Blurred image every 2 frames

AntonioCorrenti

AntonioCorrenti

Member
Hi guys,
This is my first post.
I'm experiencing some issues with my 7d (brand new).
I've noticed that 1 frame (@30fps) is sharp and 1 is blurred, alonge the whole file. And I don't think is motion blur, maybe a setting is wrong (eg. shutter too slow)?
I uploaded an example, just to show you what I mean...
If you look at the footage frame by frame, you will notice that every 2 frame 1 is out of focus/blurred...
I used a ricoh rikenon 50mm 1.4@1.4

Thank you in advance.

Sorry for my bad english...

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Honestly, I'm not really sure. I'd do a test with 1/60 shutter speed and see if that helps.

Otherwise, did you have everything else set manually? Aperture, ISO, etc?

It could maybe have something to do with compression... I haven't seen this before.
 
It could be that you are shooting 720p at 60 frames a second and your shutter is too slow
but without knowing more about the setting you had then all we can do is guess.

Think for a minute.

If you shoot 720p 60frames per second then the fastest shutter for any one of those frames is one 60th of a second. So if your shutter is set
to 1/50th then you are forcing the camera to do strange things with every second frame.

Well thats my guess.
 
Hi guys.
First of all, thank you for the help.
Now some specs:
This is a slow horizontal pan, I've tried to be slow to avoid the infamous rolling shutter, but there is a good amount of vibration.
It was shot at 1:1.4 1/30 with a 50mm (old m42 lens via adapter) and the output is 1080p @ 30fps ntsc. The jpegs are made from mpeg streamclip on a mac from the h.264 footage direct from the camera. Obviously, if i try to stabilize the video, even with virtualdub+deshaker with rolling shutter enabled, the effect is accentuated, virtualdub can remove the shake but the blur stays.
Could it be a "lens wobble"?
If it's motion blur causated by the slow shutter, why just every 2 frames? Any chance to correct it in post?
Strarting from yesterday I'm shooting @25fps with 1/50 shutter speed, i hope this will avoid this artifacts.
 
Hi again,
Here a video example. The first part is the normal shaky footage and the 2nd part is stabilized.
If you look at his eyes, you see a really annoying motion blur.
Any chance to correct this in post?

password : fiorenzo
 
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