Photography Fundamentals, Part 1: Exposure
Good photography requires mastering a whole range of skills and techniques. No matter how much experience we have, it is easy to forget some of these techniques as we become overwhelmed with all the other things we need to remember.
The main goal of this three-part series is to provide a quick refresher course (or introductory overview) on the essentials of good photography. We will talk about how exposure, composition, lens choice, and lighting all contribute to consistently getting great images in your camera, so you don’t always have rely on Photoshop to help you “fix” things.
Sharp is Good! Most of the time we want to capture images that are sharp. (I say most of the time because there may be times when blur may be exactly the look you have in mind.) However, you can always blur selected details later in Photoshop. But you can’t always introduce enough sharpness in your final image if the details in the capture are blurry to begin with.
One key aspect of sharpness is how you hold or support the camera.
Using a Tripod Helps: The easiest way to get sharper pictures is to work with a good tripod. A solid, well-built tripod will minimize camera shake. (Note that I said minimize.) To eliminate shake, add a cable release and use the mirror lockup mode if your camera has one. These steps will remove two major sources of vibration for cameras on tripods: (1) pressing the shutter button; and (2) the movement of the mirror in an SLR.
Let’s not kid ourselves: Dragging a tripod around with all the other gear is a pain. So make sure you have a tripod that is solid enough but is still light and compact enough that you are willing to carry it with you. A great tripod left at home is not a good investment.
Tripods offer other benefits than just sharpness. For example:
You can shoot a series of images with the same framing (which is essential for HDR imaging, for example).
You can step back from the shot, consider the scene in context, and see if you have the best framing.
You can more easily control the movement of the camera when taking panorama shots.
My daughter and I share seven tripods, varying in size from tiny to large and heavy. We also share a range of heads from three-way tilt/pan to ball heads and motorized panorama heads that can be matched to the tripods as needed. This gives us the flexibility to have the right tripod at had for the right job. You may not need as many tripods for the variety of photography you do, but it certainly helps to have at least one small or tabletop model as well as a larger one.
Hold the Camera Still: A tripod is not right for all types of photography though. So, make sure you have good hand-holding technique as well. Here are three ways to improve your technique:
Find a good grip position for your camera that offers good bracing (two hands on the camera/lens and elbows braced into your sides).
Test yourself to determine just how low a shutter speed you can shoot at and get an image that is sharp enough.
Make it habit to lean against any available support.
Get the Results You Envision: Choosing the optimal combination of camera settings for each exposure is also part of getting a sharp image. You want to shoot with a high enough shutter speed to freeze any movement you want to capture in your image. Yet you also want to have an appropriate aperture for the desired depth of field. Plus, you need to keep your ISO setting as low as possible to minimize noise when shooting digitally. Sometimes you will have to compromise on either depth-of-field or ISO (or both) to get the sharpness you need.
Correct Exposure: While on the topic of exposure, we should discuss the notion of correct exposure. Basically, there is none. There is no arbitrarily right exposure, only the exposure that gives you the result you want.
Because I shoot almost exclusively digitally and all my images get processed through Photoshop, I shoot to make image adjustment in Photoshop as easy as possible while still obtaining the highest quality image I can get from my camera.
Use the Histogram: The histogram display on your camera is your friend in ensuring that you will minimize the need to fix your image in Photoshop. Set an exposure so the image data on the histogram is as far to the right as possible without clipping. If you shoot RAW you can tolerate some clipping on the camera’s LCD because you can pull this back in your RAW conversion software. The histogram display comes from a JPEG version of the image, and so does not completely represent what the RAW image has captured. Experiment with your camera to determine just how much image data you can successfully recover.
By placing your image data as close to the right as possible (i.e., overexposing), you make sure that by the time you start using Levels in Photoshop to get the exposure where you want it, you only need to pull grays down to black. Plus, image noise is minimized in the process.
This technique, combined with shooting at as low an ISO as possible with the shutter speed and aperture you want, will ensure you get as smooth an image as possible to work with.
Notice that I keep talking about what you want to say with your image. This is an important thing to work out before you shoot, because it will determine your framing (cropping), aperture and depth-of-field, shutter speed, ISO, focus point, etc. How you “previsualize” an image determines everything!
If you don’t start with a clear idea of what you want to say with an image, you’re likely to get an image that is OK, but not great. If you are not clear in what you want I recommend shooting a wide variety of approaches to the same image so that later you can choose something that works for you. In fact, it is a good idea to do this even if you have a strong previsualization because you can always change your mind later or fit the image to a different application if you have the variety.
In Part 2, we will cover composition and lens choice. Stay tuned.
The DIY Urge is Alive and Well in Photography
Because modern photographic equipment is so technological, many assume there is little you can do yourself to solve problems, and that every “solution” must be bought. But this is not the case.
On Digital ImageMaker, I recently wrote about the GigaPan Epic, a motorized camera platform for shooting panoramas and creating gigapixel-resolution images by stitching. That got me thinking about the do-it-yourself (DIY) mentality in general.
The Epic motorized platform is designed to enable people to mount compact point-and-shoot digital cameras on the platform and shoot huge panoramas. It does this brilliantly. For Digital ImageMaker, I reviewed the base model for point-and-shoots. But the company that makes GigaPan Epic also offers a more expensive model, with an adjustment that lets you mount a somewhat larger camera, including some compact DSLRs.
When I looked more closely at the basic model for point-and-shoots, I saw that it would be quite easy to adapt the unit so it could hold a larger camera. After a little bit of thinking, it took me about a half an hour to solve the problem. I simply used a $3 piece of aluminum, a hand electric drill and a device to tap a thread in a hole. Click here to see the solution I devised. This adjustment allowed me to mount a Canon 350D which I had converted to shoot infrared. Thus, I was able to use the Gigapan to do infrared panoramas, such as the one shown here.
But the DIY mentality doesn’t end with shooting. For my inkjet printer, I’ve built a small angled platform that allows me to readily feed sheets of aluminum that I’ve pre-treated with an inkjet-receptive coating.
Other devices I have built include a small-but-useful macro light that I assembled from some batteries, a couple of bright white LEDs and a switch.
Being willing to try building things myself has solved a number of photographic problems without requiring me to spend a lot of extra money on new accessories.
On the Internet, an active DIY community exists within photographic circles. One I have found fascinating is the active community of camera software hackers. It turns out that some Canon digital cameras have firmware (the software built into the camera that controls its processor) that can be modified. These modifications can open up new functions that Canon never intended for that model, such as RAW file capability, intervalvometer functions (setting the camera to take an image every so often), and much more. The CHDK software acts as an add-on to the existing firmware.
One can only imagine what wonderful things would result if camera manufacturers would open up their cameras to add-on software in the same manner as your computer or iPhone. It would be even more wonderful if they would make it easy to add this new software.
YouTube has wonderful videos on all sorts of DIY endeavors. For example, one clip I found amazing showed a Japanese photographer who has modified a scanner to act as a camera. Click here to see the YouTube video of the resulting scanner-cam. The resulting images have been posted on Flickr. There are in fact many people actively converting scanners into cameras.
Other creative do-it-yourselfers have experimented with inkjet-receptive coatings and inkjet-transfer films to create stunning works of art on different types of metals, marble, wood, and fresco materials. The best known in this field is the trio of great artists: Dorothy Simpson Krause, Bonny Lhotka, and Karin Schminke, who form the Digital Atelier. Bonny has even created her own inkjet-receptive coating that she shows how to use in the DVD training courses she sells on her Digital Art Studio Seminars website.
Certain areas of photography seem more DIY-oriented than others. Areas such as astro-photography and macrophotography have a long tradition of DIY solutions to various problems.
Studio lighting is also an active area for DIY projects, with people making their own lighting rigs and light-modification screens, etc.
Panorama photographers have often made their own rigs. But perhaps the biggest single area of DIY activity is pinhole photography. Many of us have done something in the area, either by drilling a hole in a DSLR body cap and mounting a piece of aluminum foil or by making a whole pinhole film camera.
Indeed many companies that now provide digital-imaging products started as DIYers working at home in their basements or garages. When they found out there was a small market for their inventions, they went from there. Indeed, many companies start out in the garage, including corporate giants such as Hewlett Packard and Apple.
The reward that comes from doing it yourself is not just that of saving a bit of money. When you do things yourself, it makes your photography different from everyone else’s, either because you can do something they can’t, or you are doing it in a different way.
Another benefit is the opportunity to recycle items that might otherwise end up in a landfill.
Plus, there is the satisfaction that comes from making something with your own hands. This is important to those of us who spend a lot of our time working on the computer each day.
Personally, I get a huge sense of satisfaction from identifying a problem, finding the solution and making it work.
If you are a DIY-oriented person, don’t let the technological sophistication of modern devices intimidate you and stop you from trying a project or two. You don’t necessarily have to get engaged with the electronics or software to make meaningful improvements that can help your photography as well as other people’s work. Give it a go.
Bit Depth Basics: More Than a Numbers Game
One of the most under-appreciated features of newer-model DSLRs is their ability to capture images with greater bit depth. Bit depth is a way of quantifying the amount of color information in each recorded pixel. It is also a key component of high-level image quality. In this post, we’ll look first at the numbers. Then, we’ll talk about what these numbers mean in terms of dynamic range, color fidelity, and highlight/shadow detail. These are key attributes that influence the quality of the final print.
Not long ago, most cameras functioned in 8-bit mode. Then the higher-end DSLRs became capable of using 12-bit capture. Now they are up to 14-bit, which is a huge benefit to photographers. If you don’t understand bit depth, these may sound like incremental improvements. But they are actually exponential improvements.
To see what I mean, let’s start with a brief review of the numbers. It is simple but non-intuitive:
· There are three primary colors (or color channels) in each captured digital image: red, green, and blue.
· Bit depth describes the number of tone gradations (or intensities of color) provided in each pixel. Most digital images are captured and/or stored in 8-bit, 12-bit, 14-bit, or 16-bit mode.
§ An 8-bit image has 256 tone gradations in each of the three color channels;
§ A 12-bit image has 4,096 tone gradations in each color channel;
§ A 14-bit image has 16,384 tone gradations in each color channel; and
§ A 16-bit image has 65,536 tone gradation in each color channel.
Another way to look at the depth of an image file: A 16-bit image file is twice as big as an 8-bit file.
The major benefit of working with high-bit images is increased dynamic range— the range of tones and detail that the camera can record from the darkest dark to lightest light.
One software company, DXO, now provides public access to its database on camera performance. Here are some examples of the differences between 12-bit, 14-bit, and 16-bit capture:
· The Nikon D2X captures images in 12-bit mode when shooting in RAW format; its dynamic range is rated at 10.9.
· The Nikon D3 captures in 14-bit mode; its dynamic range is rated at 12.2.
Dynamic range is measured like f/stops: an increase of one step is a doubling of dynamic range. That’s a big, big difference.
There is also a noticeable upside in image editing, and in the appearance of the final print.
Figure 1 above is a screen shot of a 16-bit image being edited. Note that the histogram is smooth and even, and shows no breaks or lines.
Figure 2 above shows a screen shot of an 8-bit version of the same image. Note the white lines running vertically in this histogram. These are sometimes called drop-outs, and they show information that is lost when the image is edited . These losses can result in color distortions, posterization, color aliasing, and more.
We lose information every time we edit or manipulate an image. So, the more image information we have to start with, the more information that is available to us as we progress in our workflow.
It pays to set up your workflow to protect as much image information as you can for as long in the process as possible. Most printer drivers can handle high-bit images without difficulty. In my own workflow, I only use 8-bit images for web publishing, e-mail, and the like.
Image-editing programs such as Adobe Photoshop Lightroom are now set up to use high-bit images. And Adobe Camera RAW and Photoshop provide pretty much the same editing tools for 8-bit images and high-bit images, making workflow choices easier for the photographer. This is all good news for those of us who love creating the most detailed and beautiful prints possible.
What’s re-complicating printing workflows right now is the fact that Adobe Photoshop Lightroom uses a bigger color space—ProPhoto RGB instead of Adobe RGB. But we’ll leave a discussion of printing through Lightroom to a future post.
If you have any specific questions about bit depth, I would welcome your comments.
Tips for Better Landscape Photography, Part Two
By David SaffirIn my first post on shooting landscape photography last month, I shared a few tips for increasing your odds of going home with tack-sharp images. In this post, I’ll dig deeper into the details of making the most of your landscape photo opportunities. This list is based in many ways on the minor, and sometimes not so minor, hiccups I’ve had in my own work.
1. Before you leave your home or studio, make a checklist of the things you’ll need. I’ve learned the hard way to carry extra batteries, camera cards, and a spare card reader. Take the camera manual with you. An extra battery charger can be a life-saver. Most of us carry only one, and if it is damaged by a faulty wall outlet, or other problem, it can become a “game over” situation. It happened to me while I was in Israel; you won’t believe what it cost to have one sent by FedEx from New York.
2. Test your camera and each lens you plan to take before you set off on your trip. If you use zoom lenses, test the lens at the short and long end of its range. Check the lens for autofocus function, too.
3. Once you’ve chosen a spot from which to shoot (or even better, before that), ask yourself these questions:
Do I need to format or change camera cards?
Is the ISO setting correct? (Generally, landscape photographers should use the lowest available ISO setting – usually 50, 100, or 200 ISO.)
Is the white balance set to the conditions (daylight, cloudy, etc)? (Please don’t use AUTO white balance; this makes batch processing difficult, if not impossible.)
Is the camera set to record in Adobe 98 RGB (if available)?
Can the camera shoot in RAW? (If so, this is your best option.
4. Make sure you’ve chosen a safe place. If you think light will be low, take a flashlight and look around carefully. You’ll sometimes find a surprise (nice skunk!) And, if you are shooting near the ocean, never, ever turn your back on the water. It’s possible to lose a camera, or yourself, to an unexpected wave. On windy days, stay close to your camera and tripod, for obvious reasons. I’ve seen them go down more than once
5. Choose the right lenses. In 35mm format, a 14mm prime will do the job (Canon and Nikon both make very good ones). Some of the lenses in the 21-24mm range are good, but check the reviews before you rent or buy. There’s quite a bit of variation in performance among this group. The perspective control lenses (marked PC) made by both Nikon and Canon are very good, because you can expand the width of your frame to near-panorama proportions. You may also wish to consider a medium telephoto, such as a 200mm or 300mm lens. These give you the opportunity to isolate parts of a landscape, making for some interesting shots such as the image below.
6. Think about how you will see the screen on top of the camera that shows camera adjustment settings. If you are working on a tall tripod, you might have to bring something to stand on to see the panel, or change the camera position to bring it into view. I carry a small plastic dental mirror in my camera bag, and use it to see the top of the camera without moving it. This saves a lot of time, and sometimes prevents a missed shot.
7. Take extra care when using slower shutter speeds. If the wind is blowing, try to wait until for a quiet (or quieter) moment to take your shot. Try to remember not to rest a hand on the tripod or camera when shooting. Keep those fingers where they belong when you are shooting – away from the camera.
8. Set your in-camera exposure meter for center-weighted exposure, or spot exposure. Generally, my Nikon and Hasselblad cameras seem to do best with center weighted exposure. Full-frame metering usually results in an underexposed image in landscape work.
9. Make sure that your meter is accurate, and compare your meter to another one. Generally, incident-light exposure metering is more accurate than reflected-light, in-camera metering. You don’t have to spend a fortune on a handheld meter. For example, the Sekonic 358 handheld meter is a very good, rugged meter. Its cost is moderate, and used ones can be found with a bit of digging. Mine seems indestructible.
10. If you are shooting with HDR developing in mind, remember that the camera must stay exactly in place while you are capturing multiple frames. If the frames don’t match up (register) it will be difficult, perhaps impossible, to make the image work back in the studio. If you bump your tripod, just start that sequence over again.
11. Check the weather and the sunset/sunrise and moonset/moonrise times every day if possible. This is particularly important in mountainous areas, where the weather is very changeable. Here in California, I’ve been snowed in during June! Keep a sheet of flexible plastic in your bag, or even a small trash bag, to use as an improvised cover in bad weather.
12. Take a small notebook. Jot down the place, time of day, conditions, camera settings, the serial numbers of your first and last frames, and your personal thoughts. You’ll find these to be a real treasure when you come back to an image at a later date. Consider a GPS gadget for tagging your image files.
I took this surrealistic-looking image of the Colorado State Capitol Building from the rooftop of the Colorado History Museum. The Capitol was reflected in multiple windows on the side of a building across the street. The image was captured around 4 pm, using a tripod-mounted Hasselblad H-series camera, digital back, 100mm lens, ISO 50, f/5 @ 1/90 sec. There was a mix of clouds and sun that day, so I had to wait until the Capitol was well-lit to bring up the contrast in the shot. I did some Photoshop editing for contrast and perspective correction.
Remembering Film
If you've been shooting digital for awhile (or if that is all you've ever known), try shooting some film while it's still available. There is something different about shooting film that you miss if you're totally absorbed in digital.Although film may no longer be the predominant method of image capture, the glory days of shooting and scanning film aren't that far behind us. Those of us who started out shooting film still have lots and lots of negatives and transparencies that we regard as integral parts of our archives.
I have many images on film that I would never be able to recreate digitally. One of the best characteristics of film is the texture and grain of the emulsion - how an image records on a particular brand of film. I was always partial to Ilford Pan F and Kodak Tri-X Black and White Negative Film (which happily I can still buy).
I learned about all of the subtle characteristics of different films when I worked in a pro camera shop in my younger days. We sold everything photographic, for both amateurs and professionals. Our store even sold used camera and darkroom equipment. So, I had access to many types of film and some great gear, including large-format cameras and lenses I could never afford at the time. I even shot the BW slide film from Agfa called Scala. I loved that film.
When digital imaging entered the scene, I got involved in the new process of scanning film. I worked with expensive drum scanners such as the Scanview Scanmate and the Crossfield Magnascan. Over time the prices of high-powered scanners have fallen so much that I now have my own 4800-ppi scanner that scans everything from 35 mm negs and transparencies to 8 x 10 negs and transparencies as well as flat artwork. You would think that my scanner would sit idle but actually it gets lots of use. Now that I co-own a design agency there is always a need to scan something.
When shooting film you have no instant verification of either the exposure or the composition. (I suppose you could use a Polaroid back, but it's never the same thing.) When I shot Ilford Pan F I had no idea what the neg would look like or if the capture was even in focus. Plus my beloved camera was mostly manual (I shot the rugged Nikon FM2 – a lifelong favorite) with a built in light meter that told me if the exposure was right on or over/under exposed by giving me a red led +,O, or -sign.
There was always a bit of mystery until I developed the film and printed a proof sheet. Watching the images appear in the darkroom was a magical process that I really enjoyed. Now, I am so grateful to have had "my time in the darkroom." Looking through my proof sheets today I feel a real sense of nostalgia that I miss with digital images. There is something about the material aspect of a proof sheet that I like.All of the images shown below were shot on black-and-white negative film then scanned on my desktop scanner. Of course, I have used Nik Software to do some tonal editing, but we'll leave that for another post.
For now, if it's been awhile since you've shot film, I urge you to go ahead, buy some film, unpack that old film SLR (or borrow one!) and start shooting! You will be glad you did. (Let me know how it goes. I would be interested to hear more about your experiences!)
