April 9th, 2008, 10:32 AM | #1 |
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Steadicam Pilot and EX1
I've had limited sucess with this combination, but im damned if i can achieve dynamic balance. I know some of you more experienced steadicam folk are using this combination so i wonder if i could ask what weights and combinations are you all using? Or even see a photo of your set up? I've tried a multitude of options but either i've been super unlucky or i'm missing something. I've read the balance primer, and also a few threads about balancing as well.
I can get static balance no problem and in fact have managed to get some reasonable shots with it but i ought to be able to achieve dynamic balance too. I have the v lock version which adds the battery weight to the bottom. Also for monitoring purposes i am stuck using the supplied sony lead to get the AV out and into the video socket under the sled. But the sony lead is long and cumbersome and i have to wrap it around the camera (not ideal). Is everyone doing this or are there other leads available im not aware of? many thanks in advance paul |
April 9th, 2008, 10:58 AM | #2 |
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Paul, perhaps you can describe the dynamic balance issue you are experiencing. When you spin balance, which way is it precessing (dipping) and what are you doing to correct it?
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April 9th, 2008, 11:25 AM | #3 |
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Charles, thanks for the reply...
In general i have: found the CG point for the camera and placed that about 1/2 behind the central post. I then move the battery fairly close to the central pole and then get some overall balance by moving the bottom pole. My drop time is around 2 to 3 seconds. I then use the sled controls to trim and get static balance. I try spining the rig and that's when it starts wobbling all over the place. I then adjust the battery and the camera on top to rebalance and try spinning again. You ask which way it's precessing (new word for me) and to be honest i cannot remember. What do i look for and what are the corrections to apply - i've not seen this term discussed in anything i've read? I've had it close but after a few spins it goes off balance. I've never managed to get it to spin perfectly for any length of time. (i've seen a youtube video of someone spinning a rig perfectly so i *think* i know what im looking for) I just wanted to confirm that others with an EX have managed dynamic balance and what combinations of weights and methods they've used. Im sure it's just me! thanks paul |
April 9th, 2008, 11:42 AM | #4 |
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Paul:
The "wobbling all over the place" is the part that needs to be addressed. What you are looking for is a repeatable, definable pattern to the wobble. Is the camera dipping towards the lens or the battery? One thing to make sure is that you are giving it a good, clean spin; that you are not influencing the rotation of the rig by the way you spin it. This takes some practice. Don't get it spinning super-fast like a top. Around 2 seconds for a full 360 degree revolution is fast enough. When you get a spin that exhibits predictable results i.e. the camera dips the same direction each time you spin, then you have spun it properly (btw, precession refers to this dipping phenomenon). So if it is, for instance, nose-heavy, you should extend the battery away from the post, then slide the camera forward. If the battery is extended all the way, you can try pulling the monitor in to the post, or if necessary add a weight to the rear of the sled. This will of course require a new static balance. It's important to keep a close eye on the spin to see if it is improving or getting worse, then that will tell you how to proceed. With relatively little mass such as the rig you are working with, fractions of an inch can make all the difference in the world. I discourage people from relying on "cookbook" settings for their cameras because it is important to learn how to balance your rig from scratch, in case you need to add accessories or jerry-rig something on set. Dynamic balance is indeed tougher than static to achieve but it is part of understanding and controlling the forces that lead to great Steadicam work, and it's best not to short-cut the learning process. Let me know if that helps or if you need clarification.
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April 9th, 2008, 11:51 AM | #5 |
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Thank you Charles,
I shall try some more and pay closer attention to the type of wobbling. very much appreciated paul |
April 9th, 2008, 02:56 PM | #6 |
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Hey Paul, a good investment I bought with my steadicam was the steadistand. What it allows me to do is set my rig up on it. Leave it, and come back later and see if it is tilting and such. So you might want to look into it.
I have a very tricky setup because of the additions I have on the camera, so I've learned that more weights on the bottom are needed.
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April 9th, 2008, 05:07 PM | #7 |
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Hey Charles, got a question:
Should you do a preliminary Dynamic balance without the camera to see if everything is ok? Would you always want to do Dynamic balance with the proper drop time or would a short drop time be easier to adjust? Thanks, Dave |
April 9th, 2008, 09:19 PM | #8 |
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Gentlemen (and anyone else who might be reading this),
I just tried to dynamically balance one of our sleds equipped with a bottom mounted monitor we use for testing. I used the non-scientific ICS (Indicam Common Sense) method and it seemed to work. I first took the camera off and did a fairly fast spin balance to see is there was any wobble in the post showing uneven weight on either side of the post. Yep, there was with the monitor side of the bottom stage swinging out a bit. I adjusted the monitor distance in a little and retried. It was better. One more adjustment and then one more spin. Seemed to spin fairly smoothly without much wobble. The drop time of course was very short (bottom heavy) but this is covered in the next step. Next I attached the camera (Z1U) and did a 2 second drop time adjustment. I then used the horizontal balance test we demonstrate in our "Stabilizer Basics" training DVD (shameless plug). Made a few adjustments to the camera platform so that the horizontal balance was on and then tried a vertical spin test. Worked pretty good. I don't know if this method would work with other rigs but it did with ours. Anyway, it's worth a try as it is fairly quick and easier for us than the complicated methods we have read about. I'm sure there are conditions where the camera might have some strange configuration which might not work with this method. Hope this helps someone. Tery Indicam |
April 10th, 2008, 11:35 PM | #9 |
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Paul,
I have the AA version of the pilot and have been able to get dynamic balance. It took a bit of work and trial and error, but the balance seems pretty good. I agree with the recommendation of the purchase of a steadistand. It helps a lot for getting dynamic balance. |
April 11th, 2008, 05:16 AM | #10 |
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I should mention that i do have the steadistand and life is obviously a lot easier with it.
im up to eyes in post at the moment, so can't take it out for a spin. But what is everyone else doing about the monitor connection and the cable supplied with the EX. Are they wrapping it around the cam or have some other clever solutions? many thanks paul |
April 11th, 2008, 05:44 AM | #11 |
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I shortened the cable by tracing which wires went to which leads and left all but the yellow lead off/dead. It only took about 1/2 an hour. I did find that replacement cables are avail before making the surgery. googleing "sony proprietary composite cable handycam" did the trick.
part number VMC-15FS for replacement if you need as original. |
April 11th, 2008, 11:01 AM | #12 |
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Dynamic balance is becoming a bit of a hot topic in the small stabilizer world these days. It's probably worth mentioning here that while it is useful to have your rig in DB, if you are a beginning operator it will likely not make a tremendous difference unless it is noticeably out of whack, i.e. this is not the likely reason that your shots might be wobbly. I will also mention that I know a few great pro operators who have NEVER spin balanced in their lengthy careers and produce amazing worki.
Someone between this and Jerry Holway's comprehensive primer on the subject lies a large area that I encourage all of you to wade through without worrying unduly. If you happen to own a rig that has linearity issues in the gimbal, you will probably never achieve a flat spin no matter how you redistribute the weights. The Pilot is a nifty rig in that it gives you more control over dynamic balance than the Flyer. I used the Flyer just once in a high-profile situation and was unhappy to learn that I simply could not adjust the lower components enough to achieve dynamic balance with the camera in use. The thought at the time was that the users of a rig like this would not be inclined to "get under the hood" and mess around with their DB, but with the introduction of the Pilot, things have changed for the better. Doing a spin balance without camera does not prove anything unless the base of your sled is perfectly symmetrical, for instance a dual set of washers a la Glidecam/Indicam etc. Jerry's primer shows a simplified version of such a sled, where two equal masses form a "dumbbell" shape. Once you have a raised monitor at one end of the sled, the masses have begun to shift and the equation is only complete with the camera onboard. As the monitor's center of gravity raises above the battery, this drives the CG of the camera backwards and the battery forwards. While it "seems" like the logical thing to do is find the fore-aft CG of the sled, line it up with the center post and then put the camera on, this again will only work with a dumbbell shaped rig with equal masses front and back on the lower sled. But again, if you can get it close, don't worry. Chances are that until you get proficient at the spin, you are imparting as many "false" forces as the effects of slight dynamic imbalance. Git out there and git a-flyin'!
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April 11th, 2008, 11:09 AM | #13 |
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Charles,
Agree to that. Our system however has the monitor on the bottom plate taking the place of the weights on the front side of the bottom plate so it has that "dumbbell" type of configuration (opposing forces). I guess I should be glad I don't have to deal with the other types of monitor configurations. Looking forward to more on this topic. Life's easy. Tery Indicam |
April 11th, 2008, 12:44 PM | #14 |
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Hi Terry:
Even with the monitor mounted on the base, it's still not a perfect dumbbell--consider where the top-to-bottom CG of the monitor vs the rear weights falls. We are talking ounces here but with a small system that does factor into the equation. Speaking of small, I had the opportunity to weigh my rig the other day on set with the Panavision Genesis onboard--a grand total of 84 lbs (sled and camera 60, arm and vest 24)...oh boy.
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April 11th, 2008, 01:09 PM | #15 |
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Charles,
No wonder you couldn't work with that bad ankle. Was it broken or just sprained? Hope you're all better now and have lots of work. Even though our monitor is on the bottom and not a true "dumbbell" shape, the balance I did seem to work well. We'll have to delve into it more deeply when we get done with the latest run of Indicam PILOT systems. Lots of parts to assemble. Thanks for all the info you impart to the rest of us. Tery Indicam |
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