I want to tackle a controversial subject in this week’s blog post.  Do you use a protective filter on the front of your lens?  You know the sort of thing I mean, it may be a ‘skylight’ filter or a UV filter, or potentially just a clear filter, but that’s not so common.

If you bought your lens from a bricks and mortar shop, almost certainly, the sales assistant would have advised you to get on.  “You need one of these, to protect your lens” they probably said, “If you scratch the glass on the front of your lens that’s very expensive.  But if you got a filter on then it’s only twelve quid down the drain, not your whole lens.”

Even if you bought your lens online, the whole idea of using a filter to protect the lens has been passed down from one photographer to another over the years that we just don’t question it and perhaps you just add a UV filter to your online shopping cart without even thinking about.  Well you’ve got to protect the lens, haven’t you?

Thinking it through

It sounds like good advice, but let’s stop and analyse this for just a moment.  How much did you pay for your lens?  If it’s a good one it might be £500.  For a really good one, you can triple that or even more.  They cost that amount of money for a reason.  The glass and the mechanics are precision engineered to give you the sharpest possible image.  When it comes to lenses you really are paying for quality.  So, after paying for that engineering, to get that image to die for you are going to stick a cheap £12, bit of glass in front of it?  Really?

That extra bit of glass has not been manufactured to the same precision.  It has two uncoated surfaces (front and back) that can reflect the light, that can diffuse the light and generally distort the light.

“Yes, but…” you might say, “does it really make that much of a difference?”  Well, to be honest, it really does depend on the quality of that filter.  It is an extra bit of glass that the light has to go through so yes it will make a difference.  How much depends on its quality.  You might see a difference, you might not.  Most likely, however, you put the filter on as soon as you got the lens so you’ve never seen the difference it may or may not make.

A true story

Perhaps, the easiest way to explain is to tell you a true story.  Years before I became a professional photographer, I was a gullible amateur who really couldn’t tell the difference between a good lens and the bottom of a milk bottle.  I decided I wanted a telephoto zoom lens.  The shopkeeper sold me a UV filter to go on the end of it, and I fitted it there and then in the shop.  No point in taking any chances.

I used the lens for a few weeks and I really wasn’t happy with the sharpness of the images.  So I contacted the manufacturer and posted the lens back to them for them to check out under warranty.  A few weeks later it was returned, with a simple note attached.  “Try removing the filter.”  I was livid… how can a filter be the cause?  I decided to prove it to them, I took two shots one with the filter and one without and to my amazement, I could see a big difference.  It was the first time I had ever shot without the UV filter on the front of the lens.  Needless to say, the filter never went back on.

Bringing it up to date

From that day forward I have never used protective filters on the front of my lenses, and these days I have some pretty expensive ‘bits of glass’.  Here’s what I have found works for me.

  1. I make sure I put the lens cap on when I am not shooting – that really is the best bit of protective gear you have available to you.
  2. If I don’t want to be taking the lens cap on and off, I use the lens hood so that it makes it difficult to touch or knock the end element of the lens.
  3. I do still have a protective filter that I can use if I am in hazardous conditions, such as a sandstorm or similar, but to be honest with you I often forget I have it with me and fail to put it on.
  4. And of course, I take great care about where I place my camera and my lenses – especially with my extreme wide-angle lens whose front element is so convex that the glass protrudes forward of the rest of the lens.  It is also impossible to fix a filter to it!

I am not always as careful as I might be, what I have just described is what I try to do, I don’t always achieve it.  I don’t treat my camera gear with kid-gloves, it’s a tool and I use it as such.  And you know what?  Even with that attitude, I have found that the glass on the end of the lens it pretty hard wearing.  I still haven’t managed to scratch a lens.

What about you?

Don’t get me wrong, I am not telling you to ditch your protective filters.  What I am saying is don’t believe the ‘accepted wisdom’ that you must use them.  Do a couple of test shots with and without the filter and compare the results, then decide if the peace of mind from using a filter is worth any difference in quality/sharpness.

If you do decide to ditch the protective filter, follow my tips for how to protect the lens.  And don’t blame me if you scratch it first time out.

If you do decide that you are happier keeping the filter on, please do yourself a favour, check it really is a UV or Skylight filter and not a polarising one.  Before you ask, yes I have come across at least two photographers who were having all sorts of problems because they had a polarising filter on the front of the camera and not a UV/Skylight.

Until next time, keep MAKING great images,

Ian.