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-   -   Everything you wanted to know about the Steadicam Merlin... (https://www.dvinfo.net/forum/stabilizers-steadicam-etc/64062-everything-you-wanted-know-about-steadicam-merlin.html)

Mikko Wilson September 21st, 2006 02:26 AM

It is in development, I don't know when it will be ready though.

- Mikko

Phil Bloom September 23rd, 2006 08:18 AM

merlin help
 
Hi.

I am still having Merlin problems and could do with some help.

I have both a z1 and an a1 and am getting the same problems with both.

Mainly it concerns walking/ every footstep there is a slight judder. The Merlin seems very tight, all the screws are tight. I am not even touching the gimbal, and when i do it is very light. What am i doing wrong? tried to walk more lightly, this helps slightly but not enough.

Also top/bottom heavy and the z axis. Can someone give me an idiots guide as to what situations top/bottom heavy can be advantageous in and how the z axis relates to changing the top/bottom heaviness (e.g. if it is bottom heavy does turning the z axis towards the bottom make it less so?) I change lenses and all sorts on my a1 constantly so need to understand how the balancing works so i can do this more easily. If the drop time is less than a second does it mean it is bottom heavy?

When the camera sways left and right whilst walking is the camera bottom or top heavy? sorry for all the dumb questions!

thanks very much

Nick Tsamandanis September 23rd, 2006 09:47 AM

Does your G-platz screw have a firm connection with the camera? I find that if it doesn't, vibration is evident in the picture. Turning the ring clockwise will make the rig more bottom heavy. Turning it counter clockwise will make it less bottom heavy. The quicker the drop time means it is more bottom heavy. Less than 1 sec is too quick. The recommended drop time is 1 second. If the camera sways left and right whilst walking you are probably too bottom heavy, but you will always get some sway, especially with a change of speed/direction. That is the nature of Steadicam. You can learn to control the swaying by applying light pressure to the gimbal at the right time. This takes many hours of practice to get perfect.

Phil Bloom September 23rd, 2006 11:14 AM

thanks Nick

appreciate the help.

i havent been able to get the g platz to touch the camera. neither my a1 or z1 are anywhere near it. i have followed the cookook settings fo both. is there anyway to get it to connect?

phil

Mikko Wilson September 23rd, 2006 01:06 PM

1 Attachment(s)
I'll expand a little on Nick's answers.

The G-platz is in deed needed to slightly tension the camera on the stage as most cameras don't have super ridged mounting structures.

Where on (or off) the camera does the G-platz hit on your cameras? The first thing to try is to try the G-platz screw in both holes.
The next solution is to slide the camera (by sliding the dovetail plate) so that the screw can press on the camera. On the A1 the back of lens hood is a good spot to press on lightly, on the Z1, anywhere on the lens barrel that isn't a zoom or focus ring. You will then need to use the trim roller to correct fore-aft balance.

Another thing to check for to prevent vibration is to make sure that the dovetail plate is ridged. Current Merlins come with the 2 halves of the dovetail plate riveted together at the back, older Merlins (including mine) however, don't.
The solution is to carefully undo the screw in the dovetail locking clamp to seperate the black and blue plates. Then a small peice of double sided tape is placed between the plates at the back (stick to the blue side first, it has larger holes so you can align te tape around them). Then press the plates together and then put the clamp back. The result is a stronger more ridged plate which will furthur reduce vibration.

As to balancing...

The Z axis moves the gimble up and down, in relation to the center of gravity of the system. The furthur up (closer to the stage) the gimble is, the lower the center of gravity and more more "bottom heavy" the rig is. This means that the bottom of the rig will pull down harder like a pendulum.

A rig has 3 states:
Bottom heavy - it hangs bottom down.
Neutral - it hangs at whatever angle you leave it at and does not return to vertical.
Top heavy - the camera is heavier than the counterweights and the rig wants to topple and hang upside down.

A shorter drop time means that the bottom of the rig falls faster and is more bottom heavy. This will also cause the rig to act more like a pendulum and "lean" when you corner or accellerate.


- Mikko

Phil Bloom September 23rd, 2006 01:17 PM

thanks mikko.

i managed for the first time in a month to get vibration free walking shots. very exciting!

Mikko Wilson September 23rd, 2006 01:26 PM

That's great news Phil! :)

- Mikko

Phil Bloom September 23rd, 2006 02:11 PM

is the drifting up and down as i walk straight a balancing or operating issue?

After using the merlin with the a1 for the past few days, putting the z1 back on is a bit of shock. That's one heavy camera. i bought the accessory plate for it so I can use a radio mic with the camera. Nice idea that plate.

I have spent 12 years as a cameraman, doing news and docos, although i have directed steadicam operators have never done it myself. It's always been handheld and tripods so this is all new to me. I have realised as much use as the cookbook and instructions are, you have to understand how the balancing effects the movement and why. Until you understand the "why" you are just guessing if you make any changes to the camera, wide angles, filters, different batteries, and especially the accessory bracket with the z1. I find myself thinking back to my school Physics class! Makes my head hurt!

Mikko Wilson September 23rd, 2006 07:28 PM

Quote:

Originally Posted by Phil Bloom
is the drifting up and down as i walk straight a balancing or operating issue?

Can you explain what you mean in more detail? Is the camera tilting or the whole sled bobbing up and down? Does it show in the shot or is it something the camera is just dooing?


I agree that it is very important to understand all the adjustments of the Merlin. I don't use the cookbook anymore and I can balance a camera from scratch in about 3 minutes. The cookbook is a great place to start and get you going, but after that it's important to experiment to discover how each adjustment affects the system. The wost thing that can come from experimenting is an out of balance camera, so definatly worth a go!

- Mikko

Phil Bloom September 24th, 2006 02:44 AM

When walking the whole camera looks like it is on a boat at sea. The camera tilit drifts up and down. It very much shows in the shot. Like i am tilting it up and down

Mikko Wilson September 24th, 2006 02:53 AM

Try trimming your Z to give a slower drop time, try almost 2 seconds.
- Mikko

Phil Bloom September 24th, 2006 03:02 AM

will try! thanks. you are up up very late or you are in Finland!

Phil Bloom September 24th, 2006 04:12 AM

the a1 is working beautifully, still not worked out how to go from walking up/down stairs to carrying on straight. I trim to make it point in the right direction but then of course when i reach a flat surface it still points that way.

now the z1. it STILL VIBRATES when moving! the g-platz is there and solidly touching the lens barrel, everything should work but it still vibrates. it looks like it is solid. i just don't get it!

Robert Johnston September 24th, 2006 08:32 AM

Sorry I cant help you phil, i am trying to get to grips with the merlin too with a sony pd 170 on top. I have a few clips put together and would like the experts to tell me where i am going wrong and where am i going right.

This is the link and it is 29 mb in size. http://www.v-i-cstudio.com/Show.html

The rest of the site is still work in progress. Still a lot to learn about the camera and the web.

ps dont worry about the picture it was from other footage of a parade that i shoot also with the merlin. Again, windy lots of people about "not easy" If you want I can put this clip up as well. Looking forward to your comments and be honest as this is how i like to learn.

Phil Bloom September 24th, 2006 09:06 AM

Hi Robert

I watched your clips, you are certainly getting there! It really takes so much practice, in a month I have improved so much, I even have managed to shoot some stuff which is going out on Sky this week...

It is so hard in the wind isn't it. Is your spirit level dead on, it does seem to have a tendancy to lop to one side. I found that you really need the spirit level to be absolutely dead on.

With regards to vibration on the z1...cured it. I stripped the camera down by taking the lens hood off (although i did put a red eye wide angle adaptor on which weighs just a little more than a standard 72mm filter) and put a small battery on. Put some more gaffer tape on the camera before putting the dovetail plate on the balanced the camera. Dovetail was at the cookbook setting place but I balanced at 0 with some trimming so I could get the gplatz to hit the lens barrel for that extra stability. It seemed to work.

It is such a shame that I can't use my fish eye or a proper wide angle adaptor with the z1 because of the weight issue. I wonder as the gimble is removable and replacable Tiffen might bring out a new one that can take an extra pound or two!!! In the meantime for anything fancy, like the century .3x fish eye, and for a lot less grief...and pain, I will mostly be using my a1e. The picture quality is so close to the z1's with good light that once graded you won't know any different. It is astonishing that such a tiny camera can create such lovely pictures, even in DVCAM mode. It's a shame that inside the cmos chip struggles.


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