Rear Element of lens touching the sensor?

[Joshua Echevarria]

Hi All,
I am new to the community but I am really excited to be a part of it.

I am currently having an issue with my Epic X which I purchased not too long ago.
I am shooting a feature this month and rented out an old set of cooke s2 and s3 35mm primes. When I did check out, I tested the lenses out on the company's red epic. Everything was fine. When I got home and tested them on mine, there was an issue.
When I put the 18mm on, it would not go in all the way and felt as if it was pushing against something . I then inspected the sensor and the lens was pushing against the sensor and left a circular mark that I of course cleaned. I wish I had taken pictures to give a better understanding but I was freaking out about it.

Anyway I was looking into what the issue could be and thought maybe it is because I have a motion sensor? Which could possibly put the sensor closer and the 18mm back element is too long? I'm not entirely sure but I was wondering if anyone had an issue with this before and if so, how do I resolve it.

Thanks

 

[A. Clint Litton]

It's not your sensor OLPF that the rear element/shroud was touching, but the motion mount optical glass, which is closer to the lens mount than the stock sensor. There are definitely S35 lenses that are not compatible with the motion mount because of an extruding rear element...I don't know if there's a list floating around of lens compatibility, but it seems clear that the cooke panchro 18mm does not work safely with your motion mount. So you can either use a regular PL mount wih this lens set, or choose a different lens set that works with your motion mount.

It would also be worth inspections the rear element of the 18mm to make sure there was no damage caused when touching the motion mount glass...

 

[Joshua Echevarria]

Litton

Thanks for the quick reply. Really appreciate it. Is there anyway to remove the motion mount optical glass? This of course is not the ideal situation but we begin shooting tomorrow.

 

[Kemalettin Sert]

have you read Motion Mount manual first?
Just get the standart PL mount from RED.

 

[Stacey Spears]

Joshua,

The glass in the motion mount is what makes it a motion mount. You need a standard mount to not have the glass element in it.

 

[Joshua Echevarria]

Hi Sert

I did but there was no mention of the cooke s2s and s3s