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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

OCT-18 to PL

D

Daniel Dols

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Hi all,

Hope i'm posting this in the right category.

Say i have a OCT18-mount lens (OKC8-35-1). Found a OCT18->PL adapter on eBay.
Anyone know if this works without a problem on the RED One? eBay seller says it does, but aren't there any focus/length problems? Not sure what to expect with all these different silly mounts.

Thanks in advance!
 
The better way to do this would probably be to get the Oct-19 lens mount. Not sure if they are still being made, but there may still be some around for sale on the web. Doug Underdahl was making it. The advantage is you don't have to worry about consistency when it comes to those adapters. If I remember correctly there were some bad ones out there. Anyway, that's about all I know.
 
But you want Oct-18, sorry missed that. I'm not really sure then.
 
OCT 18 to PL should work fine. Some OCT 18's have an outer mount that rotates with the inner optic capsule held in place by a prong - kind of like some old Arri S lenses I think. Have fun and don't expect too much... I've got a Turret Konvas in my basement somewhere with some OCT 18's

Matt Uhry
www.mattuhry.com
 
I just got one from ebay. Will test on my Red with my OCT-18 mount lens and let you know.

Adnan
 
Here are pics of the Oct-18 Squarefront with PL adapter on R1. Will add video of focus test soon.
red_oct18_3.jpg
red_oct18_1.jpg
red_oct18_2.jpg
 
Adnan Siddiqui said:
Here are pics of the Oct-18 Squarefront with PL adapter on R1.
Click to expand...

The photos links don't seem to show anything(?)

Could you please post some snapshots of the back of the lens from the rear and side view with the lens+adapter off the camera so we can see what the adapter looks like and what the clearances are? Thanks.

PS, if you go to advanced when posting you can store (upload for attachment) the images on REDUSER in a way that should display for people signed in.
 
Anamorphics

Anamorphics

With the Russian Anamorphics to get best resolution you may need to have small adjustments for each lens, so having a PL adapter for each lens may let you get the flange-to-focal equal for a set, by adjusting each adapter on a lathe or adding shim rings etc.

If you are just using one lens at a time, with RED ONE (tm)'s PL mount you should be able to adjust the flange-to-focal to get that one lens to focus right wide open.

Its more of an issue since with the anamorphics there are TWO focus adjustments, the anamorphic group and the prime group, you cannot compensate for small errors in the flange-to-focal distance using the focus adjustment on the lens, that needs to be done adjusting the back-focus distance.

You can setup a black card with a small round hole in it at the focal plane to some marked distance on the lens, say the 2 meter mark, then set wide open the lens to that distance mark, and look at the spot made by shooting a second and process that R3D into TIF frames. Look at the TIF frames at maybe 800% so you can see the spot shape. You then adjust the flange-to-focal distance so that the spot is round rather than oval horazontal or vertical.

Don't overexpose the round hole in the black card, put some with frost behind the black card and adjust the exposure so that the histogram peak for the spot is near midtone (if you can't see the peak, remove the black card and read the frost gel then put the card with the small round hole back to shoot the tests).

When you are done you should be able to test all the distance marks on the lens by moving the camera and black card to each of the marked distances and see a small round spot about 9 pixels in size, rather than an oval spot.

If you see an oval spot, try making the PL ring loose and if when you pull the lens away from the camera a bit the image gets smaller and rounder that means that the flange-to-focal is too short (or the anamorphic cam is warn and not tracking), if the spot just gets larger then the flange-to-focal is already too long.

Its worth getting the anamorphic flange to focal adjusted right since those lenses can be quite good if adjusted right, otherwise its going to be maybe half as sharp wide open etc.
 
The good news is that I received the mount and it works great! Really great build quality and works perfect on the Red One... havent tried it on the EPIC but I did try it on the ALEXA but unfortunately the pin used to hold the lens in position hits the inside of the camera. However thats not a fault of the design of the mount but just the way the lens works!
 
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