© Brooke Clarke, N6GCE 2002 -2023

    Surplus Shed T1655 Spotting Scope
    Passive IR Viewer
    Thermal Viewers
        Game Finder
CCTV Cameras
Light Sources
Light Meters
Electro Optical Gadgets
Optical Spectrum Analyzers
    K-8 Aerial Camera
Panoramic Telescopes
Camera Lucida
Pinhole Camera
Camera Obscura
    Color Match Problem
    Hockney–Falco thesis
    Tim's Vermeer
    Comparator Mirror
    Epidiascope (overhead projector)
    Bonfoton Up
        Newtonian - got these parts because of the Hockney-Falco thesis
        NC-3C Aircraft Collimating Gun Sight - Heads Up Display
        Telescope Unit Navy Bureau of Ordnance 417414 
    Oriel 120 VAC (+) Projector
    K&E Mystery Eyepiece
    Ednalite Projection Pointer
    Promaster Lighted Projection Pointer PB-387
Integrating Sphere
8" Plano-Convex Lens
HMMWV - Optics
Optical Patents - 2015 web page


Bausch & Lomb StereoZoom 4
Binoculars in general Orion 9x63 astronomical
Bushnell - Range Finding Binoculars - one objective is for IR Tx and the other objective is for IR Rx. Visible view is through a small central scope.  resolution is 1 meter with some hundreds of yards range to non cooperative targets, much longer with Scotch brite reflectors.  Can be used for rough surveying.
Cloud Sensor - IR or heat sensing
Exotech 100BX Radiometer -
M-227 Signal Lamp p/o Signaling Equipment SE-11 (flashlight with shoulder stock & sights)
MC-1 Magnetic Compass reference fluxgate sensor with small telescope
Leitz 115A transit (now Sokkia 7327-60) surveyors transit (4 leveling screws model 116)
T. F. Randolph Level - for land leveling
K&E hand Levels -
K&E 76 0000 Alidade - used for map making
Mitutoyo Toolmakers Measuring Microscope 176-134
Nikon Labophot Microscope
Nikon SMZ-U Stereo Microscope
Rangefinders - Bushnell, Laser Technology, Stadiameters -
EdscorpFRF Edscorp Field Range Finder by Edmund Scientific Corp.
Dragunov PSO-1M2 Rifle Scope night illumination
Theodolites - mainly for measuring horizontal and vertical angles with a range of a full circle in both directions.
Panoramic Telescope M12 -

Surplus Shed T1655 80mm 20-60X Spotting Scope (Wollensak Rally) - similar specs as the Konus 7120
Fig 1
                      Shed T1655 80mm 20-60X Spotting Scope (Wollensak
Fig 2
                      Shed T1655 80mm 20-60X Spotting Scope (Wollensak
Fig 3
                      Shed T1655 80mm 20-60X Spotting Scope (Wollensak
Fig 4
                      Shed T1655 80mm 20-60X Spotting Scope (Wollensak
Fig 5
                      Shed T1655 80mm 20-60X Spotting Scope (Wollensak


Flashlights - Xenide   AEX25 1500 Lumen HID flashlight
Binoculars in general Orion 9x63 astronomical (note with large (7mm) exit pupil diameter they work well at dusk and dawn)
PAS-6 Metascope IR viewer and source
T3C - Russian monocular Image Intensifier (star light scope)
TVS-2 Crew Served Weapon Sight
M18 IR Binoculars - near IR not hot people or car engines
M32 Periscope 105mm IR Gun Sight
MD-1 Automatic Astro Compass - also can see stars in the daytime
Astro-Compass for sighting Sun & stars
Periscopic Aircraft Sextant - Sun & stars
NextStar60 - cleaver microcontroller telescope using DC motors and shaft encoders
Orion - 9x63 binoculars - When the objective diameter (63 mm) is divided by the power (9X) if the exit pupil size (7 mm) is around 7 mm then the binocs are designed to be used with night adapted eyes, like for looking at the stars or to see things on the ground you could not see with bare eyes.  I once watched a dear swimming while being chased by a dog just after Sunset.  Although I could not see anything with my bare eyes, I could see fine with a pair of 7X50 binocs.  See my Binoculars page for more on star gazing binocs.
Orion GoScope 80 Table Top Telescope 80mm x 350mm objective
Celestron 8" Telescope with Equatorial wedge and tripod- This model has a clock drive but no computer control.  It's big and heavy, not something you pull out for a quick 5 minute look up.  Would be much better if used with a permanent pier.  It takes quite some time to do a Polar alignment, but when done you can find about anything just using the hour angle and declination scales.
Shadow or Projection Clocks
PVS-4 Starlight Scope
PVS-5A Night Vision Goggles
US Navy Infrared Signaling Telescope US/C-3 -
M32 IR Gun Sight -
VVS-2(V)4 Driver's Night Vision Viewer

Passive IR Viewer


These were issued in sets of 5 to allow seeing near IR lights used with early night vision equipment.  They do not need batteries.
Shining a UV light on the screen (Fig 3) shows no Phosphor activity.
When the screen (Fig 3) is illuminated using a TV remote it turns bright green.  There is no after glow, i.e. it follows the flashing of the remote.
The image is inverted.  Why the Filter (let me know)
The viewing screen is a glass disk about 19mm diameter and is loose.  You can hear it rattling when the unit is shaken.  I don't see any provision to trap it.
Fig 1
Passive IR Viewer
Fig 2
Passive IR Viewer
Fig 3
Left: Eyepiece & IR sensitive screen
Center: Visible cut filter
Right: Astronomical telescope
Passive IR Viewer
Fig 4 Top: eyepiece with Filter
Bottom: telescope
Passive IR Viewer
Fig 5 Set of 5 viewers and one near IR lamp.
Passive IR Viewer
YouTube Video of TV remote flashing screen

Radio Shack Infared Sensor 276-1099

These were intended for checking IR remote controls (Wiki) which operate at 940 nm.  Also see IR USB Toy for decoding IR remotes and Big Ass Fans for an example.

On the back of the package the IR response curve peaks at about 940 nm which is consistent with IR remote operation.

Also note the operation of this card is is very similar to the above Passive IR Viewer.  Note the instructions say to charge the sensor using UV light prior to use.

Fig 1
Radio Shack
Fig 2
Radio Shack

Near IR Patents

3327120 Infrared imaging system using a photochromic glass viewing screen, Sidney Weiss, Jun 20, 1967, 250/461.1, 359/356, 250/330, 250/342, 348/E05.9, 348/164 - uses UV light and needs DC bias so not this case.
4705952 Communications apparatus using infrared-triggered phosphor for receiving infrared signals, Joseph Lindmayer, Quantex Corporation, Nov 10, 1987, 250/484.4, 398/202, 250/483.1 - the Quantex patents seem like this material.
4812660 Photoluminescent materials for outputting yellow-green light, Joseph Lindmayer, Quantex Corporation, 14 Mar 1989, 250/484.4, 428/691, 252/301.40S, 252/301.40H, 427/64, 428/690 - this may be the one. Peak input sensitivity (Fig 3) at 1170 nm and peak output at 500 nm.   

Thermal Viewers

Cloud Detection - as part of weather forecasting like used as part of an automated observatory
Hughes Probe Eye far (heat) IR viewer
Thermal Hand Held Imager DFOV thermal IR viewer
UAS-4 Infrared Surveillance System, AN/AAS-14 Infrared Detecting Set, MK-898/AAS-14A Optical Filter Kit

Seek Compact Thermal Imager for Android (Amazon) - seems better than the stand alone units by Fluke and others. Most models have 206x156 resolution and come in two fields of view (20 or 36 deg), but the CompactPro has 320x240 resolution, but for twice the price (about $500 list).  Don't have one yet.

Game Finder (home page) - a PIR sensor (requires manual scanning) with LED bar graph display.  Button on right side & menu on left side, but without a manual very difficult to use.  This model uses a 9V battery (see polarity marks in Fig 2 below.
Fig 1
Game Finder
Fig 2
Game Finder

CCTV Cameras

Super Circuits P-164C (KPC-350BH) Low Light Monochrome CCTV Camera
Super Circuits P-38 9Mintron 63V5) Integrating Low Light Color CCTV Camera w/RS-232 Remote Control
Harbor Freight Color Security Camera
PC33C TV camera
Super Circuits PC-38 (Mintron 63V5) CCTV Camera - used for Astronomy-Weather-Sky web cam
Cell Phones - iPod touch- have video camera capability

Light Sources

Flashlights - patents and photos of many historical examples
IR Beacons - individual identification, anti fratricide, landing marker
Survival Lights - both conventional and strobe, IR filters are available
LEDs - IR LEDs are also available
Ultraviolet - sources and detectors
Unihedron Nu-B Light Source - white, blue, green, yellow, red and IR (950 nm) pulse width modulated to get about the same output from each.


Carley Lamps - specialized lamps under 20 watts including lens and reflectors up to 6"
Newport Glass - telescope parts, Hoya CM500 IR cut filters

Light Meters

Amprobe (Meterman) LM631A Digital Light Meter
Weston Model 594 Photronic Cell plus many more Weston light meters
Macbeth Illuminometer
Spectronic 20D Spectrometer
also see Integrating Sphere for photometers
Gamma Scientific Photometer - some on eBay this may be patent: 3813172 Photometric device with a plurality of measuring fields, R Walker, R Weisner, Kollmorgen Corp , 1974-05-28 - maybe Gamma Model 700, Spectra 1970 PR-1

Electro Optical Gadgets

Simple things I've made for looking at electro optical effects.

Optical Spectrum Analyzers (Spectrometers)

Optical Spectrum Analyzers
Monolight Optical Spectrum Analyzers
Beseler PM1 Darkroom Color Analyzer
Wollensak L3524D Direct Vision Spectroscope
Ocean Optics HR2000 Spectrometer
HP 70950 Series OSA
Spectronic 20D spectrometer

Hilger Watts Spectrometer - prism based, but I think there was a grating upgrade.  Let me know.

Exotech 100BX Radiometer -
AN/UAS-4 Infrared Surveillance System -
Pyranometers -
Campbell Stokes Sunshine Recorder -


Bausch & Lomb StereoZoom 4
Optical Bench - with draw tube microscope
Omnicon 3800 Tumor Colony Analyzer (TCA) Automated Inverted Biological Microscope
Mitutoyo Toolmakers Measuring Microscope 176-134
Nikon Labophot microscope
Nikon Multiphot - List of Nikon "phot" microscopes for photography
Nikon SMZ-U stereo
Simple Microscopes - Foldscope - Leeuwenhoek Replica - Bullet
Micro Photography - Including many microscope objectives used directly on camera, Direct projection of microscope objective lenses & Infinity tube camera adapter
Unitron No. 83444 Student Microscope


Photographic Studio Strobe System
High Dynamic Range Digital Photography
DigitalPhotography101 Digital Photography 101: The Basics
Digital Photography 201 Stacking Images
Digital Photography 202: Close-Up, Macro & Micro
Digital Photography 203: Color Management
Digital Photography 204: Studio Flash
Digital Photography 205: Astrophotography
Digital Photography 206 Micro Photography

K-8 Aerial Camera

Aerial Reconnaissance (Wiki), Fairchild K-20 aerial camera (Wiki) takes 4"x5" negative images on roll film.
Evolution of Airborne Remote Sensing 1783 - 1950.pdf - mentions Heliograph, Kettering Bug (Wiki), "Sherman Fiarchild took on the task of constructing a focal plane shutter equipped aerial camera during World War I, but didn’t get it completed until 1920. This camera revolutionized aerial photography.", Norden Bombsight
Hand held 15" focal length lens. 
Patent number plate seen on K-8, K-19B, L-2A, F-56 Fairchild and on the Keystone F-20 aircraft ca8 aerial cameras
Universal mounting for aerial cameras, S.M. Farichild
Information-recording attachment for cameras
"a group of instruments"  1929-08-06
Driving and controlling mechanism for automatic cameras
Electrically operated camera shutter
Aerial camera, Fairchild ,1927-01-04 -
Looks like eBay camera
Process of and apparatus for making
aerial photographs, Leon T Eliel, 1929-11-12 -
takes octagon shaped photo
Aerial camera control mechanism
Photographic apparatus
Intervalometer (Wiki)
Camera, Fairchild
Warning signal (shutter about to be released)
Camera magazine
Surge timing system for electromagnetic devices (fixing L/R problems)
Airplane view finder, Stevens
Transformer printing camera
(negative angles relative to lens)
Camera mechanism
Photographic enlarger
Photographic shutter, S.M. Farichild
1779424 (also for K20)
ReWinding and resetting mechanism
(for each exposure, by feel)
Multilens aerial camera
4-lens turret
Camera, Sherman M Fairchild, 1926-01-12
Aerial camera (Lens cone), S.M. Farichild
Aerial camera, 1930-11-25,
Camera mount
2131926 (also for K20)
Camera magazine
Camera shutter, Fairchild Sherman Mills, 1929-04-02
Film-changing and positioning device for cameras
1974842 (also for K20)
Camera, 1934-09-25
Focal plane camera shutter, 1938-10-11,
William A Black

K-20 Specific Patents
1779424 see above
1974842 see above
2131926 See above


Also see Periscopes on my Submarine web page.
The common understanding of periscopes (Wiki) comes from their use on submarines (Wiki).  But there are also used on armored vehicles, like the M32 IR gun sight and VVS-2(V)4 Driver's Night Vision Viewer
There some key concepts. 
1. The image should be right side up (erect) and correct left to right so the direction of movement is instinctive.
2. A relay lens (Wiki) system is used where parallel rays of light are in the part of the periscope where it changes length.  This way there's no effect on focus.
3. For a fixed eyepiece periscope, i.e. one where the top mirror or prism is rotated in azimuth but the eyepiece stays pointing in the same direction, some method of keeping the image from rotation with the change in azimuth is needed.  See the Panoramic Telescope M12.
1006230 Periscope F.L.G. Kollmorgen (working for K&E), Oct 17 1911, 359/401, 89/36.14, 359/402, 114/340 - meets all of the above concepts

Prisms and their Applications - Found this link in relation to camera obscuras, but it's more applicable here

Panoramic Telescopes

A panoramic telescope (or panoramic sight) is very similar to a periscope.  They are used on fixed artillery in the process if aiming.
The eyepiece is fixed so all the concepts needed for a fixed eyepiece periscope apply.
M12 Panoramic Telescope.

Camera Lucida

The Camera Lucida (Wiki) uses the brain to fuse an image of some subject and the surface being drawn upon.  But there is not a real image on the surface.  Also if the eye position changes the image position changes making it use difficult.
 YouTube: DIY Camera Lucida Project - plain mirror + glass sloped forward so image is right side correct

The Etchr Lab Mirror is a from of Camera Lucida.
Fig 1 from Ancient Magic Art Tools
Camera Lucida
Fig 2
Camera Lucida

Pinhole Camera

A Pinhole Camera (Wiki) depends on the idea that a small small (1/100) compared to the distance from the hole to a white reflecting surface will form an image on the surface.  A lens with an f/number of 100 or greater can be replaced with a hole of the same diameter.  There's a school of photography called Group f/64 (Wiki). 

I made a Noon Mark (Wiki) using a metal plate at the bottom edge of a long narrow skylight with a hole.  It acted as a lens so instead of getting just a spot of light on the floor there was an image of the Sun.  Using a 3x5 card (these were originally developed for time keeping, see Calculagraph) with a number of ellipses drawn with different ratios and matching the Sun's image to an ellipse to track the Sun until exactly noon, then stopping and driving a brass tack into the hardwood floor an Analemma (Wiki) was drawn after a year of this.  After another year you could see that the brads were slightly offset, and again after three years they were in small groups.  During the summer when the distance from the hole to the floor was shortest the image was both bright but not a well focused as in the winder when the image was a lot dimmer but better focused.

The problem is that a well focused image is dim.  A Lens can fix that problem.  Note when a lens is it's focal length from a screen objects at infinity will be focused.  As objects get closer to the lens it needs to be moved away from the screen and for an object that's 2xFL the lens needs to be 2xFL from the screen.

Camera Obscura

One type of Camera Obscura (Wiki) is a dark room with a pinhole in one wall and the opposite wall a smooth white reflecting surface.   But the more common version uses a lens in order to get a brighter image. 

Many of the circular table type viewing screens are concave to match the focal plane of the optical system.  How to figure this out?
Answer: Petzval field curvature (Wiki)
"The Voigtländer-Petzval was the first camera and lens specifically designed to take photographs, instead of being a modified artist's camera obscura."..."...it had what would now be considered severe field curvature and astigmatism" (Wiki).

Edinburgh's C.O. - some technical info on lens diameters and focal distance, questionable if enough for reverse engineering.
A Look Into Camera Obscuras - visiting a number of C.O. in Europe  (click on image to open pdf)
Camera Obscuras - George T. Keene designs them
Discovery Park, Safford, Arizona  The Magic Mirror of Life, an appreciation of the Camera Obscura - Links to more CO web pages-The Magic Mirror of Life by Jack & Beverly Wilgus - They have a 7' x 7' portable tent and a single person tent.
Scientific American - Amateur Telescope Making Advanced (Book Two) - telescope in attic used as a camera obscura
Ancient Magic Art Tools - Camera Obscura -
San Francisco - Cliff House - Camera Obscura -2019 June 7: she said it's open when the weather is good like now. - Camera Obscura in Cliff House? - yes there was one - Terrace - Giant Camera -
2019 July 19
GiantCamera.com - email -
Flyer -
Exploratorium - Video about this Camera Obscura -

LIFE magazine Mar 1, 1954: "Speaking of Pictures" photo of building as first built (did no look like a camera from the outside.) - 150" focal length lens. Viewing table/screen 6' diameter.

Fig 1 Front of Camera Obscura building.
Stairs to Cliff House on left.
Cliff House -
                  Camera Obscura
Fig 2 Ocean, waves & Island seen on viewing screen
Cliff House -
                  Camera Obscura
Fig 4 Viewing screen has a large amount of dish
Very large hole in ceiling
Cliff House -
                  Camera Obscura
Fig 5 Separate entrance and exit doors.
Notice overcast
Cliff House -
                  Camera Obscura
Fig 6 Notice ocean and now sunny
On back wall a reference to Veremeer
Cliff House -
                  Camera Obscura
Fig 7 The pyramid "all seeing eye" is motor driven.
Note it's pointing different directions in different photos.
Cliff House -
                  Camera Obscura

1973921 Color finder and method for the Study of Painting, A.K. Cross, Sept. 18, 1934 - dual camera obscuras, one looking at the subject the other at the painting.
1387439 Drawing and painting glass, A.K. Cross, Aug 9, 1921 - depends on blurring subject and painting using a lens to get color match
1041435 Drawing-tablet, , A.K. Cross, Oct 15, 1912 - glass surface to check perspective
491160 Process of testing and correcting free-hand drawing, A.K. Cross, Feb 7, 1893 - clear glass plate used to compare drawing, not a camera obscura

Bonfoton Up

Bonfoton makes a simple lens to be used in a room to make it into a camera obscura and the "Up" which is a lens + prism combination so that the image is right side up.  The up comes with both 3.2 and 4 meter focal length lenses.  That means the distance between the "Up" and the room's opposite wall should be betweem 10.5 feet and about 13 feet to get objects at infinity is sharp focus.

 YouTube: Mathieu Stern: Turning a Paris Apartment into a GIANT CAMERA!, 8:36 -

Color and Gray Scale Match Problem

While it's possible to do a pen or pencil drawing inside a darkened room (camera obscura) it is not possible to match colors.  The only color that will match is white.  In order to match colors white light needs to fall on the canvas so the color can be seen.  This suggests that instead of using black cloth for a camera obscura white cloth should be used.  The idea is to have white light inside the tent that is much dimmer than the outside but still enough light to see the colors being used.

Hockney–Falco thesis

Something I have not seen mentioned is that keeping the lens to image distance constant allows focus stacking.  The idea is to take a number of photos where the camera to subject distance is changed and then combine all the photos to get a dramatic improvement in the depth of focus.  For this to work the camera focus setting can NOT be changed.  This means that many of the optical artifacts mentioned in the literature in relation to paintings were caused by the artist changing the lens to canvas distance in order to focus on different areas.  But if instead the lens to canvas distance was kept constant these artifacts could be eliminated.  I wonder if there are examples of this improved technique?

YouTube: Short version: David Hockney, The Lost Secrets of the Old Masters: camera lucida obscura 2010 - related to his book Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters (Ref 1).

The telescope (Wiki: telescope history) was a Dutch invention in the early 1600s.  The microscope is invented in this same time frame (Wiki) but it wasn't until the late 1600 that Leeuwenhoek popularized the simple microscope.  It was not a coincidence that the Dutch Masters (Wiki) were located where optics was being developed.  "The new Dutch Republic was the most prosperous nation in Europe, and led European trade, science, and art."  The period of the Dutch Master painters is 1615  to 1702

Hockney–Falco thesis - Art-Optics.com  (Wiki) - "...optical aids were the key factor in the development of artistic realism...starting about 1420..." not camera Lucida, but Camera Obscura done with mirrors since lenses were not yet available.  Referenced Books:
Digital Photography 201 Stacking Images
Digital Photography 202: Close-Up, Macro & Micro
Digital Photography 206 Micro Photography
YouTube: Ibn Al-Haytham’s Contributions to Optics and Renaissance Art -  Charles Falco (27:31 no slides, 14:15 with  slides & poor audio) - demonstrates some of the optical distortions (slides not shown, see below)
Paintings Referenced in above talk (go to Wiki page for much higher resolution):
Van Eyck - Arnolfini Portrait
 (Wiki, July 2000 paper)
Chandelier, carpet just below joined hands
Van Eyck - Arnolfini Portrait
Husband and Wife by Lorenzo Lotto (WikiArt)
IR camera analysis paper, tablecloth
Husband and Wife by Lorenzo Lotto
The French Ambassadors to the English Court
Hans Holbein the Younger 1532
Skull & Globe (a World History of Art)
                    French Ambassadors to the English Court Hans Holbein
                    the Younger 1532
Charles Falco: The Tyranny of the Lens (1:15:06) - This contains some of the Ibn Al-Haytham talk with good sound and slides. linked to from one of his his UoA web pages
YouTube: ΦBK Visiting Scholar Charles Falco on: "The Art and Science of the Motorcycle" goes with the very heave coffee table book The Art of the Motorcycle.  See Europe v. U.S. Roads.

The New Yorker, January 31, 2000 P. 64 - The Looking Glass - This article started the Hockney - Falco collaboration.
When doing focus stacking photography, in order to get great depth of filed, you can not change the camera focus setting, instead you need to move the camera and lens as a unit.  The StackShot holds the camera on a rail where a computerized system triggers the shutter and then moves the camera repeatably to take dozens of images all with identical perspective that can later be combined.
This same principle applies to an artist working with a lens.  Although it's much easier to change the focus (lens to canvas distance) that changes perspective.  Instead what needs to be done is move the lens and canvas as a unit to bring different parts of the subject into focus.

YouTube: Caravaggios Secrets - realistic painting (Wiki) - Hockney proposes the idea that Caravaggio used optics. - misses Tim Jenison's idea that a comparator mirror is the only way to match tone or color.  All that can be done in a camera obscura is to make line drawings and most of the photo realistic paintings have no underlying line drawing.  It's a common mistake to change the lens to canvas/film distance to change the focus, but a better way is to change the subject to lens distance thus preserving the perspective.  The scale was 1:1 which is an artifact of using just the comparator mirror.  The two medusas (Wiki) of slightly different sizes, but otherwise congruent is consistent with the comparator mirror with a slightly different mirror to canvas distance. 23:29 the lines may have been used to return the actors to the proper pose rather than being used as drawing aids.

Tim's Vermeer 2013 movie (IMDB, Sony Classics, Essential Vermeer)

Tim's daughter gave him the book Vermeer's Camera by Steadman for his birthday and that was the start of the project the lead to the movie. Not clear if that was 2001 (UK edition) or 2002 (US edition).
YouTube: SFI Community Lecture Tim Jenison (1:13:44) -
After the movie David Walsh, founder of the Mona museum in Tasmania, hired Tim Jenison to do a project where various people would paint Vermeer like paintings using his equipment.  After that Tim went to Delft to paint a city view that includes a few of the original buildings.
Mona - Hound in the Hunt - Catalog/book on order 4/28/2019 - Mona Blog: Hound in the Hunt -

A lens alone makes an image that's both upside down and left to right reversed.  So if the image is turned upside down to put the top of the subject at the top of the image it's still reversed left to right.

A lens and a mirror results in an image that's upside down.  But when the image is turned upside down it's correct top to bottom AND left to right.  So this is a good combination for a camera obscura.

Tim's Vermeer 2013 movie
Vermeer's Camera and Tim's Vermeer 33:52
Final Setup
0. Note white light washing wall (6).
1. Subject to the right of photo in room with North light.
2. Lens of camera obscura.
3. Convex mirror can be positioned to project bright image.
4. Camera Lucida mirror to allow color matching at edge
5. Canvas on table.

In a prior setup there was a white screen on the wall (6)
and a mirror somewhere.  But this was not adequate for
very fine detail, so was replaced with a flat mirror which
made for a much brighter image, but still not enough
magnification for very fine work.  The flat mirror was
replaced with the magnifying mirror (3).
Tim's Vermeer OPtical setup
                    Camera and Tim's Vermeer
Setup Explained YouTube: Tim's Vermeer with Fine Art Connoisseur

Makes some interesting points:
1. You can not paint when looking at the image inside a camera obscura.  This is because the only color that will match the projected light is white (see note 0 above).  So, while you can do pencil sketches in a camera obscura you can not paint with color.
2. You can do an excellent job of color matching by using a mirror type camera Lucida (4 above).  Where white light is falling on the surface of your painting.
3. If the camera obscura projects a real image the brightness and resolution will be degraded.   This makes sense since a white surface will scatter the light making the light that reaches your eye much dimmer.  Also the surface roughness of the white surface will lower the resolution.  Tim got around this by replacing the white surface with a mirror (3 above).  At first he used a flat mirror (at 6), but later changed to a concave mirror which added some magnification to the image of the scene making it easier to paint fine details.
4. Tim saw curvature in one of the lines.  I think it was barrel distortion (Wiki) from his lens.

What I think is missing is to use magnification between the artist's eye and the canvas.  The quality of details when working at say 4x magnification makes a tremendous improvement in the results.  Hand - Eye coordination improves with optical magnification, see Surface Mount Components.
YouTube: Triangulation 118: Tim Jenison - 58:32 - interview Tim Jenison
YouTube: Tim's Vermeer // Featurette - Tim explains Vermeer (OV) - Martin Mull
Teller talks Tim's Vermeer 32:30 -
Tim's Vermeer pals Penn & Jenison
YouTube: David Hockney's Secret Knowledge part 3 of 8 - Falco calculates lens parameters for Lorenzo Lotto painting (center above), in part 7 they use a candle in a camera obscura
YouTube: David Hockney's Secret Knowledge - Parts: 1, 2, 3, 4, 5, 6, 7, 8.
Essential Vermeer, Tim’s Vermeer…from a painter’s point of view, comments - June 21st, 2014,  Newsletter no. 33 Feb 1, 2015: 15. Vermeer-related film, Tim's Vermeer  - 
NYT: A Vermeer Restoration Reveals a God of Desire - It took a year and a half to remove the paint to expose the Cupid image. 
See: Girl Reading a Letter at the Open Window -
BBC: Five hidden symbols in Vermeer's paintings:

Comparator Mirror

This is similar to a Camera Lucida, but different.  The Comparator Mirror results in a reversed drawing when compared to the subject and also it's restricted to 1:1 size ratios.
YouTube: Tomas Georgeson's videos -
YouTube: Technical Art History: Using camera lucidas in painting class 12:44 - inspired by the movie "Tims Vermeer" Mentions a "Zorn palette" (Wiki: white, red, yellow, and black pigment [no blue or green?).

Anders, Great video! I'm glad you enjoyed Tim's Vermeer. I have a few suggestions after watching your experiments.
  • Try moving the mirror closer to the easel and closer to the subject (Keeping the distances equal to each other to prevent parallax). Then you wouldn't have to stretch your arms so far, and you can see and paint details much easier. Also,
  • it is very important to establish and maintain similar light levels on the canvas and the subject. I sometimes place a white card next to my subject (facing the light source) and another card flat against the canvas. Looking through the comparator mirror, adjust the light on the canvas and subject so the white cards match each other. The combination of natural and artificial light can be a problem because one fluctuates and the other is constant. Try to avoid using both at the same time.
Tim Jenison
Brooke's additional comment: the painting is literally a mirror image of the subject.  A slightly more complex optical system (lens + mirror) would allow the painting and subject to be correct top to bottom and left to right. Which allows looking at the subject, which was not allowed here.
YouTube: The Comparator Mirror at West Buckland School by Tomas Georgeson 7:08 - The Comparator Mirror as a Teaching Aid at West Buckland School, Tomas Georgeson, 2015.pdf (link on YouTube)
YouTube:  How to use a Comparator Mirror Lesson 1 (Part 1) 14:41 Tom Georgeson, Part 2 -
YouTube: A comparator mirror for everyone? 10:31 - This device has the mirror mounted on the easel that holds the drawing - a correct thing to do.
YouTube: Scarlet's Rembrandt copy by Tomas Georgeson -
YouTube: Optics in Art: Girl with a Pearl Earring - time lapse by an artist who knows how to mix and match colors.
YouTube: Mirror alignment process, Tim's Vermeer device 0:23 - setting magnification

The next step would be to make a device that combines a comparator mirror and lens (or set of lenses) to work at different reductions, like 1/2 size, 1/4 size, &Etc.


Mona blog: Norman Rockwell (Wiki) said, ‘I use the epidiascope (Wiki: Opaque projector) but I don’t talk about it. It just saves so much time to take a photograph and trace it.’ But he acknowledged that there was a stigma, that it was not something he would openly talk about.
1904695 Epidiascope, Plies Heinrich, Leitz Ernst Wetzlar GmbH, 1933-04-18


Orion 9x63
Nikon 6x15
Viper 8x42
Zeiss 8x20
Pentax 7x35
Russian yM8-2 Monocular
Chinese 8x20 Monocular




Was looking for a small 45 degree first surface mirror (Wiki) and found these for a much lower price than a mirror.
Newton developed this style of telescope (Wiki) in the 1600s maybe from an idea dating to 1613.  So these parts may have been available to Vermeer.
I think the focal length of the primary mirror is about 1 meter.  When it's 2 meters from a window the reflected image of the window is in focus on the wall.

This may have come from the Levenhuk Skyline SUPER 10 120x1000 telescope.

Focal Length (Wiki)

1. When light from infinity (the Sun) is focused the distance from the lens to point of light is 1 focal length (FL).
2. When a point source of light is focused at a point the lens is 2 x FL from the light source and 2 x FL from the point of light, for a total length between subject and image of 4 x FL.

Fig 1. 120mm diameter primary mirror on 3-point adjustable mount
27mm diameter secondary mirror glass on 3-point adjustable mount.
also a couple of dust caps.
                    telescope mirrors

NextStar60 - cleaver microcontroller telescope using DC motors and shaft encoders
Celestron 8" Reflector & Wedge Tripod mount.
Orion GoScope 80 Table Top -
Galileoscope -
Telescope Mounts -
Pendulum Astrolabe
Sky Scout -
Sky Scan -
Warren-Knight Pilot Balloon Theodolite - Got these because they can view high elevation angles because of the Nasmyth (Wiki) design the eyepiece is always horizontal.


Leitz 115A transit (now Sokkia 7327-60) surveyors transit
T. F. Randolph Level - for land leveling
K&E hand Levels -
K&E 76 0000 Alidade - used for map making
Theodolites - Sokkisha/Leitz N010C, Nikon NT-2S, Wild T2, Wild T16
Warren-Knight Theodolites - Pilot Balloon (PiBal) tracking, but should also work for astronomy

Telescopic Sights

By adding cross hairs in the focal plane of the eyepiece they will be in focus at the same time as the far object.
SOPMOD M4 Accessory Kit for M-16/M-4 includes many different types of optical sights: Telescopic, Reflector/Reflex, Collimator, Holographic
PVS-4 Starlight Scope -
PVS-5 Night Vision Device -
Mk 20 Mod 4 Gun-Bomb Sight -
Navy Mk. 18 Gyro Gun Sight -

NC-3C Aircraft Collimating Gun Sight

In the Edmund Scientific booklet on Collimating Systems the NC-3 shown uses what appears to be a 28V aircraft screw based lamp.  But there is no mention of the sight model, even though it appears to be the NC-3.  The NC-3C uses the 222 pre-focused penlight lamp, see Fig 2 below.
Fig 3 below made by using a flashlight to light up most of the green filter-reticle seen in Fig 2.  Maybe the A and/or B versions used the larger lamp?  Camera aimed into55mm dia. lens.

Fig 1 Note trap door at left for lamp replacement
NC-3 Aircraft
                    Collimating Gun Sight
Fig 2 Trap door open
NC-3 Aircraft
                    Collimating Gun Sight
Fig 3 Pilot's view directly into NC-3.  In a plane there would
be a half-silvered mirror at 45 degrees so the pilot would
have a Head Up Display combining the cross-hairs and his view.
NC-3 Aircraft
                    Collimating Gun Sight

                    Collimating optical sight with transparent mirror
                    means, Thomas D Martin, App: 1945-02-09, Pub:
2441160 Collimating optical sight with transparent mirror means, Thomas D Martin, Navy, App: 1945-02-09, Pub: 1948-05-11, -

for aircraft fixed guns

Panoramic Telescope M12

Telescope Unit Navy Bureau of Ordnance 417414 

Bought this as a pig in a poke (Wiki).  The eBay description did not match the photos but it looked interesting and sold at a steep discount.

The presence of a circle reticle that's illuminated for nighttime use and clear or two levels of yellow filter as well as the weight of this item and the U.S. Navy markings seem to indicate it's for use on a ship or boat, not an aircraft.  Most likely as part of a sighting system where the reticle moves in response to some X - Y type input.

Fig 1 proped up "looking out into the forest"
Telescope Unit
                  Navy Bureau of Ordnance 417414
Fig 2 View from Fig 1 note the circle reticle
Telescope Unit
                Navy Bureau of Ordnance 417414
Fig 3 Lamp cover removed - the wires shown in the eBay ad are only to power the MAZDA 626 6 - 8 Volt lamp
The two shafts at right might move the right angle prism the bends the image relative to the reticle? TBD
The two rubber gaskets would be mounted to a bulkhead that would allow changing the lamp, setting the filter and some machine would control the reticle position using the two shafts.
Telescope Unit
                  Navy Bureau of Ordnance 417414
Fig 4 Label:
Telescope Unit
Part No. 649969 - Ser. No. 3371
Bur. Ord. No. 417414 -   -1
Sperry Gyroscope Co. Inc.
Brooklyn, N.Y.

Telescope Unit
                  Navy Bureau of Ordnance 417414
Fig 5
Telescope Unit
                  Navy Bureau of Ordnance 417414
Fig 6 Camera focused at infinity to show off the reticle.
Round plate is for access to filter wheel.
Telescope Unit
                Navy Bureau of Ordnance 417414


An optical collimator (Wiki: Optical Collimator, Collimated light) makes a light beam where all the rays are parallel, like coming from infinity.  An addition would be to place a reticle at the focus of the output lens so that the reticle image is projected along with the light.
In 1955 Edmund Optics (this part now called Anchor Optics) printed a white paper "Collimating Systems" that talks about modifying the military N-3x gunsight and also how to build a collimator starting from scratch including a reticle.  Also included were simple procedures for using it as a target at infinity, measuring the angular field of a telescope, the focal length of an eyepiece.  Another white paper "Condense and Project Light" includes similar information as well as more about lamps and other types of projectors.

The assembly tolerances are very loose.

Oriel 1373 Illuminated Alignment Collimator w/ 1375 Adjustable Scope Mount

This came with the lens cell misaligned, but it was easy to square it up.

There are three parts.
On the left is the lamp house with a solid metal (+) reticle located where the OD steps down.
In the center is a cylinder each end of which has three thumb screws and on the bottom a 1/4-20 tapped hole.
On the right is the objective tube with a lens ( 33m dia x 7" (180mm) FL) at the right end.
When the length is set to minimum the exit light is collimated, but by extending the tubes it's possible to focus the (+) much closer.
Fig 1
Oriel 120 VAC
                  (+) Projector

Fig 2 Zoom lens focused at infinity FL=200mm
Oriel 120 VAC (+) Projector
Fig 3
Zoom lens focused at infinity FL=50mm
Oriel 120 VAC (+) Projector

K&E Mystery Eyepiece

This device is marked K&E.  It has three optical ports.  One is an adjustable eyepiece which is at right angles to the other two ports.
There's a 2 position "switch" that changes the optics.
When the green sleeve is positioned where the eyepiece was removed from a telescope you an see an image through the telescope.  When the switch is moved the image goes black but then a flashlight into the clamp ports shines through the telescope.

With the tube lengths set for infinity when you look into the light beam with binoculars it's very difficult to get everything aligned so you can see the (+) when hand holding both of them. So the "optical lever" effect is very strong.

Note in both Fig 4 and Fig 5 below there are triangles pointing to the center located at the edge of the lighted circle at 12, 3, 6 and 9 o'clock positions.
Fig 1 marked K+E on eyepiece tube.
Clamp port at top.
Green sleeve at bottom rotates.
Eyepiece at left has diopter adjustment.
Bump at bottom right is the "switch".
                  Mystery Eyepiece
Fig 2
                  Mystery Eyepiece
Fig 3
                  Mystery Eyepiece
Fig 4  This is the flashlight projects through telescope
switch position.
                  Mystery Eyepiece
Fig 5  Note yellow filter
This is the eyepiece works position of the switch.
                  Mystery Eyepiece

Ednalite Projection Pointer

This unit is line powered and has the transformer and fuse in the carry box with long cords for the line and pointer.  The pointer has a push-button to turn on the lamp.
Uses a ______ automotive type lamp which tests as good. It arrived DOA.  Troubleshooting to follow.  When the hand grip (the part which includes the push-button switch) is unscrewed from the head of the projector and a flashlight is used to supply light an arrow symbol can be focused on the wall.

Like the Promaster pointer below the symbol that's projected is light against a dark background.  So projecting a black symbol against a light background is not a good idea when the subject is a slide show, Power Point presentation or video on a screen.

3183773 Projection pointer, Alex J Weinstein, Ednalite Corp, May 18, 1965, 353/42, 353/43, 362/308 - based on flashlight

Fig 1
                  Projection Pointer

Promaster Lighted Projection Pointer PB-387

This is a two "C" cell flashlight with an added plastic extension that holds an objective lens about 5" in front of the special lamp (p/n NP3560LPB).  The lamp filament is in a "V" shape with the plane of the "V" at right angles to the flashlight centerline.  The objective lens has a helical focusing mechanism that allows focusing the objective on the filament and the screen.  The flashlight body can be rotated so that the "V" can be pointed to the subject of interest.

It's not clear how you access the lamp.  Tell me if you know.

Fig 1
                  Lighted Projection Pointer PB-387
Fig 2
                  Lighted Projection Pointer PB-387


The autocollimator (Wiki: AutocollimatorAutocollimation) encompasses the collimator with a reticle but adds a viewing telescope. By comparing the reflected image from the reticle with the reticle itself by means of the telescope very small angles can be measured.  A half silvered mirror or prism is involved which shows up as an optical system with a right angle axis.
The assembly tolerances are very tight.

In patent search for autocollimators things come up which I think should be called retro-reflectors (Wiki), like used for traffic signs.  The idea is that light will be reflected back in the direction from which it came.  These are used in surveying to increase the range of optical rangefinders.

1736682 Optical Lever, Tuckerman Louis Bryant, Nov 19, 1929, 356/154, 359/872, 359/226.1 - although not exactly like modern units, still captures the idea.  Maybe the oldest patent for an autocollimator?

8" Plano-Convex Lens

8" Plano-Convex
8-5/16" diameter x 1.56" thick at center, 0.14" thick at edge.
From geometry:
From Autocad Draw circle 3 points the glass radius is 6.8"

Equation from AZO Optics: (Wiki: Lens Equation)
1/f = (n-1) * (1/Rf – 1/Rb)
n: refractive index of glass (about 1.5) Wiki
f: focal length
Rf= Front radius
Rb = back radius = infinity for flat surface.
1/f = (1.5 - 1.0) (1/6.8" - 0) = 0.5 / 6.8", or f = 13.6"
This checks out using a flashlight.
This may have been used in a collimator.

Graphoscope (Wiki)

165241 Stereoscope, Henry J. Lewis, E. and H.T. Anthony & Co, 1875-07-06 359/476; 359/474 - title is a typo, subject of patent is for both a  Graphoscope & Stereoscope.

HMMWV - Optics

HMMWV with Optics
                  on Roof
New York Times - 2018 April 11: On the Border With the National Guard: An ‘Extra Pair of Eyes and Ears’
Click photo at left for a better view of the HMMWV with optics on roof.

This is the Raytheon  Long-Range Advanced Scout Surveillance System (LRAS3) -


Ref 1 Secret Knowledge (New and Expanded Edition): Rediscovering the Lost Techniques of the Old Masters by David Hockney, 2006
The first section uses paintings as source documents.  A key observation is that drafting methods fail when the subject is something like cloth, armor, or complex three dimensional objects.  When very early paintings are compared to more modern versions there's a dramatic difference in that the newer paintings are photo realistic.  Camera Lucida and Camera Obscura receive many mentions but Time's Vermeer shows that was not the solution.  The key new element Tim brings is the Comparator Mirror.

Hockney seems to think using optics is a shortcut.  For example in the painting of smiles.  But Tim's Vermeer shows that using optics really slows down the process of painting since it requires paying attention to very fine details.  Maybe different artists used optics differently from Vermeer is such a way as to capture fleeting events?
YouTube Filmed prior to his book "Secret Knowledge": David Hockney on Photography & Other Matters (Secret Knowledge) 51:38 -
David Hockney, The Lost Secrets of the Old Masters: camera lucida obscura 23:15 - by 1430 they knew about concave mirrors
YouTube:  Jeremy Isaacs talks to David Hockney (Face To Face, 1993) 38:08 -

The overall theme of "Secret Knowledge" is that there were four phases in the imaging art:
1. Very early drawings were 2D, i.e. flat and not at all photo realistic.
2. The realistic paintings based on optics.
3. The photograph which is a much quicker and lower cost way to get a photo realistic image.
4. The abstract image.  Done since artists could not compete with cameras.
Ref 2  Vermeer's Camera: Uncovering the Truth behind the Masterpieces by Philip Steadman, 2002 - talks about camera obscura a lot, but so far has not mentioned the color match problem. - VermeersCamera.co.uk - Comment on Tim's Vermeer - Vermeer's Camera and Tim's Vermeer by Philip Steadman 2015 - this book got Tim Jenison started on what became the movie Tim's Vermeer.  Steadman often mentions the camera obscura, but Time's Vermeer shows that was not the solution.

Ref 3  "The Camera Obscura," Horace Dall, Amateur Telescope Making, Book Two, 1954,pp. 417ff., with diagrams.​ - telescope in attic works as camera Obscura

Ref 4  Eye of the Beholder: Johannes Vermeer, Antoni Van Leeuwenhoek, and the Reinvention of Seeing by Laura J. Snyder, 2015 - found on my bookshelf, probably related to Leeuwenhoek.

Ref 5 Hound in the Hunt, sold by the Mona museum in Tasmania and called a Catalog, but is not about Tim Jenison's exhibit at Mona but rather is about the movie Tim's Vermeer.
Ref 6 xx


Optical Books: Search Term (eBay, Amazon, &Etc): "SPIE Field Guide"
Suddarth Optical Repair - mainly binoculars

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page created 13 Feb 2002.