Glidecam/Steadycam Question

[Buba Kastorski]

Originally Posted by Charles Papert

How do you adjust for side-to-side trim?

I wonder too,
without that 'crap'?

[Craig Terott]

Originally Posted by Charles Papert

How do you adjust for side-to-side trim?

Originally Posted by Buba Kastorski

I wonder too,
without that 'crap'?

I have no need to ever trim in side-to-side direction. The release is positioned so that the cam is perfectly balanced side-to-side. A different lens requires front to back adjustment only, which I do on the fly because there's enough play/slack for the release plate positioning within the release.

[Noa Put]

When I change lenses on my 550d/blackbird (I use a canon 10-22 or a Samyang 14mm) I have to make adjustments sideways each time to get it balanced again so in my case your solution would not work.

[Craig Terott]

Hi Noa,

I assure you the only weight imbalance from one lens to the next is front to back, not side to side. Cylindrical glass and the cylindrical components around it are not appreciably heavier on one side than the other. And because the outer part of the lens is so close to the center axis of the lens (in proportion to the entire load above and below the gimbal) this marginalizes the impact if there is, hypothetically, a weight difference from one side of the lens the other. So what's the reason for your re-balancing? I think there's a good chance that if I had your glidecam in front of me I could prove to you it's not 'perfectly' balanced side to side. As a test, I attached 6 different lenses to my cam and it balanced perfectly side to side with all of them.

[Buba Kastorski]

Originally Posted by Craig Terott

A different lens requires front to back adjustment only

that is not true, I certainly wish it was that way, and I could adopt your less complicated setup, but unfortunately, I need to keep "that crap" for side to side adjustment

[Craig Terott]

Originally Posted by Buba Kastorski

that is not true, I certainly wish it was that way, and I could adopt your less complicated setup, but unfortunately, I need to keep "that crap" for side to side adjustment

Hi Buba,

I attended a conference with guest speaker Joe Simon, who took the time to demo his gear. He demonstrated how quickly he can swap lenses on his glide, and (as I expected) going from one lens to the next he made heel n toe adjustments ONLY.

This is because, if you divide any lens in half along it's long (front to back) axis, the weight of each half will be nearly identical. The (hypothetical) imbalance (if measurable) is so close to the lens axis in proportion to the load above and below the gimbal it would have a negligible effect - something in proportion to taping a penny to a bowling ball.

If you are making side-to-side adjustments from one lens to the next, it's more likely that the lighter of the two lenses is masking the imperfect side to side balance you have to start with. If I had your glidecam in front of me, I think I could prove that you don't have perfect side to side balance to begin with.

[Craig Terott]

I do see a small flaw in my argument if you had a significant weight difference between lenses since the lens axis and the camera axis are offset. But real world, I switch lenses and don't see or feel any difference, at least with the lenses I glide with which are all very close in weight.

[Buba Kastorski]

Originally Posted by Craig Terott

Hi Buba,
I attended a conference with guest speaker Joe Simon, who took the time to demo his gear.

Joe Simon? Damn, I missed that!

Originally Posted by Craig Terott

If I had your glidecam in front of me, I think I could prove that you don't have perfect side to side balance to begin with.

thank you Craig,
even though I am not even advanced steadicam user, but at least i know how to balance
when your have perfect balance and your drop time is around 3 seconds just a few gramms will through your rig out of it;

Originally Posted by Craig Terott

I do see a small flaw in my argument if you had a significant weight difference between lenses since the lens axis and the camera axis are offset.

aha! now we're talkin :)

Originally Posted by Craig Terott

But real world, I switch lenses and don't see or feel any difference,

if it works for you that's great, but what if you need to use different camera, or you add/remove some accessory, of course it is only my opinion, but fixing mounting plate to the central post is not something I would do , or recommend to anybody;
AND, i need side re-balance switching from 14mm to 24-70mm

[Charles Papert]

I have yet to see any stabilizer, big or small, of any brand, that didn't require minute adjustment in either lateral axis throughout the course of the day. As I recall, the handheld Glidecams require one to add weight or lower the center post rather than adjust the gimbal when rebalancing. This changes the weight ratios of the system significantly and it's unfathomable to me that it wouldn't require fine side to side adjustment, especially since (again, by memory) the Glidecam posts aren't indexed or have a keyway so it's possible for the lower section to be rotated very slightly out of square any time you adjust the length of the post.

With as low a payload as a DSLR, fine tuning of balance is exponentially more critical. I never used a small stabilizer of any type that didn't require constant fine-tuning. Any sized stabilizer, for that matter.

[Craig Terott]

Originally Posted by Buba Kastorski

Joe Simon? Damn, I missed that!

He demonstrated how fast he can swap lenses. I can't remember what he switched from and to but in about 8 seconds he detached a lens, attached another, made a heel/toe adjustment, done.

Originally Posted by Buba Kastorski

when your have perfect balance and your drop time is around 3 seconds just a few gramms will through your rig out of it;

Not referring to drop time. Referring to perfect balance side to side.

Originally Posted by Charles Papert

I have yet to see any stabilizer, big or small, of any brand, that didn't require minute adjustment in either lateral axis throughout the course of the day.

Are you making adjustments throughout the day with the same lens? I don't understand why. Either it's balanced or it's not balanced. The camera doesn't get heavier on one side as the card fills up. :) Maybe your adjustable plate assembly is slipping?


I am curious Buba, is your Glidecam balanced so the lens is at a slight downward angle?

[Craig Terott]

Originally Posted by Charles Papert

it's unfathomable to me that it wouldn't require fine side to side adjustment

Fathom it. I just weighed my lenses on a 0-5lb digital postage scale. Sigma 20mm (with clear filter) = 1lb 3.3ozs. Rokinon 14mm = 1lb 3.4oz. I held the glide parallel to vertical site level and I see no difference between the two.

But really, instead of shooting down the whole concept Charles... let's say the side adjustment is major for whomever is considering the modification... slot the two holes and use wingnuts - problem solved. They could even take it a step further and scribe a line to mark the position for each lens so there is no guesswork when they are run and gun. Now you can highly recommend it. lol

Incidentally, removing the top plate not only reduces some weight (fatigue) - it adds more capability to glide low to the ground because the handle is not obstructed by an over-sized adjustable assembly.

[Noa Put]

Fathom it

Craig, I can only speak from my experience with my blackbird steadicam but just to see how your claim works in my case I just set my steadicam up and balanced it with a canon 10-22mm lens, I don't have my samyang 14mm with me now as it has been send in for repairs but for test purpose I used my samyang 85mm, it's about the same size but a bit heavier then the canon, same as for the 14mm from samyang which also wheighs more.

For the canon lens I only had to use 1 big wheight on each side of the horizontal tube (couldn't get it to balance with 2 wheights which is also because of my very light 550d), I balanced it perfectly side to side and front to back, then I placed my 85mm on and front to front adjustment did not help at all because the drop time had been affected meaning I had to add 1 additional small wheight on each side and I had to reposition the vertical tube in order to get my 3 sec drop time again. Once that was done I balanced front to back and side tot side (which I didn't touch) it was a few cms off so I had to rebalance quite a bit.

So like I said earlier, your claim does not work at all with my steadicam, it's not just a matter of switching lighter with heavier lenzes and just adjusting front to back on the top plate only but since the drop time is affected as well that is just not possible.

What type of glidecam are you using ?

let's say the side adjustment is major for whomever is considering the modification... slot the two holes and use wingnuts - problem solved.

Even better, why not weld together your own steadicam, who needs that presicion mechanics anyway ;) Just the slightest turn of the knob on the side of the topplate of my blackbird and it's off balance sideways and that's just a micro adjustment. I can balance my blackbird quite quickly but I do need those micro adjustment capability to balance it perfectly.

[Noa Put]

Ok, another go, this time I exchanged the 85mm samyang with a 17-85mm canon, the canon was just a little bit more front heavy so I did not have to change the wheights and droptime was still ok but after balancing from to back to front, side to side balance was off, not much but needed to turn the side knob a quarter to get it right again, then went back to the samyang and same scenario.

So for me at least your trick does not work.

[Jonathan Lau]

Can you take a full photo of your stabilizer or tell us what brand it is? Having used both a Merlin and Glidecam I have never been able to balance it WITHOUT side-to-side adjustments...even the act of placing your camera on the QR plate would cause some balance issues each time you put it on, unless you're amazing and can get it to the exact perpendicular angle to the body of the camera every time you take it off and put it back on...

[Craig Terott]

Originally Posted by Noa Put

Craig, I can only speak from my experience with my blackbird steadicam

What type of glidecam are you using ?

Hi Noah,

My post is specific to the Glidecam. I posted a picture of a Glidecam. I used the word "Glidecam."

If I had a Blackbird I would NOT remove the adjustable assembly because it's already a small compact design - there's nothing to gain.

The difference is that the Glidecam's upper assembly is massive/bulky.

Originally Posted by Noa Put

Even better, why not weld together your own steadicam.

I'll gladly take what Glidecam offers and customize it.

Obviously, removing a top plate assembly and refitting with a release plate is no where in the neighborhood of the expertise/materials required to design a complete gimbal system.