What size clamp rings are needed for Canon L series glass?

[Neil Shelley]

I know this may be a rather simple question, however my experience with higher quality video equipment is rather limited. I was wondering how do I know which size clamp rings to buy for an OConnor O-Box when using Canon L series glass on my Scarlet? If anyone could share their insight on this simple question I would greatly appreciate it.

The Canon L series lenses I will be using are:
16-35mm 2.8
24-70mm 2.8
70-200mm 2.8
100mm 2.8 macro
50mm 1.2
24mm 1.4

Thank you!

 

[Max M.]

i know the oconnor 80mm fit neatly over the canon 77mm front lenses like the 24-70 and the 70-200, but this not clamp on, just normal donut with the mattebox attached to bars

 

[Jon Carr]

I know this may be a rather simple question, however my experience with higher quality video equipment is rather limited. I was wondering how do I know which size clamp rings to buy for an OConnor O-Box when using Canon L series glass on my Scarlet? If anyone could share their insight on this simple question I would greatly appreciate it.

The Canon L series lenses I will be using are:
16-35mm 2.8
24-70mm 2.8
70-200mm 2.8
100mm 2.8 macro
50mm 1.2
24mm 1.4

Thank you!

Depending on what your 16-35mm is, it can be 77 or 82mm. Everything else is 77 or smaller. You buy the 80 clamp ring cause it gives the extra mm to fit the 77mm lens in. You can't use the O'Box as a clamp on mattebox, its way too heavy for canon glass. I just recently upgraded to the bellow ring after buying a circular Polarizer, so I'm planning on selling the clamp ring seeing that I don't need it now.

 

[Neil Shelley]

Thank you for input. I guess what I am realizing is that you only need a clamp ring if you plan on "clamping" the O-box to the lens? (Makes sense now that I think about it) Am I right in this assumption? I will actually be running 15mm rods underneath the lens so I will be using the rods to support the matte box. My question then is do I need to purchase anything extra the Canon L series glass to fit into the matte box or does the matte box come ready to use with those lenses on 15mm rods? Thanks again.

 

[Les C.]

Thank you for input. I guess what I am realizing is that you only need a clamp ring if you plan on "clamping" the O-box to the lens? (Makes sense now that I think about it) Am I right in this assumption? I will actually be running 15mm rods underneath the lens so I will be using the rods to support the matte box. My question then is do I need to purchase anything extra the Canon L series glass to fit into the matte box or does the matte box come ready to use with those lenses on 15mm rods? Thanks again.

When I bought my O-Box, I also bought:

Bellows Ring 150-114 140.00
Reduction Ring 114-110 45.00
Chrosziel 450-22 Flexi-Insert Ring 110:50/85mm 94.00

The rubber flexible Chrosziel ring made a complete barrier against light, and would adjust somewhat each way when I zoomed my lens (but not enough for the entire zoom range without moving the O-Box).

I just received my Canon 24-70 II, and realized that the ring is too small (it's an 82mm filter, but ... the lens is actually 88.5mm).

So, I need a "Flexi-Insert ring Ø 110:75 to 98 mm - for lens of Ø 75 mm to Ø 98 mm 450-20".

BTW - I'm a bit new to using a Matte box. When I use the 24-70 II lens without the ring inside my studio, I really don't see where the ring would be blocking any light?

Maybe outside in the sunlight?

When is the ring that totally block light actually needed?

 

[Jeff Zueger]

Les, anytime you have a drop in filter in the tray of the mattebox (indoors or outdoors), you always want to have your matte box light tight. You may (and will) get all sorts of reflections from the back, which you may or may not be able to see in the field. Not as important if you are using screw on filters. I am also planning on buying the new 24-70 and am disappointed the front is larger than standard 80mm.