How can I keep a tilted 1/3-inch sensor subject in focus at close range without designing my own lens?
Asked 12/29/2017
22 views
2 answers
0
I'm building a small inspection system and currently use a camera with a 1/3-inch CCD. The camera is about 6 inches from the target, which is roughly 0.7 inches in diameter. The target is viewed at about a 30° angle rather than straight-on, and that causes the top and bottom edges to fall out of focus because the depth of field is very shallow.
I had been considering designing my own lens and 3D-printing the barrel, but I don't have lens-design experience. Is making a custom lens realistic here, or are there better optical approaches for this kind of setup? I'm also interested in any useful software or reference material for solving this kind of focus problem.
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
8y ago
2 Answers
2
You would likely be foolish to make your own lens. Likely Edmunds Scientific http://www.edmundscientific.com/ will have everything you need. Make sure to be ready with the specifications of the lens you want when you contact them.
Originally by user44949. Source · Licensed CC BY-SA 4.0
user44949
8y ago
0
Generated from our catalog & community — verify before relying on it.
Designing your own lens is probably not the practical solution here. Custom lens design is complex, and for a working inspection machine it’s usually better to buy or adapt existing optical components from specialist suppliers.
From the answers, the main issue is not necessarily the lens itself, but the geometry: your subject is tilted relative to the sensor, so the plane of focus doesn’t match the target. A better approach is to use tilt (or possibly shift) so the focus plane aligns with the target. If you tilt or shift the lens, you may need a lens with a larger image circle so the sensor remains fully covered.
Other possible workarounds:
- Reorient the optics so the lens is more nearly perpendicular to the target.
- Use focus stacking if the subject and camera are stationary.
- Source off-the-shelf or custom optical components from industrial suppliers rather than fabricating a lens from scratch.
In short: solve this as an optical alignment / tilt-shift problem first, not as a DIY lens project.
Recommended products
UniqueBot
AI8y ago
Your Answer
Related Questions
How can I get sharper 1:1 macro photos with a Nikon 105mm macro lens?
How do I align a camera exactly edge-on to a very thin plate?
Why are my 4x5 enlarger prints sharp in the center but soft at the edges?
What tripod head thread size fits my monopod: 3/8" or 1/4"?
How do I calculate focal length for a required horizontal field of view on a 1/3-inch sensor?