R26
A while ago I wrote this basic tutorial on camera filters for another forum which Im not so active on now, I thought I'd post it up here as it may help someone! 
This tutorial will cover two main types of filters: Circular Polarizers and Neutral Density (ND).
Before I begin, I will start by saying that these are luxury items, and are not necessary to take great photos. They are tools to help improve photos, or provide new ways to take photos (more on this later).
So first up: Circular Polarizers.
The main use for these, and forgive my unscientific answer, is to make photos prettier.
Circular polarizers:
- darken the sky
- improve the contrast between the sky and clouds (pics below)
- remove glare from water surfaces ie. sea and lakes etc.
- generally increase the saturation of all colours in the photo
Enough talk, lets see some pics:
Photo 1: Photo taken under normal conditions with no filters.
Photo 2: Photo taken with circular polarizer (correctly set <-- more on this later)
Photo 3: Photo taken with circular polarizer and NDx8 filter <-- more on this later.
The visual differences between photos 1 and 2 are very obvious. The sky is a much darker and richer colour, and the contrast has been improved. Also, the very ligh clouds at the top of the frame are much more obvious in photo 2.
Photo 3 is slightly different from photo 2, the colour cast is different, and the sky has lost the rich blue colour. On the negative side, note how the clouds are slightly over exposed.
Unlike most filters, the circular polarizer can be adjusted by rotating it. So care must be taken to correctly set the polarizer before taking the photo. You will see as you rotate the polarizer as the sky becomes darker - that is when the polarizer is at maximum effect.
Left: Polarizer incorrectly set
Right: Polarizer correctly set.
Another BIG use for circular polarizers (CPLs) is in motorsport. If you want to seriously get into this type of photography, then a CPL is a MUST.......NO QUESTION!!
The biggest effect thats noticable is that it removes the glare from the windscreen, so you can see that driver, see these two pics:
The glare is so bad that you can only just make out the driver's helmet.
The CPL has completely removed the horrible glare, and now we can see the driver
Again, to create this effect, the CPL has to be correctly set. My tip is to find some other car/ambulance to use, and then rotate the CPL until the glare has been removed.
NOTE: If you change position, remember to re-set the CPL.
TIP: To see if your CPL is working correctly, remove it from the camera, hold it up to a LCD/TFT monitor, look through it with your eyes and rotate it - see what happens
Well, that's CPLs covered. Now lets talk about Neutral density (ND)filters.
NDs are a lot more basic, they just attach onto the lens, and that's it, no adjustments to make. Basically, the job on an ND is to block light - that's it.
This may sound dull, but it can be VERY useful. Common applications of it are shooting waterfalls. Classic waterfall shots show a lot of movement:
The classic style waterfall shot, the low shutter speed (3 seconds!) creates the smooth flowing effect.
To create this effect, you need a low(ish) shutter speed, and on a bright sunny day and at f/32 you may not be able to go low enough. So this is where an ND filter is essential. The ND blocks light, allowing you to use a much lower shutter speed.
Other very common applications are when using automotive rig shots. The cars are driving (usually pushed!) very slowly, so to create the sense of movement, a ND is needed to drop the shutter speed right down.
Here, an ND helped me to use a shutter speed (4 secs) slow enough
to create the sense of movement needed. Without one, it would have been impossible.
NDs also have an effect on landscape photography:
The ND has darkened the sky, but the contrast is still
very similar. The clouds are a little darker, showing a little more detail.
NDs come in various ratings ie. x4, x8. The higher the number, the more light it blocks.
Well I hope that's helped some people, like I said before - these are luxury items, but they're worth every penny. They can be quite expensive depending on the size you require. I've found some bargains on eBay (reputable dealers!!!).
Any questions, feel free to ask. I'm sure ive forgot some things, but hopefully the pics say more than words ever could!
Dan
This tutorial will cover two main types of filters: Circular Polarizers and Neutral Density (ND).
Before I begin, I will start by saying that these are luxury items, and are not necessary to take great photos. They are tools to help improve photos, or provide new ways to take photos (more on this later).
So first up: Circular Polarizers.
The main use for these, and forgive my unscientific answer, is to make photos prettier.
Circular polarizers:
- darken the sky
- improve the contrast between the sky and clouds (pics below)
- remove glare from water surfaces ie. sea and lakes etc.
- generally increase the saturation of all colours in the photo
Enough talk, lets see some pics:
Photo 1: Photo taken under normal conditions with no filters.
Photo 2: Photo taken with circular polarizer (correctly set <-- more on this later)
Photo 3: Photo taken with circular polarizer and NDx8 filter <-- more on this later.
The visual differences between photos 1 and 2 are very obvious. The sky is a much darker and richer colour, and the contrast has been improved. Also, the very ligh clouds at the top of the frame are much more obvious in photo 2.
Photo 3 is slightly different from photo 2, the colour cast is different, and the sky has lost the rich blue colour. On the negative side, note how the clouds are slightly over exposed.
Unlike most filters, the circular polarizer can be adjusted by rotating it. So care must be taken to correctly set the polarizer before taking the photo. You will see as you rotate the polarizer as the sky becomes darker - that is when the polarizer is at maximum effect.
Left: Polarizer incorrectly set
Right: Polarizer correctly set.
Another BIG use for circular polarizers (CPLs) is in motorsport. If you want to seriously get into this type of photography, then a CPL is a MUST.......NO QUESTION!!
The biggest effect thats noticable is that it removes the glare from the windscreen, so you can see that driver, see these two pics:
The glare is so bad that you can only just make out the driver's helmet.
The CPL has completely removed the horrible glare, and now we can see the driver
Again, to create this effect, the CPL has to be correctly set. My tip is to find some other car/ambulance
to use, and then rotate the CPL until the glare has been removed. NOTE: If you change position, remember to re-set the CPL.
TIP: To see if your CPL is working correctly, remove it from the camera, hold it up to a LCD/TFT monitor, look through it with your eyes and rotate it - see what happens
Well, that's CPLs covered. Now lets talk about Neutral density (ND)filters.
NDs are a lot more basic, they just attach onto the lens, and that's it, no adjustments to make. Basically, the job on an ND is to block light - that's it.
This may sound dull, but it can be VERY useful. Common applications of it are shooting waterfalls. Classic waterfall shots show a lot of movement:
The classic style waterfall shot, the low shutter speed (3 seconds!) creates the smooth flowing effect.
To create this effect, you need a low(ish) shutter speed, and on a bright sunny day and at f/32 you may not be able to go low enough. So this is where an ND filter is essential. The ND blocks light, allowing you to use a much lower shutter speed.
Other very common applications are when using automotive rig shots. The cars are driving (usually pushed!) very slowly, so to create the sense of movement, a ND is needed to drop the shutter speed right down.
Here, an ND helped me to use a shutter speed (4 secs) slow enough
to create the sense of movement needed. Without one, it would have been impossible.
NDs also have an effect on landscape photography:
The ND has darkened the sky, but the contrast is still
very similar. The clouds are a little darker, showing a little more detail.
NDs come in various ratings ie. x4, x8. The higher the number, the more light it blocks.
Well I hope that's helped some people, like I said before - these are luxury items, but they're worth every penny. They can be quite expensive depending on the size you require. I've found some bargains on eBay (reputable dealers!!!).
Any questions, feel free to ask. I'm sure ive forgot some things, but hopefully the pics say more than words ever could!
Dan
