important thing for Depth of Field is how close and how far away is your subject. When your subject's 100 meters away, probably everything is going to be in focus no matter what Aperture and what Lens you are using. And so it seems to me that distance has the greatest impact on Depth of Field and then the Lens and then the actual Aperture setting. But by judging all three of these, you should be able to kinda guess what that photograph is gonna look like. And so generally as we're getting into these smaller Apertures, there is going to be lots of Depth of Field. But when you're shooting with a long telephoto lens focused up very close, you're gonna get very shallow Depth of Field even at f/11. Once again, 100 meters away, you are going to get a lot of Depth of Field. Closing down to 16 with a Wide-angle lens, you can bet tons of Depth of Field, even very close to the camera. Staying at the same f/16 with a Macro lens focused very close up, it's that close up that's really causing us to have that shallow Depth of Field. F/22, gonna get lots of Depth of Field with that. And our final one, long lens but it's a long way's away so we're gonna have probably a lot of Depth of Field.