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-   -   PL and OCT19 mounts for the Brevis35 (https://www.dvinfo.net/forum/alternative-imaging-methods/76994-pl-oct19-mounts-brevis35.html)

Dennis Wood October 6th, 2006 05:43 PM

PL and OCT19 mounts for the Brevis35
 
At long last we've sorted out both PL and OCT19 mounts for the Brevis. The mounts are modular meaning once you have one mount, adding the other is less expensive. Pictured is a 28mm f1.5 LOMO cinema lens. I'll have footage shortly.

Pic1
Pic2

Needless to say, using lenses like these is not a run'n gun option :-)

Amos Kim October 6th, 2006 05:53 PM

Hi Dennis. What does the OCT19 mount allow for?

Sam Jankis October 6th, 2006 07:13 PM

Nice.

Pic 2 (fixed) ;)

Dennis Wood October 6th, 2006 07:38 PM

Thanks for the fix Sam...I edited my post to fix pic2 :-)

Amos, OCT19 and PL mounts are large bladed mounts typically used for cinema lenses, with the PL mount being the modern "standard" ... if there is such a thing. OCT19 was a spec used on russian 35mm film cameras. Both mounts are large, have locking rings, and offer very precise lens placement to satisfy the needs of film cameras and their lenses.

Toenis Liivamaegi October 7th, 2006 03:30 AM

I`m dreaming about PL lens to Nikon mount adaptor...
... there could be huge demand for serious projects shortly.

Cheers,
T

Dennis Wood October 7th, 2006 07:40 PM

It's a good idea Toenis. My only concern would be the strength/rigidity of the nikon mount itself with one of these cinema lenses on there via an adapter. Once I post some comparitive shots, it will become evident. I understand now why the OCT19 and PL mounts are so much more robust than even my favourite SLR mount, the Canon FD. These lenses are big and heavy. I will definitely be adding a new rails support to the Cinevate line specifically for these mounts to better isolate the mass and torque of these lenses from the video camera.

Sam Jankis October 8th, 2006 08:38 AM

Quote:

Originally Posted by Dennis Wood
These lenses are big and heavy. I will definitely be adding a new rails support to the Cinevate line specifically for these mounts to better isolate the mass and torque of these lenses from the video camera.

You might also consider beefing up the adapter-to-rails mount... maybe some sort of a clamping system (like Cavision's lens belt mount).

Dennis Wood October 10th, 2006 12:35 PM

Sam, that's the rails support I was referring to. The existing unit is great for SLR lenses, but the cinema lenses are a whole different story. Over Thanksgiving (in Canada anyway) I came up with a new design while ruminating over turkey. It won't use a belt but a solid CNC clamp, and unlike the current unit, will be specific to the adapter.

Sam Jankis October 10th, 2006 03:22 PM

Sounds like you're a step ahead. :)

Michael Maier October 11th, 2006 03:35 AM

Quote:

Originally Posted by Toenis Liivamaegi
I`m dreaming about PL lens to Nikon mount adaptor...
... there could be huge demand for serious projects shortly.

Cheers,
T

Dreaming is the right word.
A PL to Nikon adapter is a pretty goofy idea if you ask me and defeats the whole purpose of having a sturdy PL mount in the first place if all your lens will be secured for is the fragile Nikon mount. As Dennis says, PL lenses are heavy!
Why somebody who can afford PL lenses would ever even think about attaching his expensive lenses to such a fragile mount as Nikon or even think about using a still mount or lens for cinematography beats me.

Dennis Wood October 14th, 2006 02:57 PM

Footage from 80mm and 50mm OCT19 mount lenses
 
Here are a few quick shots using the 80mm and 50mm LOMO cinema lenses. Note that I was not using an FF unit, so the footage demonstrates my lack of skill at endless hand cranking. These cinema lenses have very, very fine focus adjustment and should complement HD cams very well. A good quality production monitor is going to be an asset for sure to get focus perfect...or a measuring tape! This is plain old NTSC SD.

10MB, 436x240 SD (fast)
10MB, 436x240 SD (slow)

30MB, 872x480 SD (fast)
30MB, 872x480 SD (slow)

Kristin Stewart October 15th, 2006 03:18 AM

Dennis, are you planning to release a Pentax K mount ?

Another thing : how exactly does this adapter attach to the camera's lens ? Like the Redrock ? Or is it screwed ?

Cheers,

Kristin

Dennis Wood October 15th, 2006 09:37 AM

The Brevis is screwed onto the filter threads and is designed for a one time alignment (about 5 minutes). This is the only easy way to ensure that the camera lens and GG are properly aligned to each other. Subseqently, for cameras with metal filter threads (DVX and up) you can mount up a 50mm lens and be shooting hand held in 60 seconds or less. Rapid setup was one of the design goals for the adapter.

The cinema lenses are a different story and really should be used on rails. The OCT19 mount and 80mm lens used in that test is just over 1 kg all by itself! The rails system, once set up, will accept the camera and adapter in less then a minute as the camera and adapter just drop on. Keep in mind that at 12" long, the rails aren't huge so you could definitely do hand held using the rails sytem.

On tripod, my thinking is that a Bogen 501 head or stronger is the appropriate choice for support as lower end heads will be at their limit. All that movement in my clips is not from the camera, adapter, or rails. It's from the now inadequate 701RC2 tripod plate.

I do have a complete FF unit and gears now (sculpted by Dan D.), but the requirements of SLR lenses are quite different from the cinema lenses...so a bit of adaptation will be required to gear these up. Unfortunately, all the LOMO lenses I purchased had their stock rings removed...otherwise I would have been fine.

Kristin Stewart October 15th, 2006 03:25 PM

Thanks Dennis... and have you planned to release a Pentax K mount ?

Dennis Wood October 15th, 2006 07:43 PM

Yours would be the first request :-) I'll look into these.


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