CoC technical-question wcu-4 
 By lovewept 

 on 2/11/20, 3:48 AM • 390 views
Excuse me, everyone.
WCU-4's menu->Lens Data->Circle of con. 
What does circle of confusion mean? I don't understand what it means in the manual? The circle of confusion (coc) menu has 0.013mm/0.025mm/0.035mm/0.050mm. Where are these used? How will adjusting him affect wcu-4?

 

 Clemens Hönig 

 On 2/11/20, 8:29 AM
The circle of confusion refers to to the measurement of a point of light that falls on the focal plane (camera sensor) that's often referred to as the focal point. This also depends on the sensor size. So you can put in the value of the CoC, to match your camera, so the WCU-4 calculates the correct depth of field.
Here you got some links about this topic: 
 https://filmmakeriq.com/lessons/the-circle-of-confusion/ 
 https://www.fujifilm.com.au/blogs/digital-photography/circle-of-confusion-and-what-it-means-to-be-in-focus 
There are also websites or apps, to find the correct circle of confusion, I can recommend the pCAM app:
 https://pcam.app/features.php 
 https://www.studiojpic.com/calculators/circle-of-confusion-calculator/ 

 

 Rafael del Campo 

 On 2/11/20, 1:55 PM
Explaining technically is the answer of Clemens. (The CoC is a world) and for practical use is the correct value for calculate the deep of field. 0.013mm for S16, 0,025 for S35mm, 0,035mm for VV/FF (24x36mm sensor), 0,050mm for 65mm cámaras. 
 


 E. Roni Beraha 

 On 2/12/20, 1:12 PM
This was asked in Camera Assistant group in Facebook.
This was my reply.
WCU is integrated to the camera. Depending on the Project settings, whether it is opengate, 2k, hd, the circle of confusion number changes. You can test this with Pcam. By putting the setting on the wcu4, wcu4 bases this information with the distance and the t stop and gives you the DOF results. The results you get are guidelines for you to adjust your pull as the image can look soft even tough dof chart or the guideline says it should be in focus. 

So stick to Pcam or Pocket AC. Moreover, I have worked in a TV series that the DOP used 2 polas. Even tough the stop was T2.8, the recorded image was very dark. So for that job I did the following.
As for the job we are working right now, 0.025 is very appropriate cause wcu4 gives you the dof setting depending on the info of T stop and the lens and metric measurement but you have 2 polas stacked and making the image darker without playing with the stop and I find that even though the image should be in focus depending on the depth of field info on wcu4, it was in some cases actually soft.
