A circular polarizer (CPL) filter is an important piece of kit in any photographers bag. Especially that of a travel/landscape photographer. In this post we'll examine some tips that will allow you to efficiently share a single CPL filter across your lenses of different size.
Why share CPL filters?
First off, you may ask why share a CPL filter at all ? Why not use a dedicated filter for each lens avoid all this hassle in the first place. Here are some reasons why..
- Its cost effective. Why buy many filters (costing 100-200$ each) and when you just buy a single highest quality filter available and share it across your lenses.
- Minimize the clutter in your kit bag. Carrying all those extra filters just adds extra weight and clutter in your kit bag, so why do it.
- Use your CPL with a hood. Typically not be able to use the manufacturer supplied lens hood along with a CPL filter. Even of you are able to somehow screw in the CPL with a hood attached, you'll still not be able to rotate your CPL filter to get the desired polarization effect. But by following the tips mentioned below, you'll get an pleasant bonus feature of being able to use a hood along with your CPL filter.
Here's how you do it
- Consider your current and future lens needs to choose the size of your CPL filter. You'll need to buy the largest size CPL filter which will cover all the lenses in your kit. Also consider any possible future lens acquisitions while making that decision.
Also make sure that the CPL filter you buy has a front filter thread. Some manufacturers do not provide a front thread with their Slim-CPL filters, so be careful to avoid these brands and buy from brands like Hoya which provide a front thread even on their slim filters.
- Use step up filter thread adapters. Using step up adapters you can attach a large diameter CPL filter (say 82mm) on lenses with smaller filter threads (48mm, 67mm, 77mm etc). These rings can be had for around 2$ each on sites like Amazon or eBay.
Ideally you'll want to leave the step-up adapter permanently on your lens. This makes it easier in the field to attach and remove CPL filters on your lens.
- Use a screw in lens hood. You'll not be able to attach the manufacturer supplied hoods on a lens with a step-up adapter. So you'll need a hood which can be mounted on the filter thread of the step-adapter or the CPL filter. These adapters sell for around 3-5$ on Amazon and eBay and are well worth the money. I prefer the collapsable rubber hoods as they are compact and easy to store while mounted on the lens.
Note : Be careful with Ultra-wide lenses which require a petal shaped hood to minimize vignetting. In such cases select the hood appropriately.
- Attach hood to the CPL filter. Start off by attaching the CPL filter to the step-up adapter and then attach hood to the filter thread of the CPL filter. Now, rotating the hood would rotate the CPL filter and get you the desired polarizing effect. Rotating a CPL filter this way is more effective than rotating it by the rim of the filter.
- Use center-pinch lens caps. Finally, you'll need to bigger lens caps to use with the step-up adapters. Be sure to buy the center-pinch caps which makes it easy to attach and remove the lens cap even with a hood attached.