October 2009, 23:530Piezoelectric actuator for mobile auto focus camera applicationsAuthorsArticleFirst Online: 27 June 2008Received: 31 May 2007Accepted: 22 May 2008DOI: 10.1007/s10832-008-9529-8Cite this article as: Ko, H., Jeong, H. & Koc, B. J Electroceram (2009) 23: 530. AbstractRecently, various multimedia devices such as MP3 player, camera and even TV are integrated into a mobile phone. Consumer demands image cameras in mobile phone to have similar quality and performance as those of dedicated digital cameras. For a good image quality, increasing of resolution requires optical auto focusing, where a small lens group needs to be moved in a limited volume. Due to the efforts for reducing the size of each component in mobile phone, many types of motors have been investigated to achieve AF or zooming functions. However, a motor should be able to provide high controllability and performance to perform auto-focus (AF) camera function. One of the important features that piezoelectric motors have is the ability to maintain moving element position when the motor is not electrically excited.

For mobile device application where power consumption is critical, this feature is fitting very well for lens positioning application in phone cameras. In this paper, we have applied our own development of piezoelectric motor for auto focus phone cameras. During auto focusing, we have measured total motor operating time that is less than one percent of total auto focusing time. Average instantaneous power, which is about 65 mWatts, is consumed only when the motor operates, which make piezoelectric motors to be superior over electromagnetic counterparts in terms of energy efficiency.DJI FOCUSAdvanced, Precise Follow Focus SystemThe DJI Focus uses DJI’s expertise in brushless motors for previously unheard of levels of precision and accuracy. The brushless motor puts just ±0.02° of accuracy in your hands so that turning the remote is just like turning the lens itself. It also features high torque and a fast reaction speed so you can keep your subject in focus no matter how it moves.100mRANGEFast Wireless TransmissionOn the ground, the remote control transmits at distances of up to 100m with just 14ms of lag in open space.

Attached to an Inspire carrying either the Zenmuse X5 or Zenmuse X5R, it connects directly to the aircraft remote, giving you seamless camera control across your entire flight range.Ebay Iphone Leather CasesAdjustable EndpointsWhile cinema lenses feature built-in hard stops, photography lenses do not. Ikea Curtains DesignOn the Focus you can tune the lens to match the end-points of any lens you want to use. Black And White Checkered Flannel FabricBecause it uses a brushless motor, the onboard processor knows exactly which position the motor is in, letting you set up in seconds simply by turning the lens to infinite and marking it, then repeating at the other end.Customizable Focus WheelThe already tactile and sturdy focus wheel is customizable so that it feels how you want it to feel.

Simply turn a control knob until it reaches a stiffness or looseness that feels right to your hand.Removable Marking RingA white marking ring around the focus dial can be swapped out and customized instantly using everything from masking tape to wax pencil for different lenses or projects. A light behind the ring illuminates it from behind ensuring markings are visible even on a dark set.Programmable and CustomizableAn OLED display menu on the remote lets you fine-tune how the Focus works for you. You can even set multiple focus points, and the speed the camera racks between them making complex moves simple and repeatable.X5 Series CompatibleFull compatibility with the DJI Zenmuse X5 camera series is built in, giving you absolute control of your camera focus when in the air.  connected to the Inspire remote*, control of the X5 series is transmitted through Lightbridge providing control up to 5km away.*The dedicated CAN Bus cable for the Inspire 1 remote controller is not included with the DJI Focus and should be purchased separately.

need to connect the Focus Remote Controller and the X5 Adapter using the DJI Focus - Osmo Pro/RAW Adaptor Cable.Learn More about the X5 SeriesRonin and Ronin-M SupportWhen used with a DJI Ronin or Ronin-M you can pull focus from all around the set wirelessly, adding new depth to your Ronin footage.Dual Communication PortsTwo ports have been built in, so that as technology develops and improves you can expand your Focus with even more features and capabilities.Rosette MountConnect other accessories to the Focus or even connect it to other pieces of your equipment. A built-in rosette mount means it can be fitted wherever you need it securely.Rechargeable BatteryThe included long-lasting single cell battery can power the Focus throughout a shoot, and can be swapped in seconds if it runs out. You can charge it in the studio or even on the move from a power pack through its USB recharging port.Everything You NeedIncluded in the padded, waterproof case are the handheld remote follow focus remote controller, focus motor, neck strap, additional focus

marking rings, 60mm, 70mm, 80mm, 90mm lens gear rings, and accompanying cables.Community TestedHow to Photograph Motor Racing Four Parts:Get the Right GearFind a Good LocationSet Up Your CameraTake PhotosCommunity Q&A One of the most rewarding sports to photograph is motor racing. The cars are colourful, and the action is fast without being impossible to capture. And you don't need a ton of expensive gear to get amazing photographs. Buy the appropriate equipment. You can get great shots without buying stuff; after all, any great motorsports photo taken before about 1988 would have been done with a manual-focus film camera! But you will make a lot less work for yourself if you get the right kit. Camera: No compact or bridge camera can match the high-ISO performance and brutally fast auto focus of a real SLR. So get any Canon or Nikon digital SLR camera, even an obsolete used one if that's all your budget will stretch to (remember, professional photographers shot with the obsolete cameras too, back when they were new).

Don't bother with other brands; just about all professional sports photographers use Nikon or Canon for very good reasons. The more expensive SLR's are nice; they'll generally give you faster frame rates and better high-ISO performance. But they are not essential. Lenses: If your budget will stretch to it, then of course you should get a top-line professional 70-200 f/2.8 zoom. But remember that fast auto focus is much more important than anything else; indeed, some older professional f/2.8 telephotos have slower autofocus than newer, cheaper lenses. If your budget won't stretch to a fast-focusing telephoto, and you know you can get close enough to the action to use one, get yourself a fixed 50mm f/1.8 lens. These are the cheapest lenses in the Nikon and Canon systems. They're also among the sharpest lenses you can buy, they autofocus as quickly as any professional $1000+ f/2.8 zoom, and they'll let you shoot in less than half as much light. Even photographers who own the big professional telephotos will often carry a fast 50mm as well for these reasons.

And of course, if you can't do that, shoot with your kit lens. Learn its limitations and work around them. Storage: Get as much as you can afford. Getting at least 16GB of storage is a good idea for high-resolution cameras; your "keep rate" will be low at the start. If an opportunity presents itself, chat with the marshals during the downtime (only the downtime. Ask longtime veteran photographers what they do to get good shots at a particular venue.Be sensible and set up in a safe location. If a car comes at you, all of those great shots you got will be published posthumously. Know where you will go in the event of an emergency. A car out of control comes fast. You won't be running out of the way, so you had better be within a step of a pole or barrier that can shield you. A struggling driver will not have time to assess what he is seeing, so don't hunker down and make it hard for him to decide whether he needs to avoid hitting you. Make that choice easy.Your view of the action may be limited to what you see through the eyepiece, but keep alert to the track as a whole.

Even with earplugs, you can usually hear variations in the drone of engines and tell when someone is having trouble. Find out where it is coming from without delay. If it is coming at you, this may save your life. If it is not, it may present a great shooting opportunity. Always obey track rules and track marshals. They are there for your safety. Ask them if it is OK to go out to this point or that point. Do what they say. Never do what they say not to. Set up your camera. If you don't know some basics about camera exposure, white balance and ISO, learn them now; see How to Adjust Your Digital Camera's White Balance, How to Understand Camera Exposure and How to Use Your Digital Camera's ISO Setting. Pick an exposure mode. Professional photographers will use any of the PSAM modes (program, shutter-priority, aperture-priority, manual), or even all of them on the same day. Use whatever fits your shooting style. Don't use your camera's "sports" mode, though; this is an "idiot mode" that locks out some critical controls, such as ISO.

Set up your autofocus. Set your frame rate.worse Set your camera to shoot JPEG photos.Focus on the "face" of the car. Just like one always focuses on the eyes of a portrait subject, focus on the closest headlight or the front grille of the car. Otherwise, focus on the closest thing to you, like a door (if you're shooting from the side) or a tail-light (if you're shooting from the rear). Practice following cars while zooming in and out to keep them in frame. If you have time, do this for a few minutes without taking any photographs just to get used to following fast-moving subjects.A monopod or tripod severely restricts your ability to react to events on the track, which makes you less safe and results in worse photographs. You may have to use a faster shutter speed than you'd like (although the VR of most modern telephotos helps you out there), but you'll get the shots the "monopod mob" will miss. Start off with a shutter speed of 1/250. This will minimize camera shake while showing some wheel spin.

If you have rock-steady hands you may be able to shoot slower. Don't be afraid to crank up your ISO as high as you need to get the shutter speed you need; today's digital SLRs look great at ISO 1600 and up, and a noisy sharp photograph is always better than a clean blurry one. Shoot from as low a position as you can. Cars look much more dramatic if they're at eye level.If you see one particular car drifting dangerously at a sharp corner, be prepared for the spin-out.At first, 90 per cent of your shots will be blurry, badly composed or have some other flaw. Much of the time you'll be pointing the camera at something and praying. Don't be disheartened if your first time out results in only one or two keepers; stick at it and your keep rate will rise dramatically. After you've mastered the basics of getting well-composed, non-blurry shots, start getting creative. Try some panning shots at slow shutter speeds. Shoot as slow as you can using hand-held without getting shots blurred from camera shake.

If you've gotten good at tracking motion through your viewfinder then this will result in much more exciting shots; the background will be blurred and, if you have planned it right, the subject should remain sharp. Zoom in "too far" to get some get semi-abstract shots. See the photo above. Shoot into the sun in the late afternoon to get great silhouettes and lens flare. Shoot at last light when the light is at its most beautiful..The moment you look away, there will be a spectacular crunch. Don't relax until the racers have gone out of sight. If you get hooked on this stuff and feel the need to upgrade your equipment, spend your money on lenses -- better quality optics and faster auto focus. A camera with a higher frames-per-second rate will help, but not if the frames are of poor quality. Upgrading to a camera with cleaner high-ISO performance will let you keep shooting when the clouds roll in. To get a "group shot" (lots of cars), be in position to shoot the pace lap and the first couple of laps.

Cars tend to spread out as the race goes on and it may be the last chance you'll get. A clear view of the cars is essential. If there's absolutely no unobstructed spectator viewpoint (no wire fences or barricades) you have two choices: try to wangle a media pass from the track honchos, or go to another track. If your images start to look strangely soft during the summer, don't panic. Increased humidity in the atmosphere combines with long focal lengths to create a gauzy effect. Console yourself with the knowledge that everyone else's pictures will look gauzy, too. Many stock car races are in the evening when it is difficult to get clear dramatic shots. However, most of the bigger races will have daytime practice sessions and qualifying. During the day, lower ISO settings and slower shutter speeds are available and can lead to bright, dramatic panning shots with vivid colors. The track marshals are less restrictive during these periods, but you still need to be very, very safe in where you position yourself.