A Practical Tool for Ambient Illumination Comparisons at Dusk/Dawn

2016 ◽  
Vol 60 (1) ◽  
pp. 470-474 ◽  
Author(s):  
Hilary Lam ◽  
Sayf Gani ◽  
Randy Mawson ◽  
Jason Young ◽  
Erin Potma
Keyword(s):  
Human Perception ◽  
Time Lapse ◽  
Time Of Day ◽  
Ambient Illumination ◽  
Adjustment Factor ◽  
Lighting Conditions ◽  
Accurate Knowledge ◽  
Ambient Lighting ◽  
Practical Tool ◽  
Sky Conditions

Nighttime visibility is an important consideration in collision reconstruction and personal injury investigation. Decreased contrast in low ambient lighting conditions can greatly affect human perception and response. Because ambient lighting levels change rapidly at dawn and dusk, forensic investigators must have an accurate knowledge of the time of day and the cloud conditions at the time of the incident before initiating a nighttime visibility assessment. Previously, human factors experts attempting re-enactments at dawn or dusk have had to wait for sky conditions that match those at the time of the incident, making the investigation of those cases extremely difficult, if not unfeasible. In this study, an ambient illumination equivalency tool has been developed based on a database of time-lapse light meter readings collected by the authors. This new tool can be used to facilitate nighttime visibility assessments on any day by providing a time adjustment factor to account for the changes in ambient illuminance due to differences in the cloud conditions between the day of the incident and the day of the re-enactment.

P–188 Ambient light intensity and wavelength in the IVF laboratory does not affect life birth rates

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Farrera. Ayestaran ◽  
V Montalvo ◽  
J Masso ◽  
A Garcia-Faura ◽  
B Marques ◽  
...  
Keyword(s):  
Light Intensity ◽  
Clinical Outcomes ◽  
Light Exposure ◽  
Time Lapse ◽  
Control Group ◽  
Ambient Light ◽  
Ambient Illumination ◽  
Birth Rates ◽  
Lighting Conditions ◽  
Ambient Lighting

Abstract Study question Do different wavelengths and intensities in ambient lighting affect clinical outcomes? Summary answer Variations on ambient lighting intensity and wavelength do not affect life birth rates. What is known already Light is one of the factors to consider when designing an IVF laboratory. Most IVF clinics work under reduced illumination, trying to mimic uterine conditions as much as possible. Nevertheless, it has been described that 95% of the light that affects an embryo comes from the microscope, not ambient lighting. It is well accepted that exposure to extreme lighting conditions affects embryos through photo-oxidation and the creation of reactive oxygen species. Still, there is no study that documents the effect of different wavelengths on human embryos. Study design, size, duration Prospective study performed between january 2019 and february 2020. Every 60 days we changed ambient illumination conditions using the LED lighting installed throughout the IVF laboratory. Six different groups were created: Cyan (470nm), Green (550nm), Yellow (600nm), Orange (625nm), intense white (WH), and low intensity white (WL) as control group. Participants/materials, setting, methods A total of 572 egg donation cicles with 355 fresh single embryo transfers were included in the study. In all cycles ICSI and Time-lapse culture was performed (Embryoscope, Vitrolife). PGT and testicular biopsy/aspiration treatments were excluded. Eggs and embryos were exposed to ambient illumination during pick-up, denudation, ICSI, and embryo transfer procedures. Main results and the role of chance Light exposure during embryo/gamete manipulation is inevitable. Hence, we analyzed parameters linked to the success of an IVF cycle to assess the effect of different lighting conditions concluding that neither light color nor intensity affect IVF success rates. No differences were found between groups regarding maternal age, age of the recipient, diagnostic, or number of eggs received (p > 0.05). Fertilization rates were similar between groups (C = 77.04%; G = 73.72%; Y = 75.64%; O = 78.1%; WL = 76.4%; WH = 75.2%; p = 0.216) as well as good quality blastocyst rates (C = 57.35%; G = 57.37%; Y = 62.30%; O = 59.75%; WL = 63.28%; WH = 60.55%; p = 0.234). Regarding clinical outcomes both implantation and miscarriage rates were found to be equal between groups (C = 61.67%; G = 52.89%; Y = 55.10%; O = 66.18%; WL = 66.00%; WH = 53.55%; p = 0.194, and C = 24.32%; G = 19.15%; Y = 11.11%; O = 24.44%; WL = 15.15%; WH = 8.11%; p = 0.301). The main outcome for this study was live birth rates and no differences were found (C = 51.85%; G = 50.00%; Y = 52.17%; O = 53.97%; WL = 57.14%; WH = 50.75%; p = 0.168). Limitations, reasons for caution We must take into account that embryos were cultured inside a time-lapse incubator, diminishing the effect of ambient light. Wider implications of the findings: This study demonstrates that, with advances in culture technology, neither light intensity nor light wavelength affecting gametes/embryos during manipulation influence clinical outcomes. Trial registration number Not applicable

Flight By Periscope: Making Takeoffs and Landings; The Influence of Image Magnification, Practice, and Various Conditions of Flight

1966 ◽  
Vol 8 (1) ◽  
pp. 13-40 ◽  
Author(s):  
Stanley N. Roscoe ◽  
Scott G. Hasler ◽  
Dora J. Dougherty
Keyword(s):  
Image Magnification ◽  
Flight Experience ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
Experience Effects ◽  
Detailed Determination ◽  
Accuracy Speed

The proficiency with which pilots can make takeoffs and landings using a periscope as the only source of outside visibility was studied under various conditions of flight. A detailed determination was made of the effects of variations in image magnification upon landing accuracy. Speed of transition to flight by periscope was related to flight experience. Effects of various weather, runway surface, and ambient lighting conditions upon flight by periscope were investigated.

scholarly journals Software package for testing three-dimensional shape measurement methods using structured lighting

2021 ◽  
Vol 2057 (1) ◽  
pp. 012087
Author(s):  
S V Dvoynishnikov ◽  
V O Zuev ◽  
I K Kabardin ◽  
D V Kulikov ◽  
V V Rahmanov
Keyword(s):  
Software Package ◽  
Three Dimensional ◽  
Measurement Methods ◽  
Shape Measurement ◽  
Structured Lighting ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
Dimensional Shape ◽  
Shadow Maps ◽  
Three Dimensional Shape

Abstract This work aims at creating a universal software package for the development and testing of triangulation methods using structured lighting for measuring the three-dimensional geometry of objects in difficult ambient lighting conditions. As a result, a software package meeting the stated requirements is created. Lighting is based on the Fong model. A method for preloading objects is implemented to optimize the operation of the software package. An accelerated method for creating shadow maps is proposed and implemented. The developed software package is shown to successfully perform all required functions.

Clinical Study of the Influence of Ambient Lighting Conditions on the Mesh Quality of an Intraoral Scanner

2020 ◽  
Vol 29 (8) ◽  
pp. 651-655 ◽  
Author(s):  
Marta Revilla‐León ◽  
Sai Ganesh Subramanian ◽  
Mutlu Özcan ◽  
Vinayak Raman Krishnamurthy
Keyword(s):  
Clinical Study ◽  
Mesh Quality ◽  
Intraoral Scanner ◽  
Lighting Conditions ◽  
Ambient Lighting

The relationship between ambient lighting conditions, absolute dark-adapted thresholds, and rhodopsin in black and hypopigmented mice

2004 ◽  
Vol 21 (6) ◽  
pp. 925-934 ◽  
Author(s):  
GERARD H. DALY ◽  
JESSICA M. DILEONARDO ◽  
NATALIE R. BALKEMA ◽  
GRANT W. BALKEMA
Keyword(s):  
Bright Light ◽  
Visual Sensitivity ◽  
Segment Length ◽  
Single Strain ◽  
Photoreceptor Layer ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
Dim Light ◽  
Albino Mice ◽  
The Relationship

Significant variation in absolute dark-adapted thresholds is observed both within and between strains of mice with differing ocular pigmentation levels. Differences in threshold within a single strain are related to the Williams' photostasis effect, that is, photoreceptor rhodopsin levels are dependent upon ambient lighting conditions. To examine threshold differences among strains, we equalized rhodopsin levels by maintaining albino mice (c2J/c2J) at 2 × 10−4 cd/m2 (dim light) and black mice at 2 × 102 cd/m2 (bright light). This resulted in ocular rhodopsin levels for albino mice (albino—dim) of 494 ± 11 pmoles/eye and rhodopsin levels for black mice (black—bright) of 506 ± 25 pmoles/eye. For comparison, rhodopsin levels in black mice maintained in dim light are 586 ± 46 pmoles/eye and 217 ± 46 pmoles/eye in albino mice maintained in bright light. We found similar dark-adapted thresholds (6.38 log cd/m2vs. 6.47 log cd/m2)) in albino and black mice with equivalent rhodopsin determined with a water maze test. This suggests that dark-adapted thresholds are directly related to rhodopsin levels regardless of the level of ocular melanin. The number of photoreceptors, photoreceptor layer thickness, and outer segment length did not differ significantly between albino (dark) and black mice (bright). These results demonstrate that the visual sensitivity defect found in hypopigmented animals is secondary to abnormal rhodopsin regulation and that hypopigmented animals have either an improper input to the photostasis mechanism or that the photostasis mechanism is defective.

‘No More Unexplored Countries’: The Early Promise and Disappointing Career of Time-Lapse Photography

Film Studies ◽  
2006 ◽  
Vol 9 (1) ◽  
pp. 1-8 ◽  
Author(s):  
David Lavery
Keyword(s):  
Twentieth Century ◽  
Human Perception ◽  
Time Lapse ◽  
Ernst Mach ◽  
Use Of Time ◽  
Extended Duration ◽  
Time Lapse Photography

Time-lapse photography—the extremely accelerated recording and projection of an event taking place over an extended duration of time—is almost as old as the movies themselves. (The first known use of time-lapse dates from 1898.) In the early decades of the twentieth century, cineastes, not to mention scientists, artists, and poets, waxed eloquently on the promise of time-lapse photography as a means for revealing “things we cannot see,” and expanding human perception. This essay examines time-lapses tremendous initial imaginative appeal for such figures as Ernst Mach, Germaine Dulac, Jean Epstein, Rudolf Arnheim, Laszlo Moholy-Nagy, and Collette, and speculates about the possible reasons for its diminution over the course of the century.

scholarly journals Intellectual productivity under task ambient lighting

2016 ◽  
Vol 50 (2) ◽  
pp. 237-252 ◽  
Author(s):  
H Ishii ◽  
H Kanagawa ◽  
Y Shimamura ◽  
K Uchiyama ◽  
K Miyagi ◽  
...  
Keyword(s):  
Objective Evaluation ◽  
Average Concentration ◽  
Cognitive Tasks ◽  
Colour Temperature ◽  
Time Ratio ◽  
Lighting Conditions ◽  
Concentration Time ◽  
Ambient Lighting ◽  
Normal Colour ◽  
Intellectual Productivity

An experiment was conducted to evaluate intellectual productivity in three lighting conditions: (a) conventional ambient lighting, (b) task ambient lighting with normal colour temperature (5000 K) and (c) task ambient lighting with high colour temperature (6200 K). In the experiment, cognitive tasks were given to 24 participants. The concentration time ratio, which is a quantitative and objective evaluation index of the degree of concentration, was measured. The results showed that the average concentration time ratio under the task ambient lighting with high colour temperature was 72.5%, which was 5.0% points higher than that under the conventional ambient lighting. It is believed that intellectual work can be performed better when the concentration time ratio is high.

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