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Electronic level/horizon indicator


DavidMcGill
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I find that the frame is level or isn't level according to the verticals which occur within it. They are generally the best thing to refer to when trying to keep your frame level beautiful and level.

 

Unless you are working with the sled directly in front of you that won't always work. since we work at an oblique to the monitor that influences what we perceive as level. Frequently even though you may think that it's level it's not.

 

Use a level, it's foolproof

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I'm not against using a level, albeit a bubble or an electronic one, I use both, one a bubble superglued to my topstage and an in built electronic one in my Transvideo monitor. I guess my point was that if you are spending too much energy looking at the level to check that it is level, one may well be compromising the composition of your frame.

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I liken a level to a tachometer in a car. You don't drive by it but its a damn fine tool to have as a reference.

 

And further to that point, it's really the only way to fully maximize the car's performance.

 

I've become fully used to, when watching the monitor during a shot, keeping the digital level in the periphery of my vision. I'm not staring at it, but I am looking for that nice, solid white square the whole time. It's easy to see, it keeps everyone honest, and I can confidently comment one way or another on how level the shot was throughout the take.

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Dear fellows!

 

I know about the physics of acceleration, but I use the internal level of my Transvideo and it works just fine for me. Actually never had any problems with it. And I like the many options for displaying the horizon level on the Transvideo. Most of the time I actually like to have it right in the center of my monitor and in the "flight attitude indicator" kind of style. Many of you may think it deflects your framing. Well, in most cases it absolutely doesn't, and if is does I just simply change it to the "regular" style and move it to the bottom of the frame! For me it is a great way of having total control of my level, but it is just me ;-)

 

Here is how it looks like:

post-2833-0-63254200-1335367876_thumb.jpg

 

 

My 2 cents.

Lukas

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Most of the time I actually like to have it right in the center of my monitor and in the "flight attitude indicator" kind of style. Many of you may think it deflects your framing. Well, in most cases it absolutely doesn't, and if is does I just simply change it to the "regular" style and move it to the bottom of the frame! For me it is a great way of having total control of my level, but it is just me ;-)

 

That may work for you but it would drive me crazy.

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I thought I was going to get email notifications to replies in this thread but I didn't so I missed out on all of this discussion till now. Never thought it would go the direction it did, but seems to be some valuable info brought out. One thing I'd like to point out is the discussion of "verticals" in the frame as a reference for level. It is true that quite often vertical lines will be skewed in the frame, but one place where this never occurs is dead center. Each time I mount a camera on my rig, I zero the level by pointing it at something I know is a true vertical and putting the crosshair right on it. I hold it so that the vertical line of the crosshair lines up with the vertical line in the shot and then press the zero button. And it doesn't matter if the sled is tilted up or down. If it is a true vertical in the world and it is running right through the center of the frame, it will appear vertical in the frame IF the camera is level to the world. For me, this is the most fool proof way of calibrating the level of the whole system (camera + rig).

 

As to location of the sensor, it seems to me that on the main part of the rig is far preferable to on the monitor. My main reason for this is my concern about the need to adjust the monitor from shot to shot. Would that not necessitate re-calibrating it each time it is moved? Or is there circuitry in place on most of these electronic levels that would compensate for that?

 

Glad to hear Greg is coming out with an HD level. Looking forward to checking it out as soon as it is available!

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One thing I'd like to point out is the discussion of "verticals" in the frame as a reference for level. It is true that quite often vertical lines will be skewed in the frame, but one place where this never occurs is dead center. Each time I mount a camera on my rig, I zero the level by pointing it at something I know is a true vertical and putting the crosshair right on it.

 

This might be true of dead center to the LENS... which isn't always exactly where the crosshair is placed, or the center of your monitor. Furthermore, the crosshair indicates a vertical area consisting of about 10-20% of the vertical field. Plus, the crosshair vertical itself is 5-10 pixels wide (just a guesstimate). What I'm getting at is there's plenty of room to have a vertical look like it's "true" because it appears to line up with the crosshair, but if you were to extend the crosshair to the full top and bottom of the screen, you'd see that even a slight deviance over the small area in the center equals a very large deviance over the entire height of the frame. This is made even worse still when it is usually the horizontals we're more concerned with, and the horizontal width can be twice the height - depending on your aspect ratio.

 

A good analog, old fashioned bubble level (high accuracy, high speed) - the ones made for machinists - is really your best friend when it comes to finding a true level. Glue one to the base of your sled somewhere. Use it to check your electronics whenever you set things up. Mine cost about $70, but it's fully worth it. It's really the best and easiest way to be certain.

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, I zero the level by pointing it at something I know is a true vertical and putting the crosshair right on it. I hold it so that the vertical line of the crosshair lines up with the vertical line in the shot and then press the zero button. And it doesn't matter if the sled is tilted up or down. If it is a true vertical in the world and it is running right through the center of the frame, it will appear vertical in the frame IF the camera is level to the world. For me, this is the most fool proof way of calibrating the level of the whole system (camera + rig).

 

 

While that may work for you it's far from the easiest or most accurate. Like Afton said. Get 2 machinest levels. Put a dovetail in your camera mounting stage. Put the machinest level on the dovetail and level the rig to that reference. Now crazy glue your 2nd level on the lower jbox and make sure it reads what the top level does. That's it you're done. Instant level reference

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Lucas, That would drive me crazy! But there are those shots... those crazy opening/ending shots to the film/advert that go to a wide scene to lock-off where level is SO crucial and everyone is watching you and that make-up girl is at the monitor and the coffee is wearing off.. We've all been there and yeah I'd love to be able to do that.

 

+1 for transvideo

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Steadicam newbie/non-newbie roboticist here...

 

You can get very small 9 axis IMUs that give you 3 axis accelerometer, 3 axis gyro and 3 axis magnetometer readings in real time. These are used in UAVs (flying robots basically) as a matter of course these days, where the need to tell the difference between what direction really *is* down and the apparent direction due to local acceleration is pretty much an unavoidable requirement, or you end up with the UAV going into an uncontrolled spiral and a crash. It would be pretty straightforward to build something based on one of those. I might try it myself, actually.

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Steadicam newbie/non-newbie roboticist here...

 

You can get very small 9 axis IMUs that give you 3 axis accelerometer, 3 axis gyro and 3 axis magnetometer readings in real time. These are used in UAVs (flying robots basically) as a matter of course these days, where the need to tell the difference between what direction really *is* down and the apparent direction due to local acceleration is pretty much an unavoidable requirement, or you end up with the UAV going into an uncontrolled spiral and a crash. It would be pretty straightforward to build something based on one of those. I might try it myself, actually.

 

potential buyer!

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