Hi all

I would like to clarify something with regards to rig stabilization.

On any sled system, is it more advantageous to have a longer post and balanced accordingly or a shorter post (also balanced) - what would each give you with regards to handling?

Not being an expert, my logical (I think) brain tells me that a longer post would bring about the bottom of the sled shooting out when you come to a stop - I think??

Sorry, for the basic question but I'm new to steadycam type rigs and want to get the basic correct.

Any help would be appreciated

Many thanks

The basic premise is one of weight and balance and how it relates to center of gravity. Borrowing from my pilot training, the further away from the center of gravity, the less weight is needed to bring about balance. Or, stated another way, the further away from CG you are, the less weight you need to affect the balance. In determining weight and balance for light aircraft, there is a reference datum that is the CG with all non removable equipment installed. Passengers, baggage, fuel, and engine oil are all calculated using the arm X moment from the reference datum. So, the longer posts on a stabilizer rig are essentially a tradeoff between usability and overall weight.

If you used a short post under the camera, more weight would be needed to balance the rig and would make it that much more difficult to hold up. So, a longer post is used with less weight. However, the post can't be so long that it drags the ground or becomes unwieldy to use, even though less weight would be required to balance the rig. Of course, the stabilizer rig isn't perfectly balanced or it wouldn't return to the vertical position when deflected. The idea is to bias the weight at the bottom to make the rig slowly (usually around 2 seconds) return from horizontal to vertical. The center of gravity should be the exact center of the yoke.

Hope this helps,

-gb-

Hi Greg

Thanks for the reply.

I have been able to balance the rig in both scenarios - both short post and long post without adding weight. This was achieved by moving the placement of the gimbal - hence my question.

I just want to hear from the experiences of steadycam type devices as to which option is the optimum - or is there any?

Jeremy:

Generally it is better to fly with a shorter post than an extended one. The reason for this is that the amount of intertia amongst the three axes is not distributed equally; the amount of mass that is displaced during a rotation in tilt versus pan indicates that there is much more intertia in the former. Thus it is good to limit the amount of this inertia by keeping the post shorter. This will result in a "faster" rig, i.e. more responsive, in that a diagonal move (pan/tilt combo) will be easier to achieve.

As far as the rig penduluming more with a long post, yes and no--the increased inertia will make it seem like it is doing this more because it is exerting more force and moving through a longer arc, but not in the same way as if you had added more weight at the bottom of the sled.

On a side note, it's best to avoid having too light a camera up top that requires one to slide the gimbal way down the post, the rig doesn't perform as well this way. Best to add weight to the camera to bring the gimbal back up, close to the camera.

Jeremy:

Generally it is better to fly with a shorter post than an extended one. The reason for this is that the amount of intertia amongst the three axes is not distributed equally; the amount of mass that is displaced during a rotation in tilt versus pan indicates that there is much more intertia in the former. Thus it is good to limit the amount of this inertia by keeping the post shorter. This will result in a "faster" rig, i.e. more responsive, in that a diagonal move (pan/tilt combo) will be easier to achieve.

Aha - now that answers my question. What you say makes extreme sense.


As far as the rig penduluming more with a long post, yes and no--the increased inertia will make it seem like it is doing this more because it is exerting more force and moving through a longer arc, but not in the same way as if you had added more weight at the bottom of the sled.

On a side note, it's best to avoid having too light a camera up top that requires one to slide the gimbal way down the post--the rig never performs as well as when the camera is close to the gimbal. Best to add weight to the camera to bring it back down.

I have had to add weight to the sled (my cam only being 2lbs) since the rig has been designed for for 5lbs and up. The reaon I bought it was so I CAN fly heavier cams in the future - but thats the future. At the moment I'm flying a Z1 for my own purposes. The gimbal at the moment is set very close to the sled.

I must also coin a phrase from another poster - I too have PROFOUND respect of you guys. This doesn't come easy but I refuse to give in and say its too diffucult.

I noticed that I had to move my butt forwards because the sled kept wanting to fly away from me. After a few minutes in the rig, I realised my Arny muscles are getting a decent workout for the first time in their lives - and a physio once told me sex was the best excersize for those muscles - but lets not go there!

Much appreciated you taking the time to advise on this one. I will become proficient and hopefully with advice from you fellows, I can become better in the end.

I will have to practise the basic moves to become proficient in that. What would you guys say is a good excersize regime?? Everyday for an hour or so or skip a day in between?

Again, many thanks

Jeremy, what rig are you using? Does it have an adjustment so you can change the angle of the arm, this adjustment will allow to you maintain correct posture without the sled flying away from you.

John.

Wow, I feel oblidged to respond to a thread with my name on it, but alas, all the good stuff has been said.

I will add that there is one other consideration when choosing a post length: As Charles noted, a longer post will no only 'push' the weights down, but also the camera *up* from the gimble. This can be used to your advantage if you want to raise the camera up higher. Somtimes you want a shot lookgin down from high up, teh solution is to add a lot of weight to the base, and then telescope the post up with a really light camera to get it up high.

Normally though it is in deed considered preferable to have a shorter post as noted, provided you can carry the wieght needed to do that - of course a lighter camera will need less wieght to balance it too - which is part of the beauty of the system and why the same idea works from the big Ultra all the way down to the Merlin for any camera!

- Mikko

Jeremy, what rig are you using? Does it have an adjustment so you can change the angle of the arm, this adjustment will allow to you maintain correct posture without the sled flying away from you.

John.
Hi John

I am using the Aviator from Varizoom since this was what I could afford at our exchange rate.

Alas no, it does not have an adjustment but I have thought that one out myself and plan to mod accordingly. Just need to find the correct way of doing it without messing it up. An engineering shop will have to help out here but I don't consider myself an idiot with mechanical devices.

If anyone has ideas, a possible diagram on how to achieve this, I would appreciate it

Wow, I feel oblidged to respond to a thread with my name on it, but alas, all the good stuff has been said.

Normally though it is in deed considered preferable to have a shorter post as noted, provided you can carry the wieght needed to do that - of course a lighter camera will need less wieght to balance it too - which is part of the beauty of the system and why the same idea works from the big Ultra all the way down to the Merlin for any camera!

- Mikko
I feel good that you are obliged :)

Its nice to hear comments and opinions from different users in the field.

If I refer back to one of my previous posts, you did mention that a unit was available from Steadicam at the same price as to what I paid. However, after I called them telephonically, I was told I had to purchase via a dealer and no dealer I spoke to (telephonically) wanted to match the price for the used item! So i was forced to follow the route I did. And any other model in the range just put me over the top after throwing in the exchange rate (1:6 !!!).

So, I have the Aviator and even if it means me having to spend a bit more local dollars to achieve the ultimate. It will be a dang side cheaper than spending dollars - no offence to our US friends! I must add that I'm not sorry I bought it - if there are a few mods I have to do to make it better - I will. By the same token, it will make me one of the few operators in Cape Town (there are no registered SOC's in Cape Town) let alone rig operators that I am aware of. There aren't even any to rent!

I have already thought of a "spacer" cut at a slight angle to match the base of the connecting pin (where the arm connects to the vest) to angle the connecting pin slightly towards me - hence changing the angle of the arm and causing the arms and rig to be more "neutral".

If you have other ideas, they would be appreciated.

Jeremy,

Good questions and discussion. Sorry I couldn't get in earlier but I've been building.

I wish Charles had held off in giving his comments because when he speaks-that's it! What else needs to be said?!

From the pictures I have looked at of the Aviator I can't see where the arm hooks into the vest so exactly how to alter that angle is hard to tell. It sounds like you have a fairly good grasp of stabilizer principles and should be able to make some slight adjustment to bring the rig "in" a bit.

My added take on the longer post-shorter post thing is a longer post seems to get in my way more in that my legs can bump into the bottom plate easier. Everything can be overcome by practise but I like the shorter post best. I like it better as well because I can keep all the weights on the bottom plate which gives the rig more inertia and hence more stability. It makes the sled a bit heavier but the better picture is worth it. After all, that's what we're after right?

Tery
Indicam

On a side note, it's best to avoid having too light a camera up top that requires one to slide the gimbal way down the post--the rig never performs as well as when the camera is close to the gimbal. Best to add weight to the camera to bring it back down.

Hi Charles,

I was wondering if it was a typo to say that it is not good for the camera to be close to the gimbal? Because it seems to contradict with the rest of your statement (adding weight to the camera brings the camera closer to the gimbal, no?)

I am not sure if I am misunderstanding or not.

I am new to all this and am trying to learn as much as I can. I am a recent proud new owner of Terry's Ind!cam Pilot :)

I had a similar question as to whether it is better to have a heavier sled with the gimbal lower on the post or a lighter sled with the gimbal higher on the post. Or what is a good balance/ratio? What is a good general placement of the gimbal (i.e. 1/3 of the length of the post)?

Thanks!

Hi Peter,

Good place to ask questions to the best group of stabilizer users on the web. Mikko is a good one for info as well. There are others I could name but the list would be too long!

I'll be seeing Mikko next week.

Tery
Indicam

Peter,

Thank you for drawing my attention to that--it wasn't clear, so I have reworded it in my original post.

There's no hard and fast ratio, but you shouldn't have more than three or four fingers worth of room above your gimbal, let's say that 3/4 of the post should be showing below the gimbal. If you like a more inert feel, add weight to the top and the bottom of the rig to beef up the load, maintaining the minimal amount of post above the gimbal.

One of the things that I find a little baffling about many DV-sized sleds out there, particularly the single section arm rigs, is that the camera almost always flies below eye level. On the big rigs we are able to slide in different length arm posts (that make the connection between arm and gimbal) to accomodate situations where you need to fly the camera higher, or lower. I admit to being a bit more intensive about this than some, as I have a total of 5 posts that give me a 24" offset in booming range, but I use all of them pretty regularly (my recent show with Jeff Goldblum forced me to regular mount the 18 inch "manmaker" to combat the 9" difference in our respective heights!)

I imagine this will be likely addressed in future generations of rigs, just as the adjustable pitch arm mount has been of late.

Thanks, Charles, for the clarification. Also, thank you for posting your clips on steadishots.org. Are there any clips of you at work (instead of showing the end result of your work)? That would be very educational :)

Also, can you explain the reasoning of why it is better for the weight side of the post to be longer than the camera side of the post?

I understand the reasoning of more weight = more inertia but if the system is balanced and the torques around the gimbal match, why does the length matter?

And does this mean, in your example, that when you utilize your "manmaker" posts, that you lengthen the bottom in proportion to the new height of the camera placement? How do you avoid kicking the post with our knees or getting tangled up in it?

Thanks for your kind replies,
Peter

I can't think of the physics right now but the tactile sensation is such that it feels better to have the camera closer to your pivot point (gimbal). Also, the lens is that much closer to operating nodally, meaning that the further the camera mass is placed from the gimbal, the greater an arc it must make during tilts.

The extended arm posts simply elevate the position of the rig relative to the end of the arm. This shifts your usable boom range overall. I also use a J bracket that drops the position of the rig a few inches, which is helpful when shooting as low as possible in high mode.

Once one gets used to flying a Steadicam, it is very rare to knock into the sled, you gain a sort of 6th sense about its position and can maneuver it within an inch or two of your body without hitting it.

One of the things that I find a little baffling about many DV-sized sleds out there, particularly the single section arm rigs, is that the camera almost always flies below eye level. On the big rigs we are able to slide in different length arm posts (that make the connection between arm and gimbal) to accomodate situations where you need to fly the camera higher, or lower. I admit to being a bit more intensive about this than some, as I have a total of 5 posts that give me a 24" offset in booming range, but I use all of them pretty regularly (my recent show with Jeff Goldblum forced me to regular mount the 18 inch "manmaker" to combat the 9" difference in our respective heights!)

I imagine this will be likely addressed in future generations of rigs, just as the adjustable pitch arm mount has been of late.

Charles,,

Got one of those for my rig and it has been nice. It raises the rig from about 12" to 18". It's in the Video Demos - CES - High Shot section of my web page:
http://www.indicam.com/index.php?option=com_content&task=category&sectionid=9&id=28&Itemid=57

I'm bringing the extension with me so if I get a chance to chat with you I will ask you about it's correct use. I made it for getting "basketball player" type shots. It gives a different perspective that I like. You know, another tool in the arsenal.

Tery
Indicam

Thanks, Charles, for the clarification. Are there any clips of you at work (instead of showing the end result of your work)? That would be very educational :)

Hi Peter,

I think most ops have a personal library of some behind the scenes footage of themselves. However, the exposure Steadicam gets on behind the scenes footage of the large productions is much smaller. Watching the DVD bonus features, you'll almost always see a Steadicam Op off to the side, or fly through frame for a second or two. Rarely is it more than that.

A few DVDs do come to mind though. "Nine Lives" is, without a doubt, one of the best when it comes to featuring Steadicam. They even interview Dan Kneece and Henry Tirl. A few of these can be seen on my site, but there is much that I did not include. "The Shining" is a good one since it shows Garrett in quite a few shots using the rig which was still rather young at that point. "The Missing" has a couple quick shots of Will Arnot, all covered in body armor and face masks - protecting him from the desert dirt.

As for Charles, I'm sure he could give you the full list. There are a couple quick clips of him on "Scrubs". To trump all that, however, he was a featured extra in one of the episodes! By the way, Chas, Jim Bartell actually pulled that clip and sent it over to me to post on SteadiShots. Let me know if you are critical of your performance and would rather it not be posted. I think it, along with a growing number of these other steadi-related clips, will go into a new section all their own. Stay tuned.

Best,
Afton

Hi Peter,

I think most ops have a personal library of some behind the scenes footage of themselves. However, the exposure Steadicam gets on behind the scenes footage of the large productions is much smaller. Watching the DVD bonus features, you'll almost always see a Steadicam Op off to the side, or fly through frame for a second or two. Rarely is it more than that.

A few DVDs do come to mind though. "Nine Lives" is, without a doubt, one of the best when it comes to featuring Steadicam. They even interview Dan Kneece and Henry Tirl. A few of these can be seen on my site, but there is much that I did not include. "The Shining" is a good one since it shows Garrett in quite a few shots using the rig which was still rather young at that point. "The Missing" has a couple quick shots of Will Arnot, all covered in body armor and face masks - protecting him from the desert dirt.

As for Charles, I'm sure he could give you the full list. There are a couple quick clips of him on "Scrubs". To trump all that, however, he was a featured extra in one of the episodes! By the way, Chas, Jim Bartell actually pulled that clip and sent it over to me to post on SteadiShots. Let me know if you are critical of your performance and would rather it not be posted. I think it, along with a growing number of these other steadi-related clips, will go into a new section all their own. Stay tuned.

Best,
Afton

This is from memory but I think it was "My blind date" part 1 that Charles featured in, correct Charles?

John.

That wasn't me, that was "MRI Tech (Uncredited)". Looks a lot like me, though...(sure, go ahead and post).

That wasn't me, that was "MRI Tech (Uncredited)". Looks a lot like me, though...(sure, go ahead and post).

DOH! I thought that was you :D

John.

I can't think of the physics right now but the tactile sensation is such that it feels better to have the camera closer to your pivot point (gimbal). Also, the lens is that much closer to operating nodally, meaning that the further the camera mass is placed from the gimbal, the greater an arc it must make during tilts.

That makes sense. Also, if you get the pendulum effect (for beginners like me ;), the closer the camera is to the gimbal, the less the pendulum will affect your footage since it is a smaller arc.

The extended arm posts simply elevate the position of the rig relative to the end of the arm. This shifts your usable boom range overall. I also use a J bracket that drops the position of the rig a few inches, which is helpful when shooting as low as possible in high mode.

Yeah, I guess it doesn't apply to me, then, since I only have the sled, which is a forearm and back killer, by the way(!) I'm just trying to hold it and walk around with it whenever I can so that I can build up those muscles... Any suggestions to reducing the strain? I know Terry recommends using a tennis elbow elastic band.

Afton, thanks for your steadishots.org site! It's great to be able to see the masters' work. I just need to find resources that help me to learn how to create footage like that ;)

Thank you all for your help and input! I am so thankful for this forum.
:-Peter

Peter,

I'll jump in again. More good questions.

The following refers to the DV camera type of stabilizers like Peter has and not the big guys.

Anything that helps a "sled only" user to operate easier and longer is a good thing. The Ace Tennis Elbow Brace (207288) is a cheap way to extend operating time. Glidecam sells their "Forearm Brace" and it helps to extend shooting time even longer.

If you are really serious about stabilization though you're going to end up with a body mounted support vest and arm. The more I test the PILOT sled without it's support system (flying a DVX-100a ) the more evident it becomes. Any similar sled i.e. Glidecam 2000, 4000 will have the same stress factors as well.

It sounds kind of like a sales pitch for a vest and arm but it needs to be said. This is the only way I know of that can change the operating strain to something very managable. A vest and arm combination makes a HUGE difference. You can use it for hours and not just minutes. At least that is what I have experienced.

There are a number of vest and arm support systems available for the smaller handheld sleds which are interchangable. Varizoom, Glidecam, Indicam, M516 are some that come to mind.

Tery
Indicam

Ok here's an update to where i was when I started the thread. My unit comes with a neat trolly case so I was thinking about packing up/taking out and setting up again. In order for the unit to fit into the case, the post needs to be at its shortest adjustment so I got to think a bit.

So, I decided to set the post at its shortest. This was fine until I put it back up to balance the sled - hmmmm - top heavy!! I added two small weights (supplied) to the bottom of the sled and balanced again. The gimble propably had to move about 15cm to get a dop time of between 2-3 secs.

And would you know, the rig is much easier to fly and I've gone from swinging like a dead cat to some really smooth shots (for my level of expertise anyway). The monitor is now at a more viewable level and the rig stays closer to me as well without wanting to fly out. I must add on this point that there is a very simple adjustment for middle-aged men like me - its called a paunch!! By raising the vest slightly, yours truly's gut auto adjusts the angle of the arm in relation to the vest. Who says beer don't have its advantages!!!!

Only problem now is that at the rate I'm practising, the gut ain't going to be there much longer and the physio is going to be impressed with my Arnie muscles in the near future! My wife did comment as well that my posture had improved!!! There's life in them bones yet!

I'm going out tommorrow to shoot some test footage so I'll try and post something later tommorrow if I'm not too embarrassed.

Ah Jeremy--I too once thought that operating a stabilizer would keep me lean forever--somehow it doesn't manage to work that way (unless one is running up and down the sidelines of a soccer pitch 4 times a week, that would do it)!!

Glad the rig is feeling better to you.

Shoot me for wishfull thinking Charles:)

I'll stay in bleachers - running up and down with a rig for an hour or two doesn't seem to appeal to me!