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Topic: Diffraction limited


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  Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks
Diffraction is an optical effect which can limit the total resolution of your photography-- no matter how many megapixels your camera may have.
Diffraction thus sets a fundamental resolution limit that is independent of the number of megapixels, or the size of the film format.
Just because the diffraction limit has been reached with large pixels does not mean the final photo will be any worse than if there were instead smaller pixels and the limit was surpassed; both scenarios still have the same total resolution (although one will produce a larger file).
www.cambridgeincolour.com /tutorials/diffraction-photography.htm   (1797 words)

  
 Diffraction-limited - Wikipedia, the free encyclopedia
In astronomy, a diffraction-limited observation is one that is only limited by the optical power of the instrument used, as opposed to seeing-limited, where the main limit is given by atmospheric effects.
The resolution of a given instrument is proportional to the diameter of its objective, and inversely proportional to the wavelength of the light being observed.
Diffraction effects are the main contributors to this limit.
en.wikipedia.org /wiki/Diffraction-limited   (235 words)

  
 Diffraction -- from Eric Weisstein's World of Physics
Diffraction is a phenomenon by which wavefronts of propagating waves bend in the neighborhood of obstacles.
Diffraction around apertures is described approximately by a mathematical formalism called scalar diffraction theory.
Diffraction problems are among the difficult encountered in optics, and exact rigorous solutions are quite rare.
scienceworld.wolfram.com /physics/Diffraction.html   (462 words)

  
 Diffraction in Photographic Lenses   (Site not responding. Last check: 2007-10-13)
The diffraction limit of resolution is 100 lpmm at f/16, 70 lpmm at f/22, and 50 lpmm at f/32.
Diffraction limited resolution will roughly be halved when going from f/5.6 to f/11, but if the lens still manages to resolve as good as diffraction would allow, it still is diffraction limited at the smaller aperture, despite the reduction in resolution compared to wider apertures.
Diffraction limited resolution is inversely proportional to f/# : the resolution cut-off for a diffraction limited lens is 1/(W x f/#), W is the wavelength of the light.
medfmt.8k.com /mf/diffraction.html   (21077 words)

  
 NIFS Diffraction Analysis
The 501 mm focal length collimator reimages the pupil on to the diffraction grating.
The telescope diffraction rings are seen clearly, along with the smearing of the pupil images in the dispersion (horizontal) direction and the diffraction effect due to the finite lengths of the pupil mirrors and the grating on the final slit image at the detector.
It is therefore necessary to examine diffraction effects as a function of the source position in an IFU slitlet.
www.mso.anu.edu.au /nifs/sdns/sdn0005.06.htm   (2173 words)

  
 Optimum Aperture - Format size and diffraction
Diffraction is the name given to the observation that when light squeezes through a small opening it tends to spread out.
The image of a point is known as the diffraction limited spot size and the value is given in microns (1 micron is 1/1000 mm).
In diffraction calculations the COF defines the maximum allowable value of the diffraction limited spot size which will result in acceptably sharp prints in the in focus plane.
www.bobatkins.com /photography/technical/diffraction.html   (1080 words)

  
 Diffraction
Diffraction is a loss of sharpness or resolution caused by photographing with small f/stops.
Physicists know the limiting resolution is defined by the diameter of the Airy disc which is defined by the f/number, and astronomers and spy satellite designers know that angular resolution is defined by the diameter of the clear aperture.
Diffraction is accurately predicted by both ray and wave theory.
www.kenrockwell.com /tech/diffraction.htm   (638 words)

  
 Demonstration of Coherent X-Ray Diffraction Imaging
But lenses have limitations, and for scientists in the burgeoning realms of nanotechnology and life science at the molecular level who want to peer at three-dimensional images of the interiors of submicroscopic objects with features measured in billionths of a meter (nanometers), there is no lens that can do the job.
A growing number of researchers are now taking image reconstruction from diffraction patterns a big step further by studying individual, nonrepeating objects by the new technique of coherent x-ray diffraction imaging, more colloquially known as lensless imaging.
An essential constraint is the requirement that the intensity of the diffraction pattern be zero outside the boundary of the object (the support).
www-als.lbl.gov /als/science/sci_archive/74lensless_imaging.html   (1006 words)

  
 Diffraction Limited Resolution
All telescopes have an inherent limitation to their angular resolution due to the diffraction of light at the telescope's aperture.
The limit for the telescope's resolution is set by the diffraction at the aperture of the telescope.
Thus the limit of the angular resolution is
www.pha.jhu.edu /~jlotz/aoptics/node2.html   (399 words)

  
 Sharpness at the Depth of Field Limits - Bob Atkins Photography
The resolution values given in the table below are the result of multiplying the diffraction limited defocus MTF function by the MTF of a typical sharp slide film, thus they represent lp/mm on film.
It's clear that there is an optimum aperture for sharpness at the DOF limits, which is a function of the COF from which the DOF limits are calculated.
Sharpness at the limits of the DOF falls off at small apertures because of increasing diffraction effects (ignored by the simple geometric optics model).
bobatkins.com /photography/technical/dofdiff.html   (486 words)

  
 Melles Griot Optics Guide - Diffraction   (Site not responding. Last check: 2007-10-13)
Fresnel diffraction is primarily concerned with what happens to light in the immediate neighborhood of a diffracting object or aperture.
Diffraction is always present, although its effects may be masked if the system has significant aberrations.
When an optical system is essentially free from aberrations, its performance is limited solely by diffraction, and it is referred to as diffraction limited.
www.mellesgriot.com /products/optics/fo_3_1.htm   (947 words)

  
 Diffraction Effects   (Site not responding. Last check: 2007-10-13)
It is a function of the wavelength of the light and the aperture size of the telescope, and is also known as the angular resolution.
Where theta is the (diffraction limited - see below) angular resolution in radians, lambda is the wavelength of the light, and D is the telescope aperture (both have to be in the same units, e.g.
By this they mean that the limiting factor on the quality of images produced is the effect of diffraction of light when it passes through the optics - i.e.
www.ulo.ucl.ac.uk /~diploma/diffraction_effects.html   (494 words)

  
 Depth of field and diffraction
Of course the actual image sharpness at the DOF limits is degraded by diffraction, lens aberrations, film properties and possible lack of film flatness, so the overall sharpness at the DOF limits will be inevitably worse than the simple circle of confusion would indicate.
The equation for the Rayleigh diffraction limit, adapted from R.
Film sharpness, which is the critical factor in limiting the sharpness of 35mm images (assuming high quality lenses are used), and which affects medium format images to a lesser degree, is also omitted.
www.normankoren.com /Tutorials/MTF6.html   (4837 words)

  
 Diffraction - Wikipedia, the free encyclopedia
The effects of diffraction were first carefully observed and characterized by Francesco Maria Grimaldi, who also coined the term diffraction.
The diameter given is enough to contain about 70% of the light energy; it is the radius to the first null of the Airy disk, in approximate agreement with the Rayleigh criterion.
Twice that diameter, the diameter to the first null of the Airy disk, within which 83.8% of the light energy is contained, is also sometimes given as the diffraction spot diameter.
en.wikipedia.org /wiki/Diffraction   (1746 words)

  
 Diffraction: When Smaller Apertures No Longer Mean Sharper Pictures - Photo Tips @ Earthbound Light
This means that resolution will be limited by diffraction if the Circle of Confusion for the film or sensor format we are using is less than twice the diameter of the Airy disk as determined by the aperture being used.
The f/40 shot (the limit of the lens I was using) is downright horrible on the right-hand end of the chart where the lines are closest together.
As it does, there gets to be enough diffracted light contributing to the exposure that it causes a noticeable decrease in the sharpness of the resulting image.
www.earthboundlight.com /phototips/diffraction-small-apertures.html   (1182 words)

  
 diglloyd: Consumer Digicams and Diffraction
Diffraction is an optical phenomenon which places an absolute limit on achievable lens resolution.
Knowing the fixed optical limits, the camera ought to first raise the shutter speed before it begins stopping down such that resolution begins to be limited by the lens.
In actual fact, other factors are limiting resolution to considerably less than the advertised maximum (5.95 megapixels for the DMC-FX01), and an aperture of f11 shows little degradation over an aperture of f5.6.
www.diglloyd.com /diglloyd/free/DigicamDiffraction/index.html   (1599 words)

  
 diffraction limited   (Site not responding. Last check: 2007-10-13)
Since there is a good definition for "diffraction pattern" and for "limited", I think it should be easy to come up with a definition for "diffraction limited".
Diffraction spreads out the light from a star into a pattern, and that limits the quality of the view through a telescope (or other lens).
Either way, diffraction limited means that you have a Strehl ratio of 100%.
www.johnspics.com /diff_lim/diffraction_limited.html   (1260 words)

  
 Diffraction-Limited
A telescope is said to be "diffraction limited" if its optics are made with enough accuracy so that all the light rays from a star fall within that star's Airy disk and diffraction rings, with no excess light being scattered out of the disc and rings by defects in the mirrors.
Technically, a telescope is diffraction limited if it meets the Rayleigh limit - which specifies the separation in arc seconds of two equally-bright binary stars which appear to be just touching as being equal to 140 divided by the aperture in mm.
The Rayleigh limit, which deals with a telescope's ability to separate closely-spaced stars, should not be confused with the Rayleigh criterion, which deals with how accurately an optical system is made.
www.astronomics.com /main/definition.asp/catalog_name/Astronomics/category_name/t0bna4bqvsuwa9glqfm/Page/1   (306 words)

  
 Diffraction Limit
The diffraction limited resolution of a perfect optical system is defined by the diameter of the optics and the wavelength of interest.
When selecting a set of test targets, the limiting resolution will generally be defined by the smaller of the two optics, i.e.
However, camera resolutions can exceed the nominal diffraction limit when image enhancement or multiple scanning techniques are employed.
www.electro-optical.com /unitconv/convertcalcs/diffract.htm   (152 words)

  
 diffraction limited, whats this mean? - Astronomy.com Forums
To me, "diffraction limited" means the errors in the figure and surface quality of the optic are sufficiently small as to not contribute to image degradation before the effects of normal diffraction do.
However I have heard that diffraction limited is not necessarily unimprovable, and that even great advancements have been made in optical quality.
Actually, "diffraction limited" is simply marketing speak to get you to think that their mass-produced optics are good enough.
www.astronomy.com /ASY/CS/forums/266372/PrintPost.aspx   (1270 words)

  
 Lightholder Optics--Premium Newtonian Mirrors
As a footnote, in the opinion of the author, it should be stated that any attempt to compare the performance of different diameter/f-ratio combination using their wave ratings, even if the wave ratings are accurately calculated, is a difficult process and not straightforward.
This is a figure obtained by a calculation, where the blur spot size produced by the mirror, is divided by the theoretical diffraction disk size calculated for the aperture.
The term "diffraction limited" is an absolute, relevant indicator of optical accuracy on the primary's surface.
www.lightholderoptics.com /optical.htm   (2971 words)

  
 Circular Aperture Diffraction
This example of diffraction is of great importance because the eye and many optical instruments have circular apertures.
If this smearing of the image of the point source is larger that that produced by the aberrations of the system, the imaging process is said to be diffraction-limited, and that is the best that can be done with that size aperture.
This limitation on the resolution of images is quantified in terms of the Rayleigh criterion so that the limiting resolution of a system can be calculated.
hyperphysics.phy-astr.gsu.edu /hbase/phyopt/cirapp2.html   (504 words)

  
 Diffraction, Ltd. - Technology for the New Century
Diffraction Ltd. is an established company recognized as a technology and invention pioneer.
For more than a decade, our highly skill team has proven itself to be a successful and profitable company that has and will continue to develop technologies and products of immense value.
Diffraction LTD is currently comprised of over twenty people, each working in a secure private facility located in the beautiful mountains of Vermont.
www.diffractionltd.com   (146 words)

  
 Diffraction
This is known as diffraction, and it was first shown in the 1600s to be a general characteristic of wave phenomenon which occurs whenever a portion of a wavefront is obstructed in some way.
Even in all of the potential defects in the lens system were eliminated, the ultimate sharpness of the image would be limited by diffraction.
is limited to a small region extending out directly in from of the aperture, and it is only there that all of the wavelets interfere constructively.
physics.tamuk.edu /~suson/html/4323/diffract.html   (2004 words)

  
 Diffraction Limited Beams and Gaussian Optics
Uniformly Illuminated Apertures: Generally, when discussing beam widths and beam shapes of microwave dishes and optical telescopes, it is usual to assume the simple case of uniform illumination, i.e., constant beam intensity across the aperture, with a sudden cut-off of the beam at the extremes of the aperture.
The angular distance between the first zeroes of this polar response or diffraction pattern, corresponds to the width of the central bright zone.
In the far-field, the FWHM diffraction limited beam diameter is given by:
www.coseti.org /radobs14.htm   (2178 words)

  
 Definition: diffraction limited   (Site not responding. Last check: 2007-10-13)
In optics, pertaining to a light beam in which the far-field beam divergence is equal to that predicted by diffraction theory.
In focusing optics, pertaining to a light beam in which the impulse response or resolution limit is equal to that predicted by diffraction theory.
This HTML version of Telecom Glossary 2K was last generated on Wed May 8 15:36:48 MDT 2002.
www.its.bldrdoc.gov /projects/devglossary/_diffraction_limited.html   (62 words)

  
 Electron Diffraction
Most electron diffraction is performed with high energy electrons whose wavelengths are orders of magnitude smaller than the interplanar spacings in most crystals.
LEED and RHEED are therefore considered to be surface science techniques, while transmission electron diffraction is limited to specimens less than 1 mm thick.
(3) Lenses are able to focus the diffraction pattern and to change the camera length, which is equivalent to moving the film in an x-ray experiment.
www.matter.org.uk /diffraction/electron/electron_diffraction.htm   (200 words)

  
 Violet Diode Lasers for DVD
Note: There are claims by others that their laser have diffraction limited optics.
What is important is wheather the "Beam", which is a combination of laser and all optics in it's path, is diffraction limited.
The final beam output needs to be diffraction limited in order to generate diffraction limited spots.
www.microlaser.com /blueDVD.html   (319 words)

  
 Oxford Diffraction – X-ray Diffraction: Driving X-ray Innovation
Study in situ X-ray diffraction in multi-well crystallisation plates using the unique PX Scanner; a combined optical and X-ray imager.
Oxford Diffraction has produced an innovative range of X-ray systems for small molecule applications.
Oxford Diffraction announces the launch of the PX Scanner: the first ever commercial instrument for in-situ X-ray inspection of protein crystals in multi-well plates.
www.oxford-diffraction.com   (204 words)

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