With the bettering of smart phone cameras and a growing general interest in digital photography one thing that gets left out of geeky talk is the use of on-lens filters. Not the filters that you apply after you take an image (ala Instagram), but filters you stick on the front of your lens prior to taking the photo.
I’m not a trained photographer, but I have had experience with many of these filters and I wanted to share a few thoughts for those of you moving towards more pricey digital cameras. (I wish they made some filters for the iPhone — then again that’d be silly.)
A Note About Filters and Prices
There’s two really important things to remember when purchasing any filter:
- You are putting another piece of glass between your scene and the image sensor. With every piece of glass your image quality can degrade. Don’t put a $20 filter on the front of a $1,000 lens. Buy high-quality filters or your really sharp lens may not be so sharp anymore.
- Adding more glass can increase lens flare and other “undesirable” things. (Though this could be good if you aspire to be JJ Abrams, but bad if you want clean and crisp photos.)
There are things that help reduce these factors, but keep those two important points in mind before you click ‘buy’ on anything or read any further.
This may be the most common of camera filters. The UV filter is essentially a clear filter that goes on your camera lens (some people call them “protective” filters too). These filters serve two purposes:
- To help block UV rays from the actual film inside the camera.
- To protect the front lens element from damage.
With digital cameras, for the most part, my understanding is that these filters are only useful for protecting the front lens.
In other words, I personally skip these filters, but if you are prone to bashing your camera around then maybe you need one — but buy a high-quality filter in that case. Remember $150 for a filter is far less than your lens cost.
For the most part you can skip these filters and just smirk when people tell you that you need one.
The Circular Polarizing filter is the one filter I would encourage you to get. Like polarized sunglasses it can cut down on glare.
The circular part means that the filter (once attached) can rotate independently of the lens so that you can shift the polarization.
Update: I was mistaken here as the circular part refers to the type of polarization. My apologies.
This comes in handy for photographing reflective surfaces as you can truly cut down the reflections, or capture better (subjective) color when shooting landscapes.
Wikipedia actually has a good article on the usage of CP filters with some great example shots. I highly, highly, recommend you have one of these and the Wikipedia article is a good place to start understanding why (just look at the photo comparisons if nothing else).
It is important to note that depending on the filter you select, you will lose some light coming into the lens, so they aren’t made for shooting in low-light. If you shoot products1, landscapes, or real estate this is a must have.
There’s also three specialty filters that I want to mention, as you may bump into them as you look around.
Close Up Filter
To take a really close up picture of an item you need to buy a true macro lens. Short of that are specialty filters called “close up” that allow you to get the lens closer to the item while maintaing focus — creating a poor-mans macro lens.
I really do not recommend these. They are just magnifying glasses (more or less). I’ve only ever owned one and I was really underwhelmed by it. Better to save up for a macro lens and fake it until then.2
Neutral Density Filter
Have you ever seen those shots of ocean waves, or waterfalls, and the water looks like a fine smooth blurry mist? Those are long exposure shots — slower shutter speed — and a neutral density filter was most likely (but not always) used to get the them.
Essentially an ND filter is sunglasses for your lens, making a bright afternoon much darker. The neutral part denotes the fact that they do not change the coloring of the photo, but you really need to spend good money if you want a truly neutral filter.
They are sold in “stops” meaning how much light they block out. Again, if you shoot water this is a great tool and dead simple to use. (Though you will need a tripod when using one.)
Graduated Neutral Density Filter
Like the ND filter, the GND filter seeks to stop down the light in the image. Unlike the ND filter it doesn’t do it over the entire front of the lens. This is what landscape photographers love to use, as typically half of the filter is an ND and the other half is clear. The graduation comes into play because there is no hard line between the two halves, instead they gradually blend into each other.
This allows you to stop down the sky, but not the terrain, creating a (hopefully) better exposed image.3
I would not recommend buying a GND filter that screws on to the front of your lens. Buy a square filter, where you can just hold it in front of your lens, allowing you to adjust the angle and position of the graduation depending on the scene.
Do note that you can fake this a bit digitally (Lightroom has a tool for this), but the results just aren’t quite the same as you would get with a filter.
Coatings, Brands & Prices (etc)
You will notice some filters saying things like MRC — this is a type of coating applied to the glass on the filter. The better the coating, the better the glare/lens flare control is, I am told. Overall it’s best to look for filters with the MRC moniker and buy those.
I’ve used a ton of MRC and Kaesemann MRC filters and have been very happy with them.
I’ve bought all sorts of brands, but the ones I trust are:
- B+W (pro-sumer type grade, and mostly what I own/buy)
- Heliopan (more expensive)
- Lee (pro-level gear)
- Rodenstock (very expensive)
As far as prices go you can spend a lot or very little. I personally don’t think it’s worth wasting money on cheap filters, but I don’t make money from my photography either, so I try not to waste all my money on expensive filters.
Here are the filters I recommend:
- UV Filter: If you must, I’d go with this.
- Neutral Density Filter: I’d go with something like this. Though it really depends on how many stops you want.
- Graduated Neutral Density: I’d get this to start, or if you have money to burn get the set.
- Circular Polarizing Filter: I have this one.
Some things to note as you look through filters:
- They come in different sizes. I linked to 46mm versions as that is common in micro-4/3, but your lens should be marked with its size. Be sure to check that before you buy anything. (Larger sized filters cost more, sorry.)
- You may run across “slim” filters but be warned that they often prevent you from attaching a lens cap. They are slimmer, so they have nothing to attach a standard lens cap to. Non-slim filters should work with your lens cap.
- The Lee filters that I linked to above are square/rectangles. They make holders for them but don’t bother. You can just hold them in front of your camera and shoot — you are going to want a tripod anyways.
Right now, for my micro-4/3 setup I only have a CP filter, and I will likely get a GND next and an ND last. You don’t need a filter to get good photos but it can help you get the photos you envision and they are a lot of fun to play with.