OM System OM-1 – Shutter, Sensor Readout Speed, Banding and Anti-Flicker
Mechanical Shutter
Standard Focal Plane Shutter.
Maximum shutter speed: 1/8.000.
Flash sync Speed: 1/250.
Use for: flash photography, very fast moving subjects, flickering light.
Electronic Shutter
Vibration-free.
Silent.
Maximum shutter speed: 1/32.000.
Flash sync speed: 1/100 or 1/50 at ISO 16.000 or higher.
Use for: general purpose & vibration-sensitive scenarios (macro, telephoto).
Not for flickering lights & very fast moving subjects.
Active in: Silent Mode, Pro Capture, High Res Shot, Focus Bracketing, Focus Stacking, Live ND, HDR.
Electronic First Curtain Shutter (Anti-Shock)
Vibration-free.
Maximum shutter speed: 1/8.000; faster than 1/320 automatically switches to mechanical shutter.
Flash sync speed: 1/250.
Use for: vibration-sensitive scenarios (macro, telephoto) when dealing with very fast moving subjects, flickering light.
Enable separately: [C1]-[7. Drive Mode] – [Anti-Shock].
Sensor Readout Speed and Rolling Shutter
Sensor readout speed: around 1/120 (120 fps maximum sequential shooting speed).
Rolling Shutter: Negligible.
Luminance Banding and Luminance Variation
Flickering light sources (e.g. LED & fluorescent lights) can cause two different effects:
A) Luminance variations from frame to frame caused by slow flickering light sources.
B) Luminance banding effects in each frame caused by fast flickering light sources.
Countering Luminance Bands and Luminance Variations
Mechanical and Electronic First Curtain Shutter
Practically eliminates luminance banding. Luminance variation is still possible.
Shutter Speed
Luminance variation: Use a shutter speed that is a multiple of the local power grid – 1/50 or 1/60.
Luminance Banding (Electronic Shutter): Set a shutter speed of at least 1/100. When using ISO 16.000 or higher, set a shutter speed of at least 1/50.
Anti-Flicker Shooting
When active, the OM-1 will re-time the shutter to mitigate the effect of flickering light sources.
This eliminates frame-to-frame luminance variations.
It cannot eliminate banding, but makes the effect more consistent by synchronizing with the power frequency. The banding therefore appears at the same position in the frame.
Flicker Scan
Only when using electronic shutter.
Allows for setting an optimal shutter speed to eliminate or reduce banding.
Workflow in Practice
If possible, use a non-flickering light source (e.g. flash). If not, adhere to the following workflow:
1) Select the shutter type. Preferably mechanical shutter.
2) Set the shutter speed.
3) Lock the exposure parameters to counter disturbances of the light meter caused by the flickering. Use [AEL] or manual settings (ISO, shutter speed and aperture).
4) Take a series of test images and evaluate the results.
5) Adjust shutter speed (use [Flicker Scan]) or enable [Anti-Flicker Shooting] if needed.
