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#1 LeighWanstead

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Posted 23 October 2004 - 02:52 PM

Hello everyone,

I set a target which is a window and the distance from the camera to the window is around 20 to 30 meters. I set my fujinon lense focal length to be 128mm. I got a cross on my lcd screen which is in the center of the screen. I walk towards the window and I saw the image displayed on the screen turn left and right and is very hard to center on the window. May I ask in this situation what is an acceptable ship away distance? Less than 50cm left or right of the window? The ideal situation is always in the center of the window of course.

TIA
Leigh
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#2 RobVanGelder

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Posted 23 October 2004 - 08:53 PM

Though it is very brave of you to zoom all the way in and want to hold the target perfectly, I think it not something that can be done and is asked from you in daily practice.

If your camera is a 2/3" camera, than your angle of view is about 3,5 degrees.
even smaller with smaller CCD´s.
That would be the same as using a 300 mm on 35mm film! Nobody can maintain the crosshairs spot-on while walking!

Though we regularly use longer lenses on Steadicam, the main range is between 16 and 85 mm. (Talking about 35mm format)
Of course, we get the 135 and 180 sometimes, but the use is limited, the sort of shots that you can make too..

When directors and DP´s want to use these long lenses, it´s mostly because of the different look you get compared to operating these on sticks, dolly or handheld. There will always be some swaying, overshooting the subject, specially if the subject has a fast pace or is moving irratic. But it is this "imperfect" framing that can be very interesting.
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#3 LeighWanstead

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Posted 23 October 2004 - 10:49 PM

Hi Rob,

That is just for my training exercise.

My camera is 1/2" camera. And the camera model is JVC gy-dv5000u. May I ask what is equivalent to on 35mm film?

What formula you use to get that number 300mm on 35mm film?

TIA
Leigh
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#4 Mitch Gross

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Posted 23 October 2004 - 11:30 PM

Leigh--

Go to the Panavision New Zealand website to find a nice calculator to convert relative focal lengths between formats.

http://www.panavisio...lenseqvform.asp

On your DV5000, if you can keep the cross in the middle at around 50mm then you're doing quite well. You'll want to practice walking forward and backwards and Don Juan (body facing away from subject with the camera facing back). The next exercise is to follow moving objects. Time to terrorize your dog!

If you ever get to the point where you can keep that cross stable at 128mm, congratulations--you've just become a Fisher dolly!
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#5 LeighWanstead

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Posted 24 October 2004 - 01:08 AM

Leigh--

Go to the Panavision New Zealand website to find a nice calculator to convert relative focal lengths between formats.

http://www.panavisio...lenseqvform.asp

On your DV5000, if you can keep the cross in the middle at around 50mm then you're doing quite well.  You'll want to practice walking forward and backwards and Don Juan (body facing away from subject with the camera facing back).  The next exercise is to follow moving objects.  Time to terrorize your dog!

If you ever get to the point where you can keep that cross stable at 128mm, congratulations--you've just become a Fisher dolly!

<{POST_SNAPBACK}>


Dear Mitch,

Thanks for the link.

Is the following parameter right for that link?

First Format: Video 1/2" TV 4:3 4:3 CCD Sensor 6.4x4.8mm
Format: Panavision Std 35mm Widscreen 1.85 Projected 0.825x0.446"
Choose Dimension to use in the Calculation: Diagonal
Enter the Starting focal length for the Left Column:6.4
Enter the Increments to list in the Left Column:2
Enter the Highest focal length for the Left Column:128

Do you know what formula the website use to get that table?

Thanks

Regards
Leigh
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#6 Markus Rave

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Posted 24 October 2004 - 04:44 AM

Without confusing too much. Choose something between 10 and 15 mm on your lens and start with that. This will leave you with good result and low frustration. Good for a start. You may increase focal length when you get better. You have a presumably light camera which is harder to operate than a heavier one, except for weight :-) since the inertia is less and needs more accurate operating techniques.

Good practice anyway

Markus
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#7 RobVanGelder

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Posted 24 October 2004 - 09:06 AM

My camera is 1/2" camera. And the camera model is JVC gy-dv5000u. May I ask what is equivalent to on 35mm film?

What formula you use to get that number 300mm on 35mm film?

TIA
Leigh

<{POST_SNAPBACK}>


That would be 419mm, calculated on my Palm with PCam from David Eubank.

If you have a palm, visit his site:
Good Focus
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#8 Alec Jarnagin SOC

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Posted 24 October 2004 - 11:38 AM

Leigh,

If your sled has the ability to move the monitor and batteries, it can really help with longer lenses. By increasing the distance between your monitor and batteries (horizontally; i.e. make the sled longer) you'll add pan inertia that makes longer lens work easier. As for 128mm on a 1/2 CCD? I see no problem with trying this as an exercise, but don't let it discourage you or distract you from practicing "real-word" situations. What you are doing reminds me of the exercise using a laser pointer and trying to keep it on a given spot while you walk in and then out, switching from missionary to Don-Juen.
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#9 LeighWanstead

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Posted 24 October 2004 - 12:44 PM

What you are doing reminds me of the exercise using a laser pointer and trying to keep it on a given spot while you walk in and then out, switching from missionary to Don-Juen.


Hi Alec,

That is a good idea.

Do you mean this laser pointer?

I will go buy this one for my training.

Regards
Leigh
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#10 thomas-english

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Posted 24 October 2004 - 03:43 PM

watch out....

lasers like that you often need to hold the button in for the laser to stay on. Better a gun laser, they have switches.

Point them at the floor as well, helps the focus puller sometimes.
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#11 Alec Jarnagin SOC

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Posted 24 October 2004 - 08:01 PM

I have a couple of different laser pointers sitting around. They all have buttons instead of switches. Easiest cure is to take a rubber-band and put it on the shaft so you can simply roll it over the button, keeping it pressed when needed.
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#12 Eric Fletcher S.O.C.

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Posted 24 October 2004 - 11:30 PM

Point them at the floor as well, helps the focus puller sometimes.

<{POST_SNAPBACK}>



That's not really a good idea since the dot moves with tilt and boom height.

Besides good first's judge distance from the mattebox to the subject. Not from their feet and a laser dot....
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#13 LeighWanstead

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Posted 24 October 2004 - 11:40 PM

Now I found to get excellent steady footage needs lots of hard work. I will do my 128mm focal lense trainning exercise every day for an hour and wish in next 30 days everything will be fine. :D
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#14 LeighWanstead

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Posted 04 November 2004 - 03:08 PM

I found learn to operate stablizer is just like learn to ride bicycle. Now gets better and better. :P
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#15 LeighWanstead

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Posted 05 November 2004 - 03:14 PM

Here is a divx video.

The file size is around 18mb.

http://www.salenz.com/movie/go.avi

You may get divx decoder from www.divx.com

Regards
Leigh
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