You can download a USAF 1951 chart as a PDF and print it, but a printed target is limited by your printer’s resolution — realistically to around Group 4–5 (roughly 16–32 lp/mm) with soft, uneven edges. That’s fine for a quick visual check or teaching, but not for measuring real optical resolution, which needs a chrome-on-glass target reaching up to 912.30 lp/mm.
New to Group and Element numbers? See our guide to reading a USAF 1951 chart first.
Can I just print a USAF 1951 target?
Yes — for coarse, low-resolution work. A home or office printer lays down ink at a fixed dot pitch, and the finest line it can render cleanly is several dots wide. Even a 1200–2400 dpi printer struggles to produce clean bars below roughly 30–60 µm, which caps a printed target well short of the fine end of the pattern. The bar edges are also fuzzy and the substrate (paper or film) expands with humidity and temperature, so the geometry drifts.
That makes a printed chart usable for:
- Teaching and demonstrations
- Rough “is it roughly in focus?” checks
- Very low-magnification, low-resolution systems
Free printable USAF 1951 chart (PDF)
Need a chart today? Get our free, print-ready USAF 1951 PDF — laid out to MIL-STD-150A, ideal for layout reference, teaching, and quick focus checks. Enter your email and we’ll send the download link.
Note: printed resolution is limited by your printer and this PDF is not a calibrated measurement reference. For quantitative testing, use a chrome-on-glass target (below).
Why printed charts fail for real resolution testing
Resolution measurement depends on two things a printed target can’t hold: fine, sharp edges and dimensional stability. When the target’s own edges are softer than the optics under test, you measure the target — not your lens. And because paper and film move with the environment, repeat measurements don’t agree.
| Printed / film target | Chrome on glass target | |
|---|---|---|
| Max usable resolution | ~Group 4–5 (16–32 lp/mm) | Group 9 Element 6 (912.30 lp/mm) |
| Edge quality | Soft, ink-spread | Lithographic, sub-micron sharp |
| Dimensional stability | Drifts with humidity/temperature | Stable on fused silica |
| Line width floor | ~30–60 µm | Down to ~0.55 µm (custom to 0.1 µm) |
| Best use | Demos, coarse checks | Metrology, lens/camera/microscope testing |
When do you need a chrome-on-glass target instead?
If you are testing a real lens, camera, microscope objective, or machine-vision system — anything where the result feeds a spec, a report, or a pass/fail decision — you need a chrome pattern on fused silica (quartz glass). It resolves far finer than the system under test, holds its geometry, and gives repeatable readings. A printed PDF simply cannot reach the resolution or edge quality these measurements require.
Is there a free USAF 1951 chart PDF?
Free PDF versions of the pattern exist online, and they’re useful for learning the layout or a rough check. Just treat them as what they are: a low-resolution reference, not a measurement tool. For any quantitative resolution work, the printed version’s limits will dominate your result.
Frequently asked questions
Can I print a USAF 1951 resolution chart? Yes, but a printed chart is limited by printer resolution to roughly Group 4–5 (16–32 lp/mm) with soft edges, and paper or film drifts with humidity and temperature. It suits demos and coarse checks, not quantitative resolution testing.
What is the highest resolution a printed USAF 1951 target can reach? Realistically around 30–60 µm line width (roughly Group 4–5), because a printer cannot render finer bars cleanly. Chrome-on-glass targets reach 0.55 µm (912.30 lp/mm), with custom versions to 0.1 µm.
Why use chrome on glass instead of a PDF? Chrome-on-glass targets have lithographic sub-micron edges and stay dimensionally stable on fused silica, so they out-resolve the system under test and give repeatable measurements — which a printed PDF cannot.
CalibVision manufactures USAF 1951 resolution test targets in chrome on fused silica, resolving to 912.30 lp/mm (0.55 µm line width), positive and negative, in three sizes, with custom resolution to 0.1 µm. See specifications and request a quote.
