Lens filters solve real photographic problems that cannot be fixed in post-processing: controlling exposure in bright light, cutting reflections on water and glass, polarizing skies, and protecting expensive front elements. For Sony FE lens users, choosing the right filter involves understanding thread sizes and picking brands that do not degrade the exceptional optical quality of G Master glass. Here is the complete guide.
ND Filters: When and Why You Need Them
ND (Neutral Density) filters reduce the amount of light entering the lens without affecting color. They solve two specific problems:
- Video in bright outdoor light: Proper video exposure requires following the 180-degree shutter rule — shutter speed approximately double the frame rate (1/50s for 25fps). In bright sunlight this requires very small apertures (f/11+) unless you use ND filters. A 3-stop or 6-stop ND allows shooting at f/2.8 or f/4 in full sun.
- Long exposure photography: Waterfall, seascape, and light trail photography requires slow shutter speeds during daylight. A 10-stop ND enables 2-4 second exposures in daylight.
Variable ND vs Fixed ND
Variable ND: One filter that adjusts from low to high density by rotating. Convenient for run-and-gun video work. Quality variable NDs are expensive; cheap ones produce a distinctive X-pattern cross pattern in wide-angle shots and degrade image quality. Recommend: NiSi True Color VND or PolarPro Peter McKinnon Edition.
Fixed ND: Single density (ND4 = 2 stop, ND8 = 3 stop, ND64 = 6 stop, ND1000 = 10 stop). Higher quality than variable NDs at equivalent prices. No X-pattern issue. Require filter swapping for different conditions. Recommend: Breakthrough Photography X4, B+W 10-stop ND1000.
CPL Filters: Cut Reflections and Polarize Skies
A circular polarizer (CPL) rotates to selectively cut reflected light. Practical applications:
- Shoot through glass windows without reflections
- Photograph water surfaces showing underwater detail instead of sky reflection
- Darken blue skies by 1-2 stops (most dramatic at 90 degrees from the sun)
- Reduce haze on distant mountains in landscape photography
CPL effects cannot be replicated in post-processing — they happen at the physical level of the light entering the lens. This makes a quality CPL one of the most impactful photographic filters available.
Best CPL for Sony lenses:
- B+W XS-Pro Kaesemann MRC Nano (~$80-130): The standard professional recommendation. Multi-resistant coating resists smudges and condensation. Used by working professionals globally.
- Breakthrough Photography X4 CPL (~$90-150): Higher contrast than B+W in some conditions, excellent multi-coating. Popular with landscape photographers who want stronger sky effect.
- NiSi True Color CPL (~$80-120): Color-neutral polarization without the warm shift some CPLs introduce.
UV Filters: Protection or Optical Tax?
UV filters were essential in film days to block UV radiation that film was sensitive to. Digital sensors are not UV-sensitive. Their only practical purpose today is protecting the front element of the lens from scratches, dust, and impact.
The optical trade-off: any filter introduces additional glass elements into the light path. Cheap UV filters reduce contrast, increase flare in backlit situations, and can soften fine detail on high-resolution sensors like the 61MP A7R V. On a $2,300 lens, a $20 UV filter is a false economy.
If you use a UV filter for protection: Use only multi-coated, optically clear filters from Hoya, B+W, or NiSi. The B+W XS-Pro UV MRC Nano (~$50-70) is the benchmark — optically clear enough to leave on full-time without measurable degradation.
If you prefer bare front elements: The front elements of G Master lenses use Sony’s ARC (Anti-Reflective Coating) and fluorine coating — they are scratch-resistant and easy to clean. Using a lens hood provides adequate impact protection for most shooting scenarios.
Common Sony Lens Filter Sizes
| Lens | Filter Thread |
|---|---|
| FE 24-70mm f/2.8 GM II | 82mm |
| FE 70-200mm f/2.8 GM II | 77mm |
| FE 16-35mm f/2.8 GM | 82mm |
| FE 85mm f/1.4 GM | 77mm |
| FE 50mm f/1.2 GM | 72mm |
| FE 35mm f/1.4 GM | 67mm |
| FE 24mm f/1.4 GM | 67mm |
| Tamron 28-75mm f/2.8 G2 | 67mm |
| Tamron 70-180mm f/2.8 G2 | 67mm |
| FE 100-400mm f/4.5-5.6 GM | 77mm |
Tip on standardizing filter sizes: Many Sony FE lenses use 77mm or 82mm threads. Purchasing one high-quality CPL and one ND in 82mm with a step-down ring to 77mm allows using the same filters across multiple lenses — significantly more cost-effective than buying separate filters for each lens.
Filter Systems for Landscape Photography
For serious landscape work, drop-in filter systems allow using rectangular graduated ND filters (for darkening skies while keeping foregrounds bright), variable soft or hard-edge grads, and 10-stop NDs with precise positioning.
NiSi 100mm System: The professional standard for Sony landscape photographers. Accepts 100×100mm and 100×150mm graduated filters, plus a 100mm polarizer that mounts at the front. Adapts to virtually any Sony FE lens via thread-size adapters. Complete kit ~$400-600.
Kase Magnetic Filter System: Magnetic attachment for faster filter changes in the field. Compatible with popular Sony FE lens thread sizes. Excellent quality, though premium pricing.
Frequently Asked Questions
- Do I need an ND filter for Sony video if my camera has a built-in ND?
- The Sony RX series (RX100 VII, RX10 IV) and some cinema cameras have built-in ND filters. The Sony A7 V, A7C II, and FX30 do not. For these cameras, an external ND filter is required for proper video exposure in bright conditions.
- What ND strength do I need for outdoor video?
- For 25fps video in bright sun, a 6-stop (ND64) filter allows shooting at f/2.8 or f/4. A 3-stop (ND8) is useful for overcast or shade. Carry both, or a variable ND that covers 2-7 stops.
- Can I stack filters on Sony lenses?
- Yes, but avoid stacking more than two filters simultaneously. Each additional filter layer increases the risk of vignetting (dark corners), flare, and minor optical degradation. If stacking a CPL and ND, use a slim/thin CPL to minimize depth.
- Are cheap UV filters bad for G Master lenses?
- On high-resolution sensors, cheap UV filters can reduce contrast and detail. A $20 UV filter on a $2,300 G Master lens is counterproductive. Use a quality multicoated filter or no filter at all.
- What filter size do I need for the Sony A6700 kit lens?
- The Sony E PZ 16-50mm kit lens uses a 40.5mm filter thread — an unusual small size. Most after-market filter systems require a step-up ring (40.5mm to 55mm or larger) to accept standard circular filters.