Filters & lens care
The 62mm and 67mm threads, which filters earn their place, and keeping two lenses clean and safe.
- Know your filter thread sizes and how to share filters between lenses
- Choose which filters are actually worth carrying
- Keep both lenses clean, protected, and working
Filters and care are unglamorous, but they are where good glass is either protected and extended — or scratched and wasted. A little discipline here pays off for years.
Your thread sizes
Filters screw onto the front of a lens, sized to its thread:
- Sony 10-20mm — 62 mm.
- Tamron 17-70mm — 67 mm.
Because they differ, a filter bought for one will not fit the other directly. A cheap step-up ring (62→67 mm) lets you buy filters at 67 mm and use them on both lenses, which is the economical way to build a small filter kit.
Which filters earn their place
Not every filter is worth carrying. The ones that are:
- Circular polarizer (CPL) — the one filter you cannot replicate in editing. It cuts reflections off water and glass, deepens skies, and saturates foliage. Costs you a stop or two of light; rotate it to taste.
- Neutral density (ND) — darkens the scene so you can use slow shutters in daylight: silky waterfalls, and the 180° video shutter in bright sun (Part III). A variable ND is the flexible choice; fixed ND filters are optically cleaner.
- Protective / UV — a clear filter that guards the front element in harsh conditions. Useful in spray, sand, or dust; leave it off when you want the cleanest possible image, since any extra glass can add flare.
Skip the rest. Coloured and special-effect filters belong in software now.
Caring for two lenses
- Keep caps on and lenses in a padded bag when not shooting.
- Blow, then brush, then wipe — remove grit with a blower before any cloth touches the glass, so you do not grind particles across the coating. Finish with a microfibre cloth and, if needed, a drop of proper lens fluid on the cloth (not the lens).
- Use the hoods — they cut flare and, just as importantly, take the knock when a lens meets a doorframe.
- Mind the mount — swap lenses with the camera facing slightly down to keep dust off the sensor, and do it quickly in clean air.
In the field
Put a polarizer on the Tamron and photograph water or wet leaves, rotating the filter as you watch reflections vanish and colours deepen. That effect has no slider in any editor — proof that one or two good filters still belong in the bag.