Zoom Lens
How do I work the magnification of a zoom lens for a DSLR camera?
I recently got a Canon EOS 400D digital SLR camera, and I am me more time to upgrade to the lens with a zoom. However, separate lenses are new to me, so I am struggling to find out to which lenses are more than any other figure. I was hoping someone can tell me how you can work either from the strength of the optical zoom on Canon lenses, or give me suggestions of lenses, to . consider Any help is greatly appreciated. Thank you, Martin.
You already have two good answers, but I have it in the box at all times, so here you go. My answer adds a little visual aid. There is no lens-to-distance equation. When we talk of a "35-mm-equivalent", a 50 mm focal length is approximately "normal" View without magnification. For most DSLR's, the lens factor of 1.5-1.6 means a "normal" focal length would be about 31-33 mm. If we return go on a 50 mm "normal" lens then would be a 100-mm lens, a "2 power" lens, 200 mm would be 4X, and so on. Just divide the smaller number In the greater number and you get the "X" power of the lens. For example, a 35-80 mm zoom lens is 2.3x. Divide 80 by 35 and you will be the result preserved. 35-80 mm zoom lens is 2.3x. Divide 80 by 35, and you will get the result. Normally it is better to know what the focal length of a lens in "35 mm equivalent" and judge that, rather than relying on the "X" power of the lens. Thus, most point and shoot cameras start at 35 mm and have either a 3x or 4x zoom. This makes it would be an 35-105 or 35-140. I have some that start times at 28 mm, though. A 3-fold from 28 mm 28-84 and a 4X 28-112. Neither is a particularly strong telephoto lens and the 4X is about the same as the 3X that was initially at 35 mm. It is also important to recognize that the tradition prescribes that lens focal lengths, usually in the form of "35 mm are equivalent to the expression, "where" 35 mm "refers to a 35-mm film camera. This is because of the relationship between the sensor and the actual size Focal length of the lens and the resulting angle of the lens. I have a Point & Shoot which is actually a 5.8-24 mm zoom. This is a 4X zoom. The 35 mm equivalent 28-116 mm. The sensor is 7.2×5.3 mm. (1/1.8 ") (And I wish I knew someone who could explain the how the hell they are with sensor size terminology!) I, another point & shoot that is actually a 5.7-17.1 mm zoom. This is a 3x zoom. The 35 mm equivalent 34-102 mm. "How could a shorter focal length give a longer 35 mm equivalent? "you might ask. It is because the sensor is only 5×4 mm. (1/2.5") I have a few Nikon DSLR, and – luckily – they all have the same size sensor. They all have a "lens factor" 1.5. This means that you frequently represents only the actual focal length of the lens to the 35 mm and then you can get accurate comparisons of the camera make-to-camera. Most of Canon, for example, have a lens factor of 1.6. On a Nikon DSLR, a 28-mm lens "35-mm equivalent" of a 42-mm lens. On most Canon DSLR's, the same 28-mm lens is the equivalent of a 45-mm lens. This example is only to show how freaking confusing it can all be when you try to mind the "X" power to make a zoom lens. Bottom line … Check the 35 mm equivalent specifications for the lens. In this way you will be leveling the field and compare apples to apples. More or less. I Here is a mini-tutorial I compare myself to focal lengths. This is NOT a lens test or test a camera! It is just to show the difference between various focal lengths. The lens was the Nikon 18-200 VR lens, which (by definition) an 11X lens, is that to say, but not 11X, which will look like the final image. I added a frame with a 300-mm lens taken. The camera was a Nikon D200, so there is a 1.5X "crop factor", "lens factor" or "focal length multiplier." There is further explanation on the image itself. It would help if you click "All sizes" above the picture. http://www.flickr.com/photos/7189769 @ N04/476181737 / This was done with two different lenses: the Nikon 17-55 and 70-300: http://www.flickr.com/photos/samfeinstein/1245831147/
|
|
Opteka HD² Professional Digital Accessory Kit for Canon Powershot G10 & G11 Digital Camera $89.95 The following items are included: (1)Opteka .45x High Definition Professional Wide Angle Lens (2)Opteka 2.2x High Definition Professional Telephoto Lens (3)Opteka High Definition² Pro Filter Kit (UV, Circular Polarizer, FL-D) (4)Lens/Filter Adapter (5)Opteka 5 Piece Camera & Lens Cleaning Kit (6)Opteka Tabletop Tripod (7)Opteka LCD Screen Protectors (8)54″ Deluxe Professional Video/Camera Tripod … |
|
|
Opteka Pro – Converter $31.99 Two of the best selling conversion lenses, offered in a combined value kit, will help you capture creative and stunning images. Included in the kit: 2x Telephoto – Capture better images of far-off subjects with the Digital Optics Telephoto lens for digital cameras and camcorders. The 2x magnification allows you to bring your subject closer while you stay where you are. The 2x Tele-C… |
|
|
Sigma 55-200mm f/4-5.6 DC Telephoto Zoom Lens + Hoya 55mm UV Haze Protector Glass Filter + Sigma Spudz XL Microfiber Cleaning Cloth – for Nikon Digital SLR Cameras including Nikon D50, D70, D70s, D80, D100, D200 & D300 $199.99 Kit includes: 1) Sigma 55-200mm DC Telephoto Zoom Lens; 2) Sigma Spudz Microfiber Cleaning Cloth; 3) Hoya 55mm UV Protector Filter. ♦ Sigma 55-200mm Lens includes: Front & Rear Lens Caps; Lens Hood; Soft Case; Instructions; Sigma USA Warranty. ♦ The Sigma 55-200mm is a lightweight, compact 3.6X telephoto zoom lens exclusively designed for digital SLR cameras featuring the standard APS-… |
|
|
Life Thru A Lens $28.98 … |
|
|
Zoom Kidz Shades Girls Oval Plastic Sunglasses, Purple and Pink Camouflage Frame/Smoke Lens $7.99 Zoom’s Kidz Shades are colorful and fun while at the same time provide kids’ eyes with 100% UVA/UVB protection. Important since children’s developing eyes let in more UV rays than adults. These Kidz Shades also have impact resistant lenses and are styled after the coolest kid trends of today including wraps and aviators…. |
|
|
Zoom Boulevard Cat Eye-Style Plastic Frame Sunglasses, Retro Tortoise Frame/Brown Lens $16.99 Zoom sunglasses feature the highest quality impact and scratch resistant aspheric lenses as well as durable and fashionable frame materials. These Boulevard sunglasses are a fashionable collection of sophisticated styles of the season with designer flare, inspired by the latest trends in department and specialty stores…. |
|
|
Zoom Boulevard Cat Eye-Style Plastic Frame Sunglasses, Retro Black Frame/Smoke Lens $16.99 Zoom sunglasses feature the highest quality impact and scratch resistant aspheric lenses as well as durable and fashionable frame materials. These Boulevard sunglasses are a fashionable collection of sophisticated styles of the season with designer flare, inspired by the latest trends in department and specialty stores…. |
|
|
Pentax K-x – Digital camera – SLR – 12.4 Mpix – PENTAX-DA L 18-55mm AL lens – optical zoom: 3 x – supported memory: SD, SDHC – white $649.95 The K-x camera design is a compact, lightweight body and simple, user-friendly operations. With the addition of a newly designed CMOS image sensor and an upgraded high-performance imaging engine, the K-x offers outstanding photographic performance at nearly the same level as upper-class models. This includes high-resolution, fine-detailed images delivered by approximately 12.4 effective megapixels… |
|
|
Canon REALiS SX7 Mark II Multimedia LCOS Projector, 4000 ANSI Lumens, Powered 1.7x Zoom Lens, SXGA+ (1400×1050) Resolution, LCOS and AISYS Technology $4,899.99 The REALiS SX7 Mark II is a high performance SXGA+ (1400 x 1050) resolution projector using LCOS technology, providing outstanding image quality and resolution. Featuring 4000 lumens of brightness, the SX7 Mark II also uses Canon’s proprietary AISYS optical system to handling light even more efficiently resulting in exceptional brightness and color reproduction. Using a special color filter for su… |
|
|
Coolpix S-70 12.1 Megapixel 5x Vr (Vibration Reduction) Wide-Angle Optical Zoom Lens 3.5 Inch Oled Touch-Panel Lcd Screen Digital Camera – Red & Red $323.54 Nikon’s sleek, sensuous COOLPIX S70 combines 12.1 effective megapixels and 5x wide-angle zoom with a beautiful, bright 3.5-inch High Resolution Organic LED TOUCH PANEL display that makes taking and sharing pictures easy. The COOLPIX S70 combines Nikon’s 5-way Optical VR Image Stabilization system and a touch shutter that gets you sharp pictures throughout the zoom range. The COOLPIX S70 features N… |
