flashes, diffusers and filters

[Lesco]

Hi I recently brought an SB-600 flash and it came with three diffusers?

My question is, what does a diffuser actually do and what situations would you use them??

Also I brought a job lot of Cokin filters off of fleabay, I understand the ND concept that they block out 1 stop of light ect, etc, depending on the density of the filter, but I also have Tobacco colored ones, Orange ones, and various other colors, again what situations would you use these strange colored filters??

Thank in advance for any help and advice.

 

[mrthingyx]

Bigger light source = better spread of light on subject = less 'blown' photos.

As a flash noob myself, they basically make the light source bigger by "diffusing" the light coming from a flash... in all directions.

In the same way a flash bounced off a low, white ceiling gives nice, diffuse light, adding a "diffuser" enhances this effect (by varying degrees, depending on the size/design/etc.) by redirecting the light through the sides of the lightbox/stofen/tupperware.

The more diffuse the light (the more surfaces it is bouncing off) the more natural the photo will look.

As such, they're useless outdoors because there is nothing to bounce the light off...

I think.

They also come in different colours to get light temperature... flash photography in a room lit by tungsten bulbs benefits from orange filters, whereas fluorescent lighting is aided by the funky green ones.

 

[LongLensPhotography]

Plain coloured lens filters are useless for digital photography. They belong to BW film.
Coloured grads can be used for example to enhance sky blue, to fake a red sunset and so on. Again, I prefer doing it in post, as the effect can be tweaked or removed altogether if needed.

Flash diffusers obviously diffuse light. Depending on the actual shape you may have to experiment with different flash angles and power to get the best result. It should look better than just a bare flash. It is best if you can bounce flash of the ceiling, a wall, or in even go for multi-flash setup.