Role of aberrations in the relative illumination of a lens system

Reshidko, Dmitry; Sasián, José M.

doi:10.1117/1.oe.55.11.115105

Cited by 13 publications

(5 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pupil walking effect was observed on the pupil plane. It is induced by spherical aberration of imaging optics and is a common effect in wide angle lenses [31][32][33][34]. The lens combination (L1, L2, and L3 lenses) was designed for the wide angle fundus image thus pupil walking was observed.…”

Section: Discussionmentioning

confidence: 99%

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid

Son

Toslak

et al. 2022

Preprint

View full text Add to dashboard Cite

A wide-field fundus camera, which can selectively evaluate the retina and choroid, is desirable for better detection and treatment evaluation of eye diseases. Trans-palpebral illumination has been demonstrated for wide-field fundus photography, but its application for true-color retinal imaging is challenging due to the light efficiency delivered through the eyelid and sclera is highly wavelength dependent. This study is to test the feasibility of true-color retinal imaging using efficiency-balanced visible light illumination, and to validate multiple spectral imaging (MSI) of the choroid. 530 nm, 625 nm, 780 nm and 970 nm light emission diodes (LED)s are used to quantitatively evaluate the spectral efficiency of the trans-palpebral illumination. In comparison with 530 nm illumination, the 625 nm, 780 nm and 970 nm light efficiencies are 30.25, 523.05, and 1238.35 times higher. The light efficiency-balanced 530 nm and 625 nm illumination control can be used to produce true-color retinal image with contrast enhancement. The 780 nm light image enhances the visibility of choroidal vasculature, and the 970 nm image is predominated by large veins in the choroid. Without the need of pharmacological pupillary dilation, a 140° eye-angle field of view (FOV) is demonstrated in a snapshot fundus image. In coordination with a fixation target, the FOV can be readily expanded over the equator of the eye to visualize vortex ampullas.

show abstract

Section: Discussionmentioning

confidence: 99%

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid

Son

Toslak

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…By way of reversibility, if all of the rays from these SSFs were to travel towards the lens, they would fill the exit pupil, so the image irradiance for those rays would be determined by integrating over the exit pupil. This integration is precisely what is done to obtain relative illumination in computer-aided lens design programs [12][13][14][15][16]. However, calculations for relative illumination in lens design programs generally either assume that the object is sufficiently extended, or otherwise, if ray aberrations are present, then these aberrations would first be corrected prior to determining the relative illumination [12].…”

Section: Geometrical Optics Approach To Image Irradiancementioning

confidence: 99%

“…where x and y are coordinates at the image plane, E is the image irradiance given by radiometry, V is the volume of the PSF, P(x − x , y − y ) is the PSF, and G(x , y ) is the image distribution (with unit irradiance) predicted by geometrical optics. Note that E in equation ( 3) is of course generally regarded as a function of x and y (such as that given by the relative illumination of a lens system, which would be computed through any of the methods discussed in references [12][13][14][15][16]), but the explicit writing of E(x, y) in equation ( 3) has been omitted in order to minimize clutter in the expression. Equation ( 3) is not just an expression of the relative distribution of the image given by convolution that is discussed in the subject of Fourier optics.…”

Section: Fourier Optics Approach To Image Irradiancementioning

confidence: 99%

Image irradiance in the absence of aplanatism and isoplanatism

Siew¹

2022

Eur. J. Phys.

View full text Add to dashboard Cite

Textbook chapters on the subject of optical radiometry often impose the condition of aplanatism when deriving a well-known expression for image irradiance in optical systems, yet at least two authors (including this author) have shown that such a condition is unnecessary for the expression to hold. In this paper, theories and computer-aided ray-tracing analyses are provided to support the validity of the expression for even wider cases, where stigmatism, aplanatism, and isoplanatism are all not assumed. Further, it is shown that when both diffraction and aberrations are involved, one may apply a fusion of the expression with the fundamentals of image formation by convolution (if the image is isoplanatic) or superposition (if the image is not isoplanatic) in Fourier optics. To highlight how graduate students and researchers in the laboratory can benefit from the concepts presented here, a practical application is discussed involving signal detection.

show abstract

“…Unlike paraxial optical system, pupil aberrations increase sharply in the optical system with large field of view [ 40 ]. Pupil aberrations in the optical system with large field of view will make the location and size of the entrance pupil at the off-axis field of view different from that at the paraxial field of view.…”

Section: Image Plane Illumination Analysismentioning

confidence: 99%

Optical Design of Imaging Spectrometer Based on Linear Variable Filter for Nighttime Light Remote Sensing

Xie

Liu

et al. 2021

Sensors

View full text Add to dashboard Cite

Nighttime light remote sensing has unique advantages on reflecting human activities, and thus has been used in many fields including estimating population and GDP, analyzing light pollution and monitoring disasters and conflict. However, the existing nighttime light remote sensors have many limitations because they are subject to one or more shortcomings such as coarse spatial resolution, restricted swath width and lack of multi-spectral data. Therefore, we propose an optical system of imaging spectrometer based on linear variable filter. The imaging principle, optical specifications, optical design, imaging performance analysis and tolerance analysis are illustrated. The optical system with a focal length of 100 mm, F-number 4 and 43° field of view in the spectrum range of 400–1000 nm is presented, and excellent image quality is achieved. The system can obtain the multi-spectral images of eight bands with a spatial resolution of 21.5 m and a swath width of 320 km at the altitude of 500 km. Compared with the existing nighttime light remote sensors, our system possesses the advantages of high spatial and high spectral resolution, wide spectrum band and wide swath width simultaneously, greatly making up for the shortage of the present systems. The result of tolerance analysis shows our system satisfy the requirements of fabrication and alignment.

show abstract

Role of aberrations in the relative illumination of a lens system

Cited by 13 publications

References 16 publications

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid

Image irradiance in the absence of aplanatism and isoplanatism

Optical Design of Imaging Spectrometer Based on Linear Variable Filter for Nighttime Light Remote Sensing

Contact Info

Product

Resources

About