To use a lens filter or not to use a lens filter, is a veritable Pandora’s Box of a question, because it’s not one with a binary answer. In fact, it spawns other questions like, “which is best?” And that’s probably tertiary, as really what it all comes down to, what we really want to know is: which should we get? That’s a tricky question because there are so many, and most of us who can would rather eat crow than test a chest of lens filters, and even fewer of us who could assemble the findings in a way that’s remotely interesting to consume. Thankfully, Roger Cicala is there, and this is just what he’s done.
I typically can’t get through anything these days that’s not remotely enjoyable to read or practically utilitarian, and there are so few out there I find are able to speak about photography-related subjects in a way that isn’t as bland as beige paint. Roger is one. What he has done here is test $1,500 worth of lens filters ranging from $10 Chiaros to $225 Leicas, and everything in-between, and reduced his findings to easy-to-interpret charts and a few words.
One of the primary issues discussed when addressing filter-use is light transmission, and that was certainly the primary focus of their test, though other metrics pertaining to things like distortion were taken into account. Just how much light is getting through the filter is important, and this importance is a reason why some manufacturers list the light transmission ability of a given filter on the packaging.
Roger states that, “Plain uncoated glass passes through about 96% of light and reflects back 4%. It does this at both surfaces so if you shine a light through a flat piece of uncoated glass, about 92% of the light passes through. The rest reflects hither and yon.” If we accept this, we quickly get an appreciation for how important transmission figures for filters are, and how important coatings are, as they can greatly improve light transmission. So what were the findings? Here’s a taste:
What’s interesting to see here is just how price is no guarantee of quality. Sure, the most expensive filter tested performed the best, but there’s a steep drop after in terms of cost to transmission benefit. Furthermore, if you read the full blog post-and you should–you’ll see Roger addresses QC and how that appears could be a factor to consider, further making some choices harder to make, and perhaps others more clear. It’s a good read, and you can see the full post here on Lensrentals.
You can have a look at our own Matt Saville’s take on general filter use.