canon lenses fitting issue with Sony nauticam housings

Hello all, 

I have a set up that includes a sony a7rii in a A7ii nauticam housing. But i shoot using canon lenses, i have a sigma adator for my lenses and a port adaptor from n85 to n120 and then a macro port on top for my canon 100mm usm is macro lens. This all fits fine until I add the focus gear on the lens and there is no way i can lock the port system and have the gear on the lens as it is to wide to be put on between the n85 adaptor and housing. Is there a way nauticam have adjusted to this issue ? i can theoretically put everything together but the port adaptor and macro port wont be locked which is very risky underwater. any advice or comments would be appreciated. Thank you.

11 hours ago, Jacobguymedia said:

Hello all, 

I have a set up that includes a sony a7rii in a A7ii nauticam housing. But i shoot using canon lenses, i have a sigma adator for my lenses and a port adaptor from n85 to n120 and then a macro port on top for my canon 100mm usm is macro lens. This all fits fine until I add the focus gear on the lens and there is no way i can lock the port system and have the gear on the lens as it is to wide to be put on between the n85 adaptor and housing. Is there a way nauticam have adjusted to this issue ? i can theoretically put everything together but the port adaptor and macro port wont be locked which is very risky underwater. any advice or comments would be appreciated. Thank you.

If you use the vacuum system there is a significant closing force acting on the ports, the closing force is proportional to area and at 200 mbar vacuum (common setting used with vacuum systems) the closing force on an N120 is equivalent to 22kg.  This is about equivalent to being at a depth of 2m and the closing force only increases as you go deeper, so it would be very difficult to dislodge.  As I understand the system, the adapter features a push and turn system so the bayonet lugs are engaged.  I would think there is very little risk of dislodging the ports underwater given the significant closing force.  At 10m depth the closing force is equivalent to 136kg at the N120 port opening.

just to clarify, you say you have a A7II housing, but you mention an N85-N120 adapter.  The A7II port charts mention using the 37305 35.5mm N100-N120 port adapter to adapt EF lenses and this port seems like it has an external locking device to use to lock the ports together:  https://www.nauticam.com/products/n100-to-n120-35-5mm-port-adaptor-ii-for-na-a7iv-1  I Know it says for A7IV, but it is still an N100 port adapter and all Sony housings use N100 ports, so it will certainly fit.  Which port adapter are you using?

Thank you so much for the response that all makes sense and is very helpful and reassuring. I currently have the n100 to n120 port adaptor with lock for sony SEL24702 with 18809 so no external lock or option to rotate the focus gear.