View Full Version : Shutter speeds ...
Stuart McAlister April 14th, 2009, 02:01 AM Hello All
Getting to grips with my Z7 and as an aid bought the Vortex DVD guide to the camera and its operation.
However having learnt that in order to keep the camera in FULL MANUAL I have to 'lock down' the shutter. Therefore the shutter is never actually turned off as I have to give it a value (shown in a grey box in the viewfinder).
I am working on PAL and jumping between HDV and DVCam - depending on on the client's requirements. Whichever value I go for I find that the given image during pans and tilts are not as smooth as I would like - shutter speeds such as 50/60 or even 125 still give the impression that the picture is somewhat 'artificial' - it gives the impression that it is 'juddery'.
With the shutter 'off' the iris will adjust to suit the exposure but with it 'locked down' whichever value is given it still looks odd - both when the camera is on the move or something passes through the frame (someone gesticulates with an arm during and interview or objects passes through a locked-off shot).
If anyone is working on the same format and would care to share a few tips then I'd be eternally grateful.
Stuart
Tom Hardwick April 14th, 2009, 02:19 AM Of all the variables at your disposal (gain, iris, w/bal and shutter speed) it's the shutter speed that should be locked down for most of its life. And shooting interlaced and having it locked at 1/50th second means (in PAL land) that everything you point the camera at is recorded - each field follows on directly from the last.
If you film at 1/100th sec you only capture half of everything your lens points at, so making movement (camera or subject) look more jerky. The higher the speed, the jerkier the movement, and with CCDs (not a problem you'll face with the Z7) the more vertical smear you'll get.
As with all Sony cams you need to have the shutter speed visible in the v'finders otherwise (as you say) it won't be locked down. It sounds to me as if you might be shooting progressive unintentionally - do you have a picture profile inadvertently dialed in?
tom.
Stuart McAlister April 14th, 2009, 03:15 AM Tom
0nce again you have the answer ... so at 1/50 PAL pix should be consistent and smear-free. Therefore smooth ... will check on PP.
Many thanks again
Stuart
Uli Mors April 14th, 2009, 01:55 PM 50 should give you a smooth video look and movement. but panning leads to motion blur.
100 will give sharper single frames (therefore having less motion blur) for the price of a bit more "jerky" (as you call it) video.
If you like to hit the middle , you can also dial in something about 80 in shutter ECS mode.
Regards
ULI
Ian Campbell April 14th, 2009, 09:43 PM Hi Stuart . . .
Are you shooting progressive or interlaced? If you are shooting progressive, your footage will always have some kind of "judder" effect regardless of what shutter speed you choose.
Shooting in PAL with a shutter speed of 1/50 should be ideal for routine shooting. Sports or other fast action video will benefit from a faster shutter speed. If you find you need to adjust your shutter speed within a project, make sure to always shoot your fast action with one value but always return to your usual shutter speed setting(s) afterward.
The Vortex title you bought for your Z7 has some great examples of the effects of shutter speed. As Doug Jensen suggests in the Z7U DVD, use all of the other options the camera offers for exposure adjustment while keeping your shutter speed at 1/50th or the value you choose for your project.
Ian
Stuart McAlister April 15th, 2009, 12:12 AM Uli and Ian
Thank you both for your very useful and intelligent input.
I am afraid that I use my Z7 to make pretty boring television - interviews/gvs etc. No sport whatsoever.
Although I have already shot a number of sequences/reports I am still in the 'discovery stages' of this machine and as I come from the 'old school' of cameramen (Hi-Band in the 1980's through to Beta SP then Beta SX to DigiBeta) re-learning the art with these new but superb quality cameras is taking a little longer than expected!
0nce again many thanks.
Stuart
Marcus Martell June 6th, 2009, 12:08 PM If i wanna use it for a basketball game wich speed do you suggest?I'll shoot a daylight basketball tournament(at the beach) with it...
thx in advance
Jamie Jewett June 6th, 2009, 12:20 PM Thanks for this discussion -
I have been shooting mostly 30p at 1/60 -
mostly shooting dance and theater -
would you recommend 1/30 to match the frame rate -
it would help in the low light world I shoot in most often but I am concerned about smearing...
thoughts?
thanks
Jamie
Ian Campbell June 6th, 2009, 04:21 PM Hi, Jamie . . .
When I shoot 30p projects (which is most of the time), I will often change my shutter speed from 1/60th to 1/30th to get a "boost" in exposure when light is a real challenge. I don't find this to be problematic and haven't had issues with smear, etc. I would never recommend shooting at a slower shutter speed than your frame rate - so don't go slower than I/30th when shooting 30p.
When shooting a 60i project, you will really notice the difference when going from 1/60th to 1/30th. But it shouldn't be too obvious when you are shooting in 30p.
I only drop to 1/30th when I really need to. I like to shoot at 1/60th when and where I can.
If you have time, do a test . . . I think you might like the result. I have shot fast moving stuff in 30p at 1/30th and it looked good.
Hope this helps.
Ian
Marcus Martell June 7th, 2009, 09:52 AM Hey Ian what do u suggest to me in the b-ball tornament shooting?
Ian Campbell June 7th, 2009, 01:04 PM Hi, Marcus . . .
Are you shooting progressive or interlaced? If shooting (PAL) 25p, for example, I'd keep my shutter speed to 1/50th. In progressive, sports with fast action and camera moves will likely show a fair amount of judder. But this might be the look you like. If so, you are good to go with this setting.
If you are shooting interlaced and want a very smooth look to your video - you might want to increase the shutter speed above 1/50th to a faster speed. I don't know what the actual shutter speed options are for PAL shooting, but I'd likely choose something close to 1/100th. I wouldn't go to much higher than this, since you might start to get some rather bizarre looking footage if the shutter speed is set too high. Even shooting at 1/50th might be okay, since a bit of blur motion in individual video frames is normal and is what we've been accustomed to viewing on television and in films. If you can run a test in advance of the shoot to test various frame rates, interlaced vs. progressive options and shutter speeds you will find the look you like.
If you don't have time, keep the shutter at 1/50th for progressive. For interlaced go 1/50th or a little higher to slightly reduce motion blur if you wish to.
Try to control your exposure vary carefully, since shooting on a beach is a bitch with bright sunlight on sand, etc.
Have a great shoot!
Ian
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