Non-recoverable
CPL effects cannot be recreated later. Once reflection is either removed or retained, the RAW file contains that optical decision.
AddendumDocument 14 of 21From the GFX 100S II field guide
GFX 100S II · Field Reference
Optical Filters
Field Discipline
CPL technique
ND exposure math
Thread compatibility
Stacking protocol
Kit gaps
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Use this when field conditions require specialist technique or failure-mode handling.
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00
Current Filter Inventory
A filter kit is not a collection of accessories. It is an optical decision layer placed in front of a 102 MP sensor. The first rule is therefore simple: know exactly what each filter does, what thread it carries, and which lenses can use it without compromise.
| Filter | Type | Thread | Optical effect | Primary use |
|---|---|---|---|---|
| Hoya CPL | Circular polariser | 82 mm | Controls non-metallic reflections, foliage sheen, water glare, and sky saturation. | Direct fit for GF 20-35mm F4 and GF 45-100mm F4; adapts cleanly to the GF 100-200mm F5.6 with a 67-82 step-up ring. |
| B+W CPL MRC Basic | Circular polariser | 72 mm | Same polarising function with B+W MRC coating. | Useful only where 72 mm fits directly, or on smaller threads stepped up to 72 mm. |
| B+W 110 ND 3.0 / 1000x | Neutral density | 72 mm | 10-stop light reduction. Turns ordinary daylight shutter speeds into true long exposure. | Water smoothing, cloud drag, crowd removal, and daylight time exposure. |
| B+W 803 ND 0.9 MRC Nano Master | Neutral density | verify rim | 3-stop / 8x light reduction with higher-grade Nano coating. | Wide apertures in bright light, moderate motion blur, practical handheld/tripod crossover. |
Important correction: a 72 mm filter does not step up to an 82 mm lens. That would require placing a smaller filter in front of a larger lens thread, which is a step-down arrangement and is especially risky on the GF 20-35mm. Standardise upward: buy larger filters and use rings from smaller lens threads to larger filter threads.
Exposure tool
ND filters buy shutter time or aperture freedom. They do not add a look by themselves; the motion or depth-of-field change is the look.
System size
82 mm is the practical GFX base size here. It directly serves the 20-35mm and 45-100mm, then adapts downward to the 77 mm GF 80mm and 67 mm GF 100-200mm lenses.
01
The Optical Principle
There are two different categories in this kit. A circular polariser changes the relationships inside the scene by removing polarised light. A neutral density filter changes the exposure envelope by reducing the quantity of light reaching the sensor.
Circular polariser
Use when the scene contains reflection, glare, wet surfaces, foliage sheen, glass, sky polarisation, or water transparency. The right question is: what reflection belongs in the picture?
Neutral density
Use when the scene needs a shutter speed or aperture that the ambient light would not otherwise permit. The right question is: what duration should the subject experience?
Menu
Decision Gate · before mounting anything
3 settings
| # | Setting | Value | Action |
|---|---|---|---|
| 1 | Do I need to remove or keep reflection?Water, foliage, glass, wet stone, painted surfaces | CPL | Set |
| Reason: this is an optical content decision. Post-processing cannot reconstruct detail hidden behind glare. | |||
| 2 | Do I need a slower shutter or wider aperture?Water, clouds, people, bright portrait light | ND | Set |
| Reason: this is an exposure-duration decision. The filter creates time the camera otherwise cannot use. | |||
| 3 | Do I need both?Long exposure water with controlled glare, architecture with clouds, bright coastal work | CPL + ND | Set |
| Reason: set polarisation first, then add density. Never try to tune polarisation blind through a 10-stop ND. | |||
02
Circular Polariser Technique
A CPL is not a saturation filter. It is a reflection filter. Saturation often rises because surface glare is removed and the underlying colour becomes visible, but the control target is the reflection itself.
Aim at the actual reflective surfaceobserve
Do not rotate while staring only at the sky. Watch water, foliage, glass, paint, or wet stone and decide how much reflection the composition needs.
Rotate to maximum effect, then back offtune
Maximum polarisation is often too aggressive. Back off slightly to keep surfaces alive and avoid dead water, black skies, or flattened glass.
Check wide-angle sky bandingverify
At 20mm, the frame can span enough sky angle for the polarising effect to become uneven. If the sky forms a dark patch, reduce the CPL effect or remove it.
Recheck after every camera moverepeat
Polarisation depends on viewing angle relative to the light source. A new composition means a new CPL setting.
| Subject | CPL effect | Field caution |
|---|---|---|
| Water | Removes glare and can reveal depth, stones, weed, or reflected structure. | Do not erase every reflection if reflection is the composition. |
| Foliage | Reduces waxy leaf sheen and separates green families. | Exposure cost can push shutter speed too low in wind. |
| Sky | Darkens polarised blue sky most strongly about 90 degrees from the sun. | Uneven sky is common on ultra-wide framing. |
| Glass | Reduces window reflection and can reveal interior structure. | Some architectural reflections are essential; remove selectively. |
| Metal | Little to no true polarising benefit. | Do not expect a CPL to remove metallic reflection. |
Exposure cost: plan for roughly 1.5-2 stops of light loss with most circular polarisers. Meter through the filter after rotation, because the exact loss changes with design and angle.
03
Neutral Density Exposure Math
ND notation has three languages: density, filter factor, and stops. The field language is stops. The kit currently has a practical 3-stop tool and a heavy 10-stop tool, with a gap in the middle.
| Marking | Stops | Factor | Field role |
|---|---|---|---|
| ND 0.9 / 803 | 3 | 8x | Bright portrait aperture control, mild water drag, movement suggestion. |
| ND 1.8 / 106 | 6 | 64x | The missing middle: usable daylight blur without forcing extreme exposure times. |
| ND 3.0 / 110 | 10 | 1000x | True long exposure: cloud streaks, glass water, crowd clearing, time abstraction. |
| Base shutter | 3-stop ND | 6-stop ND | 10-stop ND | 3 + 10 stop stack |
|---|---|---|---|---|
| 1/1000s | 1/125s | 1/15s | 1s | 8s |
| 1/250s | 1/30s | 1/4s | 4s | 32s |
| 1/60s | 1/8s | 1s | 16s | 2m 8s |
| 1/15s | 1/2s | 4s | 1m 4s | 8m 32s |
10-stop discipline: compose, focus, and set CPL angle before mounting the B+W 110. After ND 3.0 is mounted, autofocus and visual polariser judgement become unreliable. Use manual exposure, live histogram, and a timed release.
04
Thread Compatibility Map
The thread map changes the buying decision. Your main GFX lenses are not a 72 mm system. They are an 82 / 77 / 67 mm system, with 82 mm as the cleanest shared circular-filter size.
| Lens | Filter thread | 82 mm filters | 72 mm filters | Recommendation |
|---|---|---|---|---|
| GF 20-35mm F4 | 82 mm | Direct fit | Step-down only; avoid | Use the 82 mm Hoya CPL. Buy future NDs in 82 mm or larger holder format. |
| GF 45-100mm F4 | 82 mm | Direct fit | Step-down only; avoid | Same as 20-35mm, with lower vignetting risk but no reason to reduce size. |
| GF 80mm F1.7 | 77 mm | 77-82 step-up ring | Step-down only; avoid | Use 82 mm filters with a 77-82 ring for portrait ND work. |
| GF 100-200mm F5.6 | 67 mm | 67-82 step-up ring | 67-72 step-up ring | The existing 72 mm NDs are most usable here if a 67-72 ring is available. |
Menu
Adapter Doctrine · buy once, avoid chains
3 settings
| # | Setting | Value | Action |
|---|---|---|---|
| 1 | Best common size for circular filtersCurrent GFX lens set | 82 mm | Set |
| Reason: the GF 20-35mm and GF 45-100mm are native 82 mm, while the GF 80mm and GF 100-200mm step up cleanly. This keeps the circular-filter kit coherent without reducing glass size on the larger lenses. | |||
| 2 | Useful rings to ownFor existing lenses | 67-82 · 77-82 | Set |
| Reason: these let a single 82 mm CPL/ND set cover the 100-200mm and 80mm without vignetting from smaller glass. | |||
| 3 | Legacy 72 mm pathFor the existing B+W 72 mm filters | 67-72 only | Set |
| Reason: this makes the 72 mm B+W ND filters useful on the GF 100-200mm. Do not build an 82 mm lens around a 72 mm filter. | |||
05
Application by Shooting Stream
Filters should follow the bank purpose. Do not mount glass because it is available. Mount it because it solves the problem of that stream.
Landscape
CPL first, ND second. Use CPL for water, foliage, wet stone, and sky control. Use 3 stops for moving texture; 10 stops for abstraction. Watch the 20mm sky carefully.
Portrait
ND is the practical filter. Use 3 stops to hold f/1.7-f/2 in bright light. CPL is occasional: glass, reflective environments, or wet surfaces.
Street
Usually no filter. The light cost, handling delay, and extra visible hardware work against responsive documentary shooting. Use only for deliberate reflective scenes.
Sport
No filter by default. Indoor sport already needs every photon. CPL and ND are incompatible with the bank's speed requirement.
Architecture
CPL is powerful but dangerous. It can control glass reflection, but total removal can make buildings look dead. 10-stop ND can clear crowds or extend cloud movement.
Pixel Shift
Use only for static studio-like work. CPL must be locked before capture; ND lengthens the exposure and increases vibration and motion risk across the sequence.
06
Stacking and Coating Discipline
Stacking is valid, but every extra ring adds thickness, reflection surfaces, cleaning burden, and vignetting risk. On the GF 20-35mm, the question is not whether the stack can physically mount; it is whether the corners survive.
| Stack | Total light loss | Use case | Risk |
|---|---|---|---|
| CPL + ND 0.9 | About 4.5-5 stops | Controlled reflection plus moderate motion blur in bright light. | Handholding may become marginal; meter through the stack. |
| CPL + ND 3.0 | About 11.5-12 stops | Daylight long exposure with glare controlled before the exposure. | Focus, CPL tuning, and composition must happen before the ND goes on. |
| ND 0.9 + ND 3.0 | 13 stops | Extreme time exposure where CPL is not needed. | Long-exposure noise, colour cast, flare, and multi-minute timing errors. |
Filter orderCPL first
Mount the CPL on the lens and tune rotation. Add ND after the polarising decision is final.
Corner test20mm
At the widest focal length, make a test frame of an even subject and inspect RAW corners. Do this before committing to a session.
Flare checklight source
Shield the front element and inspect for ghosting. Coating quality matters more as the stack grows.
07
Gaps and Buying Priorities
The current kit is useful, but it is uneven. The most important gap is not another exotic effect; it is a coherent size strategy.
| Priority | Item | Why |
|---|---|---|
| 1 | Confirm B+W 803 thread size | The 3-stop ND is the most practical daily ND. Its thread determines whether it belongs in the active GFX kit or a legacy kit. |
| 2 | 82 mm 6-stop ND | Fills the gap between 3 and 10 stops, directly fits the two main zooms, and adapts cleanly to 77 mm and 67 mm lenses. |
| 3 | 77-82 and 67-82 step-up rings | Creates one coherent 82 mm circular-filter path for the GF 80mm and GF 100-200mm. |
| 4 | 82 mm ND 3.0 or square holder system | Replaces the compromised 72 mm long-exposure path for the GF 20-35mm, GF 45-100mm, and GF 100-200mm. |
| 5 | Soft-edge graduated ND system | Optional. Useful for disciplined landscape horizon control, but less urgent than coherent circular ND sizing. |
Best minimal kit: 82 mm CPL, 82 mm ND 0.9, 82 mm ND 1.8, 82 mm ND 3.0, plus 77-82 and 67-82 rings. That covers the listed lenses without step-down compromises.
08
Field Protocol
Filters slow the act of photographing. That is acceptable only when the slowness is paid back by a better negative. Use the same sequence every time.
Menu
Pre-Capture Checklist · repeat every filtered frame
6 settings
| # | Setting | Value | Action |
|---|---|---|---|
| 1 | Inspect front and rear filter surfacesUse side light, blower first, cloth only when needed | clean | Set |
| 2 | Mount rings without forceIf a ring binds, stop before it locks onto the lens | seated | Set |
| 3 | Compose and focus before heavy NDEspecially before the 10-stop B+W 110 | locked | Set |
| 4 | Set CPL while watching the subject surfaceNot just the sky | tuned | Set |
| 5 | Meter through the final stackCPL loss is variable; do not rely only on arithmetic | histogram | Set |
| 6 | Check corners and flareCritical on GF 20-35mm at 20mm | verified | Set |
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