Chapter 3 – A Basic Digital Photographer’s Bagw3.marietta.edu/~mcshaffd/ilr/c3_cameras.pdfChapter 3 – A Basic Digital Photographer’s Bag Now that you’ve learned something

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Chapter 3 – A Basic Digital Photographer’s Bag Now that you’ve learned something about insects, let’s turn to the other side of the equation, photography. In this chapter I’ll introduce digital photography and some of the available tools for your use in photographing insects and their kin. Doubtless you are already aware of some of these, but this is a rapidly changing field and there is always something to learn. In some ways, the multitude of options when it comes to digital photography is reminiscent of the diversity of insects themselves. From Film to Digital

First a comment on terminology, in a historical context. Some purists will insist on the separation of the terms imaging and photography, so I might as well deal with that up front. Imaging and images are rather generic terms to represent a picture of some sort – a visual representation. We have many ways of doing this; primitive cavemen recorded images on cave walls with the charcoal from their cooking fires. DaVinci and Van Gogh used paints. Starting in the 1800’s a set of chemical techniques was developed to capture images made from light; this was the start of photography. Over time, photography went from chemical coatings on glass plates to chemical coatings on thin films of celluloid or plastic, and until a few years ago when someone said photograph it was pretty certain that this was the process that they were referring to. However, in the 1990’s the ability to capture (and more importantly, store) images using silicon and electronics was refined to the point that useable cameras were low enough in cost to be available, first to professional, and later to amateur photographers. By 2006 the technology was so mature that digital photography had overtaken film photography in most uses from casual vacation snapshots to photojournalism. The digital revolution has not revolutionized our vocabulary, however. Technically, what we do when we use a digital camera is to capture an image in a digital form – that is a collection of 0’s and 1’s, stored electronically. This is distinct from the

chemical process of classic photography, and some insist that a separate vocabulary be used. I don’t see the need for that, however, and I will use digital photography (perhaps an oxymoron), photograph, image, and even picture interchangeably – you’ll know what I mean. Film systems for photography were pretty simple, at least in principle. There was the camera, which held the film and the apparatus to expose it properly. In front was the lens, which focused the light on the film. That was it, although you could spend thousands of dollars on all of the paraphernalia, and endless volumes have been written extolling the virtues of this or that film. Behind the scenes was the darkroom where the film was developed and processed into the final product, usually a print or slide (the latter requiring a slide

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projector and screen in order to view it). Photo stores and drugstores did a lot of business handling the darkroom side of the business for many photographers; relatively few had their own darkrooms and attendant equipment. Digital photography did little to change the first part of the system, except that it replaced the film with a digital sensor made of light sensitive silicon (or other substances). This light sensor recorded the light, and several chips worth of electronics converted that information to digital form to be stored on yet more silicon (in most cases). Changes in cameras followed, but slowly; many of the first digital SLR cameras were much like their film counterparts. The big revolution came on the backside. The darkroom and the chemicals were all gone, replaced by computers, imaging software, inkjet printers and digital projectors. There are several real advantages. For about the same cost as a darkroom and its equipment anyone can now process their pictures. A computer is much smaller than a darkroom and it can be used for other purposes (although many amateurs multitasked their darkrooms, using them as bathrooms when they weren’t making prints). Making prints, particularly color ones, was very expensive and time-consuming in a darkroom; it is much easier and cheaper using a computer and printer. How much of a change is it? Consider this. My favorite camera of all time is the Canon EOS3, a film camera. It was a joy to handle and took wonderful pictures. My first digital SLR (single lens reflex, we’ll get back to this) was a Canon EOS D60. Somewhat similar to the EOS3, it was comparatively clunky, slow, and had a relatively poor imaging capability compared to cameras available just a few years later. When I first got the D60 I took it and the EOS3 to a nearby park, set up a telephoto lens on a tripod, and took pictures of a pair of mating dragonflies using both cameras and the same lens. A week later (when I got the slides back from the developer), I compared the results. I never used the EOS3 again. Why? Here are the real advantages of digital:

1. If your ultimate goal is to project an image to an audience (my day job is as a professor, and images are an integral part of my teaching) or to put them on the web then the digital camera eliminates the added step of scanning the images into a digital format. Yes, there is a device called the slide projector, but even Kodak, which makes slide film, isn’t going to make projectors anymore. The light on the wall is more and more from a digital projector.

2. Cost. I figured that every time I pressed the shutter on my film camera it cost me almost $1. That’s the price of slide film (bought in bulk at discount), mail processing, plastic slide pages to house the slides, and storage cabinets. If I burn my digital images onto a DVD I can put about 1,000 images on a disk that costs 25 cents; that’s about 40 images per penny.

3. Flexibility. With film, I used different films for different light conditions; a slow film in daylight, a faster film at other times of the day or night. Film comes in increments of 24 or 36 exposures; if you weren’t at the end of a roll when the light changed, you either had to sacrifice part of a roll, rewind it and hope you could advance it to the right point when you reloaded, or continue on with a film that was too fast or slow for the occasion. With digital you simply adjust the sensitivity of the sensor.

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4. Turnaround. Under the best conditions, it took at least an hour to process slide or print film. That assumes you are taking your pictures in the camera store. Camera stores are fine places, but sorely lacking in wildlife photo opportunities, so most people don’t take a lot of pictures there. As mentioned, I usually sent my film off to save money, and turnaround was at least a week. Digital gets you an image in less than a second. You know if the picture came out, and if it didn’t you can make adjustments and take another. Most animals won’t wait for you to come back a week later.

5. Creativity. When you aren’t paying $1 a pop you take some chances. If they don’t work, you can erase them. If you aren’t sure of the exposure, you take a picture and if it doesn’t work you adjust the exposure and take another. No big deal with digital. How many more pictures will you take? In 20 years I took about 10,000 slides; that’s about 500/year (most of these after my poor graduate student days). In 6 years since going digital I’ve kept over 70,000 images (who knows how many I’ve erased); that’s my entire 20 year output in one year. With autoexposure and autofocus, a higher proportion of those are good.

6. Space. In my office I have over 10,000 slides taken over a 20-year period. They are stored in plastic pages, 20 to a page. They occupy three 4-drawer file cabinets, a considerable amount of space. On one trip to Costa Rica I took 8,000 images. They fit on a portable hard drive I could fit in a pocket (a big pocket, but the drive was only ½ full at that). In the field, memory cards take up a fraction of the space that film canisters do, and you don’t have to keep them chilled.

7. Indexing. I had a pretty good system for sorting and filing the slides, but it still takes a while to physically pull out the pages and hold them over a light table to find the slide I’m looking for. If the slide was part of a lecture (and thus stored in a slide carousel) it could take quite a while to locate it. The 70,000 + images I’ve taken since going digital are all on the hard drive of my computer and I can get to any one very quickly. If I need to use one in a lecture or on a web page the original stays put, easy to find.

8. Backup. If something happened to my office – say a fire – I’d lose all my slides. My images are on a computer in my office – but also on another computer at home, and on CD’s and DVD’s in both locations. If I make a backup of my images it does cost me double – all the way up to 1/500th of a cent per image now for the original and the backup.

9. Convenience. My digital images can be emailed, edited, and printed easily. 10. Privacy. I don’t know what the girl at the photo shop I used to frequent thought of me when week after week I had her

developing roll after roll of photos of insect mouthparts. I can now do that in the privacy of my own house. Who knows, if digital was around 25 years ago I might have gotten that date…

Why would anyone still shoot film? There are a couple of reasons. First, one might have an extensive investment in film equipment. One might actually like working in the darkroom. Good films still have a resolution advantage over digital cameras with fewer megapixels. And, although it is cheaper to shoot digital, the up-front cost can be formidable. Not only is there the camera, but lenses,



flash, a computer, printer, additional hard drives, etc. Most people are likely to have the computer and printer anyway, but even here equipping them with the hardware and software to make good prints can add to the cost. Chances are you are already convinced of the advantages of digital, and so I’ll jump into the pros and cons of the various digital cameras in just a second. I’m assuming at this point that you know a little about photography – f-stops, shutter speed, ISO and the like. If you don’t, you might want to look ahead to Chapter 6 and come back once you’ve taken a look at some of that material. I’ll wait for you… The 3 basic types of digital cameras So. Digital cameras come in 3 basic types (and a bunch of specialized types). First are the simple “point-and-shoot”, which my wife calls PHD cameras (Push Here Dummy). At the low price end these are actually fairly complex cameras which make most of the exposure choices for you. If you are taking a portrait you select a “portrait mode”, often designated with a picture of a head, press the button, and the camera focuses, selects the ISO speed (sensor sensitivity), the shutter speed, the aperture (f-stop), whether or not to use the flash, and, after a short pause, actually takes the photo. These cameras work well for most people taking pictures of their kids, the Grand Canyon, the dog, their new car, etc. They are not all that useful for a nature photographer, particularly anyone working with insects, birds or wildlife in general. Most of them, however, are now capable of taking short movies.



A “PHD” (Push Here, Dummy) camera. This simple camera type can take excellent pictures (some have as many megapixels as their DSLR counterparts) but usually have a simplified control set that will soon frustrate a photographer trying to take pictures of anything other than family and friends. On the other hand, they are very portable and thus more likely to be in your pocket (with your spare change) when a great picture-taking opportunity takes place. Expect a compact body, relatively large, fixed, LCD screen on the back, a 4x optical zoom, decent macro capability – bit limited or no manual controls. Most can take movies. This camera has 5 megapixels and a 3x zoom. Newer models have over 10 megapixels.



The next group of cameras are the co-called “advanced” or “advanced point-and-shoot” digital cameras. I call them DAPS cameras for short. The “advancement” in most cases is letting the user make more of the decisions. In addition to the automatic modes mentioned above, these cameras will usually have the option for the user to determine the ISO, the aperture, the shutter speed – all of the exposure controls. Ideally, it will let the user set each control manually, overriding what the camera would recommend. These cameras also will have optics – lenses – more suitable for the insect photographer. Many will focus very close, a necessity for working with insects. Once again, the ability to make movies is common. I should at this point stop to mention the difference between optical and digital zoom. Optical zoom is a property of the lens, which adjusts its focal length to give a wider or narrower field of view. When the camera is “zoomed out” you see the forest; “zoomed in” you see an individual tree. Many digital cameras of the types discussed so far have about a 4x zoom ratio, that is they can go from a fairly wide field of view, usually akin to what the human eye sees, to magnifying objects at the center of the screen 4 times, about half what you would get with a pair of normal binoculars. More expensive cameras in these groups often have a wider zoom range, perhaps 8x, 10x, 12x, or even 20x. The 8x would be similar to what you might get with a pair of normal binoculars, and starts to make the camera useful for photographing birds and other wildlife you can’t get close to. Now, many cameras also have a digital zoom. Most serious photographers see the digital zoom as a marketing gimmick and never use it. Basically, a digital zoom works by electronically magnifying the center of the image. Since no additional information is captured, as you blow the central image up, the individual components, pixels, simply get bigger and as they do you begin to notice them as square or rectangular blocks. Cameras with more megapixels are not as prone to this, but every camera has a point past which the loss in resolution is noticeable. This does not make for a pleasing photo, which is why you should usually ignore the digital zoom feature when comparing or using a camera. Just take the picture at the maximum optical zoom and crop it back at your computer. It can take some searching to find them, but cameras with manual control are available; in late 2008 one such camera was selling for just over $100!



An “advanced point-and-shoot” or DAPS camera. Compared to the PHD camera, expect to see several more advanced features. Usually, there will be a greater zoom range on the lens (the camera pictured here has a 12x optical zoom), making the camera more suitable for wildlife photography. Often there is a flip-out LCD screen that helps when maneuvering the camera into a tight position to take a macro shot; with the tilting LCD you don’t have to have your head right behind the camera. Unfortunately, many manufacturers are dumping the swivel LCD in favor of the larger, fixed screen preferred by many casual photographers. Perhaps the most critical feature is the presence of a full set of manual controls – ISO, shutter speed, aperture, focus and even the flash can all be set manually, allowing for full creative control.



The final group of cameras are the digital SLRs. SLR stands for Single Lens Reflex, a fancy way of saying that there is one lens and the image you see in the viewfinder comes through the single lens by way of a mirror and a prism. When you actually take the picture, the mirror flips up out of the way and the image is sent to the film – or digital sensor. As of 2008, digital SLR’s were very close to their film kin in terms of basic design; it’s just that the film and motor drive have been replaced by the imaging chip and storage hardware. In many ways, the digital SLR’s – DSLR’s – are ideal for insect photography and I’ll spend a little more time on them. In terms of price they often overlap with the more advanced point-and-shoot cameras, at least at the bottom end. The biggest single advantage of the DSLR is the ability to change the lenses. You can put on wide angle lenses for landscapes (and some astonishing insect photos), macro lenses for getting up close, telephoto lenses for distant subjects, and zoom lenses to cover several bases at once. Of course, by the time you purchase all these lenses your investment will be well beyond what you would have paid for even a DAPS, but you gain tremendous flexibility, and you can add the lenses as your budget permits. Later, if a new camera comes out you can buy it and continue to use your lenses with it. Most DSLR’s will have features similar to the more advanced point-and-shoot cameras, and nearly all will allow you enough manual control to compensate for some of the tricky situations you will encounter in insect photography. One of the disadvantages of some DSLR’s on the market is that you are stuck to the viewfinder for composing your shots. The LCD screen on the back of the camera can show you pictures you have already taken, but is not “live” to preview your shots (because the light is bouncing off the mirror up to the viewfinder instead of going to the sensor. That means you have to be behind the camera and that makes getting into tight spots tricky. Accessories such as optical and electronic angle viewfinders can help, but are not as convenient as a live, swiveling LCD viewfinder (more on this later). DSLR designers have been adding this “live view” feature to even the most basic cameras in their lines; some DSLR’s now even have the ability to shoot movies.



The Digital SLR: The DSLR looks much like its film predecessor; in fact many DSLR’s can exchange lenses with their film counterparts. The big difference between the DSLR and the DAPS or PHD camera is the fact that the DSLR can exchange its lenses. This opens tremendous creative possibilities. This camera is shown sporting a wide-angle zoom lens, but a macro or telephoto lens could easily be substituted. In use, the DSLR is similar in some respects to other digital cameras. The biggest difference is that the optical viewfinder above the screen is set up to look out through the lens, so you see exactly what the camera sees. This type of viewfinder is easier to use in bright sunlight, but the photographer’s eye must be right up to the viewfinder and useful features such as live histograms are not supported in the viewfinder. In the back view of the camera shown here, the display is showing a recorded image. The display can be used to review images (and histograms), increasingly there is also a

“live view” option to preview what the final image will look like. Compared to a DAP or PHD camera, DSLR’s are bigger, heavier and more expensive.



Choosing a Digital Camera Which camera to choose? It depends on what you are photographing, and I’m going to assume that having laid out the money for this book that you want to take pictures of insects. With that in mind, let me take you through some of the features available on digital cameras which are particularly important for insect photography. With that in mind I’ll then lay out some suggestions for purchasing a camera; as we go through this you’ll see that the type of camera is not as important as how well its feature set matches up with your photographic vision. Features to look for in a digital camera:

1. Manual controls. I can’t stress this enough. You need to be able to manually override the camera’s settings for all parameters – ISO, shutter speed, f-stop, focus, white balance and flash. In some cases you can get by with what is known as “exposure compensation”, but it’s better to be able to make the settings manually. You will still use the automatic modes a lot, but when you need a manual setting you really need a manual setting.

2. Macro ability. “Macro” simply means the ability to focus on a subject close to the lens. As you might guess it is critical for insect photography. The good news is that most of the point-and-shoot and DAPS have this built in and you can easily get a macro lens for a DLSR. Be aware that many SLR lenses, particularly zoom lenses, advertise a “macro” capability that falls short of what you will need. If you are buying a DSLR, set aside the money for a true macro lens.

3. A live, swiveling LCD screen to compose your shot. This is a feature actually becoming less common on advanced cameras (it is rare on the simple cameras and DSLRs to begin with) as manufacturers move to larger screens, a big demand of the less discriminating photographer. The swiveling screen allows you to get pictures from unusual angles and in tight spaces, and is great unless you really like laying flat on your belly in the mud. Once you have the swivel then go for a bigger screen size, but never choose a larger screen that doesn’t swivel over a smaller one that does.

4. Good optical zoom range. A range of at least 4x is needed (except in DSLR’s). 5. Megapixels. Generally more is better, but for most photography you want at least a 6 megapixel camera. This will allow you

to project large images on a screen and to make decent size (8x10) prints (actually, I routinely make 20x30 inch posters from the output of a 6 megapixel camera). Actually, it’s hard to find a camera with less than 6 megapixels, and many cameras probably now have too many megapixels, to the point where image quality suffers at higher ISO’s.



6. Good image quality at ISO 400. As you increase the ISO the camera becomes more sensitive to light, which allows you more flexibility in making images. The down side is that noise appears in the image, making it look blotchy. Most cameras do well at ISO 200, but differ markedly at ISO 400 and above (if there is a higher rating at all). You want a camera that can give you a good image at ISO 400.

7. Power supply: Many of the smaller cameras achieve their diminutive size by using a small, proprietary battery. If you buy such a camera be sure to purchase additional batteries as smaller batteries will not last as long. Factor in the cost of 2 additional batteries (you need 3, one in the camera, one for standby, one charging) into the cost of the camera. Some cameras use AA batteries; a set of 4 rechargeable AA’s can be had for less that $10 and a charger for less than $20, some chargers can be used with household or automobile current. Plus, you can buy AA batteries almost everywhere.

8. Size and weight. A smaller camera may well be less capable, but you are more likely to have it with you. A larger camera can probably get any photo you want, provided you lug it and the equipment around. This is a largely personal decision.

9. Memory. Don’t buy a camera without the ability to use memory cards of some sort. Otherwise, the only way to free up your camera to take more shots is to hook it up to a computer and offload the pictures already there. There are several different kinds of memory cards available; Compact Flash and Secure Digital are the most commonly available and thus can be purchased in an emergency in more places, and at a better price. Assuming you have a 6 megapixel camera you can get several hundred JPG images on a 1 gigabyte card (a JPG file is a standardized format for compressing image data and is the most common file format used in cameras today). Depending on your shooting habits and how far away from your computer you roam, budget for at least 2 cards. By the way, the largest card available is not always the best buy. They often command a premium price, and if a bigger card fails (a rare but real occurrence) you will lose more pictures (the same applies if you lose the card itself).

10. Image Stabilization: This feature helps produce a sharp image even when low light conditions force you to use a slow shutter speed. It is particularly useful when the lens is zoomed to the longest focal length as the camera is most sensitive to movement then.



In addition, price is always a consideration; the price of a camera also determines what accessories you can afford. If you have a fixed budget for camera purchases – Bill Gates, you can skip this section – then the more of that budget you spend on a camera the less you have for the accessories. For instance, I use a mid-priced DSLR. I could buy a more expensive one, but the additional features I get – ability to take more shots in quick succession, more megapixels, tougher body construction, and a few other bells and whistles – almost double the price of the expensive camera over the one I use. For that additional money I can buy a good macro lens and a ring flash for macro work. In DSLR’s at least, the best camera in the world won’t take the pictures you want unless you put the appropriate lens on it, and those lenses can cost more that a good DSLR itself. The list above applies to digital cameras in general. I use both DSLR’s and DAPS cameras. Each has its place, and the complement each other nicely. For instance, I often have my DSLR set up for photographing insects, but I carry a small DAPS in a pocket where I can easily pull it out to record scenery without having to change the lenses on my DSLR. However, if I could only have one camera, it would be a DSLR hands-down. With that in mind, let’s take a closer look at DSLR’s and some of the features peculiar to them. Virtually all of the DSLR’s on the market have a similar basic feature set. In terms of exposure, they allow you to select an ISO. They all have built-in light meters of some sort. They usually have a full manual setting (where you select shutter speed and aperture), one or more automatic settings (the camera selects everything), and semi-automatic settings (you select shutter speed or aperture and the camera selects the appropriate aperture or shutter speed). They differ in the number and type of fully automatic settings (optimized for things such as portraits, nighttime, fireworks, scenery, etc.) These automatic modes are pretty useless once you get used to your camera, so I’d ignore them in making a purchase. Most also offer exposure compensation, which allows you to vary the exposure slightly; many also allow you to exert similar control over the flash. Since there is no film to advance, all of them allow you to take multiple images in sequence without cocking the shutter. They differ widely in the “burst rate” – the number of pictures you can take in quick succession. A burst rate of 3fps means the camera can take 3 frames (images) per second (assuming the shutter speed is less than 1/3 of a second!). Some cameras can sustain the burst rate until the memory card is full, others may have a limit on it such as “4fps for 10 seconds”. Basically, the cameras have some built-in memory (buffer) that is very fast (and expensive) which stores the images until they can be written to the card (a slower process). More expensive cameras will have more of this memory and thus higher burst rates, but at a greater cost. Also, remember that a camera with more megapixels will take longer to process and write images to memory cards than a smaller megapixel camera because there is more information in each image. That means that more megapixels translates to even more of that expensive fast memory in the buffer and is one of the reasons that large megapixel cameras are disproportionately more expensive.



Speaking of megapixels, virtually all new DSLR’s have plenty. There is a real difference in the size of the sensors, however. Again a little history will help clear up the confusion concerning the “zoom factor” you may have heard about. The first DSLR’s were based closely on film SLR’s. 35mm film cameras use film with an image size of 35x24mm (hence the name). When the first affordable DSLR’s came out, an imaging chip 35x24mm was prohibitively expensive, so a smaller chip was placed in the center of the camera. This has several consequences. First, not all of the image is used. Only the central part of the image is actually recorded; the rest of the image falls onto blank plastic and is discarded. This means that the picture looks as if it were shot with a longer lens. Usually, this effect is equivalent to using a lens 1.3 to 1.6 times as long, and you will see the cameras advertised as having a “1.3x magnification factor”. If you are taking pictures of birds, congratulations; your 400mm lens is more like a 560mm lens and those birds will look bigger in the frame. If you take scenic pictures, sorry. Your wide-angle 20mm lens now acts like a “normal” 35mm lens (we’ll talk more about the different lens designations in a bit). Camera manufacturers deal with this “zoom factor” in several ways. First, they market it as an advantage. Second, they make use of the fact that the smaller sensor gives them an optical advantage. Lenses are sharper at the center than at the edges; much of the expense and weight of a good lens goes into making sure the edges are as sharp as the center. With a smaller chip, the lens designed for a 35mm camera is overkill; all that sharpness on the edge is wasted focusing the image onto blank plastic (which would be film in a film camera). Thus, camera manufacturers have come out with new lenses designed for digital cameras that are lighter and cheaper than those designed for film cameras. Some have even produced “super-wide” angle lenses which would be a blurry mess on a film camera but which translate out to a sharp “wide-angle” lens on a DSLR with a smaller imaging chip. And, of course, the price of sensor chips and memory continues to drop so that “affordable” DSLR’s with full-size 35x24mm sensor chips are now available. These cameras, usually with over 12 megapixels, do not have any “zoom factor” and thus demand the same high-quality lenses their film forbearers did.



Lenses for Digital Photography As I mentioned earlier, one of the most important components of any digital camera system is the lens. If you’ve settled on a simple or advanced digital camera you’ve also purchased its integral lens and there isn’t much more to say on this topic. On the other hand, if you’ve decided to buy a DSLR, you are only halfway through your decision – you still need to buy a lens. First I should mention that there ARE lens options for digital cameras with built-in lenses. These are the so-called “auxiliary lenses” They may screw onto the front of the lens or attach with an adapter that your camera manufacturer will be glad to sell you. They come in 3 basic types:

1. Wide-angle adapters: These adapters expand the field of view of your lens, compressing a larger scene into your image. This is useful for dramatic impact (getting more of the Grand Canyon into view, for instance). It is also useful when taking pictures in cramped quarters or when photographing a large group of people as you can be closer to the subject and still fit it into the frame. For insect photography it allows you to take some way cool shots. Usually these adapters are sold with some sort of “magnification factor” as an indicator of what they will do, and the factor will be less than 1. For instance, an adapter marketed as 0.5x will cut the focal length of your lens in half, making a 35mm lens act more like an 18mm lens and thus greatly widening the field of view.

2. Telephoto adapters: These do the exact opposite of the wide-angle adapters; they limit the field of view and thus magnify things at the center of the image. For instance, a telephoto adapter might be labeled 2x; it will effectively double the focal length of the lens making your 100mm lens act like a 200 mm lens, with objects at the center of the screen appearing 2x as large (or twice as near).

3. Macro adapters: These lenses magnify the image; often they also limit the depth of focus to a close distance. They act a lot like reading glasses in this way. They can make close objects look bigger, and like reading glasses are sold in terms of the magnification they offer (2x, 5x, 8x, etc.). They can often be combined to give even stronger magnification. They would seem to have obvious uses for insect photography, but actually most small digital cameras can already focus close enough and DSLRs with a macro lens will give better results.



Using any of the 3 types of adapters leads to a few things you need to keep in mind. First, the adapters may make a small camera bulky – my DAPS won’t fit in my pocket anymore with its adapter attached. The adapter may not work over the whole range of the zoom on your lens; for instance a telephoto adapter may only work at the longest focal length (which is where you’d probably use it anyway). Adapters (as well as filters or any piece of glass you put in front of the lens) may reduce image quality and/or contribute to lens flare (the bright spots you get when shooting into bright light). Each layer of glass is one more layer to get dirty and obscure your image. The adapter may interfere with your camera’s flash, particularly up close where it can cast a shadow on the subject. Finally, most digital cameras (except DSLR’s) will not show the effects of the adapter on the optical viewfinder. The image will be displayed correctly on the LCD screen, but if you aren’t using the screen (say in bright light or to conserve batteries) looking through the viewfinder won’t give you an accurate idea of the image your camera is recording. DSLR Lenses There are a huge variety of lenses for DSLR’s. You can buy a special lens for many different shooting situations, allowing you the capability to make a multitude of different kinds of images (although at the expense of weighing down your camera bag and lightening your wallet). Let’s look at some of the lenses and their applicability to insect photography. First, bear in mind that not all lenses out there will fit on your DSLR. Virtually every manufacturer uses a different mount for the lens, and some manufacturers may have older lens models which won’t fit your newer camera. There are a number of independent manufacturers that make lenses to fit a number of the different camera makes, but with a few exceptions it is not possible to use a lens built for one type of camera on another. Always be sure what type of lens mount your camera uses before starting to shop for lenses.



All lenses have a number of characteristics that you want to keep in mind while shopping: 1. Focal length. This is the most obvious attribute of the lens. The focal length determines the angle of view that will be

recorded on the film and thus has the greatest impact on the final image. Since this is the variable that distinguishes most lenses from each other we’ll come back to it.

2. Zoom ratio. Many lenses do not have a fixed focal length but rather a range of focal lengths that they can “zoom” through. Zoom lenses used to be considered optically inferior to fixed focal length lenses, but the optics of zooms have improved to the point that such differences are now more imagined than real. A good zoom lens can save you from carrying a number of fixed focal length lenses (saving weight and money) and can offer focal lengths intermediate to those fixed lenses, allowing you greater freedom in composing images. More later.

3. Speed. This is indicated by the maximum aperture, or f-stop. A smaller number is better, up to a point. The larger the aperture, the more light is let in. This allows you to take pictures with less light, or to use a faster shutter speed (which freezes action and minimizes blur), or to use a lower sensitivity setting on your sensor (a lower ISO generally means less noise in your photo). A faster lens will also give you a brighter view in the viewfinder and will help you isolate a subject from the background as large apertures give little depth of field. The trade-off is size, weight, and cost. To make a lens faster, it needs to have more glass to let in more light, and this means a bigger, heavier, more expensive lens.

4. Autofocus. Virtually all digital cameras have autofocus and this is built into the camera, not the lens. Still, the lens has to have the motors to do the actual focusing and this and various other characteristics of the lens will affect the ability of the lens to autofocus quickly. It’s always a good idea to try the lens on your camera focusing on the subjects you normally photograph in the light you normally work in to judge how well the lens will autofocus for you. Alternatively, go online and look for reviews/comments on your lens/camera combination.

5. Close focus. Lenses differ in their minimum focusing distance. Some telephoto lenses will not focus on subjects closer than 20 feet away; this obviously won’t be of much use in insect photography. Macro lenses usually focus very close. Close focus is important to achieve a good magnification factor (next).



6. Magnification factor. The overall magnification of an insect in the final image is a combination of the focal length and the minimum focusing distance. Longer focal lengths combined with an appropriate close focusing distance will allow you to record images where the actual length of the subject is the same as – or smaller! – than the length of the subject’s image on the imaging chip in the camera. When the subject is 10mm long and it makes a 10mm long image on the chip then we say the magnification ratio is 1:1. If the 10mm long subject makes a 20mm long image on the chip then the ratio is 2:1, and if the 10mm subject is represented as a 5mm image then the ratio is 1:2. For insects you want a ratio of 1:1 or better (2:1, 3:1), although the largest insects like butterflies and dragonflies can be photographed nicely with lenses only capable of 1:3 “magnification” (the butterfly is being represented at 1/3 life size). Aside from true macro lenses (discussed below), most lenses do not achieve a 1:1 ratio, so for insect photography make sure you have at least one macro lens in your kit and be sure your longer focal length lenses have a fairly close minimum focus distance.

7. Image stabilization (IS). This is a new feature of the electronic age, following autofocus onto the stage in the waning days of film photography. Image stabilization (some manufacturers call this feature vibration reduction or VR) attempts to compensate for camera shake when a lens is handheld, thus increasing image sharpness. Before IS, the rule of thumb was that to ensure sharpness you should use a shutter speed reciprocal to the focal length – that is use 1/400 of a second (or faster) for a 400mm lens, 1/100 second for a 100mm lens and so forth. With IS, the 400mm lens can be held at perhaps 1/50 second – a useful improvement. IS systems have several distinctive designs; the two most common are the optical shift and the sensor shift. With the optical shift, sensors pick up the movement and make tiny adjustments to the optics to compensate. With sensor shift the sensor is actually a bit oversized; when movement occurs the extra size allows all of the image to be captured and the camera reconstructs a sharp image from what it captured. Either way, it is a very useful tool, especially for insect photographers who often can’t work from a tripod when following rapidly moving insects. Sometimes the technology is built into the lens, sometimes it is built into the camera (thus making all the lenses you put on the camera image stabilized – a neat trick). IS or VR is more important on longer lenses. Unfortunately, to my knowledge no manufacturers are currently (2008) putting IS technology into macro lenses, perhaps operating out of the stereotype of the macro photographer hovering over a flower with the camera firmly planted on a tripod.



8. Size and weight. As mentioned above, the faster the lens the bigger it will tend to be, especially in terms of width of the lens barrel and weight. This has obvious implications for your ability to carry the lens in the field all day with you (you will probably be carrying several lenses); your ability to handhold the lens when taking pictures (some telephotos can weigh 15 pounds or so), and even your ability to get all your gear on a plane! There are less obvious considerations to keep in mind as well. A lens with a wider barrel will need larger filters, and this can increase the price of the filter dramatically. While it’s always nice to use the highest quality lenses available, there may be a place in your kit for a few light lenses you won’t mind carrying to otherwise inaccessible places.

9. Ergonomics. Lenses differ considerably in the way they operate. Zoom mechanisms, for example, may be the so-called push-pull where you zoom the lens by pulling the focusing ring towards you or pushing it away; since your hand is on the focus ring you can focus at the same time. Other lenses may use a two-ring system (this is becoming rare) where one ring focuses and the other zooms, an awkward operation for most of us born with only two hands. Some lenses focus internally; the focus ring turns but the front element of the lens does not. This means that your ring flash and filters on the front of the lens stay in place and don’t rotate as you focus, a very useful feature. The placement of controls on lenses, as well as the readability of distance and magnification scales, also varies. Ergonomics is largely personal; the size of your hands, the thickness of your glasses and the state of your dexterity and coordination all come into play – if possible try the lenses on your camera before buying. Some of the pricier lenses can cost more than a car; sometimes you can arrange to rent such lenses before buying, particularly if you don’t mind putting your house up as a return deposit.

10. Coatings. Most lenses do a decent job of creating a good, sharp image with few artifacts, particularly on digital cameras. Every piece of glass in the lens, however, has the potential to add distortions or reflections (flare) to the image. The best lenses have elaborate coating to minimize these problems, and often these coatings come at a significant price. You may be confused by finding two lenses from the same manufacturer with similar specs in terms of focal length, macro capability, and so on, but a significant difference (as much as 10x) in price. If you look carefully you will see two main differences between the lenses – maximum aperture (discussed above) and the quality of the optical design including the coatings. You will have to determine for yourself if the difference in quality is worth the difference in price; differences in image quality will be most apparent when taking “difficult” shots in low light or bright light.



Focal length As mentioned above, one of the prime criteria for choosing a lens is its focal length, because the focal length is the single most important variable in determining a lens’ performance. In order to understand focal length you need to understand just a little bit about human physiology. When you look forward with both eyes, the portion of the world that is in reasonable focus to you is what we often call the “normal” view. In a 35mm camera system this view would be recreated by a 35mm lens, which would have an angle of view similar to that of your two eyes. If you closed one eye, this area of view would be closer to what a 50mm lens would provide, and thus lenses around 35 to 50mm in focal length on a 35mm camera (film or full-frame DSLR) would be considered a “normal lens”). As you move to longer focal lengths, the angle of view narrows and you get an apparent magnification of the central part of the image. This magnification is proportional to the focal length; a 100mm lens provides 2x the magnification of a 50mm “normal” lens and a 400mm lens an 8x magnification, about the same as a pair of binoculars. Wider lenses pack more image onto the same frame of film, so there is an apparent decrease in magnification, again proportional to the change in focal length. It is useful at this point to divide the lens world up into 3 parts, each of which will be considered separately. Lenses shorter than 35mm are considered to be wide-angle lenses, lenses over 50mm are telephoto lenses, and lenses from 35-50mm are “normal” lenses. If your DSLR as a magnification factor you need to take that into account; a 24mm lens that would be wide-angle on a film or full-frame DSLR acts more like a “normal” 35mm lens and a 50mm lens acts more like a short telephoto lens on the small-chip DSLR. As an insect photographer, you will find a need for all 3 types of lenses, plus a fourth, the macro lens. Wide angle lenses range from less than 10mm up to 35mm. They are good for packing a lot of image into a frame, and are thus favored by landscape and architectural photographers. Most take the frame and arrange it into a square frame – so-called rectilinear lenses, but others place the image in a circle on the film or sensor; these are sometimes called fisheye lenses. Both types make some optical tradeoffs and you might see some distortion – buildings look curved, a person’s nose seems gigantic – depending on the scene. One of the beauties of these lenses is that they have tremendous depth of field. This is the area from front to back in a photo that is in sharp focus. With a macro lens you will get used to measuring depth-of-field in millimeters; with a wide angle lens it might be measured in meters. This can be to your advantage in photographing insects in that even if the lens won’t focus as close as you might like, the tremendous depth of field will compensate.



Normal lenses fill the void from 35 to 50mm. Since they roughly recreate human vision, they are most often used for causal images that give a sense of place to a slide show. For instance, when working with insects you might switch to a normal lens to photograph the habitat. They are also good for photographing people and pets that you can approach more closely. Some have very close focusing abilities and can serve as macro lenses as well. Telephoto lenses have focal lengths over 50mm. The longest practical lenses in this category are about 800mm (although some longer ones are made they are either too expensive, or too heavy, or too poor in quality to be reasonable choices). Since telephoto lenses achieve magnification over normal lenses they are valued for their ability to bring distant subjects near without the photographer having to get close – a useful trait when photographing feeding lions, for instance. These lenses are used most often by sports photographers, nature photographers working with birds and mammals, and perverts. Some, most often those around 100 or 200mm in length, are also true macro lenses with a magnification ratio of 1:1; most will allow you to achieve a magnification ratio of about 1:3 or 1:4 – good enough for larger insects.

Macro lenses come in a number of focal lengths, as mentioned above. The key ability of a macro lens is the ability of the lens to achieve a 1:1 magnification ratio (or better). Most of the macro lenses on the market today for 35mm or DSLR systems are in the 50mm range; thus they make good normal lenses when not being used close up. Others are in the 90-100mm range and can serve as short telephotos, while still another group is in the 180-200mm range. Each range has advantages and disadvantages; as with regular lenses the longer the focal length of a macro lens the narrower its field of vision will be and the more apparent magnification there will be at a given distance. That last qualification is critical; if a 50mm, 100mm and 200mm lens all can reach a 1:1 magnification; the biggest difference you will see is how close you have to be to the subject to achieve that magnification.

Generally, the shorter lenses will mean the photographer has to get closer; this means there is less working distance between the lens and the subject. This is an issue for 2 reasons. First, getting closer is not always practical; the animal being photographed might not allow a close approach or the situation makes moving close impractical (say taking a picture of an insect far back in a formal garden). Second, when you get close light becomes problematic. As a general rule you will want to photograph with the light coming from behind you; the closer you get the better the chance of your shadow falling on the subject. Even if you use flash it can be a challenge

This damselfly was photographed with a DAPS camera, its lens set to f/8 (the smallest possible aperture). This led to a great depth of field ensuring that the entire insect is in focus.



to aim it properly if there is but a small distance between the lens and the subject. On the other hand, although longer lenses allow for longer working distances they also have less depth-of-field and are bulkier than their shorter counterparts. Finally I should mention zoom lenses again. These lenses can work over a range of focal lengths. There are some that span the range from wide-angle to telephoto (and even have decent macro capability). Such lenses mean you can get away with carrying fewer lenses into the field. In addition, with zoom lenses you end up changing your lenses less frequently; this means fewer missed shots, less dust getting into the camera, less time cropping images on the computer, and, perhaps most important, fewer dropped lenses! Zoom lenses do tend to be heavier (but are still lighter than carrying 2 fixed focal length lenses) and slightly more expensive (but you are buying fewer lenses). As mentioned earlier, the quality is almost as good as the single-length lenses (only fanatics can tell the quality differences between a good zoom lens and a single-length lens). They don’t tend to be as fast, and in fact many of them have a variable maximum aperture – they will be slower the more you zoom to longer focal lengths.

Another DAPS camera. This one is smaller than the one shown earlier. It has more megapixels (7 vs. 6) but a smaller zoom range (4x for this camera, vs. 12x for the one pictured earlier). Both cameras use 4 AA batteries and have SD cards for storage. The compact size of this camera can be an advantage, as it is small enough to fit in a pocket and thus you are more likely to have the camera when the opportunity for a picture comes up. Cameras like this can take good macro photos; the photo on the previous page was taken with an older version of this camera. On the other hand, the short zoom ration makes them unsuitable for wildlife photos.



So, what to do? I’ll cover some of the options throughout the book, and depending on what types of pictures you want to take you might find yourself opting for one lens over another. If you are just starting out you can’t go wrong with what is called a “normal” zoom, one with a range from about 35 to 135mm. This will cover everyday photos and portraits. If your finances permit, buy a macro lens too for insect photography. After that, build your lens collection by adding a longer zoom (say 70-300mm) and a wide angle lens. Another strategy is to buy a DAPS for your everyday shooting and a DSLR with a macro lens for the insects. The smaller camera can easily be carried in a pocket and pulled out to photograph scenery and habitat as needed.

Documents

Chapter 3 – A Basic Digital Photographer’s Bagw3.marietta.edu/~mcshaffd/ilr/c3_cameras.pdfChapter 3 – A Basic Digital Photographer’s Bag Now that you’ve learned something