Questions about Neutral Density Filters!!

[Jonathan Lee]

I'm still considered a newbie to cinematography and all... I just studied a few advanced Cinematography Vids & came across how Neutral Density Filters allow you to control the DOF to give it a more Filmic look!! my question is

I own 3 Rokinon Cine Lenses (24mm, 35mm, 85mm) along with my RED1MX.. when buying an ND Filter do I have to buy it the same size as the lenses I want to use it on or does a common size like 77mm fit All lenses? In Bestbuy I keep seeing 77mm and 58mm!! Id rather ask in here bc ive had a few headaches talking equipment with BestBuy

 

[Nick Morrison]

Its quite common to use STEP UP RINGS to make all your lenses a common diameter, for this very reason. So you can buy ONE SIZE accessories that can fit all.

80OD is a common lens front size in cinema, and that often corresponds with a 77mm filter thread inside. So 77mm has become a pretty common standard in the Indie/DSLR workflow, yes.

77mm generally covers a wide variety of stills primes and zooms...it's often only the very wide and very long lenses that may have fronts larger than this (for ex the Zeiss 15 2.8 or Nikkor 200 f2)...presumably because of the extra glass required for the extreme nature of these designs...Some big zooms too have larger fronts (82mm comes up quite a bit).

Cordvision cine fronts are a very convenient way to give lenses a common 80 OD/ 77mm thread front in your set:
http://www.cordvision.com/77mm-cine-ring-80mm-o-d/


When buying 77mm filter NDs, consider this TIFFEN "indie" kit that is quite popular:

http://www.bhphotovideo.com/c/product/729107-REG/Tiffen_W77INDNDKT_77mm_Indie_Neutral_Density.html

Don't forget if you are going over 0.9 on MX you'll need to be cautious about IR polution, so consider these IRND filters as well for higher ND:

http://www.bhphotovideo.com/c/produ...UGKT_77mm_Indie_Upgrade_Infrared_Neutral.html

I believe I had to get an additional 1.2 IRND to round out my set, as this pack starts at 1.5 IRND

Hope this helps

 

[jimhare]

Hi Jonathan,

To answer your original question the filters don't follow the focal length, they simply have to be the right size to screw on the front. You will usually see this designated as filter thread or front size.

A basic search suggests that both the 24mm and 35mm have a 77mm filter thread and that the 85mm has a 72mm thread.

So a couple of different power ND of 77mm is a no-brainer, then you just have to decide whether it's better to buy additional filters in 72mm or get a step up ring.

Jim

 

[Eric Santiago]

I went with a step up on my Rokinon 85.

One of my fave lenses

 

[Vance Colvig]

The Kenko variable ND is fantastic, and comes only in 77mm so far. They are not cheap, but you will never look back. Color fidelity beats the rest, even ones that are more expensive. If you want single ND's, PM me and I will make you a deal. I have switched to the Kenkos and have several stacks of Hoya Pro One Digital ND's in 77mm I no longer use, and am selling. They are high quality and work well with Epic, Red One and Nikon sensors.