The Complete Guide to Filter Sizes and Lens Cap Selection

Protecting your camera lens is essential for maintaining image clarity and extending its lifespan. Whether you're shooting outdoors or storing your camera, a properly fitting lens cap effectively guards against dust, moisture, fingerprints, and accidental scratches.

However, with the wide variety of filters available on the market—especially specialized designs like Variable ND (VND) filters or 2-in-1 filters—the front thread size is often one or even two sizes larger than the lens thread. To avoid purchasing a mismatched lens cap, always confirm the specific size of your filter before buying to ensure a perfect fit.

▶▶▶ Understanding Filter Types & Cap Sizes

◆ ◆ Standard Filters

At the Kentfaith store, we offer a range of filters—including UV, CPL, ND8, ND64, ND1000, ND100000, Black Mist, White Mist, and more—designed for various effects. For these standard filters, the front and rear thread sizes are consistent.

• Example, if you purchase an 82mm CPL filter, you will need an 82mm lens cap or can stack other 82mm filters.

◆ ◆  Specialized Filters (VND, 2-in-1, 3-in-1)

If you are using specialized filters like VND, 2-in-1, or 3-in-1 filters, note that the front thread is typically one or two sizes larger than the lens thread. Pay close attention to both the stacked filter size and the lens cap size.

• Example: Using an 82mm VND 2-32 filter and stacking additional filters or a lens cap:  
  
  For this series, the front thread diameter is larger than the back thread diameter:
  

          Back thread diameter (attaches to lens): 82mm
          Front thread diameter (for additional filters/accessories): 86mm

          If an additional filter can be attached before the variable ND filter, use the same size. If not, you will need to increase by one size.

          Here are the installation methods:
          Your 82mm lens + 82mm standard filter + 82mm variable ND filter
          Your 82mm lens + 82mm variable ND filter + 86mm standard filter           

▶▶▶ Filter Front Thread & Lens Cap Size Reference

◆◆ND2-32, ND2-400, ND8-128, ND32-512, ND3-1000, ND2-2000, ND8-128 Filter ( Contains all filter series )
Nano-Klear ND2-32&CPL,  Nano-Xcel true color ND2-32&CPL,  Nano-Xcel Pro ND2-32&CPL,
Nano-Xcel ND4-64&CPL,
ND2-32&black mist 1/4, ND2-32&black mist 1/8, ND2-400&black mist 1/4( Contains all filter series )
Black Mist 1/4 & CPL ( Contains all filter series )
ND2-32&black mist&CPL( Contains all filter series )

◆◆ Nano-Dazzle ND2-32&CPL, Nano-Xcel ND2-32&CPL

Filter size	Filter front thread	Len cap size
37mm	43mm	43mm
40.5mm	46mm	46mm
43mm	49mm	49mm
46mm	52mm	52mm
49mm	55mm	55mm
52mm	58mm	58mm
55mm	62mm	62mm
58mm	67mm	67mm
62mm	72mm	72mm
67mm	77mm	77mm
72mm	82mm	82mm
77mm	86mm	86mm
82mm	95mm	95mm
86mm	105mm	105mm
95mm	112mm	112mm
105mm	127mm	127mm

▶▶▶ Magnetic VND Filter Front Thread & Lens Cap Size Reference

◆◆ Magnetic ND8-ND128, Magnetic ND2-ND32