Susan Wilder Talks Cameras

Projector Lens Shift and the Projector Sweet Spot — A Quick Summary for digital projectors

Lens shift, or image offset, can be defined as the ability to shift a projected image vertically or horizontally in order to accommodate specific installation challenges. In most installations, lens shift can be used to optimize image geometry and scaling performance by optically landing the image on the screen without having to tilt the projector and employ keystone correction. It can also be used to position the projector such that the average viewer is placed in the illumination sweet spot – an especially important consideration in rear screen and high gain front screen applications.

Within Digital Projection’s current product lineup, the only projectors that do not offer lens shift are the iVision 30 series products. These projectors are designed to mount in a specific position with respect to the top or bottom of the screen.

With the benefit of lens shift, our other displays can be located within a much wider area of the screen. This area is usually defined as a percentage of the image (or screen) height or width. With lens shift centered, dVision, Mercury, TITAN, HIGHlite, LIGHTNING and Reference displays are designed to be installed on-axis with respect to the screen. The lens employed in the application defines the amount of total lens shift available, from that on-axis position.

Zoom lenses generally offer the most lens shift – up to 50% of the image height (vertical) and up to 25% of the image width (horizontal). Short throw fixed lenses generally offer more limited lens shift – approx 10% of the image height and little or no horizontal shift. Fixed short throw lenses are most often utilized for on–axis rear screen applications.

As an example, when using a typical Zoom Lens with a TITAN HD projector on a screen that is 60” high, the installer would have as much as 50% vertical lens shift (offset), or 30 inches of up and down image movement from the screen center. This allows the projector to be installed anywhere from the top of the screen to the bottom of the screen. Given a 16 x 9 aspect ratio, the same 60” high screen is nearly 107” wide. The same zoom lens would offer 10% of that screen width in horizontal lens shift (horizontal offset), or nearly 11 inches of image shift left and right.

It is important to remember, if both horizontal and vertical lens shift are employed, the total available lens shift in either dimension will normally be less than the maximum specified for the lens.

Although lens shift provides great flexibility in projector placement, be aware that in any installation, the goal should be to install the projector to assure maximum transfer of illumination from the projector to the average viewer position. This makes the most of screen gain and optimizes luminance uniformity, peak brightness, contrast and also minimizes hot spotting. Projector placement is especially critical in rear-screen applications, as well as in front screen applications where high gain screens are utilized.

About the Author

A digital imaging pioneer and projector industry leader, Digital Projection International (DPI) manufactures and distributes an extensive and expanding line of ultra high-performance 3-chip and single-chip DLP® projection systems. These projectors are the reference standard for demanding applications such as large-venue, live-event staging, Fortune 5000, homeland security, education, medical and scientific research, command and control, digital cinema, commercial entertainment, worship and elite home theater.

Multiple company accolades include two Emmy® Awards for Outstanding Achievement in Engineering Development by the Academy of Television Arts and Sciences. DPI remains the first and only projector manufacturer to win the coveted award.

D00564-Rear Lens Cap for Canon

Ventra Pack 2-in-1 Chest Pack / Slim Shoulder Sling Messenger Bag $64.95 VentraPack positions frequently used accessories within sight so you don’t waste time un-strapping and removing your backpack to find your camera, sun-block, etc. while on the move. A zipper releases a drop-down work surface with a map window and comprehensive organizer to store items internally; optional modular exterior pouches are available to hold larger contents. How it works: VentraPack’s 4 …

Nightmare Before Christmas Contact Lens Case Set $43.70 ·Contact lens case set made of plastic ·A mirror, solution bottle, lens remover, tweezers, lens cases and a compact included ·Different lens cases for your to tell right from left ·Ideal travel companion…

Belkin Snap Shield – Back Cover for Apple iPad 2 (CLEAR) $22.18 This Belkin F8N631ebC01 Snap Shield Back Case delivers the best features for the ultimate protection. Boasting a translucent cover in a soft-touch finish, it also snaps right on the back of your iPad, promising streamlined protection….

Incase CL57969 Mag Snap Case for iPad 2 with Smart Cover – Black $18.50 The Mag Snap Case works with your Apple Smart Cover to give your iPad complete protection, conventiently holds the Smart Cover open, and gives you an additional viewing angle. The durable hardshell construction protects the iPad back while your Smart Cover keeps the iPad front protected. Flip the Smart Cover open and it magnetically clings to the Mag Snap’s built-in metal bars, holding it out of t…

Belkin Snap Shield – Back Cover for Apple iPad 2 (SMOKE) $17.99 This Belkin F8N631ebC00 Snap Shield Back Case delivers the best features for the ultimate protection. Boasting a translucent cover in a soft-touch finish, it also snaps right on the back of your iPad, promising streamlined protection….

BasAcc Camera Body Cap and Rear Lens Cover Cap for Nikon $4.49 This is a BasAcc camera body cap and rear lens cover cap for Nikon. Protect your Nikon camera and lens when not in use by attaching a cover cap.

BasAcc Camera Body Cap and Rear Lens Cover Cap for Canon EOS $3.49 This is a BasAcc camera body cap and a rear lens cover cap for Canon EOS. Protect your Canon camera and lens when not in use.

Aimpoint Rear Flip Cap $22.13 Protect the eye piece on your scope with this Aimpoint rear lens cover flip-up cap. This cap fits the rear lens on most Aimpoint scopes.

Body Cap and Lens Rear Cover Cap for Canon EOS $3.48 This is a body cap and rear lens cover cap for Canon EOS. Protect your Canon lens when not in use with this accessory cap.

Body Cap and Lens Rear Cover Cap for Nikon $3.49 This is a body cap and rear lens cover cap for Canon EOS. Protect your Nikon lens when not in use with this accessory cap.

Acer Computer X1230PS Short-Throw Projector $469.99 Images and ideas often make a greater impact when they are projected to the workgroup. The Acer X1230PS gives you the benefits of short-throw projection, enhancing flexibility and providing greater viewing comfort without sacrificing image precision. Packed with advanced features in a sleek, attractive chassis, this projector delivers excellent performance for a range of viewing scenarios and environments.-Features:-Display Technology DLP-Native Resolution Native XGA (1,024 x 768) -Compressed Resolution Maximum UXGA (1,600 x 1,200), 1080p (1,920 x 1,080) -Typical colors 1.07 Billion Colors -Brightness (ANSI lumens) 2,500 ANSI Lumens (Standard), 2,000 ANSI Lumens (ECO) -Dimension (WxDxH) 264 x 225 x 95 mm (10.4″ x 8.6″ x 3.7″) -Weight 5.07 lbs (2.3 Kg) -Contrast Ratio 3000:1 -Noise Level 31 dBA (Standard mode), 26 dBA (ECO mode) -Computer Compatibility IBM PC and Compatibles, Apple Macintosh, iMac, and VESA Standards 1080p (1,920×1, 080), WSXGA+ (1,680 x 1,050), WXGA+ (1,440 x 900), WXGA (1,280 x 800, 1,280 x 768), UXGA (1,600 x 1,200), SXGA+ (1,400 x 1,050), SXGA (1,280 x 1,024), XGA (1,024 x 768), SVGA (800 x 600), VGA (640 x 480) -Video Compatibility NTSC (3.58/4.43), PAL (B/D/G/H/I/M/N), SECAM (B/D/G/K/K1/L), HDTV (720p, 1080i, 1080p), EDTV (480p, 576p), SDTV (480i, 576i) – Aspect Ratio 4:3 Native, 16:9 compatible -Projection Mode Front, Rear, Front-Ceiling, Rear-Ceiling (adapters may be required options) -Projection Lens F = 2.56 ~ 2.8, f = 21.00mm ~ 23.00mm 1:1.1 Manual Zoom and Manual Focus -Digital Zoom 2X -Works with a Projection Screen from 29″ (73cm) up to 300″ (762cm) -Throw Ratio 109″@2m (0.90 ~ 1.08:1) -Projection Distance 3.9? (1.2m) ~ 37.2′ (11.3m) -Horizontal Scan 30k ~ 100k Hz – Vertical Scan 50 ~ 120 Hz – Lamp Type 189 W user replaceable UHP lamps – Lamp Life up to 4000 Hours (ECO) – 3000 Hours (Standard) – Keystone Correction +/-40 Degrees (Vertical), Manual -Audio One Internal Speaker with 2 watts Output -Power Supply AC input 100~240V auto-s

Acer Computer X1261P Value Multimedia Projector $399.99 All you need is an idea, a group of people willing to listen, and an Acer X1261 porojector to explain it with.-Projection Method Ceiling / Front / Rear-3D Ready Yes -Platform Support Mac / PC-Lens – Minimum Lens Aperture F/2.41 / Maximum Lens Aperture F/2.55 / Zoom Type Digital Zoom and Manual Zoom- Manual Zoom Factor 1.1x -Digital Zoom Factor 2x -Lamp Type OSRAM 180 W Normal Mode Lamp Life 5000 Hour; Economy Mode Lamp Life 6000 Hour -Image – Standard Mode Brightness 2700 lm -Low Mode Brightness 2160 lumens -Color Support 1.07 Billion Colors (30-bit) -Native Resolution 1024 x 768 -Graphic Mode XGA -Maximum Resolution 1920 x 1080 -Minimum Projection Distance 39.37″ -Maximum Projection Distance 39 ft -Diagonal Image Size 300″ -Native Aspect Ratio 4:3 -Compatible Aspect Ratio 16:9 -Contrast Ratio 3700:1 -Vertical Keystone Correction -40?/+40? -Maximum Vertical Sync 120 Hz -Maximum Horizontal Sync 100 kHz -Video Signal Format PAL – SECAM – NTSC-Video Signal Standard HDTV -Scan Format 1080p -Number of Speakers 1 -Speaker Output Power 2 W -Speaker Output Mode Mono -Input Voltage 220 V AC / 110 V AC-Weight 4.85 lb -All of Acer projectors support a two year carry-in warranty, five years warranty for the DMD chip and one year warranty for the lamp

Ammonite Nikon Coolpix 7100 Guide $19.95 Nikon’s high-end compact Digital camera, the Nikon Coolpix P7100, a contender against Canon’s popular PowerShot G12, will appeal to those who want full control from their compact, perhaps as a DSLR backup or second camera. The P7100 is packed with features and controls, and some fun filter effects. Reassuringly weighty in the hand, at 395g it’s of barely pocketable dimensions, but a far cry from the cheaper compacts that have fewer features. -The layout of its controls looks much more like DSLR than a compact: there are dials for accessing shooting modes, Exposure compensation and major functions, so changing the ISO, bracketing or White balance can be accomplished quickly and easily. There are also front and rear thumb dials for making adjustments, so when shooting in manual shutter speed and Aperture can be altered to achieve the desired exposure. -Nineteen selectable Scene modes will cope with most situations, and there is in-camera image editing, and full exposure control modes. Although there is no Full HD Video capture available, the 1280 x 720/24p specification matches that of the Canon rival.-Megapixel CCD Sensor / 7.1x zomm Lens (28-200mm in 35mm terms) withmaximum aperture of f/2.8, offering scope for more dramatic portraiture with increased depth of field / 921k-dot articulated LCD screen / Auto and manual controls / Front screw thread for adding accessories -About the Author: Jon Sparks is an award-winning photographer and writer specializing in landscape and outdoor photography. He has travelled and photographed in Pakistan, New Zealand, Australia, Canada and Morocco as well as most European countries and supplies images to the global libraries Corbis and Alamy as well as selling images directly through his own library.

Canon 100mm f/2.0 EF Telephoto Lens USM $464.99 Similar to a standard portrait Lens like the 85mm f/1.8, Canon’s 100mm f/2 is also an exceptionally bright and short telephoto lens appropriate for both general photography and portraits. Some portrait photographers feel that 85mm doesn’t give you quite enough of what you need in a portrait lens and they prefer the 100mm focal length as it provides just a Bit more compression. Again, as with the 85mm, the wide f/2 Aperture setting allows for a Paper thin depth of field. That’s a really good thing when shooting portraits. -Aperture Range: f/2.0 – f/22 8 elements in 6 groups -Diagonal Angle of View: 24 degrees-Focus Adjustment: Rear focusing system with USM-Filter Size: 58mm-Minimum Focusing Distance: 9.75 inch-Lens Hood: EW-60-Dimensions: 2.6 x 1.9 inch / Weight: 10.5 oz

Canon 15mm f/2.8 Fisheye Lens $719.99 This ultra-wide fisheye Lens presents a 180 degree angle of viewing, permitting a variety of intriguing effects. The wide depth of field expands the possibilities even more. A minimum focusing distance of only 20 cm gives new meaning to close-up shots. Fixed petal-type hood and gelatin filter holder at the rear Lens construction: 8 elements in 7 groups Minimum aperture: 22 Number of diaphragm blades: 5 Maximum diameter x length (mm): 73 x 62.2 Weight: 330 grams Built-in lens hood