Large Depth-of-Field Integral Microscopy by Use of a Liquid Lens

Anabel Llavador; Gabriele Scrofani; Genaro Saavedra; Manuel Martinez-Corral

doi:10.3390/s18103383

Large Depth-of-Field Integral Microscopy by Use of a Liquid Lens

Sensors ◽

10.3390/s18103383 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3383 ◽

Cited By ~ 3

Author(s):

Anabel Llavador ◽

Gabriele Scrofani ◽

Genaro Saavedra ◽

Manuel Martinez-Corral

Keyword(s):

Numerical Aperture ◽

Optical Power ◽

Axial Position ◽

Depth Of Field ◽

Depth Range ◽

Liquid Lens ◽

New Apparatus ◽

Depth Ranges ◽

Limited Depth ◽

At Will

Integral microscopy is a 3D imaging technique that permits the recording of spatial and angular information of microscopic samples. From this information it is possible to calculate a collection of orthographic views with full parallax and to refocus computationally, at will, through the 3D specimen. An important drawback of integral microscopy, especially when dealing with thick samples, is the limited depth of field (DOF) of the perspective views. This imposes a significant limitation on the depth range of computationally refocused images. To overcome this problem, we propose here a new method that is based on the insertion, at the pupil plane of the microscope objective, of an electrically controlled liquid lens (LL) whose optical power can be changed by simply tuning the voltage. This new apparatus has the advantage of controlling the axial position of the objective focal plane while keeping constant the essential parameters of the integral microscope, that is, the magnification, the numerical aperture and the amount of parallax. Thus, given a 3D sample, the new microscope can provide a stack of integral images with complementary depth ranges. The fusion of the set of refocused images permits to enlarge the reconstruction range, obtaining images in focus over the whole region.

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Resolution Considerations for Photomacrography and Photomicroscopy

Microscopy Today ◽

10.1017/s1551929500068401 ◽

1996 ◽

Vol 4 (4) ◽

pp. 10-11

Author(s):

Theodore M. Clarke

Keyword(s):

Focal Plane ◽

Numerical Aperture ◽

Depth Of Field ◽

Point Light Source ◽

Maximum Resolution ◽

Total Magnification ◽

Point Light ◽

Airy Disk ◽

Limited Depth ◽

Optimum Balance

My Inter/Micro-84 presentation and subsequent article in The Microscope dealt with optimizing diffraction limited depth of field in photomacrography and is referenced by Brian Bracegirdle in his “Scientific Photomacrography. My analysis was based upon the classical solution for the diffraction pattern image of a point light source, using the Rayleigh criterion of resolution. H. Lou Gibson's method of treating combined diffraction and geometric blurring away from the object focal plane was used. The calculations and the experimental results indicated that a final print resolution, for the object focal plane, of 7 lines/mm (.29 mm Airy disk) gives an optimum balance of depth of field and resolution. The 7 lines/mm criterion is equivalent to an Abbe criterion of total magnification equal to 440 times the numerical aperture. The 500 times numerical aperture Abbe criterion recommended for microscopists with very acute vision corresponds to a maximum resolution of 6 lines/mm in the final image.

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Can Liquid Lenses Increase Depth of Field in Head Mounted Video See-Through Devices?

Journal of Imaging ◽

10.3390/jimaging7080138 ◽

2021 ◽

Vol 7 (8) ◽

pp. 138

Author(s):

Marina Carbone ◽

Davide Domeneghetti ◽

Fabrizio Cutolo ◽

Renzo D’Amato ◽

Emanuele Cigna ◽

...

Keyword(s):

Control System ◽

Clinical Practice ◽

Augmented Reality ◽

Time Of Flight ◽

Depth Of Field ◽

Liquid Lenses ◽

Good Potential ◽

Distance Sensor ◽

Limited Depth ◽

Lens Optics

Wearable Video See-Through (VST) devices for Augmented Reality (AR) and for obtaining a Magnified View are taking hold in the medical and surgical fields. However, these devices are not yet usable in daily clinical practice, due to focusing problems and a limited depth of field. This study investigates the use of liquid-lens optics to create an autofocus system for wearable VST visors. The autofocus system is based on a Time of Flight (TOF) distance sensor and an active autofocus control system. The integrated autofocus system in the wearable VST viewers showed good potential in terms of providing rapid focus at various distances and a magnified view.

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Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries

Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries ◽

10.47886/9781934874004.ch2 ◽

2008 ◽

Keyword(s):

Stock Assessment ◽

Distribution Data ◽

Depth Range ◽

Multivariate Statistical ◽

Data Set ◽

Species Checklist ◽

The World ◽

Depth Ranges ◽

The Vertical Distribution ◽

Very High

Abstract.—Extensive trawling efforts off Taiwan, supplemented by collections from trawlers’ harvest at several local fishing harbors, have raised the total number of Taiwan’s grenadier fishes to 71 species in 18 genera and 3 families. Despite a relatively limited coastline (500 nautical miles), the species diversity in Taiwan is very high. The largest genus Coelorinchus (formerly known as Caelorinchus) is represented by 21 species, followed by Ventrifossa with 8, and Nezumia with 6. All other genera had five or fewer representatives. Five species were described based on specimens from Taiwan, and two of them, Coelorinchus leptorhinus and C. sheni, have not been reported elsewhere. A total of 33 species and 10 genera are newly recorded from Taiwan; these were collected only within the past two years. Because the maximum depth trawled only reached about 2,000 m in this study, it should be expected that more deeper-water grenadiers will be found in the future. Our depth-distribution data-set of collected specimens and depth ranges from 55 stations were insufficient to effectively separate the species into groups using multivariate statistical analysis. However, the factors influencing grenadier species composition in this study still can be recognized as per the following sequence: water depth, geographical region, and type of net. The vertical distribution of grenadiers in Taiwan appears to have a separation at 600 m and 1000 m. An annotated species checklist with ASIZP cataloged specimens documenting Taiwan distributions, and detailed collecting information, including body size, location, and depth range are provided.

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Optical Projection Tomography Using a Commercial Microfluidic System

Micromachines ◽

10.3390/mi11030293 ◽

2020 ◽

Vol 11 (3) ◽

pp. 293

Author(s):

Wenhao Du ◽

Cheng Fei ◽

Junliang Liu ◽

Yongfu Li ◽

Zhaojun Liu ◽

...

Keyword(s):

Three Dimensional ◽

Numerical Aperture ◽

Microfluidic System ◽

Depth Of Field ◽

Objective Lens ◽

Flow Mode ◽

Wide Field ◽

Optical Projection Tomography ◽

Microfluidic Systems ◽

Optical Projection

Optical projection tomography (OPT) is the direct optical equivalent of X-ray computed tomography (CT). To obtain a larger depth of field, traditional OPT usually decreases the numerical aperture (NA) of the objective lens to decrease the resolution of the image. So, there is a trade-off between sample size and resolution. Commercial microfluidic systems can observe a sample in flow mode. In this paper, an OPT instrument is constructed to observe samples. The OPT instrument is combined with commercial microfluidic systems to obtain a three-dimensional and time (3D + T)/four-dimensional (4D) video of the sample. “Focal plane scanning” is also used to increase the images’ depth of field. A series of two-dimensional (2D) images in different focal planes was observed and compared with images simulated using our program. Our work dynamically monitors 3D OPT images. Commercial microfluidic systems simulate blood flow, which has potential application in blood monitoring and intelligent drug delivery platforms. We design an OPT adaptor to perform OPT on a commercial wide-field inverted microscope (Olympusix81). Images in different focal planes are observed and analyzed. Using a commercial microfluidic system, a video is also acquired to record motion pictures of samples at different flow rates. To our knowledge, this is the first time an OPT setup has been combined with a microfluidic system.

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Depth alone is an inappropriate proxy for physiological change in the mesophotic coralAgaricia lamarcki

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315419000547 ◽

2019 ◽

Vol 99 (7) ◽

pp. 1535-1546 ◽

Cited By ~ 3

Author(s):

Jack H. Laverick ◽

Tamara K. Green ◽

Heidi L. Burdett ◽

Jason Newton ◽

Alex D. Rogers

Keyword(s):

Photosynthetic Activity ◽

Single Species ◽

Pulse Amplitude ◽

Pulse Amplitude Modulation ◽

Depth Range ◽

Site Variation ◽

Depth Ranges ◽

Response To Environmental Change ◽

Pulse Amplitude Modulation Fluorometry ◽

Isotope Analyses

AbstractThe physiology of mesophotic Scleractinia varies with depth in response to environmental change. Previous research has documented trends in heterotrophy and photosynthesis with depth, but has not addressed between-site variation for a single species. Environmental differences between sites at a local scale and heterogeneous microhabitats, because of irradiance and food availability, are likely important factors when explaining the occurrence and physiology of Scleractinia. Here, 108 colonies ofAgaricia lamarckiwere sampled from two locations off the coast of Utila, Honduras, distributed evenly down the observed 50 m depth range of the species. We found that depth alone was not sufficient to fully explain physiological variation. Pulse Amplitude-Modulation fluorometry and stable isotope analyses revealed that trends in photochemical and heterotrophic activity with depth varied markedly between sites. Our isotope analyses do not support an obligate link between photosynthetic activity and heterotrophic subsidy with increasing depth. We found thatA. lamarckicolonies at the bottom of the species depth range can be physiologically similar to those nearer the surface. As a potential explanation, we hypothesize sites with high topographical complexity, and therefore varied microhabitats, may provide more physiological niches distributed across a larger depth range. Varied microhabitats with depth may reduce the dominance of depth as a physiological determinant. Thus,A. lamarckimay ‘avoid’ changes in environment with depth, by instead existing in a subset of favourable niches. Our observations correlate with site-specific depth ranges, advocating for linking physiology and abiotic profiles when defining the distribution of mesophotic taxa.

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Measurement of PSF for the extended depth of field of microscope based on liquid lens

10.1117/12.2193528 ◽

2015 ◽

Author(s):

Yujia Xue ◽

Yufu Qu ◽

Shenyu Zhu

Keyword(s):

Depth Of Field ◽

Liquid Lens ◽

Extended Depth Of Field

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Real-Time Depth-of-Field Rendering Using Depth Range Shift and Compression

Journal of KIISE ◽

10.5626/jok.2019.46.11.1106 ◽

2019 ◽

Vol 46 (11) ◽

pp. 1106-1112

Author(s):

Jeseon Lee ◽

Sungkil Lee

Keyword(s):

Real Time ◽

Range Shift ◽

Depth Of Field ◽

Depth Range

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A review of the spatial extent of fishery effects and species vulnerability of the deep-sea demersal fish assemblage of the Porcupine Seabight, Northeast Atlantic Ocean (ICES Subarea VII)

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq045 ◽

2010 ◽

Vol 68 (2) ◽

pp. 281-289 ◽

Cited By ~ 31

Author(s):

Imants G. Priede ◽

Jasmin A. Godbold ◽

Tomasz Niedzielski ◽

Martin A. Collins ◽

David M. Bailey ◽

...

Keyword(s):

Fish Assemblage ◽

Deep Sea ◽

Demersal Fish ◽

Commercial Fishing ◽

Depth Range ◽

Northeast Atlantic ◽

Porcupine Seabight ◽

Species Vulnerability ◽

Northeast Atlantic Ocean ◽

Depth Ranges

Abstract Priede, I. G., Godbold, J. A., Niedzielski, T., Collins, M. A., Bailey, D. M., Gordon, J. D. M., and Zuur, A. F. 2011. A review of the spatial extent of fishery effects and species vulnerability of the deep-sea demersal fish assemblage of the Porcupine Seabight, Northeast Atlantic Ocean (ICES Subarea VII). – ICES Journal of Marine Science, 68: 281–289. We review information from scientific trawl surveys carried out between 1977 and 2002 in the Porcupine Seabight and Abyssal Plain area of the Northeast Atlantic (240–4865 m water depth). Since the late 1980s, commercial bottom-trawl fisheries targeting mainly roundnose grenadier (Coryphaenoides rupestris), black scabbardfish (Aphanopus carbo), and orange roughy (Hoplostethus atlanticus) have been operating at depths of 500–1500 m, intersecting the depth ranges of 77 demersal fish species that would therefore be vulnerable to fishery effects. Comparisons of trawls pre-1989 and post-1997 indicate a significant decrease in total abundance of demersal fish down to 2500 m. Detailed analyses of the 15 most-abundant species showed that nine species with depth ranges within the commercial fishing depth have decreased in abundance. Other species were either not affected (Bathypterois dubius) or only affected at the shallow end of their range (Coryphaenoides guentheri). Species with a minimum depth of occurrence >1500 m (Coryphaenoides armatus and Coryphaenoides leptolepis) increased in abundance over part of their depth range. Decreases in abundance are probably caused by commercial fishing activities, an effect that is transmitted downslope by removal of fish at the shallow end of their depth range, resulting in declines at the deeper end of the depth range. The estimated fishery area is ca. 52 000 km2, but the potential impact probably extends to ca. 142 000 km2 and to many non-target species.

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