The Triangle of Exposure in Photography

The Triangle of Exposure in Photography

Introduction:

Understanding exposure is one of the most essential elements of photography. Expensive cameras can take beautiful pictures by default is a definite myth! You might carry a $10,000 camera in your hands but if you don’t know how to play with your exposure, you cannot click astounding pictures!

There are basically three basic elements of exposure i.e. Aperture, Shutter Speed and ISO. Changing one of them affects the other two. To understand this better, let us consider our camera as a window with two flaps. Now lets relate our exposure elements to this window. Consider Aperture as the size of the window. Bigger the size, more light will enter through it. The shutter speed is basically the time for which the door remains open. More amount of time it remains open, more light will enter the room. Now imagine you are standing inside the room. If you wear sunglasses you will see a darker imagine. Which means you have a low ISO. If you keep the size of the window same and remove your sunglasses, you’ll see a brighter scene. That is high ISO. 

Let us now look into details of each one of them.

 APERTURE:

As we saw, Aperture is the size of the window. When you click the shutter button of you camera, a small hole opens up in your lens. Using an aperture value, you can basically control the size of this opening when the picture is taken.

Aperture is measured as ‘f-stop’ or ‘f-number’ i.e. f2.8, f4, f5.6 etc. Changing from one value to the other either doubles or halves the opening of the lens. Large aperture means more opening and smaller aperture means less opening. Make an important point here that smaller the f-stop number, larger the opening. Which means that f2.8 will result in a bigger opening than f5.6. Which means f2.8 will have more light coming into the lens as compared to f5.6.

Concept of Depth of Field (DOF) and its relation with Aperture:

Depth of field can be either larger of smaller/shallow. Larger depth of field means all of your imagine will be in focus. Shallow depth of field will result in only a smaller area of your picture in focus and rest of the picture will be blurred. If you are taking a landscape photo with nice river and mountains in the backdrop, you’ll need a larger depth of field. On the contrary if you need to take picture of a flower and want everything else in the background to be blurred, you’ll need a shallow depth of field.

Now if you have understood the definition of large and shallow DOF, let us relate them to f-stops. Larger aperture means shallow depth of field. Which means if you want to take picture of a flower with the background blurred, you’ll need to stick with a smaller number of f-stop i.e. f2.8, f4 etc. Now as you will start increasing this number and click the same picture, you’ll start noticing that the background has started to get visible. In short, you are moving from a shallow DOF to a larger DOF.

Let us compare set of pictures so you’ll see this with a better perspective. The two pictures below illustrate how DOF changes with aperture value. You can clearly see how the background is visible at f40 and blurred at f3.5

Aperture v/s DOF

Let us look at a few more pictures and their relative f-stops.

Monument Valley, Utah; Aperture f22

Bleeding Heart; Aperture f4

The topmost landscape picture is shot at f22 because I needed a larger depth of field. That way I have all of the objects in the frame clearly in focus. On the contrary the ‘Bleeding Heart’ picture above was shot at f4. This was because I needed a shallow DOF. In other words, I only wanted the flowers to be in focus and everything else in the background blurred. There were bunch of green bushes in the background but they have been blurred because of the aperture value I chose. That way I kept the viewer’s interest locked on the flowers. A visible busch in the background would have been a distraction.

 SHUTTER SPEED:

As discussed in our opening paragraph, shutter speed is the time for which the flaps on the window remain opens. In other words, the time for which the shutter remains open. Shutter speed is calculated in terms of fraction of a second or seconds i.e. 1/10, 1/500, 1/1000, 2 secs, 5 secs etc. Remember larger the denominator, faster the shutter speed. And faster shutter speeds means better freeze of the action. Acceptable action freeze happens at 1/60 shutter speed. Anything below that (1/10 etc.) will result in shaking of the image. If you want to freeze a biker or a moving car, you will need a higher shutter speed, somewhere around 1/200 or higher.

Let us now look at the relation between aperture and shutter speed. Imagine the amount of light that will enter through the window. Say you have a higher shutter speed. Which means the flaps on the window open and close pretty quickly. So there is a pretty thin margin for the light to enter into the room. Now what will happen when you keep the shutter speed same as before and increase the size of the window? Obviously more light will enter into the room. In short to get the same exposure out of a picture, you have to simultaneously adjust shutter speed and aperture i.e. if you increase your shutter speed by one stop, you’ll have to decrease your f-number by one stop as well. For example, say you clicked a picture at 1/30 and f5.6. Now say you increased the shutter speed by one stop to 1/60. Now you are keeping the opening of the lens same but keeping the shutter open for a shorter time, hence less light would enter the camera. So to compensate and allow the same amount of light into the lens, you’ll have to increase the opening of the lens. In other words, switch from f5.6 to f4.

 Let us now look at a few examples of shutter speed and its application.

Fishing Eagle; Shutter Speed: 1/1000; Aperture: f5.6

In the picture above, I wanted to freeze the action when this eagle picked up a fish from the water. A higher shutter speed of 1/1000 did a perfect job. The aperture was kept at f5.6 so that the bird is in focus and the background is decently visible (Remember here my focus is the bird and not the background. So I wouldn't mind blurring the background a little bit).

Badwater Basin; Shutter Speed: 1/2 sec; Aperture: f22

While taking this picture at Death Valley National Park, I was not worried about freezing any motion so I stuck to a lower shutter speed of 1/2 sec. Also, as this is a landscape picture I needed a larger DOF hence I chose an aperture value of f22.

After shutter speed let us now get to the final element of exposure i.e. ISO.

ISO:

As we saw in the introduction, ISO is the amount of sensitivity to light by your camera. If you leave your camera on Auto ISO, darker the environment, your camera will try to push the ISO to a higher value. Although a very important factor to note here is that higher ISO values lead to a grainy/noisy image.  Every photographer always strives to keep the ISO value on the camera as low as possible.

There are several situations when you’ll feel the need to push your ISO to higher values like an indoor sports event, museums, indoor concerts etc. In a darker scenario if you want to keep a low ISO (to avoid grainy image), you’ll have to compensate on shutter speed and aperture. Lower aperture values will give you better results with acceptable ISO. Similarly lowering the shutter speed will also yield better results. Although lowering shutter speeds wouldn't work in many situations. Imagine you are shooting an indoor sports event and you don’t want to have a higher ISO value. In that case you will have to lower your shutter speed as well.  But then shooting a fast moving basketball player with lower shutter speeds will result in a shaky image. Hence in situations like these keeping a lower aperture value is the best alternative. All lenses have a minimum f-stop value that you can use. Lower the aperture value, more expensive the lens (Because you can use that lens in a better way in low light situations). For example, a 50mm f1.8 lens is more expensive than a 50mm f2.8 lens.

Here is an example of a low ISO night image:

Brooklyn Bridge; Shutter Speed: 30 sec; Aperture f16; ISO 100

The above picture of Brooklyn Bridge was taken at ISO 100. Because of that, the image turned out to be noise/grain free. But to achieve that, notice I had to use a shutter speed of 30 sec. If I would have used a shutter speed of 1/500 and kept the ISO 100 and aperture f16, this image would have been an extremely underexposed image, almost dark. To make the image visible, I would have had to raise the ISO. But again higher ISO means more noise. Again, since the shutter speed was 30 sec, I had to use a tripod to get this shot. If I had tried clicking this hand held, it would have been a shaky image.
 
Conclusion:

To sum things up, the world of exposure entirely revolves around three elements; Aperture, Shutter Speed and ISO. Each of them is inter-dependent on the other. Changing one element hampers the performance of the other; hence it is important to understand the balance between values of all three. Every photographer strives to come to an acceptable shutter speed, aperture and ISO, which would give him/her a perfectly exposed shot. With my personal experience, I would say you would understand these elements in a much better way when you’ll go out with your camera on field and try different settings. Try an indoor sporting event or a night shot. Try the same shot with different settings and see how your output varies. Every camera has an inbuilt digital meter which shows you whether your shot is under or overexposed. Adjust your settings until you get a perfectly exposed shot.

Exposure/Light Meter

Note that the meter runs from -2 to +2. A perfectly exposed shot will have the scale at 0. Minus values represent underexposed shot while the positive values indicate an overexposed shot. 

So don't wait! Get out there with your camera and play with it! That is the best way to have fun and learn at the same time! I hope you liked reading my post. If you have any feedback or questions, please feel free to write to me at pnbhosale@gmail.com. Happy clicking and happy learning! 

A Road Trip to National Parks of the West!

It was time to plan another photography trip and I was wondering where to go. Last time I chose Maine and New Hampshire over Florida. Florida was under consideration this time as well but after thinking for a few days, I realized two things. Firstly Florida isn’t too far from where I live and I can always squeeze in a quick trip down there. Secondly it would have been a purely birding trip. Wildlife and birding is always an uncertain equation (You have to be at the right place at the right time!) so flying so far and getting disappointed wasn’t on my plate!  I wanted to do something big that wouldn’t be possible to repeat. After a few days of research I thought the best place I can hit would be National Parks of the west. There were a few reasons why I chose those National Parks. First, it would be purely landscape based trip so no fear of luck. If you make there for sunset or sunrise you are surely getting that shot! Mountains and Trees don’t fly and run like wildlife! Another factor being that since all those parks are usually dry during this season, I could book tickets early and I didn’t have to fear about heavy rains (Plus in some situations Rain and Storm add to a much better effect for Landscape Photography). So it was decided! Landscapes it is!

Next part was research. I went through several days of research with reading two books and a few blogs. Finally came up with my travel route which was the following:

Las Vegas à Arches National Park à Horseshoe Bend à Antelope Canyons à Monument Valley à Zion National Park à Death Valley National Park à Las Vegas

I planned to take two lenses with me along with my Canon 7D. First lens was the Tamron 17-50mm f2.8 and my second lens was Canon 70-200 F4 (Just in case I needed little zoom). Flew out of Baltimore and reached Las Vegas around 7:00PM in the evening. Picked up my rental car. Although a little pricey, I got myself an all wheel drive Jeep which would make off road travel easier for me. I dropped my bags at the Vegas Hotel and took the hotel shuttle for the Las Vegas Strip. Spend the next 4 hours doing some night photography and I got some fantastic shots of the cityscape! Here is one of the shots from Las Vegas:

 I came back to my hotel room at 1:00AM the next morning from the Vegas Strip. The air travel and 4 hours of walking on the Strip had made me dead tired! It was time to doze off! Woke up at 6 AM and this was going to be a long day. Seven and a half hours of drive to Arches National Park! Major attractions at Arches were Balanced Rock, North and South Windows, Delicate Arch and a few more to name. Delicate Arch is the most attractive photographic point at Arches and you require a good hour of strenuous hike to get up there! Started my hike at 6:00PM and took one hour and five minutes to reach to the top. I was exhausted! Climbing the mountains with your camera bag, lenses, water and tripod isn’t easy! The view from the top was breathtaking! I felt as if every step and breath I took to be here was worth it! The red rock glowed beautifully under the setting sun! Here is a picture of the Delicate Arch at sunset:

After a long day and strenuous hike at Arches National Park, it was time to doze off! I found a nice diner near my motel, ate to my satisfaction and went off to sleep with another day of excitement in my dreams! Woke up next day before the sun rose and headed towards the morning session of Arches National Park. The weather wasn’t going to be co-operative that day with clouds forming above me. It was probably going to rain. Cloudy sky wasn’t an issue but carrying you gear and hiking for half a mile becomes difficult when it starts raining in the middle of your hike. You have no place to hide in a deserted park and you surely don’t want to wet your expensive gear! I didn’t take any chances that morning. I did take a lot of pictures but definitely stayed close to my car just in case it started raining. I did get some interesting shots that morning! Here is one of them:

After completing the morning session it was time to head out to Page, Arizona. The drive was about 4.5 hours and my aim was to cover three locations around Page: Horseshoe Bend, Antelope Canyon and Monument Valley. I reached Page at 4:00PM. Checked into my motel, took a quick shower and I was all set to hit Horseshoe Bend for sunset. The hike to Horseshoe bend is a medium leveled hike. You don’t strain yourself as much as the Delicate Arch Hike but you do have to take quick pit stops to catch some breath. Checked the weather and my jaw dropped! Winds close to 40 miles per hour were on the agenda! Horseshoe Bend needs to be captured from the edge of a cliff so standing at such elevation with winds would be extremely difficult. Plus the desert sand would be a pain in the eyes. Also with the sand, we have to be extremely careful with the camera gear because if the sand goes into your lens or camera, it is very difficult to blow it out. In fact there are chances that the sand particles might go deeper into your camera while you are trying to clean it. I hiked and reached at the horseshoe bend. I was expecting a cloudy sky but to my dissatisfaction, it was a clear sky. With sun setting in front of you on a clear day, light becomes extremely harsh. Plus the wind made it worst to stand on the edge of the cliff. I wasn’t happy with my overall sunset setup and I decided I needed to be back at the same location next day for Sunrise! So called it a day and headed back to my motel. When I woke up the next day, the weather was much better. Winds had calmed down and I had a smile on my face! Hiked back to the cliff and what a wonderful setting it was! I’ll let my picture do the talking here:

Quickly competed my morning session and heading back to the place from where my booked tour to Antelope Canyons was supposed to leave. Antelope Canyon is an extremely beautiful location and you cannot drive your own car here due to sand. There are tours available which take you into the canyons using special vehicles equipped with tires that can handle the sand. My tour left at 10:00AM and it took us about 30 minutes to get to the canyons. The canyons are deep into the sand and while you walk through them, there is sand falling constantly from above! So if you plan to change your camera’s lens while in the canyon, FORGET IT!! Your camera will end its life after that! Anyways. After my shirt full of sand, I was happy to have clicked one of the most unique places on earth! It was an awesome feeling. Here is one of the shots from Antelope Canyon:

After completing my tour, my destination for the evening was Monument Valley National Park which is two hours drive from Page. Again, the roads inside this park are curvy and full of bumps and rocks! I have heard people having three flat tires at one given point in time, blowing out their engines and what not! And with very limited cell phone coverage, there are changes where you’ll be stuck inside the park for hours!  I didn’t want to take a risk so I booked a tour with one of the tour guides at Monument National Park. They have special vehicles that take you into the park. The guides have Satellite phones with them so they can communicate outside the park in case of an emergency. My tour guide was from the native Navajo tribes who have stayed in the park for many decades. He knew every inch of the park and took us deep into Monument Valley. I got some wonderful photo opportunities while I was there and all thanks to him! Here is a picture from the monument valley:

Came back to my motel after my trip and called it a day.

Started for Zion National Park the next morning. The drive is about 2.5 hours from Page. Reached Zion and the sky couldn’t be more co-operative!! Beautiful clouds added up to a great setup for my landscape shots! I spent an entire day at Zion National Park. You have to walk a lot inside Zion if you want to explore its beauty. I did a few hikes inside the park and it was breath taking! If you want to hike and cover the entire park, you need to stay for at least 3 to 4 days! I just had one day with me so I covered major attractions throughout the entire day. In the evening I made it up to a famous sunset point in Zion, the “Watchman”. This location is considered to be one of the most photographed locations inside the park! Again, I’ll let my picture from the “Watchman” make all the talking!

Here is another picture from Zion:

So after a great day at Zion, it was time to call off a day and head towards Las Vegas! I just had one day left now and the destination was Death Valley National Park. I started for Vegas the same day I left Zion and it took three hours to reach to Vegas. Checked into my hotel and dozed off. I had to wake up at 3:00AM for Sunrise at Death Valley National Park! So as planned started at 3:30AM the next day for Death Valley after a mere 3 hours of sleep. Reached just before sunrise at a place called Bad Water. This place is below sea level and there are salt accumulations all over the place! In fact this place is considered to be the lowest place below sea level in the entire world!! And above all, this is one of the most photographed sunrise locations in Death Valley! Here is a picture from the Bad Water:

After Bad Water, I drove around a place known as Artists Drive in Death Valley National Park. The name says so because at any point on that drive, you can just stop and paint a picture of the beautiful road, sky and rocks! Here is a picture from the Artists Drive:

Light got harsher later in the day so there was very little chance of getting a good photo in the desert. I had to wait for the sunset. Spent some time reading a few books about Death Valley at the visitor’s center. Gave me some time to take a deep breath too as my past few days were extremely hectic. Laid down on the bench inside the visitor’s center’s shade (Caring less about what people think!) and took a good afternoon nap. Felt like heaven!! At sunset headed to the famous Sand Dunes of Death Valley National Park. The evening light made the sand dunes shine like diamonds! It was a wonderful sight! Here is a picture from the sunset at Sand Dunes in Death Valley:

I had no intentions of waiting at Death Valley for night shots as there is very little cell phone coverage and driving at night is be risky. But since the sky got clearer as day ended, I decided to stay for a night shot. And the decision paid off!! My picture will explain the rest!

Came back to Vegas that night. I had my flight at 6:00PM the next day. I decided to relax for the last day and keep my camera aside. Spent some time in Vegas that day just chilling on the streets and enjoying some street shows around Vegas. And finally my trip came to an end. What a beautiful experience it was! I would say one week is very little time if you want to explore all of the National Parks in Utah, Arizona, Nevada and California. But we as working professionals have hard time finding more than a week just for a road trip! I’ll have to win a lottery for that so I could retire from my job and do road trips for the rest of my life!!

Anyways. I hope you enjoyed reading my post and above all the pictures I took! I would cut the story short now, as this has already turned to be a larger post than I anticipated! Do visit some or all of the places I mentioned in my post. It is worth every penny you spent on visiting these places! My website is www.prithvirajbhosalephotography.zenfolio.com Please feel free to visit my site and explore some more pictures from this as well as other trips of mine. Also, if you need any additional information, feel free to drop me an e-mail at pnbhosale@gmail.com

Thanks for visiting my blog!