Ursa Cine LF 15/19 Baseplate

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

Janis Lionel

  • Posts: 327
  • Joined: Mon Apr 04, 2016 8:09 pm

Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 1:11 pm

Hey there

Can someone help me out: Why the Ursa Cine Baseplate has both 15 and 19mm rods? What is the scenario here? You use 15mm for lens support and the rest for the rest? Then why not use 19mm? I haven't seen any rigs with both.

Thanks for the insights/help.
--
Windows 10 / i4930k @4.3Ghz / 32GB RAM / GTX 1080 / 12TB RAID 0 (4 x 3 TB) / Mini Monitor 4K / Eizo CG247x / Mainly working with CDNG 4:1
Offline
User avatar

rick.lang

  • Posts: 18099
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 2:43 pm

It’s probably a good thing to have the option of using either in a high-end production. If you’re shooting with a 25-250mm zoom or longer with a complex rig, the support on 19mm is probably more reliable keeping proper alignment. If I had it, I’d use it.
Rick Lang
Offline

Janis Lionel

  • Posts: 327
  • Joined: Mon Apr 04, 2016 8:09 pm

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 5:59 pm

rick.lang wrote:It’s probably a good thing to have the option of using either in a high-end production. If you’re shooting with a 25-250mm zoom or longer with a complex rig, the support on 19mm is probably more reliable keeping proper alignment. If I had it, I’d use it.


Yes, that makes sense, just dont get the 2-in-1 concept as it also raises the height, but maybe i'm missing smt.
--
Windows 10 / i4930k @4.3Ghz / 32GB RAM / GTX 1080 / 12TB RAID 0 (4 x 3 TB) / Mini Monitor 4K / Eizo CG247x / Mainly working with CDNG 4:1
Offline
User avatar

timbutt2

  • Posts: 3285
  • Joined: Tue Nov 12, 2013 10:32 am
  • Location: St. Petersburg, Florida, United States of Amercia

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 7:16 pm

There's an individual 15mm option you can purchase if you don't need 19mm support. Bigger rigs do require 19mm rods to support big and heavy lenses as Rick pointed out. Majority of the time if you're working with Primes this isn't a worry so 15mm is sufficient enough. The dual one provides both options in the event you need both.
Last edited by timbutt2 on Tue Feb 04, 2025 7:52 pm, edited 2 times in total.
"I'm well trained in the art of turning **** to gold." - Tim Buttner (timbutt2)

Cameras: URSA Mini Pro G2 & Pocket 6K Pro
Past: UM4.6K, P6K, BMCC 2.5K
Computers: iMac 5K (Mid 2020) & M4 Pro MacBook Pro 16" (Late 2024)
Offline

Howard Roll

  • Posts: 3030
  • Joined: Fri Jun 03, 2016 7:50 am

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 7:20 pm

Janis Lionel wrote:...just dont get the 2-in-1 concept as it also raises the height, but maybe I'm missing...


The extra height is necessary to achieve the correct spacing for 19mm rods. 15mm rods use a standard distance of 85mm from rod to lens center but with 19mm rods it's 133mm, over an inch higher. Without the correct spacing you might have matte boxes and other lens-centric accessories that don't mesh properly.

Good Luck
Offline
User avatar

rick.lang

  • Posts: 18099
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 9:02 pm

Absolutely correct as Howard mentions. The 15mm rods and that 85mm distance they support is critical so 19mm rods require completely different support if your current gear is centred around 15mm rods.

Another possible hint that you need 19mm rods is the outside diameter of your lens. It’s my understanding that lenses designed for 15mm rods must not exceed 114mm OD at the front in order to work properly with a matte box designed for 15mm rods. I always use a matte box to manage my heaviest lenses and to ensure their centre is correctly aligned with the camera. So lens weight and lens outside diameter are key factors. Please correct me if I’m wrong re OD.
Rick Lang
Offline

John Brawley

  • Posts: 4460
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles CA

Re: Ursa Cine LF 15/19 Baseplate

PostTue Feb 04, 2025 11:52 pm

Lightweight rods and Studio Rods.

There are actually three "standards" for rods.

Lightweight 15mm.
Studio 15mm.
Studio 19mm.

Studio 19mm and the lightweight 15mm is how the VAST majority of accessories will work.

You use Lightweight rods for scenarios where you want a smaller build but you still need something to mount lens motors too and occasionally hand held brackets.

19mm rods are able to support heavier weights, and are spaced wider apart, allowing for larger diameter lenses. Like this.

FFD07F28-4352-45C6-AF75-33B7D62DB550.jpeg
FFD07F28-4352-45C6-AF75-33B7D62DB550.jpeg (574.14 KiB) Viewed 428 times


What's cool here about what BMD have done is they've made a SINGLE baseplate that actually does BOTH. Normally you would have two, a Lightweight baseplate and a Studio baseplate. Now you have one that can do both standards AND it's a shoulder mount too. That's a huge huge thing in my view.

JB
John Brawley ACS
Cinematographer
Los Angeles
Offline

John Brawley

  • Posts: 4460
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles CA

Re: Ursa Cine LF 15/19 Baseplate

PostWed Feb 05, 2025 12:01 am

IMG_3417.jpeg
IMG_3417.jpeg (415.98 KiB) Viewed 420 times


And for fun, here's a build that has both 15mm and studio 19 rods.

The have a different offset and different sizing so you tend to need both at some point. IN this case they've left the lightweight rods in as well for the convenience of switch back to 15mm once the honking lens comes off.

Notice too there are additional TOP mounted 15mm rods that the iris motor is attached too. That would never change no matter if the bottom was 19mm or 15mm.

JB
John Brawley ACS
Cinematographer
Los Angeles
Offline

John Brawley

  • Posts: 4460
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles CA

Re: Ursa Cine LF 15/19 Baseplate

PostWed Feb 05, 2025 12:09 am

IMG_3336 (1).jpeg
IMG_3336 (1).jpeg (320.44 KiB) Viewed 414 times


Here's a setup with my operator choosing to use hand held brackets for 19mm rods, likely because they flex less when running with momentum.

JB
John Brawley ACS
Cinematographer
Los Angeles
Offline

John Brawley

  • Posts: 4460
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles CA

Re: Ursa Cine LF 15/19 Baseplate

PostWed Feb 05, 2025 12:13 am

IMG_3252.jpeg
IMG_3252.jpeg (769.21 KiB) Viewed 412 times


Here's a shot also comparing an Alexa 35 which has 19mm Studio rods (only) behind with a large zoom, while I was operating a sort of hand held shot on the ground using the cinesadle. Top mounted focus and iris on 15mm rigs but using the baseplate as a spacer

There's a gazillion reasons to build in certain ways...

JB
John Brawley ACS
Cinematographer
Los Angeles
Offline

John Brawley

  • Posts: 4460
  • Joined: Tue Aug 21, 2012 7:57 am
  • Location: Los Angeles CA

Re: Ursa Cine LF 15/19 Baseplate

PostWed Feb 05, 2025 12:19 am

IMG_2827.jpeg
IMG_2827.jpeg (856.98 KiB) Viewed 407 times


OK last one!!

See this T series Panavision anamorphic zoom? The LW rods wouldn't clear the strange rectangular front of this lens and there's barely any room for the lens support to fit even if they did. Hence the 19mm rods.

BUT to change this camera to 15mm lightweight or hand held from this full studio becomes much quicker if you don't have to also switch baseplates! (and cheaper).

It doesn't really raise the height because the shoulder pad is still at the base of the camera with this DUAL version.

JB
John Brawley ACS
Cinematographer
Los Angeles
Offline
User avatar

rick.lang

  • Posts: 18099
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Ursa Cine LF 15/19 Baseplate

PostWed Feb 05, 2025 1:51 pm

Thanks so much for all these shots of the rigs (that leave me so humbled).
Rick Lang

Return to Cinematography

Who is online

Users browsing this forum: jhoepffner, Zzzzz350 and 51 guests