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How to get sharp photos, from the scope to the computerPosted on Friday, April 27, 2007 at 8:50 AM - Post CommentFOCUS, FOCUS, FOCUSTHE PROBLEMAchieving a sharply focused photograph directly from digiscoping is IMPOSSIBLE….. There, I’ve said it. And if you’ve been disappointed by your shots in the past, hopefully it’s at least a bit comforting to know that many other people are having those same depressing thoughts you have when you get home and look at your digiscoped photos. It’s actually usually very easy to tell from looking at a raw photo whether the shot was taken using a digiscope rig or a DLSR camera (digital single lens reflex camera….digital camera with a large attached lens).
DSLR camera rig courtesy Steve Nanz www.SteveNanz.com For one thing, close-looking shots of birds that are wary are almost always taken through a scope. Shots of warblers, and similar birds that are usually moving around a lot were most likely taken using a DSLR camera. But beyond the species level analysis, it’s also easy to tell just by the clarity of the shot. The same layers and layers of glass that cause the blue shifts discussed in the last article also cause a softening of the image; a very frustrating lack of crispness in the photo. Here are a couple of raw digiscoped shots. I took them under optimal circumstances: the bird was fairly close and in good light and was standing still.
Here are a couple of DSLR shots. It’s fairly obvious that they are clearer, with more even light and greater focus….
IS THERE A SOLUTION…?Of course I wouldn’t have written this article if the only hope you had of getting a great picture was to throw away your digiscoping rig and run out and buy a DSLR camera with a huge lens. (Or at least I would have given it a different title, like “Throw away that digiscoping rig, it sucks…” or something like that.) First of all, you don’t’ want to miss out on the shots of all of those great looking but wary birds that need the scope’s magnification to capture. And who wants to lug around a big DSLR rig along with everything else you’re taking into the field? Not everyone can afford porters… So what’s the solution?? Getting a great looking, clear bird photo using a scope requires careful attention to every step of the photographic process from how you set up your scope, attach your camera, take the shot; to how you finally process the resulting image using Photoshop. Let’s take a look at each step in the chain and see what you can do to ensure your photos will look great when it’s time to have them printed or used in a presentation. MORE ABOUT THE PROBLEM...When you are taking a photo through a telescope you are magnifying the image at least 20 times. In 35mm camera speak, that’s a 700mm lens. Zooming in the camera, which is usually required to eliminate vignetting and helps get more of the bird in the picture, translates to a 1400mm or higher lens equivalent. At these very high magnifications there are two related factors that work against you getting a sharp picture. LIGHT (or rather the dire lack of light….) As you reduce the amount of light hitting the camera, the time required to “expose” the digital sensors to get a clear picture increases. Taking a photo through a telescope reduces the available light. Zooming reduces the available light…Exposure time goes up when you take a digiscoped photo. MOVEMENT As exposure time increases, any movement by the bird or by the camera, scope or tripod causes the image to become blurred. Even tiny movements can destroy the clarity of your image. FORTUNATELY, YES, YOU CAN GET GREAT LOOKING DIGISCOPED PHOTOS…Even though the odds are stacked against the digiscoper, careful attention to detail at each step of the process can result in some very good photos. Below are some important issues to consider as you put together your rig and then proceed to take your shots. Each one of the steps below is important, and it’s the sum of careful attention to each element that will add up to making your shots look as good as they can be. In choosing a scope for digiscoping, it’s all about light….and clarity….and that means, unfortunately, expense. The larger the objective, the more light you will get through the scope and onto the camera’s elements. So an 80mm scope will perform better than a 65mm scope. The best scope that I’ve tested so far is the Zeiss 85mm Diascope FL. It is just very bright. If you have a zoom eyepiece, zooming will reduce the amount of light available for the photo. So in most cases it is much better to leave the scope zoomed “out” at 20x. A 30x wide angle eyepiece in some cases can offer more magnification but also good light. Unfortunately if you need to use the scope’s zoom for your general birding ID, then changing out the eyepiece can be a real pain. FOCUSING THE TELESCOPE Very carefully focus on the bird! It seems like this should be obvious, but because it is almost impossible to carefully focus the scope with your camera attached, this step is sometimes overlooked, and it is critical. HINT: zoom in to 40 or 50x and carefully focus on the bird, looking at feather detail. Then zoom out, attach the camera and take the picture. This process ensures the sharpest focus on most scopes I’ve seen. If a bird is moving, you have to follow it. And if the camera is attached, it can be very tough to know if the focus needs adjusting. Although it slows down the process, removing the camera and carefully refocusing the scope can result in better pictures. THE TRIPOD If your scope isn’t stable, then your picture will be blurry. End of story! If there is even a little wind, just your scope carrying case can introduce movement that will work against clarity in your photos. Wind is bad but you’re worse…. The timing of the exact moment you take your shot, of course, depends on the bird. But it also depends on your scope and rig being “settled down” so that you don’t have any bounce or tripod-induced movements from handling your rig. Notice next time what happens to your whole tripod, even heavy ones, as you move the scope and head assembly. After you stop the movement there still is a settling down time that can be as long as a couple of seconds. In the rush to take a picture of a bird that could fly at any second, this settling down time is often neglected, resulting in a disappointing picture. One solution to getting the shot as quickly as possible and still getting the best possible shot is “burst shooting”. (more on that below.) Traditional tripods are made of aluminum and the heavier the tripod, the more stable the platform for your scope. Unfortunately, lightweight, thin aluminum tripods are very unstable. Carrying a heavy tripod is no fun, but you need a stable rig. So is pain the only option? Fortunately there are some fairly new alternatives including carbon fiber and lightweight geared heads that can maintain the stability of your rig without loading you down too much. Traditional aluminum tripod legs transmit movement from the environment easily and are not well “damped”. That means they can vibrate for a long time after being bumped or moved. One of the benefits of carbon fiber tripods is that they have a high damping factor and do not transmit external vibrations as much as aluminum legs. And when they are bumped they settle down more quickly than aluminum. So carbon wins for both light weight and high damping ability. Unfortunately carbon fiber tripods are pretty pricey…although the prices are coming down quickly. The tripod head is also very important. You need a smooth movement and also one that will maintain the position of the scope after you have attached your camera. There is nothing more frustrating than seeing the Harpy Eagle getting ready to take off as you struggle to get him back in the center of your scope after attaching your camera! I’m going to review some new tripod and head options in a future column with some good news, I hope… Here’s a new model from Gitzo, the 2180, that is very lightweight and looks promising.
THE CAMERA Finding the right camera that will optimally match your scope is no small task. First of all you need a camera that takes good pictures. I recently tested a batch of small-lens point and shoot cameras and found that several models, including a couple from Sony, took very soft pictures that didn’t sharpen well later. Another model by Casio didn’t show the effects of manual exposure settings on the LCD, so I had to guess when adjusting the exposure. Check www.DPReview.com for very in depth and, from my experience, accurate reviews of any camera you might be considering. They post standard shots that you can use to compare model to model as well as lots of other tests. You also need a camera whose lens system matches the size of the exit pupil of your scope. If the camera’s lens is too large, then you will have vignetting, or a large black unused space around your image.
The problem with vignetting is that it reduces the number of pixels your camera is using for the part of the picture you care about. If a bird takes up the whole picture, then most of the pixels (6 or 7 million…) are used in defining the details of the bird and its features. If the bird is relegated to a small section in the center of the image then you may only be using a half or a third of the camera’s pixels for your image. In general, I have found that Canon’s S-50, 60, 70 models have offered the best clarity of picture along with a lens design that doesn’t vignette too much once zoomed to about 2x. They also have optional threaded adapters and infrared remotes.
Other factors to consider:
ATTACHING THE CAMERA Your camera must be securely attached to your scope. If you get a great picture hand holding your camera, then you owe it to yourself to quickly run out and buy a ticket to Las Vegas, because you are a lucky person…. Using threaded lens adapters is the best and most secure way to attach your camera to your scope. Some small cameras have optional lens adapter attach to your camera and allow for filters or zoom lenses to be attached using their threaded fittings. These adapters can be used to attach a scope mounting fixture.
Photo courtesy ET Thomas and Cin Chow
There are a few additional ways to attach a point and shoot camera using the camera’s tripod mounting screws on the bottom of the camera. I have tried a few of these adapters and many are clumsy, require almost constant adjustment, and make it very difficult to take the camera on and off when you want to use your scope for birding. One of the better ones is the Zeiss Quick Camera adapter, but it is pretty expensive.
The camera attaches using its tripod mounting screw and then the clamp goes over the scope’s eyepiece. A number of companies offer adapters for cameras including several scope manufacturers. Kowa has been a leader in this area as their scopes seem to have been the first to be used by early digiscopers. Zeiss and Celestron, amongst others, now have cameras built into their scopes. This potentially offers the fastest way to take pictures and the best “match” between the camera and the scope’s optics. I’ll have some more info on these in a later column.
This is a 4MP camera built right into the eyepiece. TAKING THE SHOT Now that you have a very stable tripod and a solid adapter attached to a great camera, you’re ready to take the picture. But WAIT…don’t touch that camera! When you press the camera’s button to take a picture, you are introducing movement to your whole rig. This will definitely reduce the sharpness of your picture. It’s important to find a way to take the picture without touching the camera! There are a couple of ways to accomplish this. Some cameras have an infrared or wired remote controls. They offer one way to keep your hands off the camera. If you use these remotes, it’s important to turn the remote delay time to 0 so that you know exactly when the picture will be taken. Most cameras also have a delayed shot function. This setting is usually used when the photographer wants to be in the picture. So he/she pushes the camera’s button, runs in to the shot and the camera takes the picture after a set time delay. For birding, you want that delay time to be adjustable to exactly when your rig “quiets down” after pressing the camera’s button. This is typically 2 seconds. If the camera only offers a 10 second delay time, find another way to take the picture. 10 seconds will be too frustrating unless you specialize in sloth shots… Another choice is to use a shutter release cable. This allows you to take the picture as quickly as you can with your finger, but without moving the camera. Unfortunately, most point and shoot cameras do not have cable release capability, so you have to build or buy a cable release bracket. Several models are available on the market.
HINT: Using a 2 second delay for your camera is a great way to improve even portraits or architecture shots when you are hand holding your camera. If you carefully watch what happens to your camera as you press the shutter button to take a shot, you will see that the camera moves down with the button press and then back up as you instinctively try to hold the camera “steady”. Delaying the shot until the camera has righted itself and has stabilized will definitely help your images. SETTING UP YOUR CAMERA There are several things you can do to help your odds in getting a great shot. Here are some suggestions RAISE YOUR ISO The ISO number on your digital camera correlates to the old fashioned film speed you may remember from the virtually prehistoric days of film cameras. The higher your ISO number, the “faster” your camera captures the image. Since a bird may move, and you are working at high magnifications in low light, the faster you can take the picture the better. However there is a trade off. Most point and shoot cameras get noisy as you raise their ISO. Typically point and shoot camera noise begins to get annoying at 400 ISO, but it can happen at 200 in some Canon cameras, especially. To check your camera’s noise, take a picture of a white sheet of paper at each ISO level. When you begin to see colored or black and white dots in the picture, your noise level is getting too high to use effectively. You can see some noise in the fur of this lemur shot since I cranked up the ISO due to the low night-time light.
SHOOT IN BURSTS Most cameras have a burst setting. This setting takes several pictures at once, giving you a second and third chance to get the bird in the right attitude, or not moving. Since digital “film” is basically free, taking many shots is a valid strategy for improving your odds of getting a good picture. It helps if the camera will do this automatically, so you don’t have to hold the shutter button down to get the extra shots. BRACKET YOUR SHOT Most cameras also have a mode that will shoot three pictures, one at your nominal settings, one a step higher and one a step lower. If you choose Exposure Bracketing, for example, you will get the settings you have chosen (or the automatic settings) and then one step more exposed and one step less exposed. When you get back to your computer and look at the shots you may often find that bracketing saved a shot that otherwise might have been over exposed.
You can also try Focus Bracketing. This changes the focus to a little in front and a little behind your nominal settings. Again, if the bird moves or the scope isn’t exactly in focus, this could save the day. TURN OFF YOUR CAMERA’S AUTOMATIC SHARPENING If the setting is available, you want to NOT have your camera process your image any more than necessary. This is especially true in the sharpening department. Leave that to the Photoshop Pros when you get back to your computer… SHOOT RAW Shooting in the Raw mode means you are bypassing most of the automatic settings your camera makes such as white balance, as well as some of the camera’s compression algorithms. Raw mode results in a larger file but you will then have more freedom fixing a picture after you get back to your computer. If you have enough memory, you will always have more flexibility to work with your shots later if they were taken “Raw”. FOCUS THE CAMERA ON THE BIRD…! First of all, as mentioned above, be sure that your scope’s focus is spot on. That is critical. Very often there is a branch in front of part of your frame. Or the bird is in a tree with branches all around it. So where is the camera going to focus? Of course using a manual focus mode can solve this problem. However most point and shoot cameras have very difficult to use manual focus modes, and the LCD is too washed out in the sun to really see when you have achieved the perfect focus. A manual focus mode with a blow up digital zoom can help you see if the camera is in focus, but I have not seen this mode recently on many cameras. So usually you must rely on the camera’s automatic settings. But how can you control the location of the point of focus (and exposure?). It’s no good to have a well-focused shot of a branch with a hazy bird in the background… First of all, most cameras allow you to select from a range of focusing modes. You want to choose the mode that focuses on one point rather than a mode that uses an “averaging” focus strategy. You do the same for your exposure mode.
It’s better to set your camera to a center point focus and exposure mode rather than Auto Select. Then you need to find how to move that focal point around in your camera as you are setting up your photo. The bird may not be in the center of your shot. In a Canon S-70 you press the SET button and then use the cursors to move the spot focus and spot expose locus to the center of the bird, no matter where it is in your viewfinder. This can be very important for getting a clear, well exposed and focused shot.
The focus and exposure spot has been moved from the center, typically what you have to do when there is a branch or a bird that is off center. FOCUS IN ADVANCE Most cameras will automatically focus and expose for the image when you press the shutter button half way down. Once the image is in focus, and while you are still holding the button half way, you can set the camera to manual focus mode. This stores the automatic settings and eliminates the camera’s focusing time the next time you press the button. This can speed up your shooting, especially when a bird is moving its head and you are waiting for the perfect moment to take the shot. PHOTOSHOP TO THE RESCUE So now you’re back at home. You’ve followed all of the steps above and have taken a well focused and exposed shot with a stable tripod, remote control and a comatose bird….. Great! Now comes the most critical step in creating a great looking photo: sharpening the image in Photoshop. No matter how diligently you have followed the steps above, your digiscoped photo will still not be super sharp. And that’s due to the factors mentioned above: lots of glass, lots of magnification, and low light. But Photoshop thrives on fixing “soft” images and can really make your photos sparkle, while still retaining their natural look. WHAT IS SHARPENING? The human eye is very sensitive to contrast. It is the loss of contrast between edges in an image that makes it look soft or not sharply focused. The key tool to use in Photoshop to correct this problem is called UNSHARP MASK and it’s found under the FILTERS menu. CLICK ON IMAGE BELOW FOR A LARGER IMAGE
Basically this algorithm examines areas of contrast and then enhances the effect by darkening one side and lightening the other side.
Once the Unsharp Mask is open you work with its three parameters. AMOUNT controls the intensity of the added contrast RADIUS controls how wide the new area of contrast will be THRESHOLD determines what the size an area of contrast needs to be to get treated by the effect. This is usually used to avoid sharpening noise. RULES OF SHARPENING
GIVE SHARPENING A TRY Open your photo in Photoshop. Duplicate your Background layer. Remember, you NEVER want to sharpen your original image!! Do this by selecting the Background layer and then choosing Duplicate Layer from the LAYER menu. CLICK ON ANY OF THE IMAGES BELOW FOR A LARGER IMAGE
Now make sure the Duplicate layer is the selected layer when you open the Unsharp Mask Choose FILTER>SHARPEN>UNSHARP MASK Begin by setting Check and uncheck the PREVIEW button to see what effect the sharpening is having on the photo. Continue to work with the Radius until you have a natural looking sharpening and then adjust the Amount to fine tune the sharpening. The Radius parameter that works will usually vary from .3 to over 1 depending on the size of the image.
You can easily fit your picture into the current window size by pressing CTRL (CMD) + 0 You should check the sharpening at full pixel size by pressing CTRL + ALT (OPT) + 0 You can also move the picture around during the sharpening process by holding the SPACE BAR and dragging with your mouse. As mentioned above, be sure that the picture has been sized to the dimensions you need BEFORE you start the sharpening process. In upcoming articles I’ll cover other ways to enhance the crispness of a photo including sharpening the Luminosity Channel, using Masking and Layer Opacity to control what is sharpened, and Sharpening Color Channels to avoid enhancing the noise of a photo.
SO ONCE AGAIN, HERE ARE THE 8 SHARP PHOTO COMMANDMENTS
CLICK ON ANY OF THE IMAGES BELOW FOR A LARGER IMAGE
USING PHOTOS FOR STUDY AND SKILL BUILDING Even if your digiscoping rig isn’t perfect, you can use your photos to help study ID characteristics of difficult or even common species. What better way is there to measure primary projection on Flycatchers or look at feather edgings in Dowitchers?? The LA area in early April is a great place to see (and, fortunately, hear…) both LB and SB (Caurinus) Dowitchers in plumages varying from basic to about halfway to full breeding plumage. Taking shots of these difficult birds as you study them and using your camera’s audio recorder or some other method to record species confirmation once they call as they fly off is a great way to expand your familiarity and knowledge of these tough species. Here are a couple of shots from a couple of study sessions in LA and Florida earlier this year….
Separating out a Stilt Sandpiper based on leg length, feather color
Comparing feather edgings and side spots/bars on LB and SB Dowitchers
SEND ME YOUR IDEAS AND SUGGESTIONS This is a column, not a forum, and unfortunately I’m not going to be able to directly answer most emails. However, if you have specific questions about something that was covered in a column, please do send me a note. If something that I covered needs further explanation, I’ll try and provide that in a future column. I will also welcome and consider any suggestions for topics that might be of interest to the general birding community, especially areas of technology that you might like to explore, but feel you may need more information or some “how-tos” to get started. I’ll do my best to cover as many of these topics as possible. Send your comments, suggestions and (kind) thoughts to © 2007 Tom Stephenson |
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