GLENYS MORGAN SHOOTPETALS..COM. Hi everyone, this is Glenys Morgan from ShootPetals.com... welcome to the 3 rd video in

Transcription

1 GLENYS MORGAN SHOOTPETALS..COM VIDEO 3 APERTURE: Hi everyone, this is Glenys Morgan from ShootPetals.com... welcome to the 3 rd video in my Exposure Series. In videos 1 and 2, I gave you some insight into how to get better photos by understanding the Exposure Triangle. In video 1 you met the histogram and how it can help you get the best exposure for your image. Then in video 2 you learned about shutter speed and a little about ISO. Today, in video 3, you ll get comfortable with your camera s aperture. One more very important concept that, once you understand it, will change your photography... forever! Here s a short refresher on the 3 parts of the EXPOSURE TRIANGLE - first, your ISO is your exposure enabler. ISO dictates how sensitive your film or your camera sensor is to light, and you can adjust it right in your DSLR camera or if you shoot film, you ll buy a film with a specific ISO rating. Next.. shutter speed... or how fast (or slow) the shutter opens and closes to let a very specific amount of light into the camera. Your shutter speed has to be fast to freeze motion, like sports for instance, or use a slow shutter speed to blur motion. A good example of deliberate blurring is when you photograph a beautiful waterfall to make it

2 look ethereal. What exactly does the aperture do? This might help you understand. My friend s son is celebrating a birthday today and his parents are throwing a pool party for him. I volunteered to fill up the two kid s pools in the back yard with water. For the 1 st one, I m going to use a half inch rubber tube and the other I ll use a fire hose. Which one s going to fill up a pool the fastest? No surprise there. The fire hose wins hands down. That s exactly how shutter speed and aperture work together. If you wanted the same amount of light from both a wide and a tiny aperture, you d have to let the light through the smaller aperture for a longer time. See, you can change either time, shutter speed, or the size of the opening - aperture - in many ways to get the same end result. And you need a result that gives you the image you want. Depth of Field (DOF) So what s depth of field or DOF? This is a concept you need to understand so you can

3 make an image look like you actually planned the result. A camera can only focus on a tiny area at a time... just like your eyes. Try this, look at something right in front of you, focus on it stay focused and try to bring your entire field of view into focus, in front and behind. Can t do it, can you? Me neither. That s another similarity between your camera lens and your eyes. Depth of field is the area in front and behind the spot your camera focuses on that s going to appear sharp. The transition from what s in focus to what s blurry is gradual. Ah, ha! Do you see the creative possibilities here? What affects DOF- So many things can affect your depth of field. It changes with: different lenses for instance (the brand, the type and quality of the lens) different focal lengths (Is it wide angle, a normal lens, macro, telephoto) Then the aperture you choose your camera s sensor size - and there are several. DOF changes drastically with how close or how far away you are from what you re focusing on (are you 5 miles away from a mountain landscape or are

4 you sitting on a grasshopper that you re looking at through a macro lens? - Those are the extremes.) Here s a great example of a narrow depth of field. This little red camera s lens is obviously what we re supposed to look at. The area that IS in focus is a really narrow slice. The camera body and the background are blurred. And our eyes go straight to the lens because it s the only element that s in sharp focus in this photo.. Aperture and Eyes Your eyes are a lot like your camera lens. The circular, coloured part called the iris, has muscle tissue that contracts to open up the eye when it s not getting enough light to see properly. We call that dilation. When the brain says we need less light, the muscle relaxes and the pupil, the opening in the middle, gets smaller. We say the pupil constricts. Doesn t that sound like the aperture in your lens? How we see is a complicated electro-chemical process and it happens without thinking about it. Cameras are electronic - and we CAN put the process on Auto. Then the camera s brain (pretty flimsy compared to yours) adjusts the aperture, ISO and the shutter speed. It s different from our eyes because we can take over control of the shutter speed, ISO and aperture adjustment on our cameras if we want to.

5 Aperture Priority Mode Remember from the shutter speed video that there are 3 auto camera modes: program, shutter priority and aperture priority. If you decide your aperture is your most important decision, dial in Aperture Priority. It s the one that photographers probably use most. Use your camera manual. Set it and forget it! Because your camera will make decisions about ISO and shutter speed. And, for all typical scenes, this works great. Photos 1 - Explaining f-stops From eyes to apertures. The aperture is built into the lens, not the camera body. The aperture works WITH your shutter speed to regulate the amount of light that reaches the sensor. I erased the mirrors and the shutter to make it easier to see. Changing your lens will most likely change your range of apertures. This particular lens has the widest aperture of f 1.4 and the smallest f 16. My favourite lens is from 2.8 to 32. Here s the concept. Just like your eyes, the aperture adjusts the size of the hole that light flows though. Need more light, open up the aperture. Too much light, choose a

6 smaller aperture. This is a little puzzling. It doesn t really make much sense, does it? Isn t 16 much larger than 1.4? Yes, it is. Remember when we talked about shutter speed being a fraction and it s just understood that 125 is really 1/125th of a second? It s the same with apertures. It s understood that aperture numbers are fractions. What about f 2? It s really ½. Let s use a blue pie analogy. Two, or 1 over 2 is half a pie. Right, ½? If you go to f 4, that converts to ¼ and see here, ¼ is half of ½ so it s smaller. An eight is half of ¼, and twice as small as ½. Don t worry, math wasn t my strongest subject either! Check this cute trick to remember all your major f_stops: Look at every second f-stop. Let s start at 1.4, multiply it by 2, skip a stop and voila... there s 2.8. Multiply 2.8 x 2... and leap over the next stop... alrighty... we got 5.6. And again.. we get Yes, I know it should be close enough. Most cameras have an f 22 as well. Neat trick, huh? And that goes for the stops in between. F 2.0 x 2, 4, and 4 x 2, 8, and we end up with 16. Some cameras have f 32, mine does. Depending on your camera, you may be able to program it for ½ stops as well as ⅓ stops. If you do that, you ll see three numbers between each of these. You ll see a stop,

7 a third stop, a half stop and ⅔ stop, then the next full stop. I set my camera to use half stops but not thirds. So you just go ahead, season to your own taste... It s all good! These pretty peonies are all in focus. But, compare the backgrounds in them. I m very close to the plant so the DOF is really narrow. F 5.6 is a wide aperture and the DOF is much slimmer than f 22. So the first image has a blurry background. F 22 is a tiny aperture with a much deeper DOF so the background is also in focus. F 11 is somewhat sharp. I d choose even larger aperture like 2.8 to really blur out the background for an artistic photo. Here s a little secret about lenses. The apertures in the middle of the range gives the sharpest image. If we look at the same lens, you ll get the best possible focus at either f 4.0 or f 5.6 With a lens that has a range from f 2.8 to f 22, the sharpest aperture would be f 8. Check the specifications on your lens to see what your sharpest aperture is. And another tip. With the tiniest apertures... you ll get light diffraction. That means light scatters in all directions. So, as your aperture gets smaller, your images won t be tack sharp. I rarely use f 32. Macros This is an iphone 5s photo but with a twist. I used an Olloclip macro lens here. This is a

8 clam shell and my lens is only an inch or so away from it. Remember that your DOF gets smaller the closer you get to your subject. Well, this shell is only 2 inches in length and you can see how quickly the focus falls off. I focused on the edge of the shell. In all macro photography, it s so important that you have a tripod to keep your camera still. The tiniest movement will knock your focus right off. With this brilliant red and white tulip, focus is on the edge of the petals closest to me. F 16 has a wide DOF but the lens is so close, maybe about 18 inches away from the flower so the DOF is reduced. Even at f 16 look at how quickly the sharpness drops off. This is a telephoto lens at 300 mm, so on my camera, it s 450 mm. I m staying back from the butterfly so I don t scare it away. Because I m 10 feet away, I can get more in focus now. F 11 is my sharpest aperture and it s perfect for capturing the daylily and the butterfly and the background is blurred just the way I wanted. The butterfly inside the daylily is basically a portrait. Just like this photo of my niece. Aperture - Portraits - Landscapes With a portrait, always focus on the eyes. If you don t get the eyes clear and sharp, a portrait just doesn t look right. That goes for people and animals as well.

9 F 5.6 keeps my niece sharp and the background out of focus. My effective lens was 300 mm. My shutter speed is 1/350 because she s full of energy... always on the go. 1/350 th will stop any motion. Every photo tell a story, like these portraits of my friends. They love to be outdoors. You know that because of what they re wearing and the backgrounds are clear enough to make out that they re out in nature. And... speaking of being out in nature, what apertures do you are best for landscapes? First, get to know your own lens and how your depth of field changes with changing your f-stop. You can create whatever look you like for your landscape. But, I ll show you typical landscape photos where the whole scene is in focus... front to back. This is at UBC Botanical Gardens in Vancouver - the lens is mm and the effective length for this photo is 27 mm. This photo was taken at F 11, the sharpest aperture on this lens, and since there wasn t much of a breeze, shutter speed was 1/125 th. Wide angle lenses have a greater DOF than telephoto lenses so use a wide angle for photos of grand landscapes like this one of Flat Top outside of Anchorage Alaska. The scene is much more encompassing than the one of UBC gardens. I used the same lens but dialled it to 30 mm. - On my 1.5 crop sensor, that s effectively a 45 mm angle of

10 view. F 8.0 got everything in focus from foreground to the mountains. Shutter speed was 1/250. Here s a tip: Go to itunes and download an app for your iphone or ipad... only a little more than a $1. Called Depth of Field Calculator. For androids, itunes or Mr. Google will find one for you. Or, search online for a DOF chart that you can download as a JPG or PDF. Print it if you want to carry it in your camera bag. And last, but not least, use your DOF preview button on your camera. The scene is going to look darker than what the picture will actually turn out. Hyperfocal Distance When you shoot landscapes, use what s called hyperfocal distance. That means - What s the closest point to me that I should focus on to make sure my foreground, middle ground and background are all in the sharpest focus possible? You can get as technical as you want with this and if you re interested, use your camera manual, or go online and search for a good article. All I m going to say right here is... focus about a third of the way into your landscape and that should about do it. Here s wonderful Jeju Island in Korea. Jeju Island is a volcanic island, a mini Hawai i. This is Blackrock Beach at the Hyatt Hotel. F 8.0, shutter speed 1/90 and 185 mm. This is a more intimate landscape than Flat Top. I love that the woman s clothes exactly

11 matched the colours on the beach. If I d wanted the water to be really sharp, I would have tried 1/500 for my shutter speed. Another smaller and more intimate landscape at VanDusen Botanical Garden in Vancouver. This is a much smaller landscape than Flat Top, I used f 16 and shutter speed of 1/30 th. I don t care about my shutter speed being so slow for 3 reasons. My camera was on a tripod I used a remote, and there s no wind. But, what if there were a breeze, and I wanted to freeze any motion? Let s figure that out: My meter told me that my perfect exposure was f 16, ISO 200 and 1/30 shutter speed. Maybe I want a faster shutter speed because there s a wind but I m also concerned about keeping my DOF. I want everything in focus. If I need a shutter speed of 1/250, that s a difference of 3 stops of light. Losing 3 stops means the photo s underexposed. What can I do? Remember I called ISO the enabler? I could crank up my ISO and make it more sensitive to the light, but not too much because then there might be a lot of noise in my image. The aperture is going to have to change. Let s juggle all 3 components. If ISO increases to 800 (that s okay in my camera), I can get my shutter

12 speed to 1/250 with only sacrificing 1 stop with my aperture at f 11. That s no problem, in this scene, everything should still be sharp. I ll focus ⅓ into the scene... remember the hyperlocal distance? I try not to stray far from my sharpest apertures but, of course, that s not always possible. Here though F11 would have worked to keep everything in focus. Brilliant Japanese maple leave make up the foreground, they re tack sharp because they re my subject. The evergreen trees in the middle and background are blurred. And they re blurred because they re a distance away from the maple leaves that I focused on. Just like I d shoot a portrait of a person so you could say it s a portrait of colourful leaves! Alright... quiz time... When doesn t your DOF matter? Pause me and - Think... hard... Okay I m back... did you put me on pause? What s your answer? When the subject is totally flat - there is no depth! So a wall maybe with graffiti, a painting... or a flat rock like this... If you have enough light, use your optimal aperture. I did and I used f-11. For both of these rocks. Pretty aren t they? If there isn t enough light, use your widest aperture, you might have to raise your ISO. Whatever combinations you make in the exposure triangle, it s all good when your

13 scene is flat. Aperture Priority Mode Remember from the shutter priority video that there are 3 auto camera modes? Program mode, Shutter Priority and Aperture Priority? If you decide your aperture is your most important decision, dial in aperture priority. It s the one that photographers probably use the most. Use your camera manual, set it and forget it because your camera will make decisions about ISO and shutter speed now. And for all typical scenes, it works well. Photos 2 - What Were My Settings? Let s wrap this up with a few more photos. See if you understand all the choices I made. Let s start with a macro shot of a poppy. I used my Nikon 105 mm macro lens, f 22. I wanted the entire image in focus and my lens is inside the petals so my DOF is very slim. That s why I chose f 22, to get the maximum depth of field. This poppy was in my house and I used window light and a couple of reflectors to fill in any shadows. Shutter speed didn t matter... my camera was on a tripod and the flower was totally still.

14 Now we re in Ketchikan, Alaska... what an incredibly rainy place. The foreground is a distance away so I used f 8.0 and everything in the landscape is in focus. ISO 200 and shutter speed 1/125. Alaska to South Korea. These are mandarin Ducks on an icy winter pond. They re in the middle of the pond and I m using the 300 mm lens. You can see the way telephoto lens compresses the scene. I was far enough away to use 5.6 and get everything in focus. The ducks were quite entertaining skating on the ice so my shutter speed was 1/250 to freeze any of their motion. This was a whale watching trip off Vancouver Island... in a Zodiac... in February. Unless you re part polar bear, I don t recommend it! I thought I d never thaw out. But I did get some totally awesome photos. I used my 300 mm lens and I m far enough away to use f 5.6 and get the sea lions and the rocks they re on in focus. I needed a fast shutter speed because they were bobbing back and forth, barking away and occasionally one would jump into the water. I needed 800 ISO so I could get that fast a shutter speed. Since I know there s virtually no noise on my Nikon at 800 ISO, that was the best way to get the right exposure. A really crispy cold winter picture in Manitoba Canada... with all the hoar frost on the trees and the moon in the morning sky. F 8 and F 11 are the middle range apertures on this lens.

15 Now to Butchart Gardens on Vancouver Island. This is the dining room. The window light is gorgeous and it floods into the whole restaurant. With f 8.0 everything in the window sill and outside in the private garden is in focus. Back to Korea... this is a group of traditional dancers. They don t stand still for very long. I was worried they were going start dancing again but I caught them still for a few minutes. Wonderful rich bright colours and the girls are standing on almost the same plane right across the frame of the photo. I didn t need a large depth of field to get everything in focus. F 4.2 was good and gave me a high enough shutter speed just incase they suddenly got into action. Wow, that was a lot of information I hit you with in the last 24 minutes. So its time for you to get some serious practice in. And I ll talk to you again soon. Glenys Morgan 2016