Hello
Can somebody tell me when using the xf305 does using the digital doubler reduce the resolution of the camera & if so what to. If not is it a good way of crushing the depth of field more. Do you loose two stops of light like on a 2/3 inch doubler?
Thanks
Mark

The camera is just magnifying the pixels. The digital extender has nothing to do with optics, so therefore, it does not cause any loss of light or change the depth-of-field. Not only that, you can do exactly the same thing in post and it will look the same.

For example, if you have FCP:
1) Put a clip on the timeline.
2) Double-click on the clip and go to the Motion Tab.
3) Change the Scale to 150%.

Now you've just done exactly what the camera's digital extender would have done. But, by waiting until you got to post, you still have the option of changing your mind and not scaling it, moving the positioning around to change the composition, or scaling less than 150% if that would be more than you need.

The only time I'd ever use the digital extender if I was doing a live shot of breaking news or something where post was not an option.

Canon XF305 Digital Tele-converter on Vimeo

Doug,

I can see no appreciable difference between using the digital convert or resizing in post.

But I think there should be a difference, esp. when images have a lot of detail. This is because using the digi-tele does the upsizing before compression. While resizing done in post is done after compression.

Now maybe I'm missing something, or maybe the XF codec is so good that it really doesn't matter. But I do think there should be a difference.

Peter,

I thought the exact same things you are thinking before I did my testing. But in the real world, I can see no appreciable difference in the final video.

Thanks Doug, what a shame I thought it may be a great way of crushing the DoF. never mind.
Regards
Mark

Has anyone looked at how the digital extender functions in the 720p formats? Does it just window the center 1280x720 portion of the sensor and record that? The fact that it is a 1.5 extender suggests that might be the case, which could probably deliver pretty respectable quality on par with the regular 720p modes.