Studio L7: See the Light
Playing with Time and Glass – The Magic of ND and CPL Filters in Long Exposure Photography
Welcome back to Studio L7, where the shutter slows, the waves blur, and the light bends to your will. This week, we’re getting hands-on (and lens-on) with two of the most important tools for any long exposure photographer: ND filters and CPL filters.
If you’ve ever wondered how photographers make crowds disappear, flatten oceans into mirrors, or turn waterfalls into silken strands of mist—spoiler alert: it’s not magic. It’s filters.
What is an ND Filter, and Why Should You Care?
ND (neutral density) filters are essentially sunglasses for your lens. They reduce the amount of light hitting your sensor, allowing you to use longer shutter speeds even in bright conditions.
This is how you:
Turn midday waves into soft fog
Erase people from busy city streets
Turn clouds into dramatic, streaking brushstrokes
Think of ND filters as your permission slip to break the rules of exposure. With a 10-stop ND filter, for example, you can push your shutter to 30 seconds even when it’s sunny out.
Real World Use: I once shot the Santa Cruz Boardwalk on a crowded summer day. With a 6-stop ND and a 15-second exposure, every single person vanished from the shot—leaving only shadows, benches, and a candy-colored stillness that looked like a dream.
CPL Filters: Cutting Glare, Boosting Color
Circular polarizers (CPLs) don’t just reduce reflections—they make skies bluer, foliage greener, and water clearer. It’s like switching your image from “meh” to “whoa” with a quick twist of the ring.
CPLs are a must-have when:
Shooting through windows or water
Photographing wet foliage or rocks
Wanting richer contrast in the sky
Best part? You can stack a CPL with an ND filter. That’s where the real magic happens.
Stacking Filters: Can You Do It? Should You Do It?
Short answer: Yes. Long answer: Carefully.
Combining an ND and CPL filter can transform your photos and introduce vignetting or color casts if you’re not using quality glass.
Pro Tip: If you're using wide-angle lenses (like that dreamy 14mm you love), use slim filters to avoid corner shadows.
How to Get Started (and Not Ruin Your Shots)
If you're new to filters, here's a simple step-by-step workflow:
Compose Your Shot without any filters—autofocus and frame it.
Add the CPL Filter—rotate to control reflections and contrast.
Add the ND Filter—set the desired stops of light reduction.
Switch to Manual Mode—dial in a long shutter speed, adjust ISO and aperture.
Use a Tripod + Remote Shutter—motion blur is great in water, not in your camera.
Tip of the Week: Beware of Overexposure Drift
Long exposures with stacked filters can trick your camera into thinking it needs more light than it really does. Always bracket or use histogram peeking to avoid blown-out highlights.
New Gear on the Block
🛠️ H&Y Revoring CPL + Variable ND Filter
A fantastic all-in-one solution that auto-adjusts to your lens diameter. It’s pricey, but if you’re tired of carrying multiple filters in your bag, this might be your next splurge.
📷 Insta360 X4 Tip: Want to do long exposure with a 360 cam? Set it on a tripod and use the lowest shutter setting with ND filter caps. It won’t replace an A7R II, but it’s pure fun for creative experimentation.
The Joy of Slowing Down
Using ND and CPL filters isn’t just about making better photos. It’s about giving yourself permission to pause. Long exposure photography forces you to wait, to breathe, and to be present with your scene.
So next time you’re at the beach or in the middle of a noisy street, screw on that filter, take a deep breath, and let the world blur around you.
Until next week—slow your shutter, and shoot with intention.
— Robert
📸 Studio L7