DOI: 10.5061/dryad.44j0zpcm5
title: EnderScope: A low-cost 3D printer based scanning microscope for microplastic detection

description: The EnderScope is a novel, low-cost microscope for automated scanning and
 detection of microplastics in filtered seawater samples. This microscope
 is based on the mechanics of a low-cost 3D printer (Creality Ender 3). The
 hotend of the printer is replaced with an optics module, allowing for the
 reliable and calibrated motion system of the 3D printer to be used for
 automated scanning over a large area (&gt;20x20 cm).  Here we
 present the optical and mechanical validtion of the EnderScope. Along with
 data from some proof of concept experiments that show the EnderScope is
 capable of detecting plastics in environmental seawater samples.
description: This README file was generated on 15-11-2023 by Niamh Burke. ## GENERAL
 INFORMATION 1. Title of Dataset: EnderScope: A Low-Cost 3D Printer Based
 Scanning Microscope for Microplastic Detection 2. Author Information A.
 Principal Investigator Contact Information Name: Niamh Burke Institution:
 University College Dublin Address: Dublin, Ireland Email:
 niamh.burke2@ucdconnect.ie <br> B. Associate or Co-investigator
 Contact Information 3. Information about funding sources that supported
 the collection of the data: This work is financially supported by the
 School of Medicine, University College Dublin, Irish Research Council
 Government of Ireland Postgraduate Scholarship (GOIPG/2020/1459) ##
 SHARING/ACCESS INFORMATION 1. Licenses/restrictions placed on the data:
 CC0 1.0 Universal (CC0 1.0) Public Domain 2. Links to publications that
 cite or use the data: Currently under review 3. Links to other publicly
 accessible locations of the data: None 4. Links/relationships to ancillary
 data sets: None 5. Was data derived from another source? No A. If yes,
 list source(s): NA 6. Recommended citation for this dataset: ## DATA
 & FILE OVERVIEW ### File List: 1. RawData\_MainFigures 1.1) Fig5
 Raw Data 1.1.1) Fig5\_scale.tif 1.1.2) Fig5A.bmp 1.1.3) Fig5B.bmp 1.2)
 Fig6 Raw Data 1.2.1) Fig6\_RawImages 1.2.2) Fig6\_stitched.tif 1.2.3)
 Fig6\_stitched\_mask.tif 1.2.4) Fig6\_Stitched\_ParticleDetection.xlsx
 1.3) Fig7 Raw Data 1.3.1) Fig7\_Fluorescence\_BigStitcherInput 1.3.2)
 Fig7\_Fluorescence\_RawImages 1.3.3)
 Fig7\_ReflectedLight\_BigStitcherInput 1.3.4)
 Fig7\_ReflectedLight\_RawImages 1.3.5)
 Fig7\_Fluorescence\_ParticleDetection.xlsx 1.3.6)
 Fig7\_Fluorescence\_StitchedMask.tif 1.3.7)
 Fig7\_ReflectedLight\_ParticleDetection.xlsx 1.3.8)
 Fig7\_ReflectedLight\_StitchedMask.tif 1.3.9) Fig7\_scale.tif 2.
 RawData\_SupplementaryFigures 2.1) S1 Raw Data 2.1.1)
 2023-11-06\_10-05-45.xml 2.1.2) 2023-11-06\_10-06-48.xml 2.1.3)
 2023-11-06\_10-07-32.xml 2.1.4) Plot\_Values\_normalized.csv 2.1.5)
 NeoPixels\_Spectrum.png 2.2) S2 Raw Data 2.2.1) S2\_AB 2.2.1.1)
 S2\_AB.xlsx 2.2.1.2) S2\_Scale\_AB.tif 2.2.1.3) S2A\_RawImage.tif 2.2.1.4)
 S2B\_RawImage.tif 2.2.2) S2\_CD 2.2.2.1) S2\_CD.xlsx 2.2.2.2)
 S2C\_RawImage.tif 2.2.2.3) S2C\_scale.tif 2.2.2.4) S2D\_RawImage.tif
 2.2.2.5) S2D\_Scale.tif 2.3) S3 Raw Data 2.3.1) S3\_RawImage.tif 2.3.2)
 S3\_Scale.tif 2.3.3) S3\_WedgeShape.stl 2.4) S4 Raw Data 2.4.1)
 S4\_RawData.xlsx 2.4.2) S4\_RawImage.tif 2.5) S5 Raw Data 2.5.1) S5\_Plots
 2.5.2) S5\_RawImages 2.6) S6 Raw Data 2.6.1) S6.xlsx 2.6.2)
 S6\_RawImage.tif 2.7) S7 Raw Data 2.7.1) S7AB\_RawImages 2.7.2)
 S7CD\_RawImages 2.7.3) S7.xlsx ### Relationship between files, if
 important: The raw data supporting the main figures (Fig. 5, Fig. 6, Fig.
 7 and Fig. 8) can be found in RawData\_MainFigures.zip Within this zip
 file are three folders: Fig5 Raw Data, Fig6 Raw Data and Fig7 Raw Data.
 'Fig5 Raw Data' contains raw images taken in reflected light and
 fluorescence mode using the EnderScope, and a scale image. 'Fig6 Raw
 Data' contains raw scan images, stitched image, stitched binary mask,
 and an excel file containing the results of particle detection on the
 stitched binary mask. 'Fig7 Raw Data' contains raw scan images
 taken in reflected light and fluorescence mode, processed images used in
 BigStitcher to generate large composite image, stitched binary mask of
 reflected light and fluorescence images, excel files containing the
 results of particle detection on the stitched binary masks, and a scale
 image. The raw data supporting the supplementary figures (S1, S2, S3, S4,
 S5, S6, S7) can be found in 'RawData\_SupplementaryFigures.zip'.
 Within this zip file are eight folders: S1 Raw Data, S2 Raw Data, S3 Raw
 Data, S4 Raw Data, S5 Raw Data, S6 Raw Data and S7 Raw Data. 'S1 Raw
 Data' contains the results of measuring the spectra of a Neopixel LED
 ring with a Rainbow Light MR-16 spectrometer. 'S2 Raw Data'
 contains two folders 'S2\_AB' and 'S2\_CD', which
 contain the raw images and MTF measurements for figure 2 panel A and B and
 figure 2 panel C and D respectively. 'S3 Raw Data' contains the
 raw image and scale image used to calculate the depth of field of our
 system. The stl file for the 3D printed wedge shape used to measure the
 depth of field of our system is also included. 'S4 Raw Data'
 contains the raw image and excel file containing the measurements for
 relative illumination of our system. 'S5 Raw Data' contains the
 raw images used to measure distortion in our system. The plots generated
 by the 'Distortion Correction' plugin in Fiji are also included.
 'S6 Raw Data' contains the raw image and excel file containing
 the measurements of spherical aberration in our system. 'S7 Raw
 Data' contains two folders 'S7AB\_RawImages' and
 'S7CD\_RawImages' which contain the raw images used to calculate
 the positional deviation in our motion system in the X-axis and Y-axis
 respectively. An excel table is also included showing the measurement and
 calculation of positional deviation of our system. 3. Additional related
 data collected that was not included in the current data package: None 4.
 Are there multiple versions of the dataset? No A. If yes, name of file(s)
 that was updated: NA i. Why was the file updated? NA ii. When was the file
 updated? NA
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: Fig5 Raw Data 1. Description of
 methods for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) A mixture of fluorescent (REAL fluorescent orange PLA
 filament 1.75mm) and non-fluorescent (Prusament Jet Black PLA 1.75mm,
 Prusa Research) PLA was imaged using the EnderScope in both reflected
 white light and fluorescence modes. A block of tree supports was generated
 using PrusaSlicer (Version 2.6.1) and printed in each colour filament. The
 support blocks were cut into smaller pieces before being shredded into
 fine particles using a blender (Texet nutri-vault, BB-6088). These
 particles were filtered through a 0.6 mm mesh (JBL Artemio 4, Sieve
 combination). Particles were placed on a dampened filter paper (Whatman
 602H1/2, 90 mm diameter, 10312642). The filter paper was not used to
 filter the samples, but to provide a realistic background for imaging.
 Aquisition: Raspberry Pi High Quality Camera, 12.3 megapixel, Sony IMX477
 sensor. Illumination: NeoPixel ring, 16x RGB LED, 16xWS2812. Pixels set to
 white (255, 255, 255) for reflected light imaging and green (0, 255, 0)
 for fluorescence imaging. Emission Filter (for fluorescence imaging): Red
 lighting gel from Neewer 35PCS Universal Photography Speedlite 47x77mm
 Square Full Color Balance Gel Filter Kit. Optics: 4x 185 Biological
 Microscope, Standard Plan Achromatic Objective Lens, NA = 0.1 with 60 mm
 tube length. 2. Description of methods used for data processing (describe
 how the data were generated from the raw or collected data)
 Fig5\_scale.tif was used to set the scale for Fig5A.bmp and Fig5B.bmp in
 Fiji ((Fiji Is Just) ImageJ 2.14.0/1.54f; Java 1.8.0\_172).
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: Fig6 Raw Data 1. Description of
 methods for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) A mixture of shredded 3D printer filament (PETG, PLA,
 Nylon and ABS) was shredded further in blender (Texet nutri-vault,
 BB-6088). Particles were filtered through a 0.6 mm mesh (JBL Artemio 4,
 Sieve combination) and placed on a dampened filter paper (Whatman 602H1/2,
 90 mm diameter, 10312642). The entire filter paper was scanned by the
 EnderScope in reflected white light mode using the SnakeScan.py script
 (Parameters used in script are: x\_win = 18, y\_win = 25, x\_step = 6.2,
 y\_step = 4.5, exposure = 5000, wb.gain = 4, 1). Aquisition: Raspberry Pi
 High Quality Camera, 12.3 megapixel, Sony IMX477 sensor. Illumination:
 NeoPixel ring, 16x RGB LED, 16xWS2812. Pixels set to white (255, 255,
 255). Optics: 4x 185 Biological Microscope, Standard Plan Achromatic
 Objective Lens, NA = 0.1 with 60 mm tube length. 2. Description of methods
 used for data processing (describe how the data were generated from the
 raw or collected data) Images were moved to a desktop computer and
 imported into Fiji ((Fiji Is Just) ImageJ 2.14.0/1.54f; Java 1.8.0\_172).
 These images were flipped vertically and horizontally in Fiji and the red
 channel was extracted. A large composite image was generated using the
 BigStitcher plugin in Fiji (Fig. 6). A gaussian blur filter was applied to
 the composite image (sigma = 12). The image was then thresholded (manual
 thresholding, default method) and particle detection was performed in Fiji
 (Analyse&gt;Analyse Particles). The area, size and circularity (an
 index of shape) of the detected particles was measured
 (Fig6\_Stitched\_ParticleDetection.xlsx).
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: Fig6\_Stitched\_ParticleDetection.xlsx
 1. Number of variables: 5 2. Number of cases/rows: 138 3. Variable List:
 (*Note:* all measurements have been converted to milimetres) * Area: Area
 of selection in square pixels. Area is in calibrated units, such as square
 millimeters, if Analyze&gt;Set Scale was used to spatially calibrate
 the image. * Circ: 4π\*area/perimeter^2. A value of 1.0 indicates a
 perfect circle. As the value approaches 0.0, it indicates an increasingly
 elongated shape. Values may not be valid for very small particles. * AR:
 major\_axis/minor\_axis. Enable "Fit Ellipse" in
 Analyze&gt;Set Measurements to have the major and minor axis
 displayed. * Round: 4*area/(π*major\_axis^2), or the inverse of the aspect
 ratio. * Solidity: area/convex area. The
 Edit&gt;Selection&gt;Convex Hull command makes an area selection
 convex. 4. Missing data codes: None 5. Specialized formats or other
 abbreviations used: None
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: Fig7 Raw Data 1. Description of
 methods for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) A seawater sample was collected from Howth Harbour, Co.
 Dublin (53°23′35″ N 6°03′59″ W) in October 2023. 1L of seawater was
 collected at high tide from the surface of the water. The seawater sample
 was treated with Potassium hydroxide (KOH). KOH flakes (Potassium
 hydroxide, reagent grade 90% flakes, Sigma Aldrich 484016-1KG) were added
 to the seawater sample to make a 10% w/vsolution. The sample was left at
 60°C overnight. The sample was then filtered through a stainless steel 125
 µm sieve (Test Sieve, Endecotts Ltd., 667924). Material collected on the
 sieve was resuspended in distilled water and neutralised to a pH of \~ 6
 with 1M HCl. The resuspended sample was filtered through the metal sieve
 again and the material on the sieve was covered with Nile Red (0.01mg/ml
 in methanol, Nile Red for Microscopy, Sigma Aldrich, 72485-100MG) in the
 dark for 15 minutes. The stained plastics were both washed and resuspended
 with distilled water and filtered through a filter paper (Whatman 602H1/2,
 90 mm diameter, 10312642). The filter paper was left to dry and imaged on
 the EnderScope using the SnakeScan.py script. The filter paper was scanned
 in both reflected light and fluorescence mode using the EnderScope (Snake
 scan parameters: x\_win = 17, y\_win = 23, x\_step = 6.2, y\_step = 4.5.
 Reflected light scan: exposure = 10000000, wb.gain = 3, 1. Fluorescence
 scan: exposure = 10000000, wb.gain = 3, 1). Aquisition: Raspberry Pi High
 Quality Camera, 12.3 megapixel, Sony IMX477 sensor. Illumination: NeoPixel
 ring, 16x RGB LED, 16xWS2812. Pixels set to white (255, 255, 255) and
 green (0, 255, 0) for fluorescence imaging. Optics: 4x 185 Biological
 Microscope, Standard Plan Achromatic Objective Lens, NA = 0.1 with 60 mm
 tube length. 2. Description of methods used for data processing (describe
 how the data were generated from the raw or collected data) Images were
 moved to a desktop computer and imported into Fiji ((Fiji Is Just) ImageJ
 2.14.0/1.54f; Java 1.8.0\_172). Images were flipped horizontally and
 vertically. The red channel was extracted for fluorescence images and a
 colour composite was generated for reflected light images. The
 fluorescence and reflected light images were both stitched into a large
 composite image with BigSticher. A gaussian blur filter was applied to the
 composite images (sigma = 12). The imaged were then thresholded (manual
 thresholding, default method) and particle detection was performed in Fiji
 (Analyse&gt;Analyse Particles). The area, size and circularity (an
 index of shape) of the detected particles was measured
 (Fig7\_Fluorescence\_ParticleDetection.xlsx,
 Fig7\_ReflectedLight\_ParticleDetection.xlsx).
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR:
 Fig7\_Fluorescence\_ParticleDetection.xlsx 1. Number of variables: 5 2.
 Number of cases/rows: 154 3. Variable List: (*Note:* all measurements have
 been converted to milimetres) * Area: Area of selection in square pixels.
 Area is in calibrated units, such as square millimeters, if
 Analyze&gt;Set Scale was used to spatially calibrate the image. *
 Circ: 4π\*area/perimeter^2. A value of 1.0 indicates a perfect circle. As
 the value approaches 0.0, it indicates an increasingly elongated shape.
 Values may not be valid for very small particles. * AR:
 major\_axis/minor\_axis. Enable "Fit Ellipse" in
 Analyze&gt;Set Measurements to have the major and minor axis
 displayed. * Round: 4*area/(π*major\_axis^2), or the inverse of the aspect
 ratio. * Solidity: area/convex area. The
 Edit&gt;Selection&gt;Convex Hull command makes an area selection
 convex. 4. Missing data codes: None 5. Specialized formats or other
 abbreviations used: None
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR:
 Fig7\_ReflectedLight\_ParticleDetection.xlsx 1. Number of variables: 5 2.
 Number of cases/rows: 329 3. Variable List: (*Note:* all measurements have
 been converted to milimetres) * Area: Area of selection in square pixels.
 Area is in calibrated units, such as square millimeters, if
 Analyze&gt;Set Scale was used to spatially calibrate the image. *
 Circ: 4π\*area/perimeter^2. A value of 1.0 indicates a perfect circle. As
 the value approaches 0.0, it indicates an increasingly elongated shape.
 Values may not be valid for very small particles. * AR:
 major\_axis/minor\_axis. Enable "Fit Ellipse" in
 Analyze&gt;Set Measurements to have the major and minor axis
 displayed. * Round: 4*area/(π*major\_axis^2), or the inverse of the aspect
 ratio. * Solidity: area/convex area. The
 Edit&gt;Selection&gt;Convex Hull command makes an area selection
 convex. 4. Missing data codes: None 5. Specialized formats or other
 abbreviations used: None
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S1 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) Emission spectra of a NeoPixel ring (16x RGB LED,
 16xWS2812) was measured using a Rainbow Light MR-16 spectrometer. 2.
 Description of methods used for data processing (describe how the data
 were generated from the raw or collected data) The spectrometer outputs
 the following XML files (2023-11-06\_10-05-45.xml,
 2023-11-06\_10-06-48.xml, 2023-11-06\_10-07-32.xml). The data from these
 XML files are combined into a CSV file (Plot\_Values\_normalized.csv).
 This CSV file is used to create the spectrum plot shown in Fig. S1.
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: Plot\_Values\_normalized.csv 1. Number
 of variables: 3 2. Number of cases/rows: 401 3. Variable List: * Red:
 Intensity of red light from neopixel * Green: Intensity of green light
 from neopixel * Blue: Intensity of blue light from neopixel 4. Missing
 data codes: None 5. Specialized formats or other abbreviations used: None
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S2 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) Fig. S2 A and B: The slanted edge of a black square
 located on a USAF 1951 resolution test target (Thorlabs, R3L1S4P) was
 imaged using the EnderScope. Images were taken in reflected light and
 fluorescence mode. Aquisition: Raspberry Pi High Quality Camera, 12.3
 megapixel, Sony IMX477 sensor. Illumination: NeoPixel ring, 16x RGB LED,
 16xWS2812. Pixels set to white (255, 255, 255) and green (0, 255, 0) for
 fluorescence imaging. Optics: 4x 185 Biological Microscope, Standard Plan
 Achromatic Objective Lens, NA = 0.1 with 60 mm tube length. 2. Description
 of methods used for data processing (describe how the data were generated
 from the raw or collected data) The SE\_MTF\_2xNyquist.jar ImageJ/Fiji
 plugin was used to generate MTF plots of both images Fig. S2 C and D: The
 slanted edge of a black square located on a USAF 1951 resolution test
 target (Thorlabs, R3L1S4P) was imaged using the EnderScope with the
 generic (4x 185 Biological Microscope, Standard Plan Achromatic Objective
 Lens, NA = 0) objective lens and the Nikon (Nikon CF N Plan Achromat
 4X/0.13) objective lens. Images were taken in reflected light mode.
 Aquisition: Raspberry Pi High Quality Camera, 12.3 megapixel, Sony IMX477
 sensor. Illumination: NeoPixel ring, 16x RGB LED, 16xWS2812. Pixels set to
 white (255, 255, 255). Optics: 4x 185 Biological Microscope, Standard Plan
 Achromatic Objective Lens, NA = 0.1 with 60 mm tube length and Nikon CF N
 Plan Achromat 4X/0.13 objective lens with 60 mm tube length. 2.
 Description of methods used for data processing (describe how the data
 were generated from the raw or collected data) Images are imported into
 Fiji ((Fiji Is Just) ImageJ 2.14.0/1.54f; Java 1.8.0\_172). The scale is
 set for each image. The red channel is extracted for each image. The
 rectangle tool in Fiji is used to select the slanted edge. The
 SE\_MTF\_2xNyquist.jar ImageJ/Fiji plugin was used to generate MTF plots
 of both images (measured in: cycles/pixel, sample size = 32).
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: S2\_AB.xlsx and S2\_CD.xlsx The above
 excel files follow the same format. Output of SE\_MTF\_2xNyquist.jar MTF
 plugin (measured in cycles/pixel) is converted to line pairs per
 millimetre (lp/mm).
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S3 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) To assess the DOF of the generic lens, a small 3D printed
 wedge shape was imaged using the EnderScope in reflected light mode. The
 wedge was printed in PLA at 0.05 mm layer height, meaning each layer of
 the wedge is spaced 0.05 mm apart in Z. Aquisition: Raspberry Pi High
 Quality Camera, 12.3 megapixel, Sony IMX477 sensor. Illumination: NeoPixel
 ring, 16x RGB LED, 16xWS2812. Pixels set to white (255, 255, 255). Optics:
 4x 185 Biological Microscope, Standard Plan Achromatic Objective Lens, NA
 = 0.1 with 60 mm tube length. 2. Description of methods used for data
 processing (describe how the data were generated from the raw or collected
 data) N/a
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S4 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) To measure the Relative Illumination (RI) of an image
 taken using the EnderScope, a USAF 1951 resolution test target (Thorlabs,
 R3L1S4P) was raised on a platform \~ 40 mm above a sheet of white paper.
 The paper provides a white background for the image. The target is raised
 above the paper to ensure a consistent and clean background, minimising
 the influence of any paper imperfections or dust particles on the RI
 measurement. The EnderScope was focused on a group of lines on the target.
 Keeping the Z position the same, an image was taken of a blank area of the
 target. The Neopixel ring was set to white light at maximum intensity.
 Aquisition: Raspberry Pi High Quality Camera, 12.3 megapixel, Sony IMX477
 sensor. Illumination: NeoPixel ring, 16x RGB LED, 16xWS2812. Pixels set to
 white (255, 255, 255). Optics: 4x 185 Biological Microscope, Standard Plan
 Achromatic Objective Lens, NA = 0.1 with 60 mm tube length. 2. Description
 of methods used for data processing (describe how the data were generated
 from the raw or collected data) Images are imported into Fiji ((Fiji Is
 Just) ImageJ 2.14.0/1.54f; Java 1.8.0\_172). The mean grey value across a
 diagonal line on the sensor was measured. This was then expressed as a
 percentage of the maximum grey value measured along this diagonal on the
 sensor and plotted against the distance in pixels across the sensor.
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: S4\_RawData.xlsx 1. Number of
 variables: 1 2. Number of cases/rows: 5070 3. Variable List: * %
 Brightness: Each grey value is expressed as a percentage of the maximum
 grey value (148.5764). 4. Missing data codes: None 5. Specialized formats
 or other abbreviations used: None
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S5 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) To measure the effects of distortion on our system A 3 x 3
 grid of images was taken of a sample with high contrastand 50% overlap in
 X and Y. Our chosen sample was a printed picture on card as this has
 enough contrast and structure to ensure the plugin can detect
 correspondence points between images. Aquisition: Raspberry Pi High
 Quality Camera, 12.3 megapixel, Sony IMX477 sensor. Illumination: NeoPixel
 ring, 16x RGB LED, 16xWS2812. Pixels set to white (255, 255, 255). Optics:
 4x 185 Biological Microscope, Standard Plan Achromatic Objective Lens, NA
 = 0.1 with 60 mm tube length. 2. Description of methods used for data
 processing (describe how the data were generated from the raw or collected
 data) Images are imported into Fiji ((Fiji Is Just) ImageJ 2.14.0/1.54f;
 Java 1.8.0\_172). The Distortion Correction plugin was used in Fiji with
 all default settings.
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S6 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) The effects of spherical aberration in our system was
 measured from an image taken of Thorlabs distortion target (R2L2S3P3)
 acquired using the EnderScope with the generic objective lens. Aquisition:
 Raspberry Pi High Quality Camera, 12.3 megapixel, Sony IMX477 sensor.
 Illumination: NeoPixel ring, 16x RGB LED, 16xWS2812. Pixels set to white
 (255, 255, 255). Optics: 4x 185 Biological Microscope, Standard Plan
 Achromatic Objective Lens, NA = 0.1 with 60 mm tube length. 2. Description
 of methods used for data processing (describe how the data were generated
 from the raw or collected data) Images are imported into Fiji ((Fiji Is
 Just) ImageJ 2.14.0/1.54f; Java 1.8.0\_172). In Fiji, the pixel intensity
 (grey value) was measured along a line along the x-axis of the image,
 starting from mid way through the y-axis of the image. It was ensured this
 line was passing through the approximate centre of each dot it
 encountered.
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: S6.xlsx 1. Number of variables: 1 2.
 Number of cases/rows: 4081 3. Variable List: * Grey Value: Grey Value of
 each pixel. 4. Missing data codes: None 5. Specialized formats or other
 abbreviations used: None
 #########################################################################
 ### METHODOLOGICAL INFORMATION FOR: S7 Raw Data 1. Description of methods
 for data collection or generation (include links or references to
 publications or other documentation containing experimental design or
 protocols used) Two dots were positioned 6 mm away from eachother on a
 piece of paper. To assess the movement repeatability of the EnderScope, a
 series of repeated 6mm movements back and forth were performed (29
 movements in each direction, 58 movements in total), with an image of the
 piece of paper acquired after each movement. This was repeated for both x
 axis and y axis movements. Aquisition: Raspberry Pi High Quality Camera,
 12.3 megapixel, Sony IMX477 sensor. Illumination: NeoPixel ring, 16x RGB
 LED, 16xWS2812. Pixels set to white (255, 255, 255). Optics: 4x 185
 Biological Microscope, Standard Plan Achromatic Objective Lens, NA = 0.1
 with 60 mm tube length. 2. Description of methods used for data processing
 (describe how the data were generated from the raw or collected data)
 Images are imported into Fiji ((Fiji Is Just) ImageJ 2.14.0/1.54f; Java
 1.8.0\_172). The images acquired were thresholded (manual thresholding,
 default method). Particle detection was performed (Analyse&gt;Analyse
 Particles). The centroid of the dot in each image was measured.
 #########################################################################
 ### DATA-SPECIFIC INFORMATION FOR: S7.xlsx 1. Number of variables: 2 2.
 Number of cases/rows: 58 3. Variable List: * Positional Deviation:
 Centroid of dot - average co-ordinates of centroid, measured in microns.
 4. Missing data codes: None 5. Specialized formats or other abbreviations
 used: None