Gelatin Filter Holders

[MX5]

A potentially dim question or two or ...

Some Canon lenses have a slot at the rear into which a cut gelatin filter fits. I assume I buy gelatin filters and cut to an appropriate size (whatever this might be). What are the pros and cons?

Also some Canon lens take a Gelatin Filter Holder III or IV. I assume these screw into the front filter thread? and work much like Lee filters? But why buy Canon when you can buy Lee ....

Then there's drop in filters used on the big white lenses.

It's been a long day ... so if anyone has a link to an article that describes these various filter technologies I would be very grateful.

Thanks in advance as ever ...

[colin C]

Re: Gelatin Filter Holders

Gelatin filters used to be used for some effects on film, to affect the overall tone of the shot, or minor white balance corrections, or some special effects like “Colour Back”. With the advent of Digital, it’s largely a thing of the past, as most of the effects can be done with post processing.

Colour Back is quite interesting and would still be easier in camera than in Photoshop. It basically consists of using two filters of opposite colour, one over the lens and one over the flash. They need to be matched so that anything lit by the flash is neutral in colour. For example: fairly bland background with lots of evening sky with attractive model in the foreground. Red filter on the lens will make the background a bit more exciting, but make the model look strange, so a green filter over the flash will ensure that anything lit by the flash looks normal, while everything else looks red. They were available in matched sets of Green/Red, Yellow/Blue etc.

The big white lenses have a drop in filter with a UV as standard. There is also the gelatine holder and a polariser holder. I have never used the gelatine holder, or found the need for one, the polariser could be useful, but at £300 a pop I would have to think long and hard.

Hope that helps.

Colin

[MX5]

Re: Gelatin Filter Holders

Thanks Colin. You are a fountain of knowledge and don't mind sharing ...