Electronic level/horizon indicator

[Eric Fletcher S.O.C.]

Just stick a spirit level on the monitor and one at the base of the post and pan the camera and you will see a huge difference in the forces affecting the bubble. I pan alot so I would like a sensor at the post.

 

 

Ding. Acceleration induced error, put the lever sensor at the intersection of the gimbal axis and you greatly reduce that error

[Jerry Holway]

Ron and Eric-

 

Yes, I said that when you are panning in place, having the sensor in the center of the post works better. We agree about that. And that's more true if the post is perfectly vertical, without trimming for headroom.

 

But there are hosts of other situations where it does not matter much if at all, or it is possibly worse, and even most pans have an lateral component, like when we are also walking or making a switch when standing still.

 

So, what I'm trying to point out is that the compensation circuitry matters much more than the placement, and no one placement is so much better than another that it makes much difference.

 

The forces of acceleration we commonly put on a sled (and are read by accelerometers along with the acceleration of gravity, or the "level" signal) - those forces are much larger than the 1 degree difference we are trying to discern.

 

I just think that statements about what is best or what is right or wrong, without explanation, belong in blogs rather than a forum.

 

Jerry

[Alec Jarnagin SOC]

"Just stick a spirit level on the monitor and one at the base of the post and pan the camera and you will see a huge difference in the forces affecting the bubble. I pan alot so I would like a sensor at the post. "

 

I'd agree with this. When I started using a Cinetronics monitor with no digital level, I resorted to a bubble level on the monitor housing. It quickly drove me nuts to the point that I now opt to down-convert so I can use my XCS level.

 

FYI, in the XCS level owners manual, it says "When mounting the P.D.L. remember to place the sensor as close to the center point of the post as you can. This will give you the most accurate readings. The removable sticker on the P.D.L.'s case indicates the location of the sensor inside. This will help you with alignment."

[Alec Jarnagin SOC]

Jerry,

 

We crossed posts. Your points are taken, but I do FEEL that having a sensor by the center post helps. Both PRO and XCS do this and I see the difference. I think the good far outweighs the bad.

[Jerry Holway]

Alec-

 

To be clear, Tiffen also places the horizon sensor close the the post (the Master Series had it in line with the axis of the centerpost), and it is where we think it is most useful, and is easier to mount and keep oriented, as Anthony pointed out.

 

I'm just saying that with a good acceleration compensated electronic level (not a mechanical bubble), the location probably does not matter much, and with a really good one, not at all.

 

I am not familiar with the Transvideo level with the sensor in the monitor - so I can't speak to how good it is, but knowing Jacques, I suspect it is as useful as the Tiffen, XCS, or PRO ones with the sensors close to the post.

 

Jerry

[Eric Fletcher S.O.C.]

 

I just think that statements about what is best or what is right or wrong, without explanation, belong in blogs rather than a forum.

 

Jerry

 

It was explained Jerry, Ron and Alec even provided empirical evidence. We can provide empirical evidence and math all day long but it won't change the fact that unless you type it it's incorrect.

 

Electronic signal conditioning is not the answer, if it was a bubble wouldn't work period

[RonBaldwin]

Alec, I feel tbe same way -- after using the xcs level for 13 years it's pretty rediculous to go back to a normal bubble.

[Jerry Holway]

Eric-

 

I can read.

 

I did not start commenting on the placement of the sensor with a statement of what was best without explanation as others had.

 

I felt differently and explained my thoughts as to why.

 

Anthony pointed out something else (which is why, in part, Tiffen places the sensor near the post), and I agreed. It was a discussion, and points taken. And Alec's comment about placing a mechanical bubble level on the monitor (your "empirical" evidence) had an issue, which I pointed out.

 

I don't own a Transvideo monitor. I have no axe to grind.

 

Take it or leave it.

[Alec Jarnagin SOC]

Jerry,

 

I thought Tiffen also placed their sensors by the post and when I say "I can tell the difference" I was not meaning between brands of rigs but between the placement of bubble levels. Funny enough, my 3a was a modified sled with a DeRose upper junction box so the level indicator was moved below (on the stock 3a it was attached to the upper J-box) closer to the center post. I wonder how much of a difference that made...

[Jerry Holway]

Alec-

 

Yes, Tiffen places the sensors close to the post, and I'm all for it.

 

And I was only pointing out that you (Alec) compared a regular mechanical bubble on the Cinetronic monitor vs. the XCS electronic one, and that might explain some of the headache/difference.

 

I didn't have that DeRose mod (I had some others, to be sure), so I don't know if it made a difference. - As it was an uncompensated electronic level, I'm not sure one could tell.

 

I had, I believe, the first acceleration compensated level (for Steadicam) back in 1994. I added some basic electronic conditioning circuitry to the 3A level, which then became the circuitry for the Master Series, and it was digitally reworked for the Ultra 2. I've been using such an electronic level for 18 years now, and like Ron, I wouldn't go back to a mechanical bubble. But I always have one in the kit, just in case.

 

Jerry

[JobScholtze]

Betz made me a tiny smaal box, with a sensor in it, wich we place under my post. It takes over all the functions inside the transvideo, meaning the bubble or horizon inside the transvideo is still there, the functions like speed, place etc etc has been taken over by that small box. Its even in the transvideo software, where you can choose internal or BETZ.

Works like a dream, making it a very precise bubble

[Philip J. Martinez SOC]

I have the newish Tiffen/transvideo 8" HD monitor. I can use either the Tiffen internal sensor or the sensor built into the monitor.

 

I have been using the monitors internal level. I'm going to switch to the one in the sled right now and see if i notice a diffrence. I like the level for the end of the shot however when I'm moving the last thing on my mind is a digital line.

[Rick Woollard]

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.

[Afton Grant]

Sorry mate. This just isn't good advice. "Verticals" in the real world are rarely vertical when looking through a lens. Barreling, keystoning, and a variety of other anomalies will give you false information if that's what you're using to find your level.

[Philip J. Martinez SOC]

I prefer the internal monitor level to the sled level in HD.

 

The Transvideo internal level seems more organic. The sled level seems more electric/digital, again in HD. Meaning the indacator almost feels like it is steping when the sled goes off level. In Standard Def it does not do this. ( I'm on a shoot with the HDX900 so it is really easy to go back and forth) The standard def level from the sled looks and feels the same as the internal monitor level in HD.

 

I dont really care where the sensor is placed as long as it works and mine seems to be working just fine.