C100: C100 MKI DPAF Doesn't Consistently Work?

[puredrifting]

Hi all:

Shooting a big project with my C100 MKI I purchased last November. The shoot involves a lot of run and gun shooting with with various walk and talks with actors in challenging conditions. My camera was purchased new with the DPAF upgrade and I am mostly using my 18-135 STM IS, a little with the 10-18 STM IS. I have noticed that from time to time, it seems as if the DPAF will not activate with the one touch AF button. Sometimes I have to either turn the switch on the lens from AF to MF and back or even at times have to power down the camera, then reboot it to get the DPAF to work again? At times, I will put the center of the frame right on an actors face, push the one touch AF and nothing happens. Most of the time though, it works fine, as expected. I am also shooting long lens interviews with the actors using shallow DOF and same issue, sometimes I will hit the AF button and nothing seems to happen, or I think the DPAF worked but in reviewing the footage, the focus is often soft. I am two days into an eight day shoot so I don't have time to take it to Canon and have it all checked out but was wondering of others have experienced wonkiness with the C100 DPAF when paired with the 18-135 STM IS? When it is on, the images look as I would expect, sharp and great colors but I shoot with the Ninja Blade as my screen, it is not really a large enough screen to judge focus well when you are running around in bright daylight. I even fashioned a sun shade extension out of Cine-Foil and gaffer tape that helps a lot with screen visibility in sunny conditions but this DPAF issue is frustrating. I haven't noticed the issue as much with the 10-18mm lens but I chalk that up it being such a WA lens where most stuff is usually in focus anyway, it's harder to tell. I borrowed a friends Canon 50-250mm lens yesterday for the shoot and while the AF is slower than the STM lenses, the camera seemed to focus more positively than with the 18-135 STM IS? It would lock on to focus and be done, while the 18-135 STM IS seems to hunt and wander with the focus more.

Any feedback on what the issue could be?

 

[indiawilds]

I hope you are you using the continuous AF?

Not exactly sure what the issue may be. During the initial days of DPAF testing, I realised that once I press the No. 7 button, which I had programmed for AF, the focus locks. And I used to forget to press it again to unlock the focus. For eg if the subject is going to pass behind a tree, I lock focus on the subject and later when the subject moves away from me, I have to unlock focus to get the subject back in focus again. I found a solution to that, by display the centre AF rectangle in the screen. So when the AF is working the centre AF rectangle is highlighted. This will help you realise that you have accidentally switched off DPAF.

The AF will hunt when you focus on dark areas. The AF needs light. If your lens is hunting then it may be because the scene is underexposed. Just get the exposure right and you will see that the AF will not hunt. To test, focus on your camera bag (assuming your camera bag is black or dark).

I hope this works. Good luck!

 

[puredrifting]

Hi India:

I am using the "one shot" mode and using the "15" button to focus. Is this incorrect? Is it better to use the continuous AF? Seems like two different ways of achieving the same result, turning on the one shot and focusing on a subject, then releasing the 15 button versus the camera is always in continuous AF and using a pre-programmed button to lock it on a subject. I shoot a lot of handheld and it is physically much easier to use my left hand to grip the camera handle and rods near the lens to zoom to reframe and hit the 15 button. If you programmed the 7 button to AF, do you still use the image magnification, did you re-map that function to a different button?

 

[Burners]

When in 'one-shot' mode if you hold down the button configured to focus, the camera will do a 'one-shot' focus operation as to be expected. It would be good if the camera remained auto-focusing while the button was being held down and disengaged when released. Not sure if that's possible to set-up or not.

 

[puredrifting]

When in 'one-shot' mode if you hold down the button configured to focus, the camera will do a 'one-shot' focus operation as to be expected. It would be good if the camera remained auto-focusing while the button was being held down and disengaged when released. Not sure if that's possible to set-up or not.

I don't think it is, but the menus and options on these cameras seem pretty deep. I believe the only choices are one shot or continuous though. I should try the continuous I guess, maybe it will deliver more consistent results? One touch seems hit and miss, sometimes it works great and other times, it doesn't do anything. Not sure if it is my lens or the camera.