Express diagnostics on site: Meeting in a cafe without a laptop

Imagine the situation: you met a seller of a used carcass on a park bench or in a cafe. I don't have a laptop at hand. How to evaluate the health of a mechanical shutter in 5 minutes using only the camera itself and the phone?

Here are 5 proven express tests from my service practice.

5 Field tests of bolt mechanics

1. Test 1: Shooting a white background at 1/8000 sec (or 1/4000 sec):Point the camera at a light wall or sky. Take the photo at the fastest shutter speed. Open the photo on the screen and zoom in. **Not on picture there should be dark horizontal stripes or a dark gradient around the edges!** (Dark stripe = closing delay curtains).
2. Test 2: Visual inspection of the curtains under a flashlight:Remove the lens, turn on the `Lift' mode in the menu Lock mirror up for cleaning. Shine a smartphone flashlight into the shaft on the curtains: slats must be absolutely smooth, without waves, scratches or oil stains.
3. Test 3: “Auditory” run with a series in CH mode:Take a short burst of 5 frames. Sound The firing should be smooth and rhythmic, with no metallic squeals or delays.
4. Test 4: Sending a RAW file to a smartphone via Telegram:Ask the seller to send off what he made frame as an uncompressed file to your messenger and immediately upload it to our service directly from your phone!

Field self-test table

Express test	Sign of a working shutter	Sign of breakage/wear
Shot at 1/8000 sec	Uniform brightness across the entire frame	Black stripe at the top/bottom of the frame
Inspecting curtains with a flashlight	Matte smooth petals without oil	Waves on the metal, dents, drops of grease
Serial queue CH	Clear rhythmic click	Rattling, frame delay, Err error