In the early days of the polarising filter there was just one type – the linear. The circular type arrived when the cameras with advanced metering (and later focusing) systems arrived. The Canon T90 and Olympus OM4 both had new advanced TTL metering that would be affected by the way a linear polarising filter worked. So A circular had to be used instead.
Later, when autofocus came along, some systems got confused by the affect of the polariser. So, as a rule of thumb, use a linear on old manual and semi automatic cameras and circular on newer modern multi menu models.
If you do have a linear filter and a modern sophisticated digital SLR it will still work, but you may get inconsistent exposures. This is easily rectified by looking on the LCD preview and reshooting with necessary compensation applied.
The top ten filters you should own will obviously vary from person to person but our choice is most definitely the following:
- 1 Circular Polariser (glare reduction and colour saturation)
- 2 Grey Grad 4x (balance sky brightness)
- 3 Skylight (protects lens)
- 4 Neutral Density x4 (reduces overall exposure)
- 5 81A (warms up skin tones)
- 6 Close up +4 (for the macro shots)
- 7 Grey Grad 2x (a weaker variation on 2)
- 8 Neutral Density x8 (a stronger variation on 4)
- 9 Softar style diffuser (best softener for when you cant be bothered doing it in Photoshop)
- 10 Star 8 (Adds star burst to shot – great for jewellery)
Good selection? Let us know your top ten.
The ND filter is one of the more useful additions to the filter bag. Digital image processing can do many things but it can’t reduce the light reaching the film or CCD. That’s the job of the camera’s exposure system and an ND filter throws in a helping hand.
The name explains its purpose. It’s neutral (in colour) and it has a density (level of opaqueness)
Neutral Density filters come in a range of densities. The basic ND2 is 2x exposure factor (or one f/stop) and an ND4 is 4x (two f/stops). There’s also an ND8 (8x or three f/stops) and a less common ND64 (64x or six stops).
The filter goes over the lens and reduces the light reaching the film by the exposure factor of the filter.
If for example you had an exposure of 1/125sec at f/11 and you added an ND8 the shutter speed would reduce to 1/15sec or the aperture would need to be opened to f/4.
The reason to use an ND filter suddenly become obvious. If you want to force a slow shutter speed, for motion blur, or you want the lens at the widest aperture, for shallow depth-of-field, the ND filter can help.
It can also be used in combination with a flash to effectively reduce the guide number for close range photography.
The ND2 is hardly worth bothering with so we’d suggest you’re first ND filter be a ND4.
Many new filter buyers are unsure whether to buy a round filter that screws directly onto the front of your lens or one of the many square options that slides into a filter holder that has an adaptor ring matching the filter thread size of your lens.
There are a few advantages and disadvantages to consider.
Cost
The main advantage with a filter system, using a filter holder is that you only need one filter for a number of lenses. You just need to change the adaptor ring so the filter and holder will fit on to a different lens. Once you’ve bought the adaptor and ring system filters tend to be less expensive.
System Filters 1:0 Round Filters
Space
This not only means it’s a lower cost when you have a selection of lenses, but you also save space. Imagine wanting five different filters and you have four lenses with different filter thread sizes. You’d need 20 filters in total! Well this is not exactly true as you can buy step up or step down rings to change the size of the lens’ filter thread.
System Filters 1:0 Round Filters
Quality
Screw in filters are often better quality. They’re usually made of glass and of the highest optical quality. Being glass they don’t scratch easily either, so are easier to clean without damage.
System Filters 0:1 Round Filters
Size
Screw in filters tend to take up less room as there’s no holder required. They are less protruding on a lens too so there’s less chance of vignetting (caused by the filter obstructing the corners of the frame).
System Filters 0:1 Round Filters
Design
The filter holder type of filter design usually means there’s a gap between the lens and the filter. This not only potentially reduces quality as light has more complicated path to follow, but also means the lens could be exposed to the elements more.
System Filters 0:1 Round Filters
Range
Although there are plenty of screw-in filter options you won’t get a wider range than a system filter, especially in the more creative options.
System Filters 1:0 Round Filters
Practicallity of use
If you intend using graduated filters you can’t beat the slot in system as you have the option to move the gradient up or down in the holder, whereas a screw in filter has the gradient fixed across the middle.
System Filters 1:0 Round Filters
Fiddly
Screw in filters stand you more chance of cross threading the filter on the lens thread. They are harder to remove if you over tighten too. While system filters need a two step process, so are slower at first while you have to attach the holder then slip the filter in. If, however you can put up with the extra bulk at the front of your lens and leave a filter holder attached the slip in type become far less fiddly.
System Filters 1:0 Round Filters
Resale
If you decide to sell your filters square ones tend to fetch a better price on sites like ebay.
System Filters 1:0 Round Filters
So the winner, in our view, is System filters with 6 points and Round filters 3 points.
The skylight filter has a slight pink tint
The Skylight filter has been around for decades and is one of the most popular filters. It has a slight pink tint which is used to reduce blue haze in colour photography. This was essential for film camera owners but digital camera users can correct the problem easily using an image editing program.
The Skylight filter does not affect exposure, so some photographers screw one on the front of each of their lenses as protection for the front element.
There are some photographers who counter this action, suggesting that the filter will degrade quality. And it’s true if you put on a cheapy plastic option, but adding a high quality Japanese multi-coated filter will give minimal degradation to the image. Any change will certainly not be noticeable to the naked eye. And the advantage of having a skylight filter (or UV) is you maintain a clean lens which would cost much more to replace than a scratched filter.
If you use a skylight filter you can keep it attached all the time, but be careful if you add other filters as the extended depth could cause vignetting on wide angle lenses. Some manufacturers such as Hoya make slim versions to prevent this.
