October 5th, 2004, 01:25 AM | #31 |
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side-to-side jitteriness
Roger,
Thanks for the info. The before mentioned videos were done before I found out that the designer of my sled used a "sealed" bearing instead of a "shielded" bearing. I don't know if you know the difference so I'll explain. (If you do know...please excuse me as maybe someone else might not) A sealed bearing has a plastic cover that covers completely the bearing from inside to outside. It is used in contaminated environments on systems that rotate very quickly. The friction that the seal creates isn't very large and is negligable for its' design. Unfortunately this "very small" friction is way too much when used in a steadycam type system. A shielded bearing, on the other hand, usually has a metal shield that covers from the outside ring of the bearing to "almost" the inside. It stops short of touching the inner ring and therefore doesn't have the friction of the sealed version. This is what the designer of my sled should have used. The rest of his design was good. I fixed the problem on this sled by cutting just a bit of plastic material away from the inside area where it was touching as well as by adding some oil to loosen up the thicker lub that was there. Yes, it did make a big difference in the bearing and gimball's smoothness. I couldn't figure out why I was seeing this jerkiness while using the new sled. I tried changing around many things on my arm but to no avail until I came upon the real problem. I really need to redo all the demos on my web site to show the "new and improved" video. I was walking on uneven ground for both of the videos you saw as I feel it was a better test. It does make it harder to shoot smoothly though. Now, regarding you comment (Perhaps experienced steadicam ops learn to shift the arms ahead of the legs during those figets so the frame doesn't oscillate in the opposite direction every 2 seconds of a long tracking shot.) This is what the gimball and other arm bearings are suppose to take care of. The large Steadicam systems (and others like the MK-V etc.) have such a large mass they float that outside movement is greatly masked. Of course they are engineered extremely well to do this and the price they charge is worth it. Anyway Roger, it's time to buy a good camera and stabilizer so you can enjoy first hand creating terrific video. Thanks for the info. I'll work on the demos. Terry |
October 5th, 2004, 10:05 AM | #32 |
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What is being discussed here as "fidgeting" is mostly what we refer to at the Steadicam workshops as "overcontrolling" aka "operator error". It's a tendency for nearly all newcomers to the stabilizer world to apply too much force to the rig, which means that their body movements are translating into the frame. The best way to isolate this as a comparison is to line up the rig with a good target in the frame (shooting straight down a hallway with an identifiable object at the far end works well), then take a slow, even stroll towards that object. Tape your results. Now, do the same thing again, but this time, once you have taken a few steps, keep walking but slowly lighten up your touch on the post until you are actually not making contact at all.
Two things may be observed here. One is, did the rig start to pan by itself? If so, this is an indication that you have friction or non-linearity in your gimbal (possibly for the reasons that Terry described). This is not uncommon in lower-end stabilizers. This means that you will always have to keep a certain amount of "touch" in place on the post to keep this from happening, which is unfortunate because this makes it a bit harder to get the hang of not over-controlling. If however the shot actually improved once you took your fingers off the post, i.e. the "fidgeting" minimized and everything became smoother, this is an indication that you are indeed over-controlling. Ideally, if the rig is properly balanced and the performance of the gimbal is good, you can move at a constant speed and the camera will stay pointing dead ahead with perfect stability--with NO OPERATOR INTERACTION. Now, I'm not suggesting to operate the rig with no hand on the post, but keep that concept in mind, and use the fingertips in the absolute lightest way possible. It's only when accelerating or re-aiming the camera that you need to start using a bit more touch, and even then you only use it when you need it. If one were to transform into a fly and buzz around a good Steadicam operator's post hand during a shot, you would see that the fingers are barely in contact with the post--many operators engage in an intricate flurry of "on--off--on--on--off" behavior with the fingers, with "off" being barely a 1/4" from the surface of the post. In the material that Terry posted, the side-tracking shot in the field is a perfect example of the kind of shot I described. Once you get going (acceleration and deceleration require more finger attention to keep the fram level), you should need very little touch to maintain that shot. The "fidgeting", the rolling horizon, all of that is due to over-controlling. (you did fine, Terry, I'm not bashing your work. It takes a LOT of practice to work through all this stuff). The irony of DV-sized rigs is that they are actually harder to maintain a "steady" image because of their smaller mass. Certainly easier to wear for longer periods of time, but they require a correspondingly lighter touch. I've seen a few intrepids who have "graduated" from mastering the smaller rigs to finally getting a chance to strap on a big rig. The first thing they notice, other than the "holy cow, that's heavy!" factor, is that the rig feels so much more stable, more inert. It takes more force to make a fast pan or tilt (and more force to stop it). And yes, the rig will tend to keep itself level better. There's no free ride with Steadicam...!
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October 5th, 2004, 12:58 PM | #33 |
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fidgeting
Hi Charles,
Thanks for the input. I know what I'm going to do now. I'm going to rent a dolly and do some shots and say they were steadycam shots. Ha ha. Anyway, I wonder if there is a good, balanced, linear Gimbal out there for a decent price. I have the problem you talked about with non-linearity and as the one shot was a tracking shot I had to keep myself in it. I have used the larger rigs and they are just as you described: quite heavy but very stable. I loved how easy it was to shoot nice footage but did have the problem of over controlling due to my practise with smaller, non-linear sleds. While sort of on the topic of demo shots, I need to find the area where size and quality of video on the web is discussed. My file is a 10 meg MPG and short compared to some other ones I have seen. I haven't had the time to really search the web for info on this as well as streaming video. I would like to stream video instead of having to have it downloaded. Any comments? FYI Charles, I just talked with John from Animagique and he metioned all the improvements he has made to his stabilizer. He said he appreciated your input and help. Hopefully I will be able to meet you in the future and glean from your experience. This forum is good but in person is even better. Are you coming to N. California any time soon? The next time I'm anywhere near your area is in Jan at the WCES and later at NAB. Terry |
October 6th, 2004, 09:59 AM | #34 |
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Charles, that was such an excellent explanation you provided about the reason "fidgeting" happens. It helped me avert disappointment and frustration. I was planning to get a glidecam 4000 + bodypod + xl2 but I now think something with more mass would serve me better, the v8 or the v16 - or a DIY version thereof. The cost of retail or even used is prohibitive, so I will have to make my own or like Terry, have a friend help me along.
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October 6th, 2004, 10:48 AM | #35 |
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It's absolutely possible to make good shots with the lightest stabilizer out there. One has only to watch the Steadicam JR demo tape and see what Garrett Brown was able to do with that featherweight setup.
Certainly more mass makes for an easier job at hand, but of course it means more weight which can affect one's stamina for long shoot days. Generally it is better to get a rig that you can grow with; build your camera with all of the potentially needed accessories (wireless mikes, onboard lights, mattebox etc) and weigh it, and then look at the specs of the rig you are considering. I think it safe to say that the XL2 could easily tip over the 10 lb mark, putting you into V16 territory. Terry: Don't know when my next trip up north will be. I'm hoping to make NAB this year (with any luck, pitching that stabilizer tape!).
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October 6th, 2004, 05:17 PM | #36 |
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light vs. stable
Charles,
I absolutely agree with you that lighter stabilizers can and do take great shots. I've actually been accused of a few of them. My problem is that I'm in the area of camera and stabilizer heavy enough that I really don't want to hand hold it for long. Now, with that problem comes another problem...a support system that takes the weigh off of your wrist and arm and puts in on your body. All this without causing its own set of problems. As you know from being an accomplished Steadicam operator, the arm can get in the way sometimes such as in tight spots like doorways. It's amazing steadycam operators can do the things they do! In developing a good support arm it has to be as compact (no long arms) and frictionless as possible. It's quite a chore to make one that fits the bill. Regarding sleds...I suppose we will have to develop our own sled as the ones we presently use have some very good characteristics but also some annoying ones. I'd like to combine all the good points I have seen and eliminate the bad ones without stepping on any design toes. By the way, I believe the Steadicam patent has lapsed (talking with Garret Brown himself) can we designers use whatever is out there or do we have to reinvent the wheel? Ok a good question...What is the difference between a patent, a copywrite, and a trademark? I have studied all of these but I'd like some more clarification. Is that a discussion that's covered elsewhere on this site? Thanks for your input! Terry |
October 7th, 2004, 12:10 AM | #37 |
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stabilization systems
Roger,
We are lucky to have Charles as a resource. I tested many (all I could find) stabilier systems at NAB this year so I could be informed on how well they worked and how they felt. I did this because I had already designed and built a vest and arm system for the handheld Glidecam systems (1000, 2000, 3000, and 4000 pro) as well as the VreezeCam stabilizer and wanted to know how it compared to the big guys. I tried the: Steadicam JR, Mini, and Flyer (wow engineering!) Glidecam V8 and Gold Series (from small to large systems) MV-V for large cameras (Howard is a great guy and his stabilizers uncompromising) Hollywood Lite-now owned by Varizoom (comfortable-I liked it) A German stabilizer-name I can't remember (good rigs) Varizoom monopod stabilizer (unique-good utility) I knew a quick demo couldn't give me a real feel for the product but I did get some initial impressions. As Charles has said concerning camera weight...It will decide on which stabilizer you should use. An XL2 wouldn't be as happy on a V-8 as it would on the V-16. I put these stabilizers into four different weight classes depending on the cameras they could fly: lightweight (all the newer real small cameras), medium lightweight for the DVX100a, GL2, VX2000 and 2100-TRV950, GR-HD1 etc. medium weight (XL-1 and XL-2 etc.). and the heavyweight systems for large video and film cameras. I'm sure the heavyweights can be broken down even more but since I was more interested in the lighter camera stabilizers I didn't give them as much attention. I do know that a support system (vest and arm) can make a big difference in fatigue levels. I carried my camera around all day on my stabliizer at NAB and didn't have to go the the hospital.. Actually I felt fairly good...a bit sore in the lower back area but not too bad. Conclusion: There are a lot of good to great stabilizers out there with prices that seem high until you try to make one of your own. Terry |
October 7th, 2004, 01:12 AM | #38 |
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Terry:
<<, the arm can get in the way sometimes such as in tight spots like doorways. It's amazing steadycam operators can do the things they do!>> We have a few tricks with the arms to squeeze in through tight spaces! Yes, the basic patent has expired on many of the components. Currently I think the predominant patent is on the isoelastic arm. It sounds like you've tried the Flyer, so you know what an achievement that is. <<heavyweight systems for large video and film cameras. I'm sure the heavyweights can be broken down even more but since I was more interested in the lighter camera stabilizers I didn't give them as much attention. >> I would separate them as follows: medium to full size video cameras plus 16mm cameras for one class of rig; film-style HD and 35mm cameras for the top class of rigs (also featuring more power/video breakouts to accomodate multiple accessories). One of the nice things about owning a modular top-end rig is that it can be stripped down to fly virtually any camera. The PRO arm has an incredible lift range from 13 to 72 lbs (achievable by swapping spring canisters, an easy changeover). The beefy vest is a bit of overkill at that point, but who cares?
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October 7th, 2004, 10:58 AM | #39 |
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reworked the sled
Charles,
I took two sleds (two different suppliers) and made them into one real good sled-the best of both. I static balanced it and then checked for the infamous drift when panned 180 degrees. Guess what-only very small drift. Did the dynamic spin balance test and it looks good. Now if I would just get the guys to sell me only the parts I wanted. I then took it out for a test drive. Very nice! The suggestions you made were helpful. I did the long hall (not long haul) exercise and also took it out on uneven ground. Very smooth again. I'm going to redo my web's demo videos and let you know when they're done for a look see. I should take a couple of days, as my model is unavailable at the present time. Terry |
October 7th, 2004, 12:05 PM | #40 |
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Hello everyone,
Here is my new GS400. The file is around 8mb encoded with divx. http://www.salenz.com/movie/gs400demo.avi Using JVC GY-DV5000U with FUJINON S20X6.4BRM-SD lense. You may need to download latest divx decoder from www.divx.com Thank you for your time to read my message and I look forward to hearing from you. Regards Leigh |
October 7th, 2004, 12:21 PM | #41 |
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Leigh:
Keep working at it, I'm seeing improvement! The first shot, walking straight in at the camera, is one of the best exercises you can do. You can substitute an X on the garage door for your nice new camera as a target. Try putting a corresponding x on the middle of your stabilizer's monitor (make sure to use a dry-erase marker or use a clear overlay, don't mess up your monitor) and then walk in and out trying to keep the x's on top of each other. Make sure to include some stops along the way and hold that frame steady! Walk all the way in, stop for 5 seconds, then back out, and repeat ad nauseum. Then, try zooming your camera in halfway, and repeat the exercise. It's much harder, but once you've done that for a while, go back to the wide angle and do it all again--you'll find that you've become a whole lot smoother than you were at the beginning of the practice session. The slower you move, the more challenging this all is--so try to move as slowly as possible. It's fun to go rushing at things (like in the last shot) but it is more critical to the technique to move slowly. As I was saying earlier, try doing a version of this where you aren't holding the stabilizer by the post at all. See if that is much smoother, has less floating etc. If so, think about what you might be doing that is causing the float. Also think about your footwork, try to move in a flowing fashion (on the section that you were circling the camera, I "felt" the lurching of each step). Think of yourself as a dolly, moving in a perfectly smooth and steady fashion. Like I said, keep it up!
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October 7th, 2004, 12:37 PM | #42 |
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Dear Charles,
Thanks for the hint. Regards Leigh |
October 7th, 2004, 03:32 PM | #43 |
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newest video
Leigh,
I just watched your latest video. They are getting more interesting to watch. You are also moving around which is good. I'm sure glad I can go to school on your video and Charles' comments and exercises. I really like the quality that DivX gives your shots. Maybe you could go over the steps that you go through to get your video into the DivX format. I'd really like to do the same. You have 52 seconds of larger format video in a 7.3 meg file whereas I have 20 seconds of fair quality video in a 10 meg file size. It isn't fair so I'm switching. Your help would be appreciated. I'm going out and practise my "X"ercises as suggested by Charles. Looking forward to your next post. Terry |
October 7th, 2004, 03:41 PM | #44 |
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Re: newest video
<<<-- Originally posted by Terry Thompson : Leigh,
You have 52 seconds of larger format video in a 7.3 meg file whereas I have 20 seconds of fair quality video in a 10 meg file size. It isn't fair so I'm switching. -->>> Hi Terry, That is the reason I love divx format. But video quality is little down grade compare to mpeg2 format. I can't afford to put highest video quality on my website in terms of money and video download time. Regards Leigh |
October 7th, 2004, 04:24 PM | #45 |
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DivX
Leigh,
So.....how do you do it or is there a tutorial on the DivX website? I'll check but hearing from you would be good to. Terry |
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