lens

  1. S

    Question about zooming out with lens

    Hey guys, I need some help. I am working on a project and I am wondering if it is possible to make an object to look 100 times far away than it is actually using lens (or more than one lens). The lens (or lenses) should be near the object, not near the eye. For example if we have lens in front...
  2. C

    Fresnel lens properties

    Hi, Can anyone tell me the transmission properties of a plastic fresnel lens, that I got from a microfiche viewer? I'm particularly interested in: Will it pass UV light? If so, when focused to half, will it be double strength, so double heat, light and UV? Camerart.
  3. K

    Optics for Research

    I have a light beam with diameter of 1mm and I'm trying to reduce it's diameter to less than 50 micrometers (as shown in the image) I was thinking of using one of the high quality camera zoom lens. Any suggestions, or ideas?
  4. S

    Medical physics - Correcting presbyopia

    Hi all, I have another problem, this time involving the lens equation. (1/f= 1/v+ 1/u) v and u are in Meters and 1/f is the power in diopters (D) I have solved some problems where the near point of an eye is correct and the far point needs correcting and where the far point is correct...
  5. W

    Numerical aperture problem (optic fiber output after lens)

    Hi all, I'm facing an issue: I'm using a NA = 0.16 lens to focus light into an optic fiber with NA = 0.5 (I'm using that lens because I want it to be compatible even with a NA = 0.22 optic fiber I want to use in the future), but what is the aperture of the output of the optic fiber? I'd say...
  6. P

    Choosing a c-mount camera and a lens

    I'd appreciate some guidance with selecting a proper lens and a c-mount camera for the identification of packages moving on a belt (at the airport for instance). On each package there is a bar code, the width of the belt is 50cm, height of the package between 5-15cm and its maximum size 40X50cm...
  7. N

    How far from focal length of a lens does the nearest infinity begin

    Q. How can we make out whether the the object is beyond C or infinity? Q. At what nearest distance does infinity start from,from the focus(focus Of any lens or mirror)? Means is there any relation between the point from where infinity starts and the focal length or curvature of any lens or...
  8. B

    Help: Calculate a sphere from base curve

    Contact lenses are generally defined by their power, base curve, and diameter. Does anyone know how to calculate the sphere based on a base curve of 9? Thanks for the help.
  9. H

    what is a toric surface and what is a toric lens

    please explain in laymans language(Giggle)
  10. C

    Types of lens flare - light and optical depth?

    I'm trying to understand what's going on with lens flare in different kinds of lenses. There's a lot of lens flare out there creating weird and wonderful artifacts in people's pictures. Without understanding the kind of lens flare going on in a very flat lens (e.g. smartphone) or a long lens...
  11. T

    Bulb used as convex lens

    Dear all I have used a bulb which is filled in with water, it works like a convex lens to concentrate solar energy. The performance of the water bulb gets highest level when I incline the bulb like in the clip. Solar light beam focus on a bigger dot, in compared with the dot when let the bulb...
  12. K

    a Zoom in magnifying lens system for distant objects on windows

    Hi everyone, I am working on a project on my final project in Product design. The project is about translating digital concept into the analogue world. In my project I am especially interested in the digital “Windows” and am trying to apply the functions and possibilities of digital on to...
  13. kelsiu

    Question about lens maker's formula

    I am trying to follow the derivation of lens maker's formula from the textbook "University Physics", p.1133 (https://books.google.com.hk/books?id...page&q&f=false) I can understand the first equation because it is just the object–image relationship for spherical refracting surface. But for the...
  14. A

    Lens Help?

    Hello, Thanks so much for reading this. I think I'm close I"m just not confidant in my answer. The problem reads: For a thin plano-convex lens, what is the change in focal length (Delta f) for a 100 um change in radius (delta R) of the convex surface. Assume the lens has a visible-wavelength...
  15. A

    Anamorphic and Spherical Lens Infinity Focus

    New to the forum but stumbled upon this and thought it might be beneficial to query more scientifically minded individuals. I am a filmmaker and use a variety of lenses to acquire certain looks. One of which is anamorphic cinematography. (http://www.red.com/learn/red-101/anamorphic-lenses)...
  16. I

    Need answer on practical use of convex lens and concave mirror

    Hi all, I am an artist that is experimenting with practical use of convex lens and concave mirror in painting, but got stuck with something: image that goes thru the convex lens and gets projected on concave mirror actually gets smaller? Is there a possibility of using a convex lens in static...
  17. S

    combination of lens

    1. How will focal length of these two lenses change? i) combining two plano convex lenses attaching plane faces ii) combining two half parts of a convex lens which cut horizontally
  18. S

    Convexo-concave vs plano-concave vs concave-concave lens

    Is there a reason to choose a convexo-concave lens over a plano-concave or a concave-concave lens if each have a net divergence? (The context I am thinking about is the correction of myopia.) If more information is needed, just ask! Any input would be GREATLY appreciated!
  19. P

    Simple lens problem

    Hi, would really really appreciate if you could help this newbie out with a high school physics question. Here it is (its lens and optics) Bill with a height of 1.8m standing at a distance of 4m away from a camera. If the camera has a lens with a power of + 4.0 D, what is the height of Bill's...
  20. K

    Object at Focus of convex lens

    I see some web saying that for object placed in the focus the image formed will be at Infinity, highly magnified, and inverted . While some web says "No image will be formed" Which one is true?