Panasonic GM1 avchd 50i not proper 50i?

[AndersM]

Hi,

 

According to the menu on the Panasonic GM1 the avchd 50i setting reads the sensor at 50 fps. The files import as 50i files but the resulting files plays like a 25 fps file. I've checked the files both in fcpx with Blackmagic output, and Avid with a Mojo DX. 

 

Can anyone else confirm this? Does it say anywhere that it is not proper 50i? 

 

Thanks!

 

AndersM

[Guest Ebrahim Saadawi]

Maybe I am mistaken but I think you're not aware of the difference between 50i and 50p. 50i (i for interlaced) means there are 50 "fields" per second, and actually 25 "frames" per second. While 50p (p for progressive) means there are 50 frames per second and no fields.

If you want to slow down the footage then you should record at 50p. 50i will play like 25p. They're both 25 fps.

Is there an option for 50/60p in the GM1?

[Julian]

With panasonic 50i is always wrapper, from 25p sensor output. The GM1 doesn't have 50p, they say the sensor would run too hot in the small housing.

[AndersM]

I am perfectly aware of the differences between 50p and 50i. I work in broadcasting, that's why I use and need 50i. 

It might be the case that the 50i is a 25P wrapped, but in the menu when you choose avchd 50i it says "Image sensor output 50p, 17Mbps". See attached picture. 

 

This is why I would think it would be proper 1080 50i files like the GH3 for example. 

 

Julian: The GH3 has proper 50i in addition to the 25p in 50i wrapper. I think the GH2 too.

[AndersM]

I figured it out!

 

At first I tried the 720 50p and this had the same issue. Only 25p with every frame duplicated in the 50p file. 

Then I increased the shutter speed and now I get both proper 1080 50i and 720p. It turns out the GM1 isn't able to shoot with a 360 degree shutter like e.g. the GH3 is. When you're at 1/50 sec shutter it reduces the frame rate to 25, where on the GH3 it gets reduced if you go BELOW 1/50 sec. Strange and annoying, but now I know the reason at least. 

 

AndersM