Each installment features a photographer discussing a piece of equipment they can't do without—and a photograph they couldn't capture without it.

Photographer: Tony Sweet

Equipment: Singh Ray 15-Stop Mor-Slo

Neutral density filters are very dark, necessitating a very long exposure. Long exposures are not how we see the world and can render an other worldly, highly stylized look.

The 15-Stop Mor-Slo enabled me to achieve a 4 minute exposure in bright overcast light. The desired effects were a direct result of the very long exposure: the very smooth river surrounding the detailed foreground rock, the soft high key waterfalls, and the 4 minutes of cloud movement, creating soft cloud lines.