Revised and Corrected Version: Cracking the ISO Code: Understanding Your Camera's Sensitivity to Light - The Know Your Camera Series

Maria Baptiste:
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Hi everyone, welcome to this week's episode of Clued Up, the Behind the Scenes Photography podcast. Today's episode is entitled ISO, understanding, iso and Photography Part 3 in the Know your Camera Series. Let's get started. Welcome to Clued Up with Maria B, the Behind the Scenes Photography podcast. Clued Up is your insider's view to building successful magazine style photo shoots. We talk design and concept, fashion and style, tech, social media and, of course, business, plus so much more, including how to avoid common photography pitfalls. You'll also meet some special guests who work behind the camera and in front of the lens. Whether you're an aspiring photographer, a portrait photographer thinking about starting your own business, or you just have an interest in what it takes to plan and execute professional shoots, you've come to the right place. I'm your host, maria B. Now let's get you Clued Up. So in today's episode, we're going to talk about ISO, or ISO as some people say. I say ISO Anyhow. Iso is the third leg, if you will, of the exposure triangle. Now, back in episode number nine, we talked about understanding aperture, which was the first episode in the Know your Camera series, and then, with episode 17, we talked about understanding your shutter and shutter speed. Now I highly recommend that you go back and you re-listen to those episodes, especially if you're kind of new to this. I think those were very clear episodes. They were long, I'll admit that they were long, but they were long because I went into detail and I really drew out trying to understand these two of the three concepts related to proper exposure for photos. Again, aperture and shutter, shutter speed. And now today we're going to talk about that third leg, iso. As with the other two episodes, for the most part when I talk about this I'm going to talk about it in isolation. Understanding the discussion is not about ISO and how it works with shutter speed and how it works with aperture. We are going to talk about all three of those things together and it's really hard not to talk about the three of them. So, yes, I will make references to the other two legs in the exposure triangle, but when I'm talking about ISO, the assumption is that the scenario that I give your shutter speed is where it needs to be for proper exposure and your aperture is where it needs to be for proper exposure for the image you want to create. And we're just going to talk about ISO, which is really hard to do, but just bear with me Because the higher the number you are increasing your cameras or your sensors sensitivity to light here to say that, with the most basic concept, iso is much easier to understand than aperture and shutter speed. And that's simply because by raising the number, by raising that ISO number, you get, I'm going to say, a brighter image. But what I, what I really should say is you get better exposure. We're going to dig a little bit deeper into that. For now, let's start with the fact that every camera has what's called a native ISO. In most cameras that's about 100. In some cameras it's 200, it's some cameras it's 64. For the sake of our discussion today, our native ISO, the ISO that's recommended with a given camera, we're going to say it's 100. What does that mean? It means that your ISO at 100 pretty much does nothing for you. It means that your photo is well exposed. You don't have to go up on the ISO and you don't have to go down on the ISO. You know a very low ISO or low beyond the native number. In our scenario today, our native ISO is 100. We don't have to increase it or decrease it to get the exposure that we want. That's what we mean when we talk about our native ISO Again, for the sake of simplicity. For us today that's 100. Now bear with me. Say you want to take a photograph and your Aperture is where you want your aperture to be. You're not moving it. You want whatever aperture. You want whatever aperture you have your camera set to. Your shutter speed is wherever it needs to be. Your shutter speed determines the length of time that light is allowed to enter through your lens to hit the sensor for your camera and whatever that is, you've got it set to what you need for it to be. You look through your viewfinder, you look at the back of your screen, you look at your LCD and when you look at it, your photo is not well exposed. You don't want to move your aperture because your aperture is where you need it to be. You don't want to move your shutter speed because your shutter speed is where you need it to be. And if we're talking about the exposure triangle, the only thing left for you to play with is your ISO. Yes, we can do things like add artificial light and all of that, but we're not doing that right now. You have no in this scenario. At this moment, you have no artificial light to let in. The only thing you can do right now is adjust your ISO, which, when you took out of your camera bag, was set at 100,. Okay, you decide that, since that is the only thing you have to play with, let's say you raise your ISO from 100 to 200. And if you've listened to past episodes, we understand that when we double a number, when we double a measurement, we are increasing light, in this case by one stop, because that's the term we use in photography. So when I go from 100 to 200, I have increased my ISO by one stop, and I look through my viewfinder and the exposure is better, but it's still not where I want it to be. When I look at my histogram, the majority or most of the histogram is still left of center, meaning that the photo is, the image is still too dark, it isn't, or maybe it's just best to say it's not well exposed. So I decide well, my ISO is 200, what can I do? I still, I don't want to change my aperture, I don't want to change my shutter speed. What do I want to do? I want to raise my ISO again and I want to go up by another stop. My ISO was now at 200, and now I'm going to go up one stop, meaning I'm going to double. I'm going to double that amount from 200 to 400. I've gone up another stop. I've now gone up two stops. And I look in my viewfinder and again it looks better, but it's still not where I need for it to be. And now I'm going to go from 400 to 800. Again, doubling, doubling that ISO 400 to 800, one stop. I look at my viewfinder again and I look at my histogram and I have the image that I want. My aperture is where I need it to be, my shutter speed is where I need it to be. And now I have adjusted my ISO to give me the image with the proper exposure that I am aiming for. And I take my shot Guard it. I've gone up three stops with my ISO 100 to 200, 200 to 400, 400 to 800. That's three stops and now I have the exposure that I need for my image. Now you know, I simply cannot end there. Let's say, just so happens, I still don't have proper exposure and I have to go up another stop. That would mean my ISO is 1600. And let's say, it's still not what I want and I have to go up another stop and now my ISO is 3200. And let's say, in this new scenario, after five stops going from 100 to 3200, I finally have my well-exposed image. Wonderful, in this new scenario, I hit my shutter, I take my shot. It's exactly what I need. Now, if you recall when we talked about aperture and when we talked about shutter speed, there is always a trade-off as you move through, adjusting your numbers, adjusting your exposure. The same is true for ISO. When you increase your ISO, you introduce what's referred to as noise. Some people say grain. I often say grain. What I mean is noise, and it's hard to make the distinction. What I like to say is grain is intentional and noise is not. So as you increase your ISO, you start to notice that your photo. It's not as sharp as it should be. It has a grainy look to it. And as you increase your ISO, that graininess see there I go that grainy appearance also increases because you are increasing the amount of noise into your photo. Noise is the trade-off for increasing your ISO. Now the good news is, modern cameras handle noise like it's nobody's business. You can go pretty far up with your ISO before introducing noise into your image. And even if you have some degree of noise, it's easily correctable in post-processing by either using third-party software such as Denoise, which I've spoken about in other episodes, or in the most up-to-date versions of Lightroom. Denoise is actually part of the function in Lightroom and you have the choice of using Denoise or you can manually adjust noise reduction in your post-processing. In photography there's a trade-off for almost everything. When you manually or use third-party, or however you go about reducing the noise, you have to be very careful because it's very easy to manipulate a photo to the point where it just takes on a very plastic-like appearance in your attempt to get rid of noise. So that's something you have to be aware of. Outside of that, it is pretty amazing the level of correction that can be accomplished by using Denoise or just doing it manually in Lightroom. So it is a correctable issue if you want to reduce noise. There are times when a little bit of noise in a photo looks really cool. So photos at music events like stadium concerts. It's almost given that there's going to be some introduction of noise into those photos and it can look really cool. Same thing like photos of newsworthy occurrences, such as catastrophic events or war photos or things that happen in nature. They look better with not that they look better, but some amount of noise in those photos. It's expected that no one really criticizes when there is noise in that type of an image, because the truth of the matter is, if a photo journalist is photographing something such as a natural disaster or a protest or anything like that, no one is expecting a smooth, perfectly clear, gorgeous photo. There's a sense of grit about that. So having noise in those types of photos is perfectly acceptable. Now, to be clear, when you're photographing portraits or events, things of that nature, less noise tends to be better. So in those cases, instead of increasing your ISO, the best thing to do is to increase your light source. And again, I'm not going to get into lighting here. We talked about lighting in a previous episode and we will talk about it again. But the solution to not having to increase your ISO to the point where you are introducing noise into portraits or into a reception or a party or something like that, is to improve your light source. Another thing you can do to help you with that is in your camera, and I certainly cannot speak for every single camera. I know this function is available in every camera. However, I can only speak to the brand of camera that I use as to how to do this, and that is, you can set your camera to avoid going over a certain level of sensitivity. An example of this would be on my camera. My maximum ISO sensitivity is 12,800, which is pretty high. I've never actually needed that. I can actually, you know, bring that down a couple of stops, but my camera is set so that if I use something like auto ISO another function that's in all cameras, which is the ability of your camera to change the ISO based on the ambient light in the room or wherever you are it prevents my camera from increasing the ISO to more than 12,800. If it ever gets to 12,800, it'll be massively noisy anyway. Again, the solution for decreasing the amount of noise in your photo is to improve the lighting situation. Now here's another thing about ISO. If you are photographing in a studio and you are using strobes, or you were using off camera flash, then you can keep your ISO at 100 because you have a better source of light and your ISO can be at 100, and you just need to adjust the power on your strobes or your flashes or speed lights, whatever you want to call it as needed. So your ISO can stay at 100 and you will have an extremely quote, unquote clean photo with no noise at all. Now, just to confuse you a little bit and this is what I meant when I said ISO seems like it's the simplest of the three legs of the exposure triangle to understand, but sometimes, as in what we're going to talk about next, it can get a little hazy, no pun intended. Let's say it's a beautiful day outside and you want to photograph something, and you know it's a well lit day. You have your aperture, whatever it needs to be, you have your shutter speed, whatever it needs to be, but you want to photograph something like a bird in flight, and your shutter speed because you are photographing something that's in motion and birds move pretty darn fast you have to increase your shutter speed in order to get a sharp image right, because if your shutter speed is too slow, it'll drag and your image will be blurred, and you don't want to blur image. You want a perfectly clear image of a bird in flight. So that means your shutter speed has to be really fast. And if you understand shutter speed, you understand that with a very, very fast shutter speed you are reducing the amount of time that light comes in through your lens to hit your sensor. So if you are firing your shutter speed at I don't know something, really, really fast, the amount of light that hits your sensor is going to be. It's going to happen really, really fast. I don't want to get any more technical than this. It's going to happen really, really fast. It's going to happen so fast that your sensor needs to have increased sensitivity to light and even though it is a well lit, bright, sunny day, you are going to have to increase your ISO so that your sensor is I'm being redundant here so that your sensor is increasingly sensitive to capturing the image. So you would end up with a very fast shutter speed. I'm just going to throw a number out there, like, let's say, one, two thousandth of a second, and you may end up with an ISO that is well over a thousand, maybe 1600, maybe 3200, in order to capture the image that you need to capture. And here's the perfect case of. You would then take that photo and when you go to do your processing, your post processing, you would then have to decrease the amount of noise in order to produce a beautiful image of a bird in flight. Now, depending on your camera, you may not really have to do much, but in general, you'll probably have to do something. Photo being, when I say even ISO, can be a little bit tricky to understand because, in the most general terms, on a nice, well lit day, best lighting possible. Well, you know, as we started, our ISO was 100. And there's an assumption of well, it's a really nice day and the day's well lit, my subject is well lit, I don't need to increase my ISO. But if my subject happens to be a bird in flight, I don't know, a squirrel running across the field, a rabbit in motion, where you've got to increase your shutter speed, you will then have to compensate for that by increasing your ISO. Think about it. I know it can be a little bit daunting. It's something that you know. As with the other legs of the exposure triangle, you just have to do it and do it over and over and over again, and it'll click, you'll get it. It's one thing to hear someone say this, it's one thing to read it. God knows, I read this stuff over and over and over again and it wasn't until I did it over and over and over again that I really understood. There's nothing like practicing in order to get these concepts under your belt. But the last thing you want to do is, you know, be outside trying to take a picture of a bird, or trying to take a picture of someone you know on a skateboard, and you're doing this over and over again and your photos are blurry because you're not getting the point that in order to capture them, in order to capture a sharp image, you need not only a fast shutter speed, but you need to increase your ISO, obviously because you're working without the advantage of additional lights, of artificial lights if needed. So again, when it's possible, best case scenario is to improve your lighting. When it's not possible, when you're working in nature, you will need to increase your ISO, even when, with the naked eye, you have really good lighting. Now that I have confused you, honestly, I hope I've clarified more than I've confused Again. I you know, just do it. Just do it and it'll make sense. A couple things I need to mention before we wrap up. In my scenario I talked about, you know, increasing ISO by stops. So 100 to 200 is one stop. 200 to 400. That's another stop. The truth is, in your camera, stops come in thirds. So you know you've got some amount of manipulation in between going up full stops or coming down full stops. You can manipulate by a third of a stop if necessary. It's just easier, for the sake of explanation, to deal with the standard numbers versus dealing with the numbers that are in between. I alluded to this before. Most cameras I would think now all cameras have auto ISO. If you are going to be in a situation, if you find yourself in a situation where you know the light is constantly changing, if it's an overcast day where, yeah, for the most part it's cloudy and now here comes the sun and you know you've set your camera for more for the cloudiness or the dim or the dark, the darkness of the day, you can always put your camera into auto ISO. Most cameras now handle auto ISO really, really well. If you want to just try it out, do it in your home, sit on your couch and just take photos of stuff you know around your living room or your bedroom or wherever, and even in one room. As you take photos around the room and you see the difference in lighting, you will see the ISO and auto ISO change accordingly and you can compare the photos and that's a wonderful way to learn. You know I talked about this when I talked about shutter speed and aperture that you could be sitting in your home watching television and just photograph stuff in a room, photograph pillows, photograph ornaments, photograph furniture, photograph anything because all you're doing is learning. And same principle with with ISO. If you want to try out auto ISO, if you want to see what changing ISO does to your photos, just practice. Well, I'm just going to summarize this episode. So in photography it's really important to understand the concept of ISO, because it is one of the foundations of exposure, along with aperture and shutter speed. Remember, iso is a measurement of the sensitivity of your camera's sensor to light. It essentially dictates how well your camera will capture images in different lighting scenarios. Generally, in well lit situations, generally, your camera can operate at its native, native ISO, which in most cases is 100 or 200. I believe there are cameras now where the native ISO is actually 64. But in a typical well lit scenario, you can get away with whatever the native ISO is for your camera. The lower your ISO, the lower the amount of noise that is introduced to your image, and at your camera's native ISO whether 64, 100 or 200, there is no noise. When working in a studio with strobes or if you're using speed lights, your ISO can remain at its native number. There's no reason to increase it when photographing portraits or commercial work or product photography, etc. For the most part as you know, there tends to be exceptions to everything, but for the most part your ISO can remain at its native number for your camera. Did not go into this too deeply in this episode. Obviously, if you understand the exposure triangle or you're beginning to really get the gist of this, you understand that these three elements work together and when you make an adjustment to one element of the exposure triangle, it requires making adjustments to the other elements of this triangle. And I'm gonna leave that there because I think going into that deeper in this episode would be too much. So that's something that we will definitely talk about when we do an episode that talks about these three elements of exposure together aperture, shutter speed and ISO. Increasing ISO increases the noise in your image. Generally, cameras these days handle noise superbly and when there is the need to edit a photo and address the noise in a photo, certainly their software that does that and does it rather easily and does it really well, but the goal should always be to manipulate a photo as little as possible. In other words, going back to what I said before, introducing better lighting into the scenario is probably the most ideal thing that you can do to reduce the amount of noise in a photo, because you reduce the need to increase your ISO if there is noise again adjustable using denoise. Using denoise in lightroom or using or doing it manually in lightroom, as with the other legs of the exposure triangle, just try this out rotate those dials on your camera so that you get a good exposure. Okay and you know, I've said this with the other episodes in the know, your camera series just play with the dials until you get good exposure and then, if you're going to be paying attention just to ISO, leave your aperture where it is, leave your shutter speed where it is and see what happens as you increase and decrease your ISO, and that'll probably drive the understanding of this concept home. Okay, I hope this has been helpful. I know these episodes, they're kind of technical. I try not to be all techie about it because you know, as I've often said, it took me forever to grasp these concepts and I'll admit that I can be slow about this, but you know, if there are people out there and you've been trying to understand this. I hope this helps you to some degree. Thank you for listening. I look forward to your comments about this episode and the other episodes in the know, your camera series and, hey, any episodes that I, you know, bring up here on the podcast. If there are things that you want me to talk about, just reach out to me. Just either go to the the web page, cluedupbtscom. You'll see my info. Shoot me an email. If you want to follow me on Instagram I'm at photographer Maria B feel free to either DM me or you can go to my link tree and you can see all the different ways that you can contact me. So if you go to photographer Maria B on Instagram, you'll see my link tree. Link you open that up and you'll see all the different ways that you can contact me. Throw me any questions, any topics you'd like me to cover. I'll be glad to explore those with you and I'd like to continue to help you guys improve your photography. Thank you for listening. Talk to you soon. Thanks so much for listening to this episode of clued up with me, your host, maria B, if you've enjoyed this podcast, please be sure to rate, subscribe and review on your preferred podcast listening platform. I really appreciate your support. When you rate, subscribe and review, you're also helping other listeners find and enjoy this podcast. Until next time.