Astronomy Stack Exchange
Astronomy Stack Exchange

Questions tagged [optics]

Behaviour and properties of light, and its interaction with matter, particularly in detection of light.

147 questions
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Why are there optical differences between sunrise and sunset?

I've noticed that sunrises are not reverse sunsets regarding the sky hues and lighting. Sunrises always start pinkish and end with a glorious yellow sunshine. On the other hand as the sun sets lighting gets orange and the sky gets a hellish red…
Demis
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What are optical artifacts in source images?

In Stellarium, there are two green squares in the constellation Sextans (close to the star Alpha Sextantis). The app doesn't provide any information as to what these are. I was curious and so I decided to contact the Stellarium team, who thankfully…
William
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Is it practical to hand grind a convex parabolic or hyperbolic mirror?

I know it's practical to hand grind a convex spherical mirror and that it's practical to make a concave parabolic mirror from a spherical one. But as I understand it, the procedure for doing so depend on tracking progress by using interference…
BCS
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Projecting an image of the sun / eclipse

This might be an astronomy.stackexchange.com question, but I think it is more in line with a camera obscura. During the last eclipse I didn't plan ahead and grabbed some lousy toy "spy" telescope we had (about 2 inches long), set it up on a tripod…
rrauenza
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Arago Spot in the Shadows of Celestial Bodies

Recently, I've watched this video by Veritasium describing Poisson's Spot, or the Arago Spot. It is explained in the video that near circular (or spherical) objects can produce this optical effect, given that there aren't many obstructions about the…
BenjaminF
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Telescope and its construction

I want to build a reflecting telescope in my home. I've attached a drawing of my plan that contains some explanations of what I understand so far, and highlights the parts of the design for which I have questions. What type of mirror should i use,…
Sri vishnu Bharat
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Magnification of a telescope

I took an image of Jupiter through my 8" Dobsonian Telescope, attaching a DSLR and a 1.25" Barlow Lens where the eyepiece goes, as shown in this video: https://www.youtube.com/watch?v=reFxoF3XoaU Through numerous online sources, I learnt that to…
StopReadingThisUsername
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I am getting triple image of the moon from a 50mm telescope

I just bought a telescope and saw the moon but with the bright moon at the center there are two faint images of the moon above and below it. I figured out it was due to the periscope mirror. If I see my finger through that periscope it has a faint…
Paryag
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Are telescope eyepieces ever made with a diopter adjustment (similar to DSLRs)?

I am learning about eyepieces, and "eye relief" and what sorts of eyepieces an amateur may want for their purposes, and was wondering if there are eyepieces with diopter adjustments, or if, due to the optical systems in reflecting and refracting…
Warren P
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Stellar aberration, any prism effect?

In stellar aberration, is there any prism effect, chromatic aberration?
Viktor
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PSF magnification

I have a circular telescope pupil, a magnifying optic, and a detector. I am trying to calculate the point spread function as a function of wavelength. I am running into the issue that Python's 2D FFT or matrix DFT declare their own spatial…
voidedbowel
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