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Chapter 7: Is a UV filter needed?
The Leica Q2 Monochrom journal.
There’s much discussion over whether the Leica Q2M should have a UV filter permanently on front the lens or not. This article will help you with your decision.
What does a UV filter do?
A UV filter filters out some of the blue spectrum that can cause haze. But (maybe more importantly) it protects the lens from getting scratched or dirty. So, do you need one or not?
The protection argument.
You’ve just paid an astronomical amount of money for the lens affixed to a Leica camera, so why wouldn’t you want to protect it? UV filters obviously protect against physical scratches, but they also protect against dirt. And no matter how careful you are, lenses seem to attract crude. Without the filter, the bare lens is susceptible to dirt, residue left when the lens gets wet from even a misty rain and whatever that stuff is that seems to magically appear on your lens. With repeated cleanings, the coatings on the exposed, bare lens (the ones that help create that rich contrast by minimizing reflections) can wear off. If there’s a filter there and the nanocoatings on it get damaged, it’s substantially easier and cheaper to buy a new filter over having the lens recoated or an element replaced.
The reflection argument.
This argument is that UV filters do more harm than good to the image. While they block UV light and make the image more clear, every one—no matter how expensive—reflect a certain amount of light back onto the lens. And it’s said this can be worse than lost nanocoatings on the exposed front of the lens. Plus the glass used for some UV filters may be optically inferior and cause some loss of sharpness as well.
Is the Leica UVa II filter worth it?
This is yet another argument added to the mix, but one worth understanding. In a laser test the Leica UVa II scored the best of any filter on the market with a tiny .1% reflection percentage. For comparison: plain, uncoated glass has a reflection factor of about 4%.
Another point: While some think the lens hood that comes with the Q2M is a burden (since it makes the lens a half-inch longer). But I’m convinced it helps protect the lens and can minimizes reflections as well.
My take.
The Leica UVa II cost about $150. But if you’re buying a UV filter to protect your lens and want the clearest image possible with a UV filter on, I feel this one is worth the money. If planning on buying a cheaper UV filter, the test results above will show you just how much reflection 20 other filters cause and whether they really do more harm than good.
Final advice: Before you go shooting, inspect the filter and clean if necessary. The highest grade of isopropyl alcohol you can find and a fresh microfiber cloth is recommended for both filter and lens cleaning. I’ve had good luck with EcoPure an environmentally-safe solution that uses no chemical solvents. I’ve also been told by a chemist who develops laundry detergent that you shouldn’t wash cleaning cloths: Some of the chemicals remain that can scratch the lens or filter.
Next chapter: How can my photos have GPS when my camera has no GPS?
The above link to the Leica UVa II and EcoPure are not affilliate links, so I make no money if you click on them. If you find this series useful and want to see more consider buying me a coffee below
Photography Leica Q2 Monochrom