The second photography book I read on SLR photography was The Digital Photography Book: The Step-by-Step Secrets for how to Make your Photos Look Like the Pros by Scott Kelby. Apparently this is one of the best selling digital photography books out there and I can understand why people like it. Kelby has established himself as quite the guru when it comes to digital photography.
The book is quite light hearted and as Kelby says it is intended to read like he was with you on a shoot (or preparing for a shoot) and he was giving you advice on how to get photos. It is not very technical which can be good and bad. He is telling you how to get the shots, but not why you are using those settings.
The first chapter provides advice on how to take sharp photos (tripod! it's not a big secret, every site and book talks about, but he has other useful sharp photo tips as well). He then gets into some basic scenarios and provides advice on how to take good pictures. There are chapters on shooting flowers, weddings, landscapes, sports and portraits. He covers composition, metering, lighting, and all sorts of topics related to setting up, preparing for, taking, and post-processing pictures. He also advises on how to avoid problems (backing up shots, extra cards, etc.). He concludes with recipes for specific types of shots.
Providing shooting advice without too much technical content is an interesting concept but sometimes it is useful to understand the why so when you encounter a new situation you can make decisions on your own. But this is a good start.
It is a lot of information to take in during the first read because the book covers such a wide range of shooting scenarios and I will definitely be going through it again. On the next read I plan on designing myself some exercises to try out some of the techniques.
Update notes: Three years later and I still haven't really gone through the book again in detail but I still want to. Now that I know a little bit more about photography the "how" that Kelby provides is still useful and I can use my own knowledge to fill in the "why". I still plan on looking at the book in more detail and creating some personal assignments for the different topics.
Originally published: 13/08/2009
Updated and republished on the date of this post.
Monday, August 27, 2012
Friday, August 17, 2012
The Cottage Shoot: People
Originally published as three separate posts I have combined the three into one. These photos come from one of my first outings with my Nikon D90 and sort of represent a starting point with my SLR photography. Some of them are OK, but definitely not my best work. The descriptions also come from early in my understanding of SLR photography, so they may be a little drawn out.
I spent the weekend at the family cottage in the Muskoka region of Ontario, on Peninsula Lake (Pen Lake) near Huntsville, Ontario, and this was my first real chance to take some serious shots. All of the shots are taken with my Nikon D90 with a 18-200 mm lens.
The first shot is of my brother wakeboarding. I was on the floating dock leaning on an inner tube and in order to freeze the action I used a fast shutter speed of 1/1250 sec. I also wanted a decent DOF to get both my brother and the boat in decent focus so I used f/8. I had metered the lake before the action statred and decided that to get a fast shutter speed I would bump the ISO to 400. I then selected the aperture and using the light meter in my viewfinder selected the shutter speed. The image is not as perfectly sharp as I would like. A firmer support and a wider aperture may have been better, but this may have required a higher ISO to keep the fast shutter speed. The focal length of the lens was at 120 mm. The compression of the image for display here takes away some of the clarity. I will work on that.
The next photo was taken from the boat. I knew I wanted a fast shutter speed so I left it at ISO 400. I wanted a narrow DOF so that the focus was on the wakeboarder (his first time trying it, hence the wipe out) and for my lens the minimum aperture when at 200 mm is f/5.6 . The light meter suggested a corresponding shutter speed of 1/1250 sec. I think it worked well to freeze the motion. Not a fan of the heads being chopped off in the background. either zooming out a bit to include them or re framing the shot may have helped. They were not my main concern at the time, but it does detract from the photo.
The next picture of is in a completely different setting. My brothers and their friends were fishing at dusk. The ISO was set to 1600 so that I could hand-hold the camera. The lowest aperture was used (f/3.5) and the meter called for a shutter speed of 1/200 sec. I was on the same floating dock as the fishermen, so we were all moving together. Because the subjects were so stationary it is possible a longer shutter speed would have added some motion and drama to this shot.
While I was at the cottage there were several opportunities to photograph the local wildlife and I never had to go very far to do it. I have done much editing of the pictures so some are a little bit crooked (something I need to work on). All photos were taken with my 18-200 mm lens.
A couple families of ducks live near the dock and they are quite friendly and accepting of us as we walk up and down the dock. For most of the duck shots the goal was to get the duck in focus. The first two shots were in the open so ISO 200 was used while the rest of the duck pics were in overcast light so ISO 400 was used to allow for a fast shutter speed.
At one point a large heron walked along the shore line. I got several shots of it walking bt the highlight was when it took off from the neighbour's dock.
Several birds were feeding outside the big bay window in the cottage. The light was low so the ISO was set to 640 and the aperture to f/5.6. The window was a bit dirty but I think the focus worked out. The focal length was 170mm and the shutter speed was 1/250 sec.
While I was shooting the ducks at ISO 400 I turned and saw a lily flower and thought I would take a shot of it. I kept the aperture at f/5.6 and used the meter to set the shutter speed at 1/3200 sec. The focal length was 200mm. Just as I was about to take the picture the bug came into the shot and landed on the flower. I took a couple shots of it as it landed. I will probably crop this in a vertical format later, I think that will have a better impact.
Some of my favourite pictures from the cottage were the nighttime low-light shots. The moon was full and provided a very interesting light over the lake. I started by setting up the tripod on the stationary part of the dark and took a few shots as the clouds passed by. All pictures are taken with the 18-200mm lens.
The first picture was taken with a focal length of 26mm at ISO 400, aperture f/6.3 and a shutter speed of 30 sec. The higher film speed was used to avoid manually controlling the shutter speed since 30 sec. is the longest the D90 will go without going into bulb mode.
When I walked back down the dock I saw a neat glow from the cottage and tried to shoot it. I used a focal length of 18mm, ISO 200, aperture f/3.5 and shutter speed 20 sec.
Probably my favourite shot of the night came when I turned around just before going inside and decided to take one last set of pictures. The ISO was 200, focal length 18mm, aperture f/5.6 and a shutter speed of 15 sec.
I wanted to try some shots from the inside of the old cottage. It's a 50+ year old log cabin with all sorts of cool stuff on the walls. The first is ISO 200, focal length 18mm, aperture f/16 and a shutter speed of 3 sec.
The second is ISO 200, 18mm, f/11 for 5 sec.
Thats all from the cottage for now.
Unfortunately the cottage has been sold and is no longer in the family. I still visit a cottage in Huntsville but it is a much larger cottage and has a much different atmosphere. It will be missed.
Originally posted: 11-12/08//2009
Combined, updated and republished on the date of this post.
I spent the weekend at the family cottage in the Muskoka region of Ontario, on Peninsula Lake (Pen Lake) near Huntsville, Ontario, and this was my first real chance to take some serious shots. All of the shots are taken with my Nikon D90 with a 18-200 mm lens.
The first shot is of my brother wakeboarding. I was on the floating dock leaning on an inner tube and in order to freeze the action I used a fast shutter speed of 1/1250 sec. I also wanted a decent DOF to get both my brother and the boat in decent focus so I used f/8. I had metered the lake before the action statred and decided that to get a fast shutter speed I would bump the ISO to 400. I then selected the aperture and using the light meter in my viewfinder selected the shutter speed. The image is not as perfectly sharp as I would like. A firmer support and a wider aperture may have been better, but this may have required a higher ISO to keep the fast shutter speed. The focal length of the lens was at 120 mm. The compression of the image for display here takes away some of the clarity. I will work on that.
| Wake boarding on Pen Lake. Shot from the dock. (1/1250 sec., f/8, ISO 400) |
| Learning to Wake board. Taken from the boat. (1/1250 sec., f/5.6, ISO 400) |
The next picture of is in a completely different setting. My brothers and their friends were fishing at dusk. The ISO was set to 1600 so that I could hand-hold the camera. The lowest aperture was used (f/3.5) and the meter called for a shutter speed of 1/200 sec. I was on the same floating dock as the fishermen, so we were all moving together. Because the subjects were so stationary it is possible a longer shutter speed would have added some motion and drama to this shot.
| Fishing off the dock. (1/200 sec., f/3.5, ISO 1600) |
While I was at the cottage there were several opportunities to photograph the local wildlife and I never had to go very far to do it. I have done much editing of the pictures so some are a little bit crooked (something I need to work on). All photos were taken with my 18-200 mm lens.
A couple families of ducks live near the dock and they are quite friendly and accepting of us as we walk up and down the dock. For most of the duck shots the goal was to get the duck in focus. The first two shots were in the open so ISO 200 was used while the rest of the duck pics were in overcast light so ISO 400 was used to allow for a fast shutter speed.
| (1/250 sec., f/5.6, ISO 200) |
| Not sure why the ducks like standing on one leg. (1/400 sec., f/5.6, ISO 200) |
| (1/1600 sec., f/5.6, ISO 400) |
| (1/400 sec., f/5.6, ISO 400) |
| (1/400 sec., f/5.6, ISO 400) |
At one point a large heron walked along the shore line. I got several shots of it walking bt the highlight was when it took off from the neighbour's dock.
| (1/800 sec., f/5.6, ISO 400) |
Several birds were feeding outside the big bay window in the cottage. The light was low so the ISO was set to 640 and the aperture to f/5.6. The window was a bit dirty but I think the focus worked out. The focal length was 170mm and the shutter speed was 1/250 sec.
| If I had used a spot meter mode as opposed to a matrix metering I would have got a better exposure on the blue jay. More on that in the future. (1/250 sec., f/5.6, ISO 640) |
While I was shooting the ducks at ISO 400 I turned and saw a lily flower and thought I would take a shot of it. I kept the aperture at f/5.6 and used the meter to set the shutter speed at 1/3200 sec. The focal length was 200mm. Just as I was about to take the picture the bug came into the shot and landed on the flower. I took a couple shots of it as it landed. I will probably crop this in a vertical format later, I think that will have a better impact.
| (1/3200 sec., f/5.6, ISO 400) |
Some of my favourite pictures from the cottage were the nighttime low-light shots. The moon was full and provided a very interesting light over the lake. I started by setting up the tripod on the stationary part of the dark and took a few shots as the clouds passed by. All pictures are taken with the 18-200mm lens.
The first picture was taken with a focal length of 26mm at ISO 400, aperture f/6.3 and a shutter speed of 30 sec. The higher film speed was used to avoid manually controlling the shutter speed since 30 sec. is the longest the D90 will go without going into bulb mode.
| (30 sec., f/6.3, ISO 400) |
| (20 sec., f/3.5, ISO 200) |
Probably my favourite shot of the night came when I turned around just before going inside and decided to take one last set of pictures. The ISO was 200, focal length 18mm, aperture f/5.6 and a shutter speed of 15 sec.
| (15 sec., f/5.6, ISO 200) |
I wanted to try some shots from the inside of the old cottage. It's a 50+ year old log cabin with all sorts of cool stuff on the walls. The first is ISO 200, focal length 18mm, aperture f/16 and a shutter speed of 3 sec.
| (3 sec., f/16, ISO 200) |
The second is ISO 200, 18mm, f/11 for 5 sec.
| (5 sec., f/11. ISO 200) |
Thats all from the cottage for now.
Unfortunately the cottage has been sold and is no longer in the family. I still visit a cottage in Huntsville but it is a much larger cottage and has a much different atmosphere. It will be missed.
Originally posted: 11-12/08//2009
Combined, updated and republished on the date of this post.
Thursday, August 16, 2012
Understanding Exposure
When I first started with SLR photography I looked at the recommended reading material on several photography websites I ended up purchasing three books: Understanding Exposure by Bryan Peterson, The Digital Photography Book by Scott Kelby, and The Photographer's Eye by Michael Freeman.
I started with Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera by Bryan Peterson. At the time the second edition of the book was on the shelves but now there is a third edition, which I have quickly leaved through at the store and appears to have all of the old content with some new material on HDR, flash photographer, etc. I am certain that the book is still as valuable as, if not more than the edition I have.
For a beginner photographer this is an amazing, indispensable book. The book is based largely on the photographic (or exposure) triangle and how to use it to your creative advantage. The key word there is "creative". There are several correct exposures but there are fewer or even just one, as Bryan puts it, "creatively correct" exposures. He also discusses light meters (particularly the one built into the camera) and how to use them to your advantage.
Chapters on aperture and shutter speed discuss how to determine which settings are creatively best for your current shot (depth of field, motion blur, freezing motion, etc.) and how to adjust the other element(s) of the triangle accordingly (little is done with ISO, though it is discussed). The chapter on light is among the most important chapters, though I think I originally understood it the least. Bryan discusses several different lighting conditions and how to take advantage of them. The section on 18% Reflectance may have lost me a little bit at first, but I think I understand it much better now. It has to do with when you should trust your exposure meter or not and how to adjust accordingly (he suggests using your hand in most cases, something I have yet to try). The part about using the sky to set the exposure in certain cases is something I have long been using on my on Canon A620 point and shoot for years to avoid over exposed sky and it is nice to see that I did that correctly (though I was shooting in automatic mode for that). Also, his suggestion about metering (-2/3 exposure) to green backgrounds seems very interesting though my attempts at making that work have not turned out so well. I will continue to practise.
The example shots provided in the book are, in many cases, stunning. One of my favourites is the sunflower that illustrates Depth of Field (I'm not even a huge fan of flower photography, but that may convert me). I'm sure the updates in the new edition are also excellent.
This is a fantastic book for someone just starting out and as I have progressed it is still interesting to come back to it once in a while to revisit the basics. After reading the book I become more comfortable moving over to the manual, aperture priority, and shutter priority modes.
So now all my pictures should be perfect right? It seems that they aren't. I guess thats part of the challenge of photography, knowing the technical stuff is not all there is. It's when and how to use it properly. I continuously revisit this book to add to and update the techniques in my repertoire.
I will discuss the other books mentioned in the future.
Originally Published: 08/11/2009
Updated and republished on the date of this post.
I started with Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera by Bryan Peterson. At the time the second edition of the book was on the shelves but now there is a third edition, which I have quickly leaved through at the store and appears to have all of the old content with some new material on HDR, flash photographer, etc. I am certain that the book is still as valuable as, if not more than the edition I have.
For a beginner photographer this is an amazing, indispensable book. The book is based largely on the photographic (or exposure) triangle and how to use it to your creative advantage. The key word there is "creative". There are several correct exposures but there are fewer or even just one, as Bryan puts it, "creatively correct" exposures. He also discusses light meters (particularly the one built into the camera) and how to use them to your advantage.
Chapters on aperture and shutter speed discuss how to determine which settings are creatively best for your current shot (depth of field, motion blur, freezing motion, etc.) and how to adjust the other element(s) of the triangle accordingly (little is done with ISO, though it is discussed). The chapter on light is among the most important chapters, though I think I originally understood it the least. Bryan discusses several different lighting conditions and how to take advantage of them. The section on 18% Reflectance may have lost me a little bit at first, but I think I understand it much better now. It has to do with when you should trust your exposure meter or not and how to adjust accordingly (he suggests using your hand in most cases, something I have yet to try). The part about using the sky to set the exposure in certain cases is something I have long been using on my on Canon A620 point and shoot for years to avoid over exposed sky and it is nice to see that I did that correctly (though I was shooting in automatic mode for that). Also, his suggestion about metering (-2/3 exposure) to green backgrounds seems very interesting though my attempts at making that work have not turned out so well. I will continue to practise.
The example shots provided in the book are, in many cases, stunning. One of my favourites is the sunflower that illustrates Depth of Field (I'm not even a huge fan of flower photography, but that may convert me). I'm sure the updates in the new edition are also excellent.
This is a fantastic book for someone just starting out and as I have progressed it is still interesting to come back to it once in a while to revisit the basics. After reading the book I become more comfortable moving over to the manual, aperture priority, and shutter priority modes.
So now all my pictures should be perfect right? It seems that they aren't. I guess thats part of the challenge of photography, knowing the technical stuff is not all there is. It's when and how to use it properly. I continuously revisit this book to add to and update the techniques in my repertoire.
I will discuss the other books mentioned in the future.
Originally Published: 08/11/2009
Updated and republished on the date of this post.
Wednesday, August 15, 2012
The Exposure Triangle
It is easy to pick up most entry level digital cameras, turn the dial to auto and start shooting. There are undoubtedly people out there who do this and get some outstanding results, but to be able to control what you get from your camera requires that you move away from the auto setting towards the more manual modes. To do this you must understand the elements that go into a technically well exposed photograph, and integral to that is understanding what is often referred to as the exposure triangle or the photographic triangle.
When I first started with my SLR the two major resources I used were the website Digital Photography School (DPS) and the book Understanding Exposure by Bryan Peterson. These two sources provided the basis for this post and I highly recommend them (especially Understanding Exposure) to anyone starting out with an SLR.
There are three major elements to a well exposed photograph and they are the ISO, shutter speed and aperture. These three elements are often grouped together into what is referred to as the exposure triangle. Each of the elements are conceptually placed at their own vertices of the triangle. Changing one element of the triangle requires that one or both of the others be changed in order to maintain the correct exposure (the amount of your light source that ultimately reaches and is collected by the film or image sensor of the camera). Each element of the triangle also influences another element of the final photo and thus there are always trade-offs to ensure that you achieve your desired visual effect while maintaining proper exposure.
I will cover the three elements of the triangle from the inside out.
ISO
ISO is a measure of the camera's digital sensor's sensitivity to light (the equivalent to film sensitivity on film cameras). A more sensitive sensor needs less light to produce the same exposure as a less sensitive sensor. Equivalently, a less sensitive sensor needs to be exposed to the same light source for more time to produce the same exposure as a more sensitive sensor. The higher the ISO, the more sensitive the sensor. On my camera (Nikon D90) the ISO ranges from 200 to 3200. It may seem intuitive at first to almost always use a high ISO, however the major issue with a high ISO is that the image becomes grainy. The grain on a digital image presents itself in the form of noise, little specs all over the image. For some applications (i.e. more artsy shots) a grainy photo may be acceptable, however the general goal is to have sharp, clean images so you often want to use the lowest ISO possible for a given situation. Newer and higher end digital cameras often have much better noise reduction capabilities at the higher end of the ISO spectrum and photo editing software is getting better at eliminating this noise as well, but with my Nikon D90 the high ISO's do create a lot of distracting noise so it is best to keep the sensitivity of the sensor as low as possible for given lighting conditions.
Shutter Speed
The next element as you move away from the sensor is the shutter speed. The shutter controls how long the image sensor is exposed to light. It is essentially a door that is opened and quickly closed again to allow light in just long enough to see the image, but not too long as you want to prevent over exposure.
The selection of shutter speed is largely based on two factors: subject motion and image sharpness. Subject motion has to do with shooting a moving or stationary subject and, if you are shooting a moving subject, if you want to freeze the motion or allow some motion blur for artistic effect. To freeze the motion you need a faster shutter speed and to allow for motion blur, a slower shutter speed. Image sharpness is also a major factor, especially if you are hand-holding your camera. Generally you want sharp images and if you are shaking while taking the picture you need a relatively faster shutter speed. This also depends on the focal length of the lens you are using (measured in millimetres, mm). If you have a short focal length (are 'zoomed out' on a 'zoom' lens) then the shake is not exaggerated very much and you can use a slower shutter speed if needed. If you have a large focal length lens (are 'zoomed in') then any shake is exaggerated (it's all moment arm stuff, think of a baseball bat being swung: the grip of the bat moves slowly compared to the tip of the bat that is moving very quickly) and you need a faster shutter speed to stop the shake-induced motion blur.
Shutter speed is generally measured in fractions of a second or in seconds when using very slow shutter speeds. On my camera only the denominator of the fraction is displayed (i.e. 60, 125, 1250, etc.) or if it is in seconds the 'second quotes' are used (i.e. 1", 2", 10", etc.). The term shutter 'stop' is used to describe doubling or halving the amount of light getting to the sensor. If you decrease the speed by one stop you are doubling the amount of light getting in (and therefore, to maintain the same exposure, must alter one of the other elements of the triangle to halve the light again). The shutter stops are defined as when the shutter opening time is doubled or halved: 1/500 sec., 1/250 sec., 1/60 sec., 1/30 sec., 1/15 sec., etc. Many modern cameras also contain one-third stops in between those numbers to provide for greater control
Aperture
The final element of the exposure triangle to be discussed here is aperture. The aperture setting describes the size of the opening in the lens and is often measured in f-stops (i.e. f/2.8, f/4, f/5.6, f/8, etc.). If you change one f-stop you either double or halve the size of the opening and therefore double or halve the amount of light coming into the camera (passing through the shutter and reaching the sensor). Small f-stop numbers refer to a larger opening (and more light) while larger f-stop numbers refer to small openings (and less light). The aperture stops are when the opening size is doubled or halved: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32. Many modern cameras also contain one-third stops in between those numbers to provide for greater exposure control. The main impact of aperture on the final photo is its depth of field (DOF). The DOF refers to how much of the photo is in focus. With a low f-stop (and large aperture) you get a shallow DOF, meaning that only objects at the distance you are focused on will be in clear focus. Anything nearer or further from the camera than the focus plane will be not as clear. At the other end of the scale a high f-stop (small aperture) you get a deep DOF and a large range of distances from the camera will be sharp and in focus. Shallow DOFs can be used to draw attention to the objects of interest in a shot while keeping the rest of the image in soft focus. Deep DOFs allow for many objects to be in sharp focus (such as landscapes or group photos).
Bringing it All Together
So, one of the keys to good pictures is good exposure. If you are shooting a sporting event and need to freeze the motion you need a fast shutter speed and therefore you may need to increase the aperture size (lower f-stop) and increase the sensitivity (higher ISO). There may be a limit to your aperture size (either your lens only goes so far or your DOF gets too shallow for your needs) and you need to sacrifice and accept some graininess in your photo brought ion by upping the ISO.
It is important to recognize that simply having a well exposed photo is not the end of it. Every correct exposure has three elements: the shutter speed, the aperture, and the ISO, so if you change one, you must change either one or both of the others, leading to a virtually infinite number of possible combinations to get the same correct exposure. Determining the right combination depends on the situation and that is a much more complicated issue. Future posts will be dedicated to the different elements individually but it is always important to remember, understand, and apply the exposure triangle concept when trying to get away from the auto setting on your camera.
Integral to achieving proper balance between these three elements, and therefore proper exposure, is either a keen eye for light levels or, more likely, a light meter. Most cameras these days have a built in light meter that is seen when looking through the viewfinder or at the LCD screen on the back of the camera. Sensibly the meter indicates a mathematically well exposed photo if the meter is in the middle and an over or under exposed photo if the meter is to either side. A discussion of the different metering modes and dealing with special situations is left to a future post.
Notes on updated post: When I originally wrote this post I was very new to fully manual SLR photography and based it entirely what I had read on the Digital Photography School (DPS) website. DPS is an amazing resource for new and mid level photographers and many of the articles there are must-reads for those new to SLR cameras. Since the original posting of this article I have leaned a lot from that source as well as many others and I have tried to update this post accordingly. I have also added photos to the post to illustrate some of the concepts discussed.
Originally Published: 08/02/2009
Updated and republished on the date of this post.
When I first started with my SLR the two major resources I used were the website Digital Photography School (DPS) and the book Understanding Exposure by Bryan Peterson. These two sources provided the basis for this post and I highly recommend them (especially Understanding Exposure) to anyone starting out with an SLR.
There are three major elements to a well exposed photograph and they are the ISO, shutter speed and aperture. These three elements are often grouped together into what is referred to as the exposure triangle. Each of the elements are conceptually placed at their own vertices of the triangle. Changing one element of the triangle requires that one or both of the others be changed in order to maintain the correct exposure (the amount of your light source that ultimately reaches and is collected by the film or image sensor of the camera). Each element of the triangle also influences another element of the final photo and thus there are always trade-offs to ensure that you achieve your desired visual effect while maintaining proper exposure.
I will cover the three elements of the triangle from the inside out.
ISO
ISO is a measure of the camera's digital sensor's sensitivity to light (the equivalent to film sensitivity on film cameras). A more sensitive sensor needs less light to produce the same exposure as a less sensitive sensor. Equivalently, a less sensitive sensor needs to be exposed to the same light source for more time to produce the same exposure as a more sensitive sensor. The higher the ISO, the more sensitive the sensor. On my camera (Nikon D90) the ISO ranges from 200 to 3200. It may seem intuitive at first to almost always use a high ISO, however the major issue with a high ISO is that the image becomes grainy. The grain on a digital image presents itself in the form of noise, little specs all over the image. For some applications (i.e. more artsy shots) a grainy photo may be acceptable, however the general goal is to have sharp, clean images so you often want to use the lowest ISO possible for a given situation. Newer and higher end digital cameras often have much better noise reduction capabilities at the higher end of the ISO spectrum and photo editing software is getting better at eliminating this noise as well, but with my Nikon D90 the high ISO's do create a lot of distracting noise so it is best to keep the sensitivity of the sensor as low as possible for given lighting conditions.
 |
| Notice that the background (the sky and the trees) and the shadowed regions of the leaves appear smooth with little to no noise. This photo was shot at a low ISO of 200, the native ISO of the Nikon D90. (1/800 sec., f/4.5, ISO 200) |
 |
| Noise is much more evident in this photo taken at ISO the high ISO of 3200. There are some obvious artifacts throughout the photo but they are especially evident in the darker regions such as the reddish brown of the number three die on the left. (1/1000 sec., f/1.8, ISO 3200) |
Shutter Speed
The next element as you move away from the sensor is the shutter speed. The shutter controls how long the image sensor is exposed to light. It is essentially a door that is opened and quickly closed again to allow light in just long enough to see the image, but not too long as you want to prevent over exposure.
The selection of shutter speed is largely based on two factors: subject motion and image sharpness. Subject motion has to do with shooting a moving or stationary subject and, if you are shooting a moving subject, if you want to freeze the motion or allow some motion blur for artistic effect. To freeze the motion you need a faster shutter speed and to allow for motion blur, a slower shutter speed. Image sharpness is also a major factor, especially if you are hand-holding your camera. Generally you want sharp images and if you are shaking while taking the picture you need a relatively faster shutter speed. This also depends on the focal length of the lens you are using (measured in millimetres, mm). If you have a short focal length (are 'zoomed out' on a 'zoom' lens) then the shake is not exaggerated very much and you can use a slower shutter speed if needed. If you have a large focal length lens (are 'zoomed in') then any shake is exaggerated (it's all moment arm stuff, think of a baseball bat being swung: the grip of the bat moves slowly compared to the tip of the bat that is moving very quickly) and you need a faster shutter speed to stop the shake-induced motion blur.
 |
| An example photo taken with a fast shutter speed. Even though Mark Webber's Formula 1 car was moving fast the fast shutter speed of 1/2500 sec. slows it down enough to create a sharp image of the car. The tires were spinning fast enough that the text on the sidewall is still blurred. (1/2500 sec., f/5.6, ISO 800) |
 |
| Taken through a dirty window from the Vdara hotel in Las Vegas the Bellagio fountains are a pleasant blur in this 30 sec. exposure. The long exposure also allowed for the buildings to be well exposed despite the dark conditions, narrow aperture (high f/number), and low ISO. (30 sec., f/22, ISO 200) |
Shutter speed is generally measured in fractions of a second or in seconds when using very slow shutter speeds. On my camera only the denominator of the fraction is displayed (i.e. 60, 125, 1250, etc.) or if it is in seconds the 'second quotes' are used (i.e. 1", 2", 10", etc.). The term shutter 'stop' is used to describe doubling or halving the amount of light getting to the sensor. If you decrease the speed by one stop you are doubling the amount of light getting in (and therefore, to maintain the same exposure, must alter one of the other elements of the triangle to halve the light again). The shutter stops are defined as when the shutter opening time is doubled or halved: 1/500 sec., 1/250 sec., 1/60 sec., 1/30 sec., 1/15 sec., etc. Many modern cameras also contain one-third stops in between those numbers to provide for greater control
Aperture
The final element of the exposure triangle to be discussed here is aperture. The aperture setting describes the size of the opening in the lens and is often measured in f-stops (i.e. f/2.8, f/4, f/5.6, f/8, etc.). If you change one f-stop you either double or halve the size of the opening and therefore double or halve the amount of light coming into the camera (passing through the shutter and reaching the sensor). Small f-stop numbers refer to a larger opening (and more light) while larger f-stop numbers refer to small openings (and less light). The aperture stops are when the opening size is doubled or halved: f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32. Many modern cameras also contain one-third stops in between those numbers to provide for greater exposure control. The main impact of aperture on the final photo is its depth of field (DOF). The DOF refers to how much of the photo is in focus. With a low f-stop (and large aperture) you get a shallow DOF, meaning that only objects at the distance you are focused on will be in clear focus. Anything nearer or further from the camera than the focus plane will be not as clear. At the other end of the scale a high f-stop (small aperture) you get a deep DOF and a large range of distances from the camera will be sharp and in focus. Shallow DOFs can be used to draw attention to the objects of interest in a shot while keeping the rest of the image in soft focus. Deep DOFs allow for many objects to be in sharp focus (such as landscapes or group photos).
 |
| A wide open aperture (small f/number) of f/2.8 provides a shallow depth of field which allows for my one year old and the tree she is using for support to be in sharp focus while the trees in the background are blurred to the point where they do not distract from the main subject. (1/200 sec., f/2.8, ISO 200) |
 |
| Using a narrow aperture (high f/number) of f/22 a deep depth of field means that everything from the vegetation and rocks in the foreground to the Peggy's Cove lighthouse in the distance and even the clouds in the distant background are in sharp focus. In this case the subject (the lighthouse) is not isolated by blurring the rest of the photo like in the photo above. (1/320 sec., f/22, ISO 500) |
Bringing it All Together
So, one of the keys to good pictures is good exposure. If you are shooting a sporting event and need to freeze the motion you need a fast shutter speed and therefore you may need to increase the aperture size (lower f-stop) and increase the sensitivity (higher ISO). There may be a limit to your aperture size (either your lens only goes so far or your DOF gets too shallow for your needs) and you need to sacrifice and accept some graininess in your photo brought ion by upping the ISO.
It is important to recognize that simply having a well exposed photo is not the end of it. Every correct exposure has three elements: the shutter speed, the aperture, and the ISO, so if you change one, you must change either one or both of the others, leading to a virtually infinite number of possible combinations to get the same correct exposure. Determining the right combination depends on the situation and that is a much more complicated issue. Future posts will be dedicated to the different elements individually but it is always important to remember, understand, and apply the exposure triangle concept when trying to get away from the auto setting on your camera.
Integral to achieving proper balance between these three elements, and therefore proper exposure, is either a keen eye for light levels or, more likely, a light meter. Most cameras these days have a built in light meter that is seen when looking through the viewfinder or at the LCD screen on the back of the camera. Sensibly the meter indicates a mathematically well exposed photo if the meter is in the middle and an over or under exposed photo if the meter is to either side. A discussion of the different metering modes and dealing with special situations is left to a future post.
Notes on updated post: When I originally wrote this post I was very new to fully manual SLR photography and based it entirely what I had read on the Digital Photography School (DPS) website. DPS is an amazing resource for new and mid level photographers and many of the articles there are must-reads for those new to SLR cameras. Since the original posting of this article I have leaned a lot from that source as well as many others and I have tried to update this post accordingly. I have also added photos to the post to illustrate some of the concepts discussed.
Originally Published: 08/02/2009
Updated and republished on the date of this post.
Monday, August 13, 2012
New Camera
I bought a Nikon D90 with a 18-200mm lens. I was original leaning toward the Canon EOS 50d, but changed my mind after checking them out at the store. I will discuss more later.
Update: Not too much to explain here. Just announcing that I had made my camera choice and it was a choice I am still happy with. Of course I am envious of new cameras that have come out in the past three years and there are features missing from my camera that I would be thrilled to have, but I still really enjoy my Nikon D90. Given what I know now and given the same choices I had at the time, I believe it is a decision I would repeat.
Originally Published: 07/30/2009
Updated and republished on the date of this post.
Update: Not too much to explain here. Just announcing that I had made my camera choice and it was a choice I am still happy with. Of course I am envious of new cameras that have come out in the past three years and there are features missing from my camera that I would be thrilled to have, but I still really enjoy my Nikon D90. Given what I know now and given the same choices I had at the time, I believe it is a decision I would repeat.
Originally Published: 07/30/2009
Updated and republished on the date of this post.
Taking Pictures.
My original introductory post follows. I have now had my SLR for over three years and though my knowledge of my camera and photography is much more advanced then when I first posted this, I am nowhere near where I was hoping I would be. I like my photos, but as with most amatures, I wish they were better and I hope to reignite the desire to improve by returning to this blog.
The original post:
Welcome.
I have always been a fan of taking pictures but have very little experience beyond the basic point and shoot cameras. When I was a teenager I did play around with some film SLRs, but really didn't know what I was doing.
Within the next few days I am planning on purchasing a decent digital SLR and putting in some effort to become a decent photographer. There are several websites out there that intend to teach people like me how to become better photographers and I plan on using those, books and possible some lessons (not sure about that yet) to better my photography skills.
This website/blog is intended to track my progress. As I learn new techniques and produce post-worthy photographs I will post and discuss them here. I'm not sure who my audience will be, but we'll see how it grows.
I will work with different photographic techniques, mostly in my areas of interest (travel, landscape, sports and general 'life' stuff). I will also try to learn some post processing techniques (HDR, Photoshop manipulation, etc.) and will show and discuss the results. As time progresses I may move out of my comfort areas and work with people to do portraits our more editorial work, and as I become more knowledgable I may discuss equipment in a somewhat intelligent way. I also have some interest in seeing what I can do to bring in some money from my work, but that is in the distant future at the moment. We'll see where it goes.
Originally Published: 07/29/2009
Updated and republished on the date of this post.
The original post:
Welcome.
I have always been a fan of taking pictures but have very little experience beyond the basic point and shoot cameras. When I was a teenager I did play around with some film SLRs, but really didn't know what I was doing.
Within the next few days I am planning on purchasing a decent digital SLR and putting in some effort to become a decent photographer. There are several websites out there that intend to teach people like me how to become better photographers and I plan on using those, books and possible some lessons (not sure about that yet) to better my photography skills.
This website/blog is intended to track my progress. As I learn new techniques and produce post-worthy photographs I will post and discuss them here. I'm not sure who my audience will be, but we'll see how it grows.
I will work with different photographic techniques, mostly in my areas of interest (travel, landscape, sports and general 'life' stuff). I will also try to learn some post processing techniques (HDR, Photoshop manipulation, etc.) and will show and discuss the results. As time progresses I may move out of my comfort areas and work with people to do portraits our more editorial work, and as I become more knowledgable I may discuss equipment in a somewhat intelligent way. I also have some interest in seeing what I can do to bring in some money from my work, but that is in the distant future at the moment. We'll see where it goes.
Originally Published: 07/29/2009
Updated and republished on the date of this post.
Moving to Blogger
I have decided to move my site over to Blogger. Sure WordPress gave me more control, but I wasn't finding a need for that right now and I wanted some simplicity. Over the next little while I am going to revisit and republish most of my old material. I hope to edit and update some of the older posts and do some self-critiquing of my earlier posts.
Over the next little while I will focus on porting the old site to here and then hopefully I will still be motivated to publish some new material.
Thank you for visiting. At the time of this post the old site is still in service here: http://www.engsoc.org/~jrobinson/photog/ .
Over the next little while I will focus on porting the old site to here and then hopefully I will still be motivated to publish some new material.
Thank you for visiting. At the time of this post the old site is still in service here: http://www.engsoc.org/~jrobinson/photog/ .
Subscribe to:
Posts (Atom)