OPTARC AF51 User manual
OptArc AF51 Camera
User Guide
Document created: 28.10.2022, Last edited: 24.11.2022
Manual prepared by OptArc − Designers
and manufacturers of custom optical and
optoelectronic systems using 3D printing
rapid prototyping and based in the UK.
See optarc.co.uk for details.
Safety nformation
Identification of risk
Throughout this manual please take heed of warnings given in bold text and
ig lig ted yellow to avoid possible damage to equipment and/or harm to people.
Risk to vulnerable groups
OptArc lab supplies and equipment are not toys. They contain small parts which may
come loose, glass components that may splinter or break or otherwise present a
choking or sharp object ha ard. Please do not let babies or young c ildren play
wit or gain access to any aspect of t is product. Older c ildren s ould only
access t is product wit close appropriate adult supervision. Likewise keep t is
product away from pets.
Risk of damage to eyepiece
This eyepiece camera is designed to be fixed over an eyepiece and clamped in position
by means of pressure from its three adjustment screws, this pressure being applied to
the outer casing of the eyepiece.
Although we have taken care to design this clamp mechanism to minimise the risk of
damage to the body of the eyepiece (for example by providing a protective plastic
sheath between the metal screw ends and the eyepiece) these measures will not
eliminate all risk of damage and some risk will always remain t at pressure from
t e clamp mec anism may cause wear, scratc es and/or indentation to t e outer
casing of t e eyepiece.
The user is advised to use minimum force when clamping the camera to an eyepiece
and take whatever additional measures they see fit to reduce the risk of this external
damage even further (e.g. by applying some protective coating between the eyepiece
barrel and the camera clamp such as a thin layer of rubber sheeting or tape).
In our experience, using OptArc® microscope eyepieces, no visible damage is caused
by careful use of this clamp mechanism but other makes and models of eyepieces may
be have more fragile coatings or less rugged walls.
Do not use t e clamp mec anism if t e metal of t e screws wears t roug t e
protective plastic s eat – damage will almost certainly occur to t e eyepiece
barrel in t ose circumstances.
By purchasing and / or using this camera the user agrees to accept responsibility for
protecting their eyepieces from such damage. Dr Paul J. Tadrous, TadPath and OptArc
cannot accept liability for any damage to eyepieces that may be caused due to the use
or misuse of this product.
OptArc AF51 Camera Page 2 of 99 User Guide v1.02
Safety certifications
The supplier of the electronic modules used in the AF51 states that the electronic
components have FCC, RoSH and CE certification. We have not made independent
tests on this so have not marked the camera with those certifications. The AF51 camera
is supplied and sold on the understanding that this is an item of custom equipment for
scientific research applications.
OptArc AF51 Camera Page 3 of 99 User Guide v1.02
Contents
Safety Information...........................................................................................................2
Identification of risk......................................................................................................2
Risk to vulnerable groups............................................................................................2
Risk of damage to eyepiece........................................................................................2
Safety certifications.....................................................................................................3
Download link for the PDF version of this manual...........................................................7
Video tutorials to accompany this manual.......................................................................7
Customise the camera to fit your eyepiece......................................................................7
Legal Information.............................................................................................................8
Copyright.....................................................................................................................8
Trade Marks................................................................................................................8
Limitations of Use........................................................................................................8
Disclaimer................................................................................................................... 8
Abbreviations...................................................................................................................9
1. Introduction................................................................................................................11
What’s included in the box.........................................................................................11
Overview of the AF51................................................................................................12
2. Recommended uses and limitations..........................................................................15
Recommended uses of the AF51..............................................................................15
Extra wide field of view afocal eyepiece projection...............................................15
Colour imaging in bright conditions.......................................................................16
Medium low light level applications.......................................................................16
General and macro photo / video recording..........................................................16
Limitations of the AF51..............................................................................................18
Highest magnification imaging..............................................................................18
Short eye-relief or narrow field eyepieces.............................................................19
Extreme low light level imaging.............................................................................19
Why not just use my smartphone camera instead?...................................................20
3. Detailed hardware specifications...............................................................................21
The CMOS sensor and lens......................................................................................21
The USB 2.0 microcontroller interface......................................................................24
User Controls........................................................................................................25
Camera Controls...................................................................................................28
OptArc AF51 Camera Page 4 of 99 User Guide v1.02
Camera stream formats........................................................................................33
3D Printed housing....................................................................................................34
Heat sink enclosure...............................................................................................34
Translation adjustable mount................................................................................36
Eyepiece clamp.....................................................................................................37
Tripod attachment.................................................................................................42
4. Additional hardware and software requirements........................................................43
Hardware...................................................................................................................43
Software....................................................................................................................43
Software development kit (SDK) and custom programming.................................43
PARD Capture for Linux........................................................................................44
Guvcview for Linux................................................................................................45
Microsoft AmCap and SDK for Windows...............................................................45
Webcamoid for macOS, Android and MS Windows..............................................47
Apple macOS and iOS..........................................................................................48
5. Fitting the AF51 to an eyepiece.................................................................................49
Eyepiece body diameters – limits of usability............................................................49
Eyepiece eye relief – limits of usability......................................................................52
Adjusting on an eyepiece to get a good image..........................................................56
Preliminary steps and aims...................................................................................56
Types of adjustment available...............................................................................57
Centring the optical axis........................................................................................57
Achieving the correct eye point level.....................................................................59
6. Introduction to PARD Capture...................................................................................60
Compiling the software..............................................................................................61
Starting the program: The main window....................................................................62
Preview frame integration (night vision)....................................................................66
The settings window..................................................................................................70
Custom settings.........................................................................................................72
Optional pre-processes.........................................................................................80
Saving and loading settings files...............................................................................84
Default settings.....................................................................................................84
Incompatibility between cameras..........................................................................85
Rules for manually editing a settings file...............................................................85
7. Achieving the best quality images with the AF51 – avoiding artefacts.......................88
OptArc AF51 Camera Page 5 of 99 User Guide v1.02
Uneven illumination – flat field correction..................................................................88
Quantisation artefacts and random noise..................................................................89
Dark current signal, bias and amplifier patterned noise............................................90
Colour streak artefact in low light conditions.............................................................92
Making a master flat and master dark for astronomy................................................93
Unnatural edge sharpening.......................................................................................93
Sample images..........................................................................................................94
8. Disposal and Recycling.............................................................................................95
Recycling of PLA Plastic in the UK............................................................................95
Recycling of PLA Plastic outside the UK...................................................................95
Electronics.................................................................................................................95
Index..............................................................................................................................96
OptArc AF51 Camera Page of 99 User Guide v1.02
Download link for the PDF version of this manual
Video tutorials to accompany this manual
Customise the camera to fit your eyepiece
OptArc AF51 Camera Page 7 of 99 User Guide v1.02
You can download the latest version of this User’s anual
as a PDF file from the Support section of the OptArc
website via this link:
https://www.optarc.co.uk/support/
The CAD files for the 3D printed eyepiece clamp for this
camera have been made open source so you can attempt to
modify it and print your own version to fit an eyepiece that
the standard clamp does not fit. See the Github page here:
https://github.com/TadPath/PU A
For video demonstrations on how to use this camera as well
as the PARD Capture software see the PU A icroscope
YouTube channel:
https://youtube.com/@PU A icroscope
Legal nformation
Copyright
This user’s manual is copyright © 2022 by Dr Paul J. Tadrous. All rights reserved.
Trade Marks
OptArc and the OptArc logo are Registered Trade arks of Dr Paul J. Tadrous
(registered with the UK Intellectual Property Office).
Limitations of Use
This equipment is released to be used for research and educational purposes only. The
AF51 camera is supplied and sold on the understanding that this is an item of custom
equipment for scientific research applications.
Disclaimer
Only competent people trained in the use of handling of photographic, video, computer
and optical equipment should use this product.
There is a risk of physical damage to the body / casing of eyepieces that have this camera
clamped onto them. The camera must not be affixed to an eyepiece if such risk is
unacceptable to the user or owner of the eyepiece. This notice is given here as fair
warning. Dr Paul J. Tadrous, TadPath and OptArc cannot accept any liability for any such
damage to eyepieces.
Dr Paul J. Tadrous, TadPath and OptArc cannot accept any liability for any loss or
damages that may occur from the misuse or mis-handling of this product or from the
failure to heed and abide by the warnings and safety notices set out in this document.
All information in this document is believed to be accurate according to the research and
understanding of the author and is provided in good faith and in the hope that it will be
useful. However, errors and omissions may be included herein. If any of this information is
considered important to some application the user should verify that information from
independent sources. Dr Paul J. Tadrous, TadPath and OptArc cannot accept any liability
for any loss or damages that may occur due to errors or omissions contained in this
document.
The descriptions and data presented in this manual only pertain to the genuine OptArc
AF51 camera sold via OptArc.co.uk. Similar looking clones may claim to share many or all
of the features of the AF51 but may not respond or perform in the way described in this
manual.
OptArc AF51 Camera Page 8 of 99 User Guide v1.02
Abbreviations
3D 3-Dimensional
AC Alternating Current
ADC Analogue-to-Digital Converter (or Conversion)
AE Ali Express (an online marketplace)
AEC Automatic Exposure Control
API Application Programming Interface
AWB Automatic White Balance
BH2 BHS A brand of microscope from Olympus
bpp bits per pixel
B P S Windows Bit aP (image file format)
CAD Computer-Aided Design
CCD Charge-Coupled Device
C OS Ceramic etal Oxide Semiconductor
D LS A brand of microscope from Leica
EFI Extended Focal (plane) Imaging
FD Fused deposition modelling (method of 3D printing)
FITS Flexible Image Transport System (file format)
FOV Field Of View
FPS Frames Per Second
gcc GNU Compiler Collection (C compiler and linker software)
GNU GPL GNU General Public License
HD High Definition
HSI Hue Saturation Intensity
JPEG Joint Photographic Experts Group (compression standard for digital photos)
LENC A pattern of variable gain across the image sensor designed to correct for
uneven illumination of a lens (LENs Correction). This pattern is fixed in the
sensor chip hardware (i.e. it does not change over time) and cannot be
modified by the user.
IT assachusetts Institute of Technology
OptArc AF51 Camera Page 9 of 99 User Guide v1.02
JPEG otion JPEG (compression standard for digital video)
P ega Pixels (= millions of pixels)
S icrosoft
OS Operating System
PARDUS Programmable Affordable Remote-controlled Drive Utility Standard
PDF Portable Document Format
PG Portable Grey ap (image file format)
PLA Poly-Lactic Acid (3D printer filament plastic)
PLL Phase Locked Loop
PNG Portable Network Graphic (image file format)
PP Portable Pix ap (image file format)
PU A Portable Upgradeable odular Affordable (open source 3D printed
microscope system)
RGB Red, Green and Blue
SDK Software Development Kit
SNR Signal-to-Noise Ratio
SOC System On-a Chip
TV TeleVision
UNC UNified Coarse (screw thread standard)
US United States (of America)
USB Universal Serial Bus
UVC USB Video Class (a communications protocol standard for video devices)
v4l2 Video for Linux 2 (programming API for video devices in Linux)
VGA Video Graphics Array resolution of 640 (wide) x 480 (high) pixels
WF Wide Field
YUYV A format for uncompressed digital video data
OptArc AF51 Camera Page 10 of 99 User Guide v1.02
Table of contents
