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-   -   Too much blur with TRV950 when making very small movements... (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/11983-too-much-blur-trv950-when-making-very-small-movements.html)

Tom de Boefer July 13th, 2003 07:37 AM

Too much blur with TRV950 when making very small movements...
I just filmed a bit with a sony trv950e and this is the result (i just pressed record, no special settings)


As you can see, without too much shaking the image is very very sharp, i notice almost no noise at all. BUT when i pan the camera a big strobing effect shows up and this is completely useless for even simple cameratracking. (the reason why i need a good camera)

Does this motionblur (well, i realy didn't move fast at all) be reduced with some settings on the camera ? (i didn't have the time to test everthing ofcourse) Or do i have to film with another method?

Will this blur be less with a vx2000e??

Help me out guys, i realy can't make a choice between these 2 ;-(

Clear frame:

Blur (destroys a good previous track)

am very satisfied with this imagequality, but that blur makes this camera (at the moment) useless to me...

PS1: anyone knows where i can find a movieclip of a traveling with a trv950? that would convince me to buy it, knowing it's possible to make clear shots)

PS2: Sound is NOT important at all for my camcorder! Imagequality must be very good, that's all)

Vladimir Koifman July 13th, 2003 09:26 AM

Tom, you get pretty much natural results, that is what one could expect from a camera in full auto mode.
Unless illumination is very strong, camera tries to keep shutter speed at 1/50s for PAL or 1/60s for NTSC. At this relatively slow shutter the motion blur is very visible.
To avoid it you can chose either sport AE program or manually set shutter speed to something faster, assuming you have enough light to do this.

Tom de Boefer July 13th, 2003 09:31 AM

does a faster shutter speed needs a higher number or is it the inverse? (sorry am new to this)

higher speed is like 1/100 or 1/25? (am using PAL)

thx for your clear answer Vladimir, very much appreciated.

(i realy hope i can get rid of this blur, it's a big problem for me)

Boyd Ostroff July 13th, 2003 10:39 AM

You should also try turning off the image stabiliazation (steadyshot). When the camera is stationary and something is slowly moving, or if the camera is slowly moving, the steadyshot may try to compensate and create problems.

Vladimir Koifman July 13th, 2003 11:42 AM

<<<-- Originally posted by Tom de Boefer : does a faster shutter speed needs a higher number or is it the inverse? (sorry am new to this)

higher speed is like 1/100 or 1/25? (am using PAL)

1/100 speed is higher. However, on TRV950 screen it's displayed as "100". So looking on the screen a greater number means faster shutter.
As a matter of fact, motion blur gives your video more natural look. If you chose very fast shatter, like 1/1000, you can get each frame much sharper, but the frame sequence would look stroboscopic.
Also, with such a fast shutter you need a lot of light for proper exposure.

Rob Lohman July 14th, 2003 05:16 AM

You had a very light motion blur in that movie and personally it
added to the scene! Why are you so desperately trying to get
rid of it? For some scenes it might be better to use a high or
perhaps even a lower shutter speed.

Without knowing what your exact reasons are it is harder for
us to answer your question. But the answers given are good
ones to get "rid" of your motion blur

One piece of advise to you. Switch your camera over to manual
and try what each settings does (like shutter, iris, gain levels
etc.) with and without motion in the frame. Record it and write
down which settings you used for each run. Watch them on your
TV and make notes

Tom de Boefer July 14th, 2003 05:26 AM

i need this camera for cameratracking and cameratracking is not possible if there is lots of blur. (i need it only for PC video editing)

Tom Hardwick July 15th, 2003 07:46 AM

Then what you want to do is select a high shutter speed (something like 1/600th sec) and an aperture to give you correct exposure in the light you're filming in. Probably f4 outdoors.

This will give you very jerky pans and zooms if you watch the footage as a pure movie, but it sounds as if you're only after sharp frames. Why jerky? because at 1/50th sec you record everything that happens in front of your camera. At 1/100th sec you only record half of everything that happens, and the missing information makes the film look jerky, stuttery.

A small point re the OIS Boyd. You say "When the camera is stationary and something is slowly moving the steadyshot may try to compensate and create problems". Just to point out that I haven't found this to be so as Sony's OIS is purely camera motion sensitive and ignores the image totally. Which is why it works so well in low light situations off course - unlike EIS systems.


Vladimir Koifman July 15th, 2003 08:30 AM

<<<-- Originally posted by Tom Hardwick :
Sony's OIS is purely camera motion sensitive and ignores the image totally. Which is why it works so well in low light situations off course - unlike EIS systems.

tom. -->>>

Tom, this is an interesting bit of info.
My understanding is that the main difference beween OIS and EIS is a way the motion is compensated, rather than a way how it's measured.
I thought they both use some sort of acceleration sensors to determine a camera shake. Once the shake is measured, OIS moves some optical element to compensate it, while EAS moves read-out window across a whole CCD area.
Is this right or there are more differences between the two?
Is there some web page detailing their operation?

Tom Hardwick July 15th, 2003 10:51 AM

When Sony's OIS system is on there are sensors permanently on standby in the camera body waiting for you to move the camera. If you *never* move the camera (on a tripod say) then every so often the OIS can give a tiny "wiggle" - sort of like taking a little breather. This is why you should turn OIS off if the camera is locked down. IF you have an imperfect fluid head (and many of them exist) then you would be well advised to leave SSSS on because it'll smooth out the irregularities of the tripod head friction.

Some EIS systems don't need to know if you're shaking the camera, they will still endevour to stabilise the image. This can be useful for film to video transfer work where the camera shake on the projected cine film can be stabilised by the EIS. This is very easy to demonstrate. Lock down the camcorder on a rock-solid tripod but have the EIS turned on. Point it at the cine screen and notice how the TV picture is steadier than the original film. But beware - you have to crop the original image quite severly for this to work. Another thing. EIS should *most certainly* be turned off for tripod work as it will assume subject movement (a fidgety interviewee, for instance) is shake that needs to be "corrected".

So yes, EIS is simply looking for the same info in successive frames and locking onto this. EIS can be made very powerful indeed, but the more powerful it's made the more sticky/jerky are the zooms and pans. EIS requires good light in which to work - and not only good light but decent contrast. OIS will smooth out your footage on a foggy day whereas EIS will give up completely.

For now, OIS is the winner, but its days are numbered. It's a bulky, noisy, power hungry, expensive solution to the problem, and the hybrid EIS systems are catching up fast.


Vladimir Koifman July 15th, 2003 12:39 PM

Tom, thank you for the reply. I did not know that EIS system do not use acceleration sensors.
One strange thing remains though. TRV950 uses just a fraction of CCD area for video. One could assume that periphery of CCD is used for some form of image stabilization, even though it is supposed to be optical. Otherwise I can not explain why they waste this space. Can it be that TRV950 uses some combination of OIS and EIS?

Boyd Ostroff July 15th, 2003 02:19 PM

That's interesting. When I first got my PDX-10 I had it locked down on a tripod with no movement, at full telephoto, shooting a full moon in the sky. When I played the tape back, at one point the the moon "jumped" a bit. Then I realized I'd forgotten to turn off steadyshot. After turning it off there was no problem.

John Jay July 15th, 2003 03:25 PM

TomH's advice re shutter speed is spot on in motion tracking work if you use Boujou whatever

the problem as he mentions is that at high shutter speed the motion is very stuttered since you can see two crisp images in each frame

the workaround for this (assuming you shot with tripod and pan) is to post some motion blur into the footage after you have done the tracking

after effects can handle this - you should use a value of motion blur in the direction of motion equal to the displacement between the images you see in each frame (fill the gaps with motion blur) to make it look as if it was shot at normal speeds 1/50 or 1/60 so that the fluid look is restored

Tom de Boefer July 15th, 2003 03:26 PM

that's good to know, when i have my 950 i'll think about it ;-)

Tom Hardwick July 15th, 2003 03:26 PM

The TRV950 and many modern camcorders have to have the words "mega pixel" emblazoned along the outer panels just to survive in the market place. This can be quite useful as Sony have found out. The PDX-10 makes use of this mega-pixel chip to give true wide-screen 16:9 and at the same time record much better stills than the 900 before it.

So the chip area isn't "wasted" Vladmir, it's used for stills, 16:9 (in the DVCAM version) and for the camera advertising.

OH, and OIS is never only optical, it's a combination of electronics, mechanics and optics. It's a hybrid system that uses a vibrating front element (on the VX2000's VAP) or vibrating internal elements (of the TRV950). These are pushed and pulled mechanically by information fed and processed electronically.

In contrast, EIS systems are purely electronic. Silent, cheap to manufacture and far more compact.


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