Hybrid sharpness charts and CircleSFR software for camera testing.

Buy a physical CircleSFR target, capture it in your lab, and run CircleSFR to measure SFR/MTF from circle, star, and edge features in the image.

Buy printed chartDownload softwareView chart sizes ->
1x, 2x, 4x print sizes2024-informed SVG targetCircle and star SFR featuresSFR/MTF outputmacOS, Windows, Linux plannedSupport: rex@circlesfr.com
CircleSFR test workflow
ISO 12233:2024 informed

Configure the printed target, capture the chart, then inspect SFR/MTF curves from the same software window.

CircleSFR hybrid SVG test chart combining circle SFR rings, slanted stars, Siemens-style radial stars, slanted edges, wedge groups, gray patches, and color patches
Hybrid SVG targetCircle + star SFR
CircleSFR 0.1.0
CircleSFR analysis overlay showing colored sagittal and meridional sectors on each ring target
83 ringsdetected
0MTF50Nyquist
MTF50 0.2609 cy/pxNyquist 0.50CSV ready

Test workflow

Set up the chart, capture the image, measure SFR.

CircleSFR is a chart-and-software workflow: choose the print size, capture the target, then review SFR/MTF output from the same image.

Buy printed chartDownload software
  1. 01

    Choose the chart

    Pick a 1x, 2x, or 4x physical print of the hybrid SVG target based on camera resolution and framing distance.

    View chart sizes ->
  2. 02

    Capture in the lab

    Mount or position the print, fill the frame, control lighting, and capture the target image.

    Ask about capture guidance ->
  3. 03

    Run CircleSFR

    Import the image, detect chart regions, compute SFR/MTF, and review edge-level output.

    See software output ->
  4. 04

    Export results

    Save CSV or PDF outputs for QA, design review, customer reports, or lab records.

    View release state ->

Printed chart

Buy the printed chart in the size your camera needs.

CircleSFR will offer original hybrid SVG chart artwork with circle SFR rings, slanted-star fields, Siemens-style radial targets, slanted edges, wedge groups, gray patches, and color patches. Print process, mounting, and pricing will be attached before checkout goes live.

Pricing pendingCompare sizes
Chart size options

CircleSFR will use this buyer-facing size model while final artwork, print process, mounting, and pricing are prepared.

1x - 1.6 MP
Standard 3:2: 200 mm x 305 mm, 7.875 in x 12 in
Wide 16:9: 200 mm x 365 mm, 7.875 in x 14.5 in
2x - 6.2 MP
Standard 3:2: 400 mm x 610 mm, 15.75 in x 24 in
Wide 16:9: 400 mm x 730 mm, 15.75 in x 29 in
4x - 24.9 MP
Standard 3:2: 800 mm x 1225 mm, 31.5 in x 48 in
Wide 16:9: 800 mm x 1460 mm, 31.5 in x 58 in
Reference dimensions are modeled after common SFR chart purchase options. Final CircleSFR pricing and fulfillment are pending.

CircleSFR software

Measure SFR/MTF from the captured chart image.

The software surface follows the same restrained dark band as Gramm.ai technical sections, but shows analysis output instead of API payloads.

  • Import captured chart images.
  • Detect slanted-edge regions and chart structure.
  • Calculate SFR/MTF and review MTF50 markers.
  • Export CSV and PDF reports when releases are uploaded.
CircleSFR analysis - capture_042.tif
CircleSFR analysis overlay showing colored sagittal and meridional sectors on each ring target
Rings83 detected
SFR500.2609 cy/px
ExportCSV, PDF
0MTF50Nyquist
MTF50
0.2609 cy/px
Nyquist
0.50 cy/px
Rings
83
Status
Ready

Downloads

Download CircleSFR when the release is uploaded.

Platform builds, release notes, file size, and SHA-256 checksums should appear here before public distribution. Until then, the state stays explicit.

Ask about release timing ->
Platform
Version
File
SHA-256
Status
macOS
0.1.0
CircleSFR-macOS.dmg
Pending
Upload pending
Windows
0.1.0
CircleSFR-Windows.exe
Pending
Upload pending
Linux
0.1.0
CircleSFR-Linux.AppImage
Pending
Upload pending

Built around current ISO 12233 SFR workflows.

ISO lists ISO 12233:2024 as the current edition for resolution and spatial frequency response measurement. CircleSFR uses original chart artwork that combines circle SFR targets with license-free sharpness features; stronger compliance claims should wait for final chart and software review.

View ISO pageContact support

Start with the chart, the software, or both.

Chart artwork, checkout, fulfillment, and binaries will be attached as they are ready. The landing page keeps purchase and download states visible until then.

Buy printed chartDownload software

Questions: rex@circlesfr.com