shutter speed instead of exposure?

[Michael Stewart]

A friend of mine is sold on using the shutter speed to primarily combat the bright outdoor light situation, he says he plans on leaving it on 100 all the time and that it will allow him to keep things in focus in front of and beyond the subject, what are the drawbacks to this plan, does the picture quality suffer, he is shooting weddings and swears shutter instead of exposure is the way to go, any opinions? good idea?

Thanks
Mike

[Mike Rehmus]

Shutter speed is exposure. You probably mean aperature?

Raising the shutter speed means that the aperature has to get larger so that really reduces depth of field, it does not not, as he expects, increase it.

[Charles Papert]

The thing to know about shutter speed is that it has a visual effect. A short shutter speed has a somewhat stroboscopic look to it, most pronounced with fast action. Some may like it , some may not. Using ND filters will allow shooting at the same apertures that a fast shutter speed makes possible, without the stroboscopic effect.

[Boyd Ostroff]

<<<-- Originally posted by Mike Rehmus : Shutter speed is exposure. You probably mean aperature? -->>>

Yeah, but I think "exposure" is Sony-Speak for "aperture". At least that's how they label the dial and it's what they call it in the VX-2000 and PDX-10 manuals. Anyway, I agree with Charles, don't increase the shutter speed unless you want that staccato look. It can be very disconcerting in scenes with fast action. If the internal ND filters don't allow you to shoot at the desired aperture then pickup a couple external ND's and add them to the lens.

[Craig Seeman]

For Shallow DOF. Open iris wide (f1.6) add ND to cut down light. Change shutter speed (faster) to cut more light if you like.

BTW the original poster was talking about weddings.

Fast action at a wedding? Hmm, errr, uhh, getting married on water skis? Those flying flamingo dance floor moves . . . <grin>?

Neat thing about the faster shutter speeds is how those wedding video slowmos look.

[Tom Hardwick]

I agree with the replies. Don't vary the shutter speed from the default 1/50th (PAL) unless you want
1) to halve your vertical resolution but shoot in the gloom
2) to introduce the 'shutter-stutter' effect that high shutter speeds bring.

Much better to soak the light with the two in-built NDs and add another ND4 if you love differential focus in bright sunshine.

It's probably OK to use 1/100th at a wedding because of the gentle pace, but remember that with 1/50th you record *everything* and at 1/100th you only record half of everything that happens in front of the lens.

tom.

[Luis Caffesse]

"to halve your vertical resolution but shoot in the gloom"

"remember that with 1/50th you record *everything* and at 1/100th you only record half of everything that happens in front of the lens."

I may be mistaken (lord knows I have been in the past)
But increasing shutter speed doesn't have any effect on
resolution at all that I know of.

I guess you could make an argument that you are losing "half" of
everything in terms of 'temporal resolution,' but you aren't losing
any 'spacial resolution.'

-Luis

[Alan Christensen]

We shoot a lot of school videos. Many of the scenes are outdoors on the playground in bright sunshine. We have tried a variety of techniques to get good video in these circumstances. The default shutter speed of 1/60 sec is good because it gives maximum depth of field and it gives the smoothest, most natural looking movement. With kids moving all over the place, and often taking up only a small percentage of the screen, the focus issues become difficult. Having a large depth of field is essential to prevent occasional out of focus sequences when the camera decides to focus on the chain link fence 50 feet behind the kids, rather than the kids themselves. That said, there is something to be said for shooting at slightly faster shutter speeds. If you are interested in pulling stills from the video as well as have good video, then 1/60 of a second simply won't cut it. Motion blur, which helps make the video look smoother, is pretty bad at the individual frame level. Consequently we normally shoot at 1/125 to stop the action enough that the stills are pretty good. The slight "sharpness" that you get in the video at this shutter speed isn't very noticeable, and the stills are way better. We have tried shooting at very high shutter speeds given that there is so much light available, but the impact on the video smoothness and DOF becomes objectionable. Note that we often shoot indoors at 1/125 (assuming good lighting) because of the need for good stills. I'm not surprised that Mike's friend finds this works for him for weddings.

I guess they put all those controls on the camera so that you can pick and choose what works best for your particular situation.

[Tom Hardwick]

Good points Alan, and I'm with you on them all.

Sorry but I didn't explain myself fully Luis. You only get half vertical resolution when you drop to any of the speeds below the default 1/50th (1/60th NTSC). It's a Sony thing.

"I may be mistaken (lord knows I have been in the past)
But increasing shutter speed doesn't have any effect on
resolution at all that I know of."

Correct - but read what Alan says about stills. Remember that at the default speed your camera records very nearly everything. If you shoot at 1/50th and wave your arms about you can step through frame by frame and see that the blur from frame 2 carries on exactly where the blur from frame 1 ends. If you shoot at 1/250th (say) there's a huge chunk of time not recorded, where the hand has moved on and not been photographed. A bit like a cine camera in fact.

tom.

[Alan Christensen]

Tom-

I guess I am confused with the half resolution comment. With shutter speeds slower than 1/60 of a second, e.g. 1/30th, I can theorize how resolution might be halved. Normally the shutter closes every 60th of a second, after which a quick readout of the CCD contents is done. At shutter speeds of 1/60th or faster, the odd field is read after the first shutter close, and the even field is read after the next shutter close. These two fields combine to provide full resolution. At a shutter speed of 1/30 of a second, the shutter only closes once every 1/30 of a second. This would seem to suggest that you can only capture one field every 1/30 of a second, which effectively halves resolution. When Sony says that resolution is halved below 1/60 of a second shutter speed, I assume they mean speeds slower than 1/60. At speeds higher than 1/60th then it seems that you should always get the full resolution. Is this the way that you understand it, or am I off base with my understanding?

[Mike Rehmus]

You understand it correctly

[Gints Klimanis]

Since I do a lot of technical analysis and frame grabs with sports,
it's useful to raise the shutter speed so that individual frames
are not blurred. When sticks are involved, the usual 1/60 speed makes the sticks look more like brooms. Thus, the frame grabs are often useless. Although, I doubt you'll
have this problem at a wedding.

As the others have pointed out, the trade off is that the rest of
the action is missed.

[Ray Echevers]

Higher shutter speeds give sports and fast action footage a great look, plus great for slow mo's.
I usually use 250 or 350 when it's sunny outside while shooting sports/fast action stuff.
But of course it depends what aperature i need or desire, using the ND filter too if I need it.

Well most of this experience is from my VX-3 which I used like 4 years ago, I have barely used up one 60 min tapes on my new VX-2100.

[Michael Stewart]

Great Responses, thanks to all. It seemed like things became a little grainier when I changed the shutter speed on the camera (higher), it seems to not look as good, is this another problem with higher shutter speeds?


Mike

[Mike Rehmus]

SHould only happen if you raise the shutter speed so far that the opening the aperature cannot correct for it and the camera starts raising Gain.

At least I think the reset cycle for the CCDs stays the same with increased shutter speeds.