Drop an ARW RAW file from your Sony A7S IV and get the exact shutter actuation count in seconds — decrypted and processed entirely in your browser, never uploaded anywhere.
Check Shutter Count →The Sony A7S IV (ILCE-7SM4) is Sony's fourth-generation A7S-series full-frame mirrorless, succeeding the A7S III (2020). Built for videographers and low-light specialists, it features a 12.1 MP BSI stacked CMOS sensor — the same philosophy of fewer, larger pixels for exceptional high-ISO performance. The A7S IV inherits the proven Sony ARW format and the encrypted MakerNote shutter count architecture, storing the mechanical actuation count in tag 0x9050 with offset 0x003a after decryption.
| Model | Sensor | Est. Shutter Life | RAW Format |
|---|---|---|---|
| Sony A7S IV | 12.1 MP BSI stacked CMOS, BIONZ XR II | >500,000 est. | ARW |
| Sony A7S III | 12.1 MP BSI CMOS, BIONZ XR | >500,000 est. | ARW |
| Sony A7S II | 12.2 MP full-frame CMOS, BIONZ X | ~200,000 est. | ARW |
| Sony A9 III (pro ref.) | 24.6 MP stacked CMOS, BIONZ XR | 500,000 | ARW |
The A7S IV is primarily a video camera. Many owners shoot predominantly in video mode, which does not actuate the mechanical shutter at all. A low shutter count may indicate extensive video use rather than a near-unused body. Always consider the total usage context, not just the mechanical shutter count, when evaluating a used A7S IV.
Like all Sony ARW bodies, the A7S IV stores the shutter count encrypted in MakerNote tag 0x9050. ShutterCount applies the cubic residue decryption algorithm (modulo 249) and reads the 32-bit count from offset 0x003a within the decrypted block. All decryption happens locally in your browser — the ARW file is never transmitted anywhere.
No. The A7S IV's electronic shutter mode bypasses the mechanical curtain entirely and is not counted. The A7S IV supports high-frame-rate electronic readout for video without incrementing the mechanical counter, which is particularly significant for a camera designed for continuous video work.
| Actuation Count | % of Est. Life | Assessment |
|---|---|---|
| 0 – 25,000 | 0 – 5 % | Near new |
| 25,000 – 125,000 | 5 – 25 % | Low use — plenty of life remaining |
| 125,000 – 300,000 | 25 – 60 % | Moderate use — normal for working videographer |
| 300,000 – 425,000 | 60 – 85 % | Higher use — still well within professional range |
| 425,000 + | 85 %+ | Approaching est. life — factor in shutter service |
The A7S IV is used overwhelmingly for video in professional environments. A body with 50,000 mechanical actuations may have thousands of hours of footage captured via electronic readout. Evaluate the total wear package — sensor, LCD, ports, and body condition — not just the mechanical count.
Drop an ARW RAW file from the A7S IV into shuttercount.app. The tool decrypts and reads the count from MakerNote tag 0x9050 in your browser.
Both cameras use the same ARW format and Sony MakerNote encryption scheme with offset 0x003a. The A7S IV features updated internal recording, improved autofocus, and enhanced video specifications. The shutter count reading method is identical.
Even though the A7S IV is primarily used for video, still photography does actuate the mechanical shutter. A very low mechanical count on a heavily used video body may indicate the camera has been professionally maintained rather than lightly used.