Lens Definition and 787 Threads

Homework Statement In a 35 mm single lens reflex camera (SLR) the distance from the lens to the film is varied in order to focus on objects at varying distances. Over what range must a lens of 45 mm focal length vary if the camera is to be able to focus on objects ranging in distance from...

Homework Statement I am given 5 distances to place the object relative to the lens. I then need to calculate each of the images distances for all 5 and record them. Once I have that done, I am to conduct a graph of 1/q vs 1/p. I then need to answer these questions: 1- Is the slope of your...

Hi, I was hoping someone would be able to help me with a microscopy problem that has been puzzling me for a while. I'm building a basic microscope from scratch using a 50x long working distance Nikon objective (LU Plan ELWD, wd = 10.1mm, NA = 0.55). The sample is illuminated from above using...

Hello Need to verify please if the following custom design lens is reasonable -- Sensor: CMOS sensor, 1/3”, 6μm x 6μm pixel, Wide VGA 752H x 480V, 4.55mm x 2.97mm Imaging Area -- Focus: 50m till 200m -- Lens: f2.8; Focal length=34mm; Diameter=13mm Pay attention I am not a physicist...

Hi! I'm having some trouble with optics. When we have convex, planoconvex, concave, planoconcave, and meniscus lenses, I don't understand how to substitute with the sign for R1 and R2. How do I determine whether the radius of a side is negative or positive? A book that I'm using said to take...

This is rather simple but has me stumped. The assignment prompts me to create the construction rays of an object at infinity, refracting through a thin converging lens, with image focusing at focal point f. So where do the rays originate from? My guess was perhaps it means just a light...

Hi guys. any help with this would be greatly appreciated. I am trying to make a device like a periscope which is 100MM in length but has a diameter of 5mm. the viewing end of the periscope can be much wider to accommodate an eye optic, but the other end does need to retain the diameter of 5mm...

Hey I've been looking around about lens flare's within the eye. well not necessarily lens flares, but the category it falls under and what exactly is it. Just wondering if anyone here know's where I can find it or tell me what exactly it is and causes it. Basically when I look at street...

Hi all, I'm looking for an equation which will give me the focal length of a biconvex lens given that we know both Radii of curvature, the thickness of the lens and the refractive index inside and outside. An equation is given on wikipedia here http://en.wikipedia.org/wiki/Focal_length as I...

we can calculate the refractive index of liquids like water using a converging lens and mirror by the standard method . r.index of water is less than that of lens(glass) . now taking mercury, whose r.index is > glass, can we do the same experiment and find its r.index ? i believe the answer...

Homework Statement (a) How far from a 50.0-mm-focal-length lens must an object be placed it its image is to be magnified 2.00X and be real? (b) What if the image is to be virtual and magnified 2.00X? Homework Equations Thins Lens Equation: 1/f = 1/do + 1/di Magnification...

Hello Forum, can anyone explain why a camera, a lens, automatically creates perspective in an image? Is it explainable with ray tracing? thanks fisico30

Thought experiment. Imagine building two optical mirrors around the sun an astrophysical body of the right mass, lined and diametrically opposed, at the right distance so that the sun is acting as a gravitational lens. Mirror A reflects the light from any extrasolar object and directs...

I placed this in quantum department but since no comments came either it belongs here or is too trivial. Please comment. MY POST IN QUANTUM PH. FORUM ... " This problem I encountered in my photography forum. A new model of camera comes out with a much higher megapixel sensor (Nikon D800...

[FONT="Comic Sans MS"]Homework Statement In a thick lens, how we do to get the primary and secondary principal planes Homework Equations (1/Si)+(1/So)=1/f The Attempt at a Solution I tried to get to get that with the Newtonian equation

This problem I encountered in my photography forum. A new model of camera comes out with a much higher megapixel sensor (Nikon D800, 36mpix). I argue that such sensor will need new lenses to be meaningful. Others claim that a given lens performance (here resolution) is always utilized by a new...

Homework Statement An object is placed 60 cm from a thick double convex lens, with faces of radii of curvature 20 cm and 30 cm, with thickness of 2 cm, and index of refraction is 1.5. Find the position of the image...

Homework Statement A thick lens has an index of refraction of 1.560, thickness of 3.0cm, and radii of curvature of R1= -4.50cm, R2= -3.60cm. Calculate the positions of the focal points (relative to the vertices). Homework Equations \frac{n}{s}+\frac{n'}{s'}=\frac{n'-n}{R} ffl =...

Homework Statement Calculate the matrix for the optical system which takes rays from the object plane to the image plane for a simple lens and show how this leads to 1/v = 1/u + 1/f Also show that the matrix can be written in the form \left[ \begin{array}{cc} 1/M & b \\ 0 & M...

Hi The thin lens equation we know is given by \frac{1}{S_O} + \frac{1}{S_I} = (n-1)(\frac{1}{R_1}-\frac{1}{R_2}) assuming light is incident from air. The "usual" way to derive the thin lens formula (aka the Gaussian Lens Formula) is to say that when looking at the system when either the...

Can you have an "anti" focal point of a lens? Hi, Imagine putting a convergent lens in the path of a laser beam. I put a small light meter at the focal point of the lens. If I move the lens along the beam will there be positions of the lens where the light paths through it completely...

the radii of the curvature of the spherical surfaces which is a lens of required focal length are not same. it forms image of an object. the surfaces of the lens facing the object and the image are interhanged. will the position of the image change?

When an object is placed at the principle focus of a complex lens, then the image is A) larger and inverted B) smaller and inverted C) the same size and inverted D) not formed at all Incorrect. Your answer=C, Correct answer=D MY QUESTION: WHAT ON EARTH IS A COMPLEX LENS? CONVEX OR CONCAVE? thanks

From what I recall, determining the focal length of a double convex lens just involves an infinite light source and holding the lens close to an image-capturing surface such as a wall and adjusting the distance until the image is at its sharpest...the distance from the lens to the surface is the...

'm currently reading chapter 27 of the Feynman lectures, where he derives the thin lens equation for a single refracting surface. He arrives at the equation h^2/2s + nh^2/s' = (n-1)h^2/2r Where s is the object distance, s' is the image distance, n is the index of refraction of the second...

I am trying to find the focal length of a convex lens, so i let the sun shine through my window to create an image on my wall. Is that image the focal point or is it just the distance of the image? And if it is the distance of the image, how do I put it into the thin lens equation, since the...

Homework Statement http://www.imageurlhost.com/images/r0its2lyef7v3s0ppms2.pngHomework Equations Mirror Equation (1/q) + (1/p) = (1/f) = (2/r) Magnification M = (q/p) for two lenses M1 & M2 Total magnification = M1*M2The Attempt at a Solution we have p1 = 40cm and f1 = 30cm then the image...

Homework Statement A biconvex symmetrical lens is cut in two halves and placed as shown in figure. if a point object is placed in the left how many images will be formed options - (a) Two images (b) Three images Homework Equations The Attempt at a Solution As I...

Is the exact shape of the lens of a dragon fly ommatidium genetically encoded? I guess that the radius of curvature for both the front and back surfaces of the lens is somehow genetically encoded, call them r_f and f_b? I guess nature has come up with an optimal design for the dragonfly lens...

A diverging lens is used to form a virtual image of an object. The object is 88.0 cm in front of the lens, and the image is 44.0 cm in front of the lens. Determine the focal length of the lens. 1/f = 1/do + 1/di since do is 88cm infront of the lense, that would keep the 88 positive, and...

Dear Forum, does anyone know what a telecentric lens or optical system does? I just know that it provides a projected instead of perspective view of small objects... Why is that useful? thanks fisico30

A light passing through a lens will be focused for a converging lens. However, to look at it carefully, it'll not converge to a single point but to a certain size. The size of it and some fringes surround it is actually a diffraction phenomenon. I don't really understand that the usual...

Homework Statement A small insect is placed 6.55 cm from a 7.00 cm-focal-length lens. Calculate the position of the image. Calculate the angular magnification. Homework Equations 1/f=1/do+1/di M=angular magnification=θ'/θ=angle of image/angle of object=N/f where N=near point The...

Thin-Film Interference: Coating a Lens -- Answers found, explanation needed! Homework Statement Boxed answers are the correct ones. Homework Equations 2L=(m+1/2)(λ/n) for constructive interference (maximum reflection, bright film) 2L=(m)(λ/n) for destructive interference (minimum...

will light of all colors bend to the same extent or is it different for different frequencies?

A concave lens always forms a virtual image (for a real object), will it always form a real image for a virtual object? (that is, when rays converge on it) If yes, why? If no, why?

Homework Statement A person had a near point of 80 cm. What focal length lens would be required to correct this persons near point to 30cm, allowing then to read at this distance Homework Equations Maybe: 1/di + 1/do = 1/f = P I found another similar question which used 1/(the...

Homework Statement A lens is a transparent refracting medium bounded by two spherical surfaces.R1 and R2 are radii of two surfaces. Homework Equations Will the Radii R1 and R2 will be same or different ? The Attempt at a Solution I hope that they are same, otherwise there won't...

what happen if converging rays are made to pass to a convex lens? what happen if divergent rays are made to pass to a concave lens?

Homework Statement An object is situated at various points relative to V. The light is then reflected by the mirror, and the final image is viewed by the observer. http://www.flickr.com/photos/55153239@N03/6196518731/ Homework Equations 1/s + 1/s' = 2/R na/s + nb/s' = (nb-na)/R...

What happens if eye lens and objective lens are interchanged in compound microscope? Also what about in astronomical telescope?

Homework Statement A glass lens (n=1.50) in air has a power of +5.2 diopters. What would its power be if it were submerged in water?Homework Equations Not too sure. May be Lensmaker's Equation, Snell's Law, and Power of a Lens Equation.The Attempt at a Solution I'm trying to derive the...

Can the Newtonian Form the Lens Equation f=x'x be derived directly from the standard form the lens equation? \frac{1}{f}=\frac{1}{d_{i}}+\frac{d}{d_{o}} x is the distance between the object and the focus on the same side of the object. x' is the distance between the image and the focus on the...

How big should a lens be to focus enough light to reach 1000 Celcius? I was wondering how big should a glass lens be to focus enough light to produce a temperature of about 1000 celcius at its foci? What if the lens was made up of sth with higher refractive index, doesn't this reduce the...

then through a plane mirror (I could put that all down in the title!) Homework Statement A bright object 1 cm tall is located at x = -6 cm. There is a thin lens atx = 0 with focal length f = 4 cm, and a plane mirror located at x = 7 cm. Light from the object passes through the lens, reflects...

Homework Statement difference between convex lens formula and convex mirror formula The Attempt at a Solution for convex mirror you make focal point negative and use the 1/f = 1/do + 1/di but for convex lens do you do the same? you don't make the f negative i think am i...

Homework Statement A lens forms an image of an object. The object is 16 cm from the lens. The image is 12 cm from the lens on the same side as the object. (a) What is the focal length of the lens? Is the lens converging or diverging? (b) If the object is 8.5 mm tall, how tall is the image...

Homework Statement A convex lens and a concave lens both of 6cm focal length are placed to give an object which is 5cm from the convex lens of magnification of 10. How far are the lenses apart? Homework Equations 1/f = 1/u + 1/v Magnification=v/u The Attempt at a Solution Lens...

A converging meniscus lens has an index of refraction of 1.55 and radii of curvature for its surfaces of 6.00 cm and 11.0 cm. The concave surface is placed upward and filled with carbon tetrachloride which has n = 1.46. What is the focal length of the glass combination? So I tried using the...

Homework Statement A body is positioned 40 cm from the left of a lens (f=30) and the lens is positioned 100cm left of a convex mirror (|R|=60), where will be the image and what type and magnitude will it have? Homework Equations 1/u + 1/v = 1/f The Attempt at a Solution I tried to...