http://www.neonlightssigns.info/lens-focal/
 |
 |
NEW SAMSUNG CCTV SECURITY VARI FOCAL LENS DOME CCD COLOR CAMERA SCC-B5342P |  |
 |
US $109.43 | 11d 19h 58m |
 |
Bi-Focal Safety Glasses 1.5 clear or smoke or 2.5 clear lens | |
|
US $12.99 | 2h 35m |
 |
New ZnSe Focal Lens for CO2 Laser Cutting Engraving Diam 20mm FL 50.8mm | |
|
US $36.00 | 13d 1h 56m |
 |
20mm ZnSe Focus Lens CO2 Laser Engraving 100mm focal | |
|
US $80.00 | 18d 19h 3m |
 |
Laser Focus Lens with 7.5" Focal Length | |
|
US $79.99 | 2d 11h 18m |
 |
CO2 Laser Dia 20mm Focus 55mm Focal ZnSe Lens Mirror | |
|
US $55.00 | 20d 2h 20m |
 |
20mm ZnSe Focus Lens CO2 Laser Engraving 50.8mm focal | |
|
US $65.00 | 18d 18h 53m |
 |
Safety Glasses Radians C2 BI-FOCAL SMOKE 1.5 Lens | |
|
US $7.76 | 29d 7h 42m |
 |
Dia. 19.05mm FL 38.1mm ZnSe Focal Lens for CO2 Laser Cutting Engraving 10.6um | |
|
US $39.00 | 14d 19h 28m |
 |
20mm CVD ZnSe Focal Lens 10600nm 10.6um CO2 Laser Engraver Focus F=100mm 4inchs | |
|
US $69.27 | 28d 17h |
| Powered by phpBay Pro |
|
No items matching your keywords were found.
Lens Focal
How does the thickness of a lens affect the focal length of a lens and the size of an image? (Light Physics)?
How does the thickness of a lens affect:a) The focal length of a lens b) the size of an image?
10 points for first correct answer, anyone who supplies helpufull link automatically gets 10 points.
Assuming that the curvatures are the same...
Increasing thickness INCREASES the POWER of the lens... and hence, the focal length of the lens is DECREASED....
Now if you decrease the Focal Lenght, the Magnification (and image size) is INCREASED for Convex lenses... and DECREASED for Concave lenses.
|
|
NEW SAMSUNG CCTV SECURITY VARI FOCAL LENS DOME CCD COLOR CAMERA SCC-B5342P | |
|
US $109.43 | 11d 19h 58m |
|
Bi-Focal Safety Glasses 1.5 clear or smoke or 2.5 clear lens | |
|
US $12.99 | 2h 35m |
|
New ZnSe Focal Lens for CO2 Laser Cutting Engraving Diam 20mm FL 50.8mm | |
|
US $36.00 | 13d 1h 56m |
|
20mm ZnSe Focus Lens CO2 Laser Engraving 100mm focal | |
|
US $80.00 | 18d 19h 3m |
|
Laser Focus Lens with 7.5" Focal Length | |
|
US $79.99 | 2d 11h 18m |
|
CO2 Laser Dia 20mm Focus 55mm Focal ZnSe Lens Mirror | |
|
US $55.00 | 20d 2h 20m |
|
20mm ZnSe Focus Lens CO2 Laser Engraving 50.8mm focal | |
|
US $65.00 | 18d 18h 53m |
|
Safety Glasses Radians C2 BI-FOCAL SMOKE 1.5 Lens | |
|
US $7.76 | 29d 7h 42m |
|
Dia. 19.05mm FL 38.1mm ZnSe Focal Lens for CO2 Laser Cutting Engraving 10.6um | |
|
US $39.00 | 14d 19h 28m |
|
20mm CVD ZnSe Focal Lens 10600nm 10.6um CO2 Laser Engraver Focus F=100mm 4inchs | |
|
US $69.27 | 28d 17h |
 |
Safety Glasses Radians C2 BI-FOCAL SMOKE 2.5 Lens | |
|
US $7.76 | 26d 3h 27m |
 |
Safety Glasses Radians Rad-Sequel RSx Bi-Focal CLEAR 1.5 Lens | |
|
US $4.87 | 9d 10h 12m |
 |
18mm GaAs Focal Lens f CO2 10600nm 1.06um Laser Engraving Cutting FL=2"/50.8mm | |
|
US $55.89 | 28d 17h |
 |
2X 16mm Focus Focal Glass Lens for Green Laser 532nm-635nm-650nm-660nm Red Lazer | |
|
US $18.98 | 28d 15h 46m |
 |
20mm ZnSe Focus Focal Lens 10600nm 1.06um CO2 Laser Engraver Cutter Marker | |
|
US $34.90 | 11d 12h 8m |
 |
18mm CVD ZnSe Focal Lens 10600nm 10.6um CO2 Laser Focus 100mm Engraver | |
|
US $69.27 | 28d 17h |
 |
20mm CVD ZnSe Focal Lens for 10600nm 10.6um CO2 Laser Engraver Focus F=38.1mm | |
|
US $64.27 | 28d 17h 32m |
 |
Φ25mm ZnSe Focal Lens for 10.6um 10600nm CO2 Laser Engraving Focus 50.8mm 2" | |
|
US $58.86 | 28d 17h 32m |
 |
Φ19.05mm ZnSe Focal Lens for 10.6um 10600nm CO2 Laser Engraver Focus 100mm 4" | |
|
US $44.86 | 28d 17h |
 |
Φ20mm ZnSe Focal Lens for 10.6um 10600nm CO2 Laser Engraving Focus 100mm 4“ | |
|
US $44.86 | 28d 17h |
| Powered by phpBay Pro |
|
No items matching your keywords were found.
|
No items matching your keywords were found.
|
No items matching your keywords were found.
|
No items matching your keywords were found.
|
|
SofLens Multi-Focal Contact Lens $33.99 Bausch & Lomb SofLens Multifocal lenses have an enhanced optical design that creates crisp, clear vision multi-focal |
|
|
PureVision Multi-Focal Contact Lens $44.99 PureVision Multifocal contact lenses by Bausch & Lomb are the world's #1 multifocal design for people with presbyopia multi-focal |
|
|
Focal Length $93.99 High Quality Content by WIKIPEDIA articles The focal length of an optical system is a measure of how strongly it converges (focuses) or diverges (defocuses) light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus. A system with a shorter focal length has greater optical power than one with a long focal length; that is, it bends the rays more strongly, bringing them to a focus in a shorter distance. In telescopy and most photography, longer focal length or lower optical power is associated with larger magnification of distant objects, and a narrower angle of view. Conversely, shorter focal length or higher optical power is associated with a wider angle of view. In microscopy, on the other hand, a short objective lens focal length leads to higher magnification. Author: Miller, Frederic P./ Vandome, Agnes F./ McBrewster, John Binding Type: Paperback Number of Pages: 140 Publication Date: 2010/07/30 Language: English Dimensions: 5.98 x 9.01 x 0.32 inches |
|
|
Panasonic Camera Kit w/ vari-focal Lens POC244L5DW $348.62 Panasonic Camera Kit w/ vari-focal Lens POC244L5DW |
|
|
8.5mm*2.3mm Acrylic Lens - 10.5mm~10.7mm Focal Length (100-Pack) $2.8 8.5mm*2.3mm Acrylic Lens - 10.5mm~10.7mm Focal Length (100-Pack) |
|
|
15mm*3.8mm Acrylic Lens - 25mm~30mm Focal Length (50-Pack) $4 15mm*3.8mm Acrylic Lens - 25mm~30mm Focal Length (50-Pack) |
|
|
15mm*2.6mm Acrylic Lens - 30.5mm Focal Length (50-Pack) $4 15mm*2.6mm Acrylic Lens - 30.5mm Focal Length (50-Pack) |
|
|
MagEyes Magnifier-Bi-Focal Lens - White(Pack of 1) $82.3 MagEyes Magnifier-Bi-Focal Lens - White. MAGEYES-Magnifier With Bi-Focal Lens is a great new addition to MagEyes Magnifier with the addition of a bi-focal lens. The bi-focal lens can be attached to the right or left side and also has holes that have been |
|
|
Camera Kit w/ vari-focal lens $593.53 - Panasonic security camera kit with vari-focal lens- Color outdoor fixed camera pack- 5-50mm lens, dome housing, wall mount camera- 1/3 Inch CCD color DSP, 480 TVL, 2 lux at F1.4, 24VAC- WV-CP244 series DSP (digital signal processing) camera feature high |
|
|
Long Focal Lens Tripod Set for iPhone 4S/4 $29.99 Overview:New design long focus lens for camera phone 4GDetachable lens that adds 8X optical magnification to your iPhone 4G or 4G built-in camera.Black cover snaps on to your iPhone 4Adjustable 8X zoom lens has a manual focus16 degree angle of viewUniversal attachment that gently clamps to your iPhone 4For iPhone 4G Only8 X Optical MagnificationSize: 30 x 70 mmPackage including:1 x Long Focal Lens1 x Universal Holder1 x Mini Aluminum Tripod1 x Cleaning cloth1 x CaseSpecification:Weight Approx:94.7gSize Approx:7 x 3 x 3 cm |
|
|
2.8-12MM Lens $24.9 2.8-12mm focal length zoom lens for security cameras. |
|
|
Fixed Board Lens for CCTV Camera w. 4mm Focal Length $11.49 Description:Fixed Board Lens for CCTV Camera w. 4mm Focal Length.The 4mm CCTV Camera provides a narrower (fixed) field of view, which will make objects appear closer. This gives you better definition on smaller features of the items in front of your camera.Easy to Install: Replacement Fixed Board Security Lens easily threads in after removal of the previous lens is removedCCTV Camera Lens Weight: 7.6gPackage included:1 x 4mm Fixed Board CCTV Lens |
|
|
Variable Focal Length Lens For 1/3 CS Mount Cameras $24.3 Specification# Compatible Format Cameras: 1/3 Inch# Mount: CS-MOUNT (Lens Attitude Adjustable)# Compatible with Auto Iris Security Camera# Focal Length: Vari Focal Range f=6.0~16mm# Aperture: F/1.4# Viewing Angle: 136 deg# Object Focus Distance: .1M ~ inf# Operating Temp: -20~+50 deg C# Power Source: Powered via CameraAccessories:# Manual# Lens and Screw Cap |
|
|
5502-741 - Axis 5502-741 16 Mm F/1.8 Fixed Focal Length Lens $63.09 the Evetar 1.3 Megapixel Lens is a Light, Compact Fixed Iris Lens, With an Aperture Equal to F1.8. With a Focal Length of up to 16 Mm, The Lens Offers a Narrower Angle of View. Evetar Lenses Are Designed Specifically For Use With Surveillance Cameras. The Lens is Backed by a 1-year Limited Warranty. [86541U] UNSPC: 45121603 2.25L x 2.25W x 2.25H 0.75 LB 1 Cubes |
|
|
Low Illumination CCTV Security Camera Lens 4mm Focal Length F1.2 $11.49 Description:Low Illumination CCTV Security Camera Lens 4mm Focal Length F1.24mm Standard Board Security Camera Lens for CCTV CameraThe F1.2 4mm CCTV Security Lens provides a standard field of view which is ideally suited for most installations. A 4mm lens will bring you closer to the action than a wide angle lens, and when used with an IR Camera, it will not cause glare from the IR light, as a wide angle lens will. All IR Camera manufacturers recommend using a 4mm Security Camera Lens or higher for use with their IR Cameras.Easy to Install: Replacement lens easily threads in after removal of the previous lens is removedFocal Length (mm): 4mmAperture(F): F1.2Standard Replacement CCTV Camera LensWeight: 7gPackage included:1 x Low Illumination CCTV Lens |
|
|
Board Security CCTV Camera Lens 6mm Focal Length F1.2 $11.49 Description:Board Security CCTV Camera Lens 6mm Focal Length F1.2 Low Illumination6mm Board Security CCTV Camera Lens for CCTV CameraThe F1.2 6mm Camera Lens provides a standard field of view which is ideally suited for most installations. A 6mm lens will bring you closer to the action than a wide angle lens, and when used with an IR Camera, it will not cause glare from the IR light, as a wide angle lens will. All IR Camera manufacturers recommend using a 6mm Security Camera Lens or higher for use with their IR Cameras.Easy to Install: Replacement lens easily threads in after removal of the previous lens is removedFocal Length (mm): 6mmAperture(F): F1.2Standard Replacement F1.2 CCTV LensWeight: 7.4gPackage included:1 x Low Illumination 6mm CCTV Lens |
|
|
12mm Standard Zoom Board Lens Security CCTV Camera Lens 12 MM Focal Length $5.49 Description: Standard Zoom Board Lens Security CCTV Camera Lens with 12MM Focal Length.12mm Zoom Board Lens: The 12mm CCTV Camera Board Lens provides a narrower (Zoom) field of view, which will make objects appear closer. This gives you better definition on smaller features of the items in front of your camera.Easy to Install: Replacement lens easily threads in after removal of the previous lens is removedStandard Board Lens makes a great replacement for a damaged or broken 12 mm board lens.Focal Length (mm): 12mmWeight: 4.0gPackage included:1 x 12mm Board Lens |
|
|
4MM Lens $22.6 4mm Focal Length Lens for Professional Security Camera applications. |
|
|
12-30MM Lens $38.9 12 - 30mm lens attachment for security cameras.# Focal Length: 6-15mm |
|
|
50MM Manual Iris Lens $23.6 Manual Lris Lens; Focal Length: 50mm |
| Account limit of 2104 requests per hour exceeded. |
FRESNEL LENS PARABOLIC MIRROR FOCAL POINT FOCAL LENGTH SOLAR POWER ALTERNATIVE ENERGY HID LIGHT
Digital Photography - Zoom Lens Vs. Prime Lens
Many amateur photographers have the same question: should I use a zoom lens or should I use a prime lens? The correct answer is that both should be used depending on conditions, and both offer advantages that can be exploited by the photographer willing to accept certain trade offs in performance.
A zoom lens is a lens that uses movable internal mechanism to produce a variable focal length. They are versatile in that objects both near and far can be photographed. Due to this fact, a camera using a good zoom lenses requires fewer lens changes and the camera and lens usually stay internally cleaner as a result. This benefit can be negated, however, if the zoom lens construction is one that telescopes in and out. This can literally pump dirty air into the mechanism like an accordion. On the other hand, another benefit is that the photographer can more suitably compose and frame the photo when it is taken. This helps minimize cropping and additional work during post-processing.
Since a zoom lens has more moving parts than a prime lens, a small amount of sharpness is lost due to slight misalignment issues or inherent "looseness" of the lens train. This problem can vary in extremes, as a high quality zoom lens can rival a prime lens in sharpness, whereas a low quality zoom lens can be nearly useless with odd aberrations extending all the way to the field edge. Another drawback of a zoom lens is that they are generally slower than a prime lens, as the internal zoom mechanism must be sized for the longest focal length available. In other words, a good focal length apparatus at long focal lengths doesn't necessarily convert to a good focal length apparatus at short focal lengths. Zoom lenses are, in effect, the jack of all trades. They are capable of being used over a wide range of operating conditions at good to average picture quality.
Prime or fixed lenses do not have an adjustable focal length. Usually the only controls available might be focus and f-stop. They are usually less expensive than comparable zoom lenses due to simpler construction, have better optical quality, and are usually faster. They usually have a wider field of view for a given focal length and less glass in the optical train to absorb light. On the downside, they are less versatile and require more lens changes. Prime lenses are the masters of photographic quality. They are expected to perform over a very limited operating range, but within that range, their performance is flawless.
So which is best, the versatile zoom or the precision prime lens? It all depends on the personal skill, monetary resources, and interests of the photographer. For someone shooting action shots with varying distances to the subject, or for someone on a limited budget, a single zoom lens is ideal. In contrast, a photographer that shoots still object or subjects at fixed distances may opt for two or three prime lenses with a range of focal lengths to get that perfectly composed shot with center to edge sharpness.
At any rate, zoom and prime lenses both have a place in the camera bag of every photographer.
About the Author
David Chappell is the owner of SLR Lens Depot - Camera Lenses for Sale, Reviews, and More. A website featuring digital photography guides, lens reviews, lenses for sale, news and much more.
