Create precise pinholes for DIY or classroom pinhole cameras using stainless steel insect pins. Ten sizes available for variable aperture and focal length control.
Turn simple materials into precision optical tools with stainless steel insect pins. Each pin produces a consistent, clean hole ideal for pinhole camera construction; perfect for teaching the principles of light, aperture, and image formation. These corrosion-resistant pins come in ten sizes, allowing fine control over focal length and image sharpness.
We've offered Czech made stainless steel pins since 2005. Entosphinx stainless steel pins are 316 grade stainless steel with a nylon head; protect your valuable collections whether they're insects or textiles. Buy just a few & our delivered cost beats "free" shipping!
Google Reviews, click on the names to see in full: Alison B.: ...ordered a sample pack of insect pins for making pinhole cameras....wonderful selection and super-fast shipment...… Mary C. B. ...Indigo Instruments entomology pins...in my artwork for almost ten years now, and a big part of my studio practice!
Explain how aperture diameter affects image sharpness, brightness, and depth of field.
Photography / Art
Experiment with focal length and exposure in lensless image creation for creative or technical expression.
STEM Education
Construct functional pinhole cameras to visualize geometric optics principles using simple materials.
Biology / Evolutionary Science
Model early eye evolution: compare pinhole image formation to the pit-eye structures found in primitive organisms.
Best Practices for Pinhole Camera Aperture Creation
Step
Best Practice
Why It Matters
1. Choose Pin Size
Select smaller pins (≈0.25–0.3 mm) for sharper but dimmer images; larger pins (≈0.5–0.6 mm) for brighter images.
Controls exposure and image clarity through aperture size.
2. Prepare the Material
Use thin metal foil or heavy black cardstock as the aperture plate; ensure it’s smooth and dust-free.
Prevents light scatter and inconsistent hole shape.
3. Create the Pinhole
Press the insect pin gently into the surface without tearing; rotate slightly for a clean, circular opening.
Maintains uniform diameter and consistent optical properties.
4. Back and Mount
Support with tape or glue from the rear side to minimize fraying or bending of the foil.
Improves image stability and durability for repeated use.
5. Evaluate Results
Project the image onto tracing paper or photographic film under consistent lighting; compare multiple pin sizes.
Allows measurement of image brightness, sharpness, and focal distance effects.
6. Document and Share
Photograph setups and results for teaching resources or lab reports.
Supports reproducibility and comparative analysis across experiments.
Experimental Design / Classroom Activity
Objective: Demonstrate how aperture size controls image brightness and focus in pinhole cameras, while exploring parallels to eye evolution and biological vision systems.
Materials: 3-4 different sizes of stainless steel insect pins (e.g., #000, #1, #3, #5)
Thin aluminum foil or black cardstock
Tape, scissors, and a light-tight box or canister
Wax paper or tracing paper for the image screen
Ruler, notebook, and optional digital camera for documentation
Procedure: Use insect pins of different diameters to pierce holes in small foil squares.
Mount each foil over the camera opening using tape, ensuring the pinhole is centered.
Place a translucent screen (wax or tracing paper) at a fixed distance (e.g., 10 cm) inside the box.
Point the camera toward a bright object or window and observe the inverted image.
Record image brightness and sharpness for each pin size.
Plot or compare results to identify the optimal aperture for clarity vs. brightness.
Analysis / Discussion: Relate the findings to how human and animal eyes evolved from simple pinhole-like photoreceptors.
Discuss trade-offs between light sensitivity and resolution in both optical and biological systems.
Extend the experiment by calculating theoretical diffraction limits and comparing them to observed results.
Extension Ideas: Photograph the results with a smartphone through the wax paper screen.
Test the camera under different lighting conditions or distances.
Integrate into interdisciplinary STEM lessons combining physics, art, and evolutionary biology.
Suggested Pin Diameters for Pinhole Camera Optimal Focal Length
Focal Length (cm)
Focal Length (in.)
Pin Size
Pin Diameter (mm)
3.5
1 3/4
000
0.25
5.6
2
00
0.30
6.9
2 1/2
0
0.35
9.0
3 1/2
1
0.40
11.4
4 1/2
2
0.45
14.1
5 1/2
3
0.50
17.0
6 1/2
4
0.55
20.2
8
5
0.60
23.4
9
6
0.65
Focal Length as defined here is the distance from the pinhole at the front of the camera to rear where the photographic film or paper is placed. This is the distance of best theoretical focus of the pinhole camera's image with a pinhole of particular diameter.
The actual pinhole size/aperture made with a particular pin will likely be slightly larger than the diameter of the pin shaft.A small diameter pinhole has a shorter effective focal length; however smaller diameter pinholes will also require longer exposure times than larger pinholes. Depending on your photographic/artistic goals (ultra-sharp focus may not be required, or even desired) you may wish to choose a larger pinhole and give up some sharpness for faster more practical exposure times.
Documentation
Certificate of Analysis
Entosphinx stainless steel pins are made from 316 grade stainless steel which has a minimum of 0.36% molybdenum (Mo) for superior corrosion resistance. This Certificate of Analysis is our guarantee of truly rust resistant insect collection pins.
Reviews (1)
2019-12-17
This was my first time with Indigo Instruments. Quick service. Great products. In this case, stainless steel insect pins. I'm glad I got the sample pack because I found the right size I wanted and it helped me with my next purchase. Way to go Indigo!
— TK
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