How to Use the Solar Pinhole Camera
Build and preview a solargraphy-style pinhole setup before you cut cardboard.
What this tool answers
How large will the Sun's image be on film or paper for a given pinhole diameter, focal length (box depth), and paper size, and is that setup workable for solargraphy?
When to use it (Guyana)
Use this before a multi-week solargraphy exposure in Georgetown or elsewhere near 6°N. The Sun's path is high year-round; a short box with a small pinhole still draws long arcs. Plan humidity and rain: tropical paper/film needs a dry, sealed box.
Step-by-step
- Open Solar Pinhole Camera.
- Set pinhole diameter (start ~0.3-0.5 mm for paper solargraphy).
- Set focal length / box depth (distance from pinhole to paper).
- Choose paper or film size and confirm the predicted Sun-image diameter fits.
- Note any warnings about diffraction or undersized images.
- Export or screenshot settings for your build notes.
How to read the results
- Image size: projected solar disk diameter on the focal plane.
- Coverage: whether arcs stay on the paper across days/weeks.
- Diffraction / softness: very tiny pinholes can look soft; the tool flags extremes.
Field example, an east-facing paper solargraph after processing:
Common mistakes
- Building the box before checking that the Sun path fits the paper.
- Oversized pinholes that wash out contrast.
- Ignoring light leaks, more fatal than "wrong" math.
- Leaving paper in humid air without a sealed dark bag.
Next
- Topic: Solargraphy, sun paths, sinusoids & trails
- Optics math: Pinhole Optics
- Related tool: Pinhole Optics Calculator