How to Light, View and Photograph a Kaleidoscope

6 days ago

8 min read

Updated: 2 days ago

A kaleidoscope image is built from light that has been reflected several times between mirrors. Every reflection removes part of that light, so the quality of the image depends on how much light enters the object end and on where the eye, or the camera lens, sits at the other end. Both are under the control of the person holding the instrument.

This guide covers the best light for a kaleidoscope, eye position, the teleidoscope, and how to photograph and film through the eyepiece with a phone. The basic handling steps are in How to Use a Kaleidoscope and are not repeated here.

Why a kaleidoscope needs direct light

Light enters at one end only. In a wheel or cell kaleidoscope the objects are transparent or translucent - glass, stone, or coloured elements cast in clear resin. They are lit from behind: light passes through the object, into the mirror system and out through the eyepiece. Light on the side of the tube does nothing. The useful light is on the axis of the tube, behind the object.

Each reflection loses light. Only one sector of the pattern is seen directly. Every other sector is an image formed by one, two, three or more reflections. No mirror returns all the light it receives, and the losses multiply. As arithmetic illustration only: at 90 percent returned per reflection, a sector seen after five reflections holds about 59 percent of the original brightness. The real figure depends on the mirror, but the more reflections, the dimmer the sector.

The outer sectors are the dimmest. In a three-mirror system the pattern repeats outward from the centre, and each ring outward requires more reflections. With weak light the centre remains visible and the outer field fades to grey. Strong direct light is needed for the outer sectors, not for the centre.

Sir David Brewster examined this in Chapter VI of his 1858 book on the kaleidoscope. He notes that in the direct sector "the intensity of the light is uniform in every part of its surface; but this is far from being the case in the images formed by reflexion." His table, partly computed by Bouguer for unsilvered plate glass, shows 584 rays reflected out of 1000 at 2.5 degrees from the surface against 25 at perpendicular incidence. Those numbers do not transfer to modern front-surface mirrors, but the principle holds: brightness across the field is not uniform.

Best light for a kaleidoscope

Daylight. Point the object end at a window or at open sky. Daylight is broad and even, and renders glass colours without a colour cast. Never point the instrument at the sun.

Lamp. Point the object end straight at the lamp, on the axis of the tube, at a distance of roughly an arm's length. A diffused lamp gives an even field. A bare bulb or phone torch at short range gives a bright point repeated in every sector. A warm lamp shifts all colours toward yellow.

What to avoid:

Side light. A lamp beside or above the viewer lights the tube, not the object.

What to check: look at the outer edge of the field, not the centre. If the outer sectors show colour and detail, the light is sufficient. If they are grey, increase the light or turn to face the source.

Where to place the eye

Close to the eyepiece. The eyepiece opening limits the field. With the eye a few centimetres back, the opening masks the outer sectors.

Near the mirror junction. Brewster devotes Chapter IV to this point. His conclusion is that the eye "must be placed as nearly as possible in the plane of both the mirrors, that is, as near as possible to the angular point" - the line where the two mirrors meet. From that position the object and its reflected images are at the same distance from the eye and appear at the same size, so the sectors join without a step. He records that as the eye moves away from that point "the deviation from symmetry increases", and that the circular field becomes "a sort of ellipse".

The eyepiece of a finished instrument already places the eye close to this point. Shift the eye a millimetre or two within the opening until the sector joints are continuous and the pattern is round.

Rotate slowly. A slow turn lets the eye follow one piece of glass across a sector. A fast turn produces motion blur, more so in a camera.

Two-mirror and three-mirror systems at the eyepiece

Studio Yabaye builds several front-surface mirror systems, and they behave differently at the eyepiece.

Image - Two-mirror system: One circular pattern with a centre point; Three-mirror system: A pattern that repeats across the whole field
Eye position - Two-mirror system: Sensitive - the joints show any offset; Three-mirror system: More tolerant - no single centre
Light demand - Two-mirror system: Fewer reflections per sector; Three-mirror system: Outer field needs strong light

In a two-mirror system the third side is non-reflecting, so the image is a single round figure against a dark surround, and any error in eye position shows at the sector joints. In a three-mirror system the reflections continue in every direction; the outer field is the first area to darken in weak light. Both are covered in Two-Mirror vs Three-Mirror Kaleidoscope and in Kaleidoscope Mirror Length-to-Width Ratio.

Lighting a teleidoscope

A teleidoscope has no object wheel. A lens at the front collects the scene and the mirrors repeat it. The light source is the scene itself.

Light conditions. The teleidoscope works in every light condition except indoor artificial lighting. Outdoors, in sun, shade or overcast, the scene supplies enough light. Under indoor lamps most surfaces reflect too little light and the image is dim. Indoors by day, aim it at or through a window.

Near and far scenes. Far scenes - buildings, trees, a street - produce fine, dense patterns that change slowly. Near subjects - a plant, printed fabric - produce large shapes that change quickly with a small movement. The differences between the two instruments are set out in Kaleidoscope vs Teleidoscope.

How to photograph through a kaleidoscope with a phone

The camera lens takes the place of the eye, and the same rules of position apply as for a microscope or telescope eyepiece.

Clean both surfaces. Wipe the eyepiece and the phone lens with a dry microfibre cloth.
Fix the light first. Rest the instrument on a stable surface with the object end facing a window or a steady lamp.
Use the main camera. Select the standard 1x lens.
Hold the lens against the eyepiece. The phone lens goes flat against the eyepiece opening, in the position the eye would take.
Centre it. Slide the phone by small amounts until the bright field is in the middle of the screen and the dark border is equal on all sides.
Lock focus and exposure. On an iPhone, tap and hold on the pattern until "AE/AF Lock" appears. Most other phone camera apps have an equivalent lock.
Lower the exposure if colours wash out. The dark surround leads the camera to overexpose the pattern. Pull the exposure slider down until the lightest glass shows its colour.
Do not use digital zoom. It only crops and enlarges. Crop afterwards instead.
Release the shutter without moving the phone. Use the volume button or a two-second timer, and brace the elbows on the table.

Common faults and fixes

Dark ring or tunnel (vignetting) - Cause: Lens too far from the eyepiece, or off its axis; Fix: Close the gap; re-centre
Pattern off-centre or cut on one side - Cause: Phone shifted or tilted; Fix: Slide in small steps; keep the phone square to the tube
Blur over the whole frame - Cause: Movement, or focus on the eyepiece rim; Fix: Brace; lock focus on the pattern
Pale, washed colours - Cause: Overexposure; Fix: Lower exposure before shooting
Soft haze - Cause: Dust or grease on eyepiece or lens; Fix: Clean both

Vignetting occurs when the camera lens is not aligned with the light leaving the eyepiece. It is corrected by position, not by camera settings.

Video through the eyepiece

Fix the instrument and the phone. Only the wheel should move.
Lock focus and exposure before recording. Every refocus is recorded.
Turn the wheel slowly and at a constant rate. One full turn in 20 to 30 seconds is a workable starting point.
Use steady light. Some LED and fluorescent lamps flicker at a rate the camera registers as moving dark bands. If bands appear, change the lamp or move to daylight.
With a teleidoscope, move phone and instrument together, slowly, across the scene.

Care points that affect the image

Dust on the eyepiece. Dust and grease on the eyepiece scatter light across the entire field. Wipe it with a dry microfibre cloth before viewing and before every photograph.

Never open the instrument. A front-surface mirror carries its reflective coating on the exposed face, with no glass over it. A fingertip or a cloth marks that coating, and the mark is repeated in every sector. The mirrors are also set to their angle at assembly. If dust appears inside the image, contact the studio.

Checklist

Object end pointed straight at the light, on the axis of the tube
Daylight or a steady, diffused lamp; no side light; never the sun
Outer sectors show colour, not grey
Eye against the eyepiece; small shift until the joints are continuous
Teleidoscope used outdoors or at a window, not under indoor lamps
Eyepiece and phone lens wiped with a dry cloth
Phone lens flat against the eyepiece and centred
Focus and exposure locked; exposure lowered if colours are pale
No digital zoom; crop afterwards
Instrument never opened

Frequently Asked Questions

What is the best light for a kaleidoscope?

Direct light entering the object end, on the axis of the tube. Daylight from a window or open sky gives an even field and neutral colour. A diffused lamp at about an arm's length also works. Side light does not reach the object. Never aim the instrument at the sun.

Why are the outer parts of the kaleidoscope pattern darker?

Only one sector is seen directly. All others are reflections, and each reflection loses part of the light. Outer sectors are formed by the largest number of reflections, so they are the dimmest. Brewster treats this in Chapter VI of his 1858 book. Stronger direct light restores colour in the outer field.

How do I photograph through a kaleidoscope with a phone?

Clean the eyepiece and the phone lens. Hold the main 1x lens flat against the eyepiece and slide it until the pattern is centred. Lock focus and exposure by tapping and holding on the pattern, lower the exposure if colours look pale, and do not use digital zoom.

Why does my kaleidoscope photo have a dark ring around it?

The dark ring is vignetting. It appears when the phone lens is too far from the eyepiece or not on its axis, so part of the light leaving the eyepiece misses the lens. Close the gap, then slide the phone in small steps until the border is equal on all sides.

Does a teleidoscope work indoors?

A teleidoscope works in every light condition except indoor artificial lighting. It has no object wheel, so the scene in front of the lens is its only light source. Surfaces lit by lamps reflect too little light. Indoors by day, aim it at or through a window.

Where should the eye be when looking into a kaleidoscope?

Against the eyepiece and as close as possible to the line where the mirrors meet. Brewster states this in Chapter IV of his 1858 book: from that point the object and its reflections appear at the same size, so the sectors join. Move the eye away and the round field becomes oval.

About Studio Yabaye

Studio Yabaye builds kaleidoscopes and teleidoscopes from brass tube, cut, fitted and hand-finished in the studio, with front-surface mirror systems in several configurations. Each object wheel is poured and composed by hand, so no two pieces are alike. The studio is based in Israel and ships worldwide. The current range is at All Products; questions about an instrument can be sent through the contact page.