Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
Robbie Carman: Okay Rich, so now that we've discussed what prime lenses actually are, in the next couple movies, let's talk about some of the benefits of prime lenses. And I want to start out by talking about low-light performance. Rich Harrington: Well, so obviously people get really hung up on low-light performance. My philosophy is lighting is a good thing. But there are times when you have to shoot low-light, particularly one of my genres that I work in a lot is concert photography and concert video. And so it really comes in handy, because I can't just say, "could we turn these house lights up?" Because really, everybody else is there for the show, not for me.
Robbie Carman: Right, right. Rich Harrington: So I kind of have to give a little. Robbie Carman: So the benefit of shooting in low-light with the prime lens is that prime lenses often have, or really, always have a maximum aperture that's wider than what you are going to find on a zoom lens. On a typical zoom lens you might find aperture values of say 3.5 to 5.6, somewhere in that range, but on a good prime lens, it's not uncommon to find apertures of 2.0, 1.8, and even as low as 1.2. And I have actually seen a lens that is low as .9; that's pretty much seeing in the dark.
Rich Harrington: So we have one here and let's cut to the camera live for a second. Robbie Carman: Yeah. Rich Harrington: We are at f5 and ISO 3200. Robbie Carman: So we are shooting at a pretty typical aperture, aperture of 5, you might find on a typical zoom lens. But in this case we are shooting at f5, but we have stepped up the ISO considerably, and of course the danger of stepping up your ISO is that you might introduce visible noise. So what we can do instead, because this is a prime lens, we can actually widen the aperture. Remember, wider aperture is a lower number.
So let's go ahead and step this down a couple notches. Rich Harrington: So as we are at 3200 here, I am just going to start to change the f-stop. We go to f3.5. So we're well over-exposed there, so I am just going to pull the ISO down, and yeah, it still looks okay. We are at 1600 there. Robbie Carman: Sure! Rich Harrington: This is an acceptable ISO, still you wouldn't have problems on shooting still photos this way, but with video, you'd probably see some dancing pixels, Robbie Carman: Absolutely! Rich Harrington: So we are going to want to take this down even further. I am at 2.0, you know, a lot of prime lenses will top out around here, right, and that's going to let us drop that all the way down to ISO 500, even 400. It still looks pretty good, right? Robbie Carman: Yeah, it looks great, and so what you are telling me Rich is that when we shoot at lower or wider maximum aperture right, that lower number, we get more light into the camera? Rich Harrington: Hey, smaller number, bigger hole. I know, it's a little confusing right? But yes, the smaller the number, it's a ratio, the bigger the hole is letting in more light, and you can see that in the graphic here, just some of the common f-stops illustrated.
But in this case we're not actually done. We can go wider on this lens. Robbie Carman: Well let's try it. Rich Harrington: So this one tops out at 1.4, but we are all the way down there to ISO 250, which is perfectly normal. Now you might be noticing that in this particular case, as we open that up, things got shallower and actually that's our next movie. We're going to talk about depth of field, both artistic uses and some of the drawbacks, as you open up that aperture.
Get unlimited access to all courses for just $25/month.Become a member
110 Video lessons · 45081 Viewers
106 Video lessons · 35485 Viewers
350 Video lessons · 98414 Viewers
79 Video lessons · 12056 Viewers