GH2 Frame Rates and Shutter Speeds

[stoneinapond]

I was looking over the video tutorials (recommended) from Wrightsville Studio concerning the above topic and found myself confused about their relationships. Perhaps to others it may seem obvious but here is the question I posed to David.

I am still confused about the relationship between the 24 "movement captures" and shutter speed in a DSLR usage situation. If I use a 40 "frame?" shutter speed, each "capture" is being exposed for 0.6 of its duration, with the remainder filled in the next time the shutter opens. Am I making sense? And if that is the case, why not shoot with a 24 shutter speed, exposing each capture just once, outside of the question of exposure?

And does a slower shutter speed (in reference to the DSLR) change anything about the movement captured in each of the 24p frames? (I did repeat the final bit of part 1 several times but still can't get my head around the relationship.)

I appreciate any clarification.

Here is his reply.

There's no "filling in." If you took a photograph with a long exposure, there's still only one picture, right? Meaning, if you opened up the shutter for 30 seconds when taking a photo, you'd only have one photo, but anything moving would be blurred.

Each frame is a separate photograph. You expose each photograph for the amount of time you choose, but it's still only one photograph. You're just taking a lot of them.

So, you would choose your shutter speed based on the amount of blur you want in the picture. Faster shutter speeds have less. Slower shutter speeds have more.

I think my confusion stems from my conflating the seconds of both, in other words, there were 40 shutter clicks per the same second as the 24 frames were being captured. So now I think that what is happening is that each frame is being exposed for 1/40th of a second and that is happening 24 times per the timeline second. Which now makes sense as to why there would be more motion blur with a slower shutter speed.

Hopefully I have this right now and it will help others. If not, please correct me and hopefully David will chime in at some point.

 

[David Jimerson]

You've got it now. As we say in the tutorial, the frame rate is the number of pictures per second. The shutter speed is how long each picture is exposed. There are no "shutter clicks." Each frame is a single reading of the sensor.

 

[stoneinapond]

Just to reiterate, the confusion was mine and not something in the tutorial, which as I have said is strongly recommended for those who want to learn more about the whole issue of frame rates. And as a bonus it is also quite entertaining.

Thanks David.

:thumbup: