What shutter speed to use?

Shortly, for the first time, I'll be diving with a pro video camera instead of the prosumer cameras that I've used to the last 7 or 8 years.

I'm OK with all the functions and settings but would like some advice on shutter speed. I think that I am letting 30 years of still photography confuse me.

I'll be shooting 1080p25. Am I correct in assuming that with 1080p25, at a shutter speed of 1/25s, the shutter is effectively open all the time, right?

The two obvious choices for shutter speed are 1/50s and 1/25s.

Shooting topside in sunny conditions, I found that 1/25 is too bright and needs an iris setting of f8 or higher or lots of ND filter.

I understand that lens performance starts dropping off when the iris is smaller than f8. Right?

Is lots of ND filter OK?

Underwater, in darker conditions, I would imagine that 1/25s would give a good exposure with a range of options for iris settings.

But, with all the movement underwater (fish, particles, bubbles, etc), is 1/25s going to give too much motion blur?

Would a faster shutter speed make for sharper footage?

Would a faster shutter speed make jerky footage, like 1920s cinema?

Would I ever want to use a shutter speed faster than 1/50s?

I guess that for US videogs, you'll be using 1/30 or 1/60s.

What do you use? In what circumstances do you change to a different setting?

Regards

Peter

The general rule is to double your frame rate. 1/48 for 24p, 1/50 for 25p... 1/120 for 60p etc etc. Creates just enough sharpness and motion blur for normal use. Obviously speeds increase for over/undercranking.

Hi Peter,

1/50 would be the standard shutterspeed when you're shooting 25p. This will give the 180 degree shutter look which people seem to favour. It seems to give enough motion blur that the movement does not look jerky, but not too much, so that the detail is lost. 1/25 will show more blur where there is fast motion, but I guess you could try it if you're really pushed in low light. Also faster shutter speed can be used, but they give a slightly more jerky look. Anyway, for 90% of the time I shoot at 1/50 if it's PAL, or 1/60 if NTSC. I guess if you're going for under/overcrank you might think about adjusting it, maybe more experienced shooters will chime in.

It's one of the things that annoys me about shooting with the cx550, that you can fix the shutter speed, but then you're stuck to auto aperture and gain. And vice-versa, ie you can't manually control all of the parameters independently of one another. I'm sure your canon will be much more satisfactory in that respect.

Best,

Fergus

Edit- looks like Drew got in there first!

Hi Peter,

 

1/50 would be the standard shutterspeed when you're shooting 25p.

 

Best,

Fergus

 

Edit- looks like Drew got in there first!

Thanks guys. 1/50s it is.

What the guys said.

Minimum - 1/25, maximum - wherever the camera goes, optimum - 1/50 :-) Obviously, the more you deviate from 1/50, the more jerky or blurry it becomes.

Yes for PAl its 50 shutter but it the fstop maxes out due to too much light in the shallows spin it to 100.

I shoot on 100 with my Canon DSLR many times to get the fstop down if its just too bright and sunny.

Even did this for some video aerials of the reef and it came very nice indeed.

Yes for PAl its 50 shutter but it the fstop maxes out due to too much light in the shallows spin it to 100.

I shoot on 100 with my Canon DSLR many times to get the fstop down if its just too bright and sunny.

Even did this for some video aerials of the reef and it came very nice indeed.

Thanks Wagsy,

You don't find any jerkiness in the footage at faster shutter speeds?

Regards

Peter

With DSLR's you need to add ND if you want to keep the shutter at 1/50. I have a 3stop ND when I use my 7D outside. It starts to get expensive though when using multiple lenses as you need diff filter sizes or you go the Matte Box route.

Variable ND filters are useable for topside for any camera. It's easier to make one. Just buy 2 quality circular polarizers, reverse one and attach together. and it acts like a variable ND filter.