For anyone who's used these... do you simply use the same gels that are used for lighting (eg. Lee or Rosco)? (or do you need a higher grade gel?)
And is the quality affected massively?
(I'm guessing the idea is that the light passes straight-through at the rear of the lens and perpendicular to the gel filter itself and thus refraction through the gel material is virtually non-existent)
I'm currently contemplating an ultra-wide angle lens but my preferred choice cannot take front-mounted filters(the front element is pretty much spherical)
Pinched from Petapixel so I guess yes. You cut it from a standard gel sheet
Here’s what Wikipedia’s #Characteristics" target="_blank">L lens article has to say about this filter slot:
Wide angle L-lenses typically have a gelatin filter holder on the mounting point of the lens, which allows the photographer to cut a small, square piece of gelatin out of a larger filter sheet and place it on the lens. On film cameras, these are typically used to correct the color temperature, but on digital cameras this is largely unnecessary, as the color temperature can be corrected in software. The mount is still commonly used for neutral density gelatin sheets though, especially on certain wide-angle lenses where the protruding front element precludes the use of any screw-in filters.