Lens Definition and 836 Threads

Homework Statement An object is placed 6 metres from a convex lens of focal length 30cm. A concave lens of focal length 5cm is then placed 20 cm from the concave lens, on the side distant from the object. Determine the position, magnification and nature of the final image formed (to solve...

I own an Orion 120mm f\5 600mm telescope . I bought it last year from Orion . I recently noticed a cloudy patch about 2in. round on the inside of the scope on the lens , it looks like condensation to me . I've always been careful when i bring the scope in the house fron the nights cold air and...

Homework Statement 2. An object is placed two focal lengths from a diverging lens. What type of image forms? What is the magnification? Where is the image? Homework Equations 1/f = (n-1)(1/r1-1/r2) The Attempt at a Solution a) Virtual Image b) m = 1 c) the image is on...

Homework Statement 3. A converging lens has a focal length of 10 cm. A screen is placed 30 cm from an object. Where should the lens be placed, in relation to the object, to produce a focused image?Homework Equations 1/do + 1/di = 1fThe Attempt at a Solution Do can not be greater than 2F...

I'm tired of looking for mirrors to do my applications, so I was wondering if anyone knows where to find an off-axis collimating lens. I haven't been able to find one myself, not even in edmund optics or other major suppliers. If anyone does know, can you tell me where to get it and the place...

we used a converging lens and a screen with white paper in front of a window to form an image of a distant tree outside. This was about 15cm. When we used an optics bench and a candle to figure out the focus, it was 16.3cm... What would be a reason for the difference in the number?

hi i posted the same sort of question a few times before but this time it's a little different we did an experiment with a converging lens and a candle to find an image. When the candle was placed at the focal point, which was 16.3cm, an image appeared at 136cm. I know in theory, no image...

I'm having a little problem with this question.. my brain is too small. "A converging lens has a focal length of 10 cm. A screen is placed 30 cm from an object. Where should the lens be placed, in relation to the object, to produce a focused image?" I've started with the formula 1/do +...

Here is the problem I am working on: Two lenses that are L = 38 cm apart are used to form an image, as shown in Figure 26-52. Lens 1 is diverging and has a focal length f1 = -7 cm; lens 2 is converging and has a focal length f2 = 16 cm. [a] Determine the distance from lens 1 to the final...

Here's the problem: Here's what I understand: I know what a biconcave lens looks like, and how it behaves (for the most part). Of course I know that the index of refraction is ~1.00. And since the radii are equal that makes the equation somewhat easier. The thick lens equation is...

hi i've got to do measure hte refractive index of a liquid with mirror and lens first of all how can i measure hte refractive index of air in this way? i don't get how i can do this, please explain :| and then for the liquid, I've been told to put the liquid over the mirror and then the...

How far away from a converging lens must an object be ( in terms of focal length, f ) so that the difference between the image distance and the focal lengh is 1% of the focal length? I tried to translate the words into an equation based on the thin lens equation but i don't know if it is...

I am stuck on this problem because it been like 6 yrs since i took geometry and its due by 9 am. please help! Derive the thin lens equation: 1/object distance + 1/ image distance = 1/focal length for a divergent lens, using a diagram of a divergent lens (hint: use similar triangles)...

From using a magnifying lens under the Sun, I gather it can focus all or most of the light impinging on its surface area to a small spot and that is how it is able to create a greater intensity light at its focus (disregarding absorption in the lens.) Correct? What portion of the total light...

# A convergent beam is incident on a concave lens as shown in figure. Which of the following is not correct? a) The image formed is real b) The image formed is virtual c) The image formed is erect d) The image formed is magnified I solved it in the following way: Let f be the focal...

# Diameter of a Plano-convex lens is 6 cm and the thickness at the center is 3 mm. If the speed of light in the material of the lens is 2 x 10^8 m/sec, what is the focal length of the lens? I solved it in the following way: Let R be the radius of curvature of the convex surface. Given that AB...

# A convex lens of focal length 10 cm forms a real image of an object placed at a distance of 20 cm from it. Midway between the convex lens and the position of the image a thin concave lens is introduced. The image formed now is at a distance of 5 cm away from the earlier position. What is the...

I have to complete a problem about locating an image for a convex lens but I'm having trouble with it. I tried it out, but I can't complete it. Can someone help please? Locate the image for the convex lens below. Use any two rays to do so. Give the characteristics of the image. I'm having...

I have to complete a chart using the thin lens forumla. Can someone please help me out? I know that the formula is 1/f= 1/do= 1/di, but I don't know how to use it. Thanks.

I have a question dealing with diopters. Q: Assume that the distance from the lens of your eye to the retina is 1 inch (in effect, the image distance). Calculate the power of the lens in your eye (in diopters) for both your far point and near point. The difference between these two lens powers...

I have really no clue on how to this:cry: please help!

The distance between an object and its image is fixed at 40.0 cm. A converging lens of focal length f = 3.62 cm forms a sharp image for two positions of the lens. What is the distance a between these two positions? Determine: The distance between these two positions a = ____cm Could...

heres the question: anti-reflection coatings on a glass lens (n=1.50) consists of a magnesium fluoride (n=1.38) film, the coating thickness is chosen to eliminate any back reflectionusing the ideas of destructive interference. What is the minimum coating thickness required to eliminate the...

Here is the problem: A converging lens with a focal length of 12.0 cm forms a virtual image 8.00 mm tall, 17.0 cm to the right of the lens. I am supposed to find the position of the object. I tried using the lens eq. 1/s + 1/s' = 1/f where s is the distance of the object from the lens, s'...

I make Daguerreotypes (http://en.wikipedia.org/wiki/Daguerreotype) and I have decided that I want to move from the standard flat-plane photography and make images on silver domes instead. I have domes that are 1.85" in diameter and I want to replicate the effect that a garden gazing ball gives...

Hi, I have an optics Q here I'm not quite sure about:- a.) An astronomers uses a single thin lens of focal length 0.5m to form a sharp image of the sun on a white screen. If the angular width of the sun is 0.5 degrees, what is the diameter of the sun's image. b.) At night the astronomer...

Hey guys. I have a lens problem: A lens has a power of 300 dipoters, and a radius a of 2 mm. An object is located just beyond the focal length to get high magnification. The space between the object is filled oil with an index of refraction 1.4. Estimate the resolution for 500 nm light...

Jupiter as a Gravitational lens?? I remember reading in a swedish science mag about a planed probe to the solar foci 550 AU from the sun. When there it would use the gravity lensing of the sun as a telescop. But getting a probe out there and the cost of the project seems like to much of a...

i just need a little help with a relatively easy lens question A small fish is cast into the center of a glass sphere of radius R=5 cm and n=1.5. Where will an observer see the fish? Where will the observer see a decorative pattern painted on the back side of a sphere? So, I thought I...

Are hyperbolic lenses free of abberation?

Hi, I'm trying to set up a lens system as follows: - Laser source 612nm - This passes through an apature to act as a spatial filter... - then through non-reflective glass onto a crystal of diameter upto 150um - the lens must then take the diffraction pattern from this crystal upto...

Can anyone explain how one would normalize data from a lab? We just completed the lens equation lab in class and part of the analysis is to include "normalized" virtual object data in the graph. There are only 4 measurements taken. Any feedback would be great! :shy:

I am going be so pleased i f anyone can suggest a website where i can find information regarding the following topic: Digital video camera lens.do anyone know a website where i can download a short video regarding fiber optics.

Is there an easy way to remember what kind of images will be formed from converging/diverging lens depending on where you place the object relative to the focus? For instance, how to tell if the image is inverted vs. erect, real vs. virtual, smaller vs. magnified? I always have a hard time...

************************************************************* http://groups.yahoo.com/group/AstroDeep/12 more candidate cosmic string lens pairs in HUDF (re comment by Levon Pogosian on astro-ph/0506400); also myriad minute bright blue sources, always on dark background mesh: Murray...

I bought a new toy to play with. It's a 135mm/f2.8 lens I found used at B&H Photo for $39. I cut a hole in the back lens cap, glued a t-thread spacer to it, and built a little piggy-back rig for it and my DSI. Its pretty heavy, so I was a little worried that my ETX wouldn't be able to handle...

I was doing some reading on lens aberrations and saw some referance to 1st and 3rd order aberrations. What are they and what is the differance? Are there and 2nd order aberrations?

A convex lens is placed on a flat glass plate and illuminated from above with monochromatic red light. When viewed from above, concentric bans of red and dark are observed. What does one observe at the exact center of the lens where the lens and the glass plate are in direct contact.

I have this Physics Problem which I am not to sure where to start it from. The problem is: A real inverted image I of an object O is formed by a certain lens. The object-image speration is d = 0.40m, measured along the central axis of the lens. The image is just half the size of the...

Hi .I am reall y confused about the focal length of lens.i understand that it is the length from the lens to the point where parallel beams coming from infinity after passing through the lens cross one each other.My question ,knowing thew focal length wher exactly does it help?does it have any...

IS it possible for this one? I was given an older Meade telescope today the specs: StarQuest Model: 60AZ-M 60mm (2.4") Altazimuth refratcing telescope Lens specs: - 5x24mm viewfinder - SR4mm H12.5mm and H25mm eyepieces (0.965" barrel diameter) - 2x Barlow lenses What can i...

Lez prob hi, An object is moving with velocity 0.01 m/s towards a convex lens of focal length 0.3m. Find the magnitude of rate of separation of image from the lens when the object is at a distance of 0.4 m from the lens. Also calculate the magnitude of the rate of change of the lateral...

Hi! I am having trouble with this question: You are trying to photograph a bird sitting on a tree branch, but a tall hedge is blocking your view. However, as the drawing shows, a plane mirror reflects light from the bird into your camera. If x = 4.3 m and y = 4.5 m in the drawing, for what...

i need help! Given: A real object is located to the left of a convergent lens. The object's distance from the lens is 7/3f and its focal length is f. What is the image distance in terms of f? I tried the formula 1/f = 1/di + 1/do... it didn't work

Hey all, I recently did an experiment using a diverging or convex lens, to produce different images according to the focal point. For the experiment I found the focal length, and set up the lens and light source at that distance. I used just paper for a screen to produce the real images created...

If you could set up a system of lenses so that once a steady light stream enters the system, it will be refracted within the same system permanently, what will happen to the photons? Would it take an infinite number of lenses to get the exact refraction?

A bright object is placed on one sid eof a converging lens of focal length f, and a white screen for viewing the image is on the opposite side. The distance d_T = d_i + d_0 between the object and the screen is kept fixed, but the lens can be moved. Show that if d_t > 4f , there will be two...

An object is located 36 cm to the left of a biconvex lens of index of regraction 1.5. The left surface of the lens has a radius of curvature of 20 cm. The right surface of the lens is to be shaped so that a real image will be formed 72 cm to the right of the lens. What is the required radius...

1. A coin is located 19.6cm to the left of a converging lens (f = 16.5cm). A second, identical lens is placed to the right of the first lens, such that the image formed by the combination has the same size and orientation as the original coin. Calculate the separation between the lenses...

An object is located 36 cm to the left of a biconvex lens of index of refraction 1.5 The left surface of the lens has a radius of curvature of 20 cm. The right surface of the lens is to be shaped so that a real image will be formed 72 cm to the right of the lens. What is the required radius...