4640. PHOTOGRAPHY TIPS: The MODE Dial. PASM. Manual exposure bracketing. sunsets.

 Ref: Digital Photographer. Issue 278.

PASM is an acronym for four main exposure modes.

1. Program Mode (P).  Semi-automatic, the camera selects the aperture and shutter speed but leaves you to adjust ISO, exposure compensation and white balance.

2. Aperture Priority (A or Av), you choose the aperture. Camera adjusts the shutter speed to achieve the 'correct' exposure.  

 

 

3. Shutter Priority (S, Tv, T), you set the shutter speed. Camera adjusts everything else.
LINK EXPOSURE TO THE AF POINT.
Shoot in changeable light where exposure is the priority.
Link chosen autofocus point to the SPOT metering mode.

Your camera sets the ISO as high as needed for a 'proper exposure'.
Set the ISO range e.g. max ISO 320. MINIMUM 200.

 

 

 

4. Manual Mode (M) control over all the parameters. Not for fast-paced action, spontaneous moments, changeable light.

Use when light is not changing suddenly or high-contrast scenes containing light and shadow contrasts (landscapes with dark foreground and bright sky - manual mode allows you to balance exposure and preserve details in the highlights and shadows). 

4a. MANUAL EXPOSURE BRACKETING.  Sunrise and sunsets where the sky is much brighter than the foreground. Tripod. Shoot at 'correct' metered exposure, then deliberately over and underexpose by enough increments to avoid clipping. Blend these frames during editing will provide more highlight and shadow data than just a single shot.  

Many modern cameras offer AUTOMATIC EXPOSURE BRACKETING but manual mode lets you adapt to any lighting by choosing how you bracket.

MEASURE THE EXPOSURE DIFFERENCES.
Discover the brightness differences between two subjects.
1. To ensure both are properly exposed. Easiest approach is to use manual mode with spot metering selected.

First, aim lens over one subject. Depress shutter halfway to take a reading, and then use exposure lock which allows you to reframe the scene but maintain the current exposure settings to focus on the 2nd subject. (AE-L, AF-L).