|
|
||||||||
|
Chapter 10 - Extending Your Reach - Wide Angle |
||||||||
|
You can extend the reach of your H-Series camera using wide-angle adapters, telephoto adapters and close up lenses. In some ways, the wide-angle adapter is the most limited of the bunch. That's due, primarily, to its basic math. Most experts agree that the field of view and focal range of the human eye is very close to that of a 50-55 mm lens. For the sake of discussion, let's assume 50 mm as our baseline. There's a lot less territory between 50 mm and 25.2 mm or 50 mm and 21.7 mm (focal lengths with the Sony wide-angle adapters) than there is between 50 mm and 734 mm or 790 mm (with the Sony telephoto adapters). Your H-Series camera already goes as wide as 31-36 mm without a conversion lens. With a .7X adapter, you get down to 21.7-25.2 mm (31 X .7 or 36 X .7), a difference of less than 11 mm. That's not a huge difference:
But if you need that width, if you need to shoot something close so that it appears much farther away, if you need to shoot a group in a small room, that extra 11mm will come in mighty handy. The other limitation on wide-angle lenses is that they tend to go fisheye as their focal length decreases. Fisheye is the tendency of a round lens to display an image that conforms to its round shape instead of the rectangular shape of the image frame. By convention, 10 mm is considered fisheye, but fisheye effects can make themselves felt even in a 21 or 25 mm lens, as you'll see later on. Sony manufacturs two wide-angle lenses for the H-Series: the VCL-DH0758 for the H1, H2 and H5 and VCL-DH0774 for the H7 and H9.
Figure 10-3 VCL-DH0758 For The H1, H2 and H5
You'll note that the DH0774 is more of a "pancake" design than the DH1758. That's because both lenses mount on the included H-Series adapter barrel, but the adapter barrel that comes with the H7 and H9 is much deeper and wider than that of the earlier cameras. Hence, less lens body is required. Both are of similar, excellent, quality.
Figure 10-5 Maximum Wide-Angle With Adapters
Like most conversion lenses, the wide-angle adapters are usable as a far lens or a close lens. As a far lens, they help you express the scope and grandeur of vast landscapes.Theyt let you capture more of distant scenes, such as skylines, river valleys and mountain ranges. Shooting a party in your dining room? Use the wide-angle adapter to get everyone in the picture. Shooting architectural or real-estate interiors? Use the wide-angle adapter to show more of the space. Need either a close or far shot that appears to be perfectly in focus from foreground to background? The wide-angle adapter delivers huge depth of field. Product shots, still-lifes? The wide-angle adapter renders them close and crisp.
The wide-angle adapter works by decreasing the focal length of your lens (the distance between the focal point of the lens and the surface of the sensor), which results in three effects:
When your focal length is lower than 35 mm, it is said to be in the wide-angle range. Your viewpoint appears to be closer to your camera and hence, farther away from your subject. When you're farther away from something, you see more of it - or more of whatever surrounds it. Note: The definitions of normal, telephoto and wide-angle are not writ in stone. They are "generally accepted" breakpoints, not physical or scientific ones.The H1, H2 and H5's native 36 mm low-end limit is probably close enough to qualify as a wide-angle setting - but just barely. The H7 and H9, at 31 mm sit squarely in the wide-angle range. Let's take a look at the two images that follow. Note how the barn in the second shot (the one using the wide-angle conversion lens) appears to be farther away. You can also see more of the landscape. Missing from the first shot are the pond on the left and the telephone pole and wires on the right - none of which can be captured from this shooting location using the camera's native lens alone.
Depth of Field You may have also noted that both images appear to be in focus from the foreground all the way through to the farthest background. That's because depth of field depends on several variables, including aperture, focal length and subject distance. With far wide-angle shots, you've got two of the three factors in spades: focal length and subject distance. This is particularly true at the focal-lengths provided by the wide-angle conversion lenses. So much so, that aperture becomes relatively unimportant to your depth of field. Even in closeups or using large apertures, your depth of field will usually be more than enough to ensure clear, crisp detail throughout
Wide-angle can be somewhat more problematic than telephoto. It's hard to get a distortion-free image as your focal length gets closer to its lower limits. The wider you go, the lower the focal length. The lower the focal length, the more the image has to stretch to match the wider field of view, which can (and often does) result in one or more types of distortion. Parallax Distortion As the width of your image increases, subjects must shift to fill the space. Because of parallax distortion, they can shift in unexpected ways. Look at the reddish hedgerow in the foreground of the two pictures in Figure 10-7 and 10-8. The front edge appears to have shifted to the right in the lower picture, though neither the position of the hedge nor the position of the camera actually changed. This apparent change in position is called parallax. It is caused by the relationship of your camera to your subjects, not by any distortion in the lens. This is the same effect you experience when you look at a close subject with one eye, then close it and open the other one. Parallax generally only occurs when you have both a foreground and background subject. Note: Each lens has a nodal point around which the perspective of the scene revolves. This is particularly important for panoramic shots. Each cell stitched together to create a panorama needs to rotate around the same nodal point or parallax will occur between the cells - making it difficult to match the seams between shots. How do you match a hedge that seems to be 10 foot to the left with another cell in which the hedge appears to be 10 foot to the right? Perspective Distortion Normal perspective can be difficult to achieve in wide-angle photography. In the pictures above, the apparent distance to the barn has increased significantly in the wider-angle shot (the second photo). Because the hedge extends from the foreground all the way back to the now-more-distant barn, the length of the hedge will also appear to be much greater in the wider-angle shot. It hasn't grown between the shots. There is no real difference in the length of the hedge. Just a change in perspective caused by the change in the field of view. In some circumstances, this can result in rather bizarre distortions. Ever see an architectural photo in which the building seems to lean back? In the image in Figure 10-9, look at the building on the right. Not only is it curved, but it appears to lean back toward the center of the frame. The street lamp on the left (in fact the entire street) is leaning toward the right This is perspective distortion. You can correct perspective distortion, after-the-fact, using image-editing software. In Photoshop, you can use the Edit>Transform>Perspective Tool or the Edit>Transform>Distort Tool to correct perspective distortion. Barrel distortion is a bowing-out of the sides of your picture - basically, the rudiments of a "fisheye" effect. Why this pattern? Well, remember that your image is rectilinear; your lens is round. Something has to give as you get closer to the edges of the lens. You can correct barrel distortion by using the Filter>Distort>Lens Correction filter in Photoshop CS2 or with the freeware version of PTLens, by ePaperPress. Both are excellent and easy-to-use tools. The following picture illustrates both kinds of distortion that appeared in an H1 shot using the VCL-DH0758 wide-angle conversion lens. The picture below this one shows the same photo, corrected.
This pair of images also demonstrates Parallax distortion due to correction. Note that the corner of the building in the center of the picture remains very close to its original position in the corrected image, but the lamppost on the left has moved futher to the left and the last traffic light on the right has moved toward the edge of the frame.
The photos we've looked at so far are primarily composed of relatively distant subjects. But where the wide-angle adapter really shines is in room-size views. Take a look at the following two images. The first photo feels like an intimate view of a portion of a room - a crop of a room. The second feels like a real room. One of the best features of the wide-angle conversion lens is that it endows limited space with an expansive, three-dimensional feeling.
This mid-range expansiveness can only be achieved with the wide-angle adapter lens. The native built-in lens is just not wide enough. Do you plan to shoot children's parties? Family holidays? Graduations? Business meetings? In any of these cases, you'll pretty much have to use the wide-angle adapter or settle for a series of more intimate photos showing fewer people in a smaller space.
Macro photography is up-close photography of small subjects. I can't think of any camera with more flexibility in shooting macros than the H-Series. It supports a host of options for getting in close to a subject - which doesn't necessarily mean getting physically close. Getting close optically is enough to produce an excellent macro! Without any add-on lenses, the H-Series offers two macro modes:
There are downsides to shooting wide-angle macro. Paramount among them is that you and your camera are likely to blot out at the light. At 1-2 cm from your subject, you cast a huge shadow on a small subject. So why use wide-angle macro? Because the quality of a wide-angle shot is entirely different from the quality of a telephoto shot. The wide-angle focal lengths produce a deep depth of field. The telephoto focal lengths produce a shallow depth of field. If you want crisp detail, front-to-back, use wide-angle macro. If you want a beautiful blurred background to isolate your subject, use tele-macro. Of course, like all rules, these should be taken with a grain of salt. At the extremes (very crisp or very isolated), they hold absolutely true. But in the middle, either wide or tele macro can produce similar results, depending on the other depth of field attributes: aperture and subject distance. Still, these two rules are a good starting point. Let's take a look at a few macro shots taken with wide and tele macros:
The photo in Fig. 10-13 shows a tight focus on the rose in the foreground which quickly blurs into a beautiful background bokeh. The next photo is an extremely detailed shot of one of the same roses, taken using the H-Series native wide-angle macro mode. Note how every petal of the rose appears to be in clear, crisp focus. The third photo (Fig. 10-15) has the same attributes as the second, only over a much wider and deeper field. Every rose in this photo is in focus. This shot was taken from approximately 2 feet away, and the bouquet was about 16" across. This is an amazing range to get dead-on in a single shot. The huge depth of field exhibited in the last two shots is what makes wide-macro such an excellent option for product photos, table work, or any photo in which you need or wish to express detail.
The reason for using the wide-angle conversion lens for macro shots is to get width and depth, just as it is for landscapes. The built-in macro setting can get you in very close to your subject, but your field of view is quite small. Another advantage of the wide-angle adapter is that you don't have to get as close to your subject as you do in native macro mode. You can avoid being the shadow that ruins your shot! And let's face it, sometimes the lights, the room or the setting prevents you from getting up-close and personal. Use the wide-angle conversion lens to get in close without being right on top of your subject. The following shots demonstrate the difference between shooting wide macro with and without the wide-angle converter:
The second picture clearly demonstrates the strength of the wide-angle conversion lens. For professional quality product shots, for crystal-clear still-lifes, it's nothing less than superb.You can achieve a similar point of view without the adapter (using zoom), but it won't be the same crisp, detailed shot (note the texture on the fabric) or the same wide field of view. The adapter pushes the subject back, creates a view that's wider and higher and does its best to keep full-focus detail from foreground to background. Very impressive, indeed! Tip: Make sure your camera is set to macro mode when shooting close with wide-angle or shooting with the wide-angle conversion lens. It's what lets you get close. You'll note that as you zoom in, the macro setting has less and less effect until, at full telephoto, it's pretty much negligible. Some have reported that it helps them get a few millimeters closer when using tele-macro or closeup lenses, but this has not been demonstrated in any reputable tests up to this point. Regardless, it doesn't hurt to leave it on.
Virtually all wide-angle lenses cause some degree of vignetting - a darkening of the corners of the photo. This is not the same kind of vignetting you get from a telephoto conversion lens (as shown in Chapter 9), where the lens itself gets in the way if you zoom out too far. Instead, wide-angle vignetting is caused by light falloff - the tendency of the lens to get darker as you get towards its edge. The more wide-angle you shoot, the closer you are to the edge of the lens. There is almost no vignetting visible in the 31- 36 mm full wide-angle zoom of your camera's native lens. There is light vignetting when using the wide-angle conversion lens:
This kind of vignetting will normally only show up in bright wide-angle shots, such as landscapes with sky, and is easily corrected using the Filter>Distort>Lens Correction tool in Photoshop CS2 or using the free version of PTLens. If you've shot wide-angle in the past, you know that wide photography requires some post-processing. It's rare to get away without it. Still, it's well-worth it to achieve some of the marvelous effects you get with either the native H-Series wide-angle zoom or the wide-angle conversion lenses. The vignetting in the Sony wide-angle adapter cleans up easily and well. Warnings
Where To Buy The VCL-DH0758 and VCL-DH0774 wide-angle conversion lenses can be obtained for around $100 US at Amazon.com As of this writing, it is the least expensive vendor of the Sony wide-angle add-on lens.
There is a host of information on the Web on macro photography. It is very popular, and with good reason. Just Google "macro photography" and you'll discover hundreds of good resources. Chapter 12 of The White Paper is dedicated to macro photography and supplies much more detail about using both the native H-Series lens and all types of add-on lenses up-close. Click here for explanations, methods, tools, tips and examples.
There are lots of sources for technical and esthetic information about wide-angle photography by authors a great deal more knowledgeable than myself. There are entire books on the subject available from Amazon.com. If you're interested in more detail on this challenging, but rewarding, area of photography, you might want to read the following article online: Mastering Wide Angle, by Petteri Next: Chapter
11 - Extending Your Reach - Telephoto |
||||||||
|
|
