Ringsight for Freeflying

[wes 0]

Hello there
I was wondering if anyone had any suggestions as how to best fix a ringsight to a Freefly helmet? I am now considering filming for a Freefly team but I need to improve my framing.I have a UK made freefly helmet which has a high neoprene forehhead with an inbuilt side mount for my camera. Any help would be greatly appreciated.
Cheers
Wes

[quade 4]

For close-up freefly, you may be better off with a simple sight on you goggles.
Something like THIS has been known to work well.
It may be a little difficult to see, but those are the little paper reinforcements you put on punched holes so they don't tear out of binders.
The key to making them work is to have a pair of goggles that don't change position on your face too much from one jump to the next.
It's quick, inexpensive and fast.
If, on the other hand you find you are shooting things a bit further away and still need more precision, you can NOT go wrong with a good ringsight from Brent Finley. I have and fly one of his concentric ringsights and it is without a doubt the most accurate thing out there. Expensive, but worth every penny when getting the shot is important.
quade
http://futurecam.com

[nacmacfeegle 0]

Ummm, was about to Recommend Brents sight too, but Quade beat me to it.
I would also recommend fitting a swing mount adaptor, on nylon screws. If you are going to get a collision, or a line snarl, these will do less harm than metallic alternatives...
Cya
D
Gravity Rat # 37
Remember, we can do everything right, and still get hurt.

[freeflir29 0]

Quote

I have a UK made freefly helmet which has a high neoprene forehhead with an inbuilt side mount for my camera

Those helmets are the poop!!! I want one if they will make one to fit my Panasonic! The goggle site thing....I was really suprised how well it works. At the time I just wanted something to help but was pleasantly suprised by the results. I went the even cheaper route of just using a marker to draw a little circle around my target. I sighted in about 10-12 feet from the target.
"Here I come to save the BOOBIES!"

[quade 4]

Quote

I sighted in about 10-12 feet from the target.

Interesting point for debate.
I like to sight in on an point as far away as possible -- usually limited by the size of my backyard -- about 40 feet. This reduces the parallax error at all distances.
A lot of camera flyers that I help sight in though like it sighted in at the distance they think they'll be from the target. To me this has never made much sense.
quade
http://futurecam.com

[freeflir29 0]

Quote

I like to sight in on an point as far away as possible

No debate necessary....if I had a high speed, accurate ring sight.....yep...I'd sight in way out but with the precision "marker circle on goggles" I figured I would cut down on the error rate a bit by getting closer. Kinda like when a rifle won't hit the paper at 100 YDS. It's easier to just start at 25..."Here I come to save the BOOBIES!"

[diverds 0]

Quote

I like to sight in on an point as far away as possible -- usually limited by the size of my backyard -- about 40 feet. This reduces the parallax error at all distances.

I am having a hard time grasping this. The parallax issue does reduce at further distances. But how does sighting your camera farther away reduce parallax at close distance? I don't think it does.
If I sight my top mount in at 50 feet it will be very close to the same as if I sight it in at 100 feet. However, If I move to within a few feet of a subject and use that same sighting point, I am still going to be shooting high. I simply use my own judgement to change where I point my sight as I get closer to my target. If I am right in their face I am aiming my sight slightly low to overcome the parallax angle.
If I'm wrong, please explain it to me because I would love to find a way to get my sight to be dead center at all distances, but short of mounting the camera inside my eyesocket, I just don't see how it is possible.
.
-Dave
"Gas...Undercarriage...Mixture...Prop...Beer"

[Remster 30]

Quote

Those helmets are the poop!!

I'm not up and up on the Freeflying street talk, but thats means good, right???
Well, in my non-camera flyer opinion, these helmet are not good at all if you want to mount any kind of ringmount.
Wes: you're talking about the 2K composite helmets, right?
Well, the hard shell is way to short on the forehead and it makes the scafolding needed to mount the ring stick WAYYYY out there.... brings me visions of skull and crossbones....
Remster
Muff 914

[freeflir29 0]

Quote

but short of mounting the camera inside my eyesocket, I just don't see how it is possible.

You could go out and buy one of those "Holographic" goggle systems that projects the eyepiece feed from the camera on your goggles. Then there's no guesswork. Of course, I heard it costs about $2000-3000 for the system...."Here I come to save the BOOBIES!"

[quade 4]

Camera Sights and Parallax.
OK, here's my view on aiming cameras and sights.
Ideally, you'd want to see the exact same image for framing as you would of what's being shot by the camera. Unfortunately, HUDs that can superimpose the camera image onto your goggles is just not an economically practical solution. So, some sort of sight, not actually bound to the camera image must be used. Because the sight is not through the lens, parallax comes into play. For my camera and for the purposes of this discussion, the parallax starts with the lens and my eye being about 9 inches apart. A larger distance will create a larger parallax error, while a smaller distance will create a smaller parallax error.
Before we get too far into parallax issues, let's look at a few types of sights available.
Camera flyers can use a number of types of sights. From the least accurate and least expensive to the most accurate and most expensive they are;
Dot on goggles (grease pencil or paper reinforcement)
Ring w/ optics (piece of PCV or old ringsight w/ optics knocked out)
Lollypop w/ dot (piece of plastic w/ dot in center)
Newton Cross (polarizer, stressed plastic, polarizer)
Concentric Ring (glass, polarizer, calcite, polarizer, glass)
The first three vary in accuracy according to how they can be repositioned on the head for each use. Each time you put on a pair of goggles they'll position themselves on your face slightly differently -- same thing with a helmet.
What makes matter worse, is that since the goggles are so close to the eye, that even a very small positioning error creates a very large angle of misalignment. For instance, assume the surface of your goggles are 1 inch away from your eye. A misalignment of your goggles on your face of just 0.0875 of an inch would create a misalignment of 5 degrees. At 10 feet, that 5 degree angle is a misalignment of about 19.5 inches -- over a foot and a half. At 40 feet, that misalignment is about 41.8 inches. That said, if you're shooting very close-up freefly with a very wide angle lens, an angular offset of 5 degrees is probably not going to be all that noticeable.
The key advantage of Newton Cross and Concentric Ring sights is that they do not require exact repositioning of the helmet in order to work correctly. The axis of the sight optics will maintain their orientation all by themselves. All that is required is that they be aimed properly and then fixed in place. The optics will then present the eye with an aim point that represents the optics axis of orientation. The Newton Cross gives a somewhat vague aim point, the Concentric Ring gives a very well defined and precise aim point.
Since the difference between the position of the lens and the position of the eye is about 9 inches, the very best you could ever hope for in terms of accuracy at all distances would be a parallel offset of about 9 inches. What I mean by this is that even if you had a perfect setup with perfectly parallel lens and eye alignment at every distance from close up to infinity the alignment would be about 9 inches off. Now, at very large distances a 9 inch parallax is no big deal, but as you get very close to the lens of the camera, say a shooting tandem distance of maybe 3 to 5 feet, it could be the difference between having the tandem master completely in the shot or having his head cut off by the top of the frame. Even with a perfect alignment you must take the parallax into account for very close distances.
Some camera flyers align their sights at fairly close distances in order to attempt to correct for the parallax issue, however, in my view this is just flat out wrong. While it may be correctly aligned for a specific distance, at all other distances, it would be misaligned.
I shoot 4-way. When it comes to camera flying, that's my bread and butter. My ideal distance and position from the team is about 10 feet above with the lens of the camera right over the center of the formation. By aligning the camera and sight specifically for that point the angular offset would be 4 degrees. That could be a perfect setup specifically for shooting 10 feet away, but if I were to then shoot a 20-way at a distance of say, 40 feet, then that 4 degrees translates to a misalignment of 26.9 inches -- maybe an arm length.
So, the upshot of this is that when I try to align my cameras, I take all of this into consideration and attempt to align them not to a specific distance, but so that the camera and sight are as parallel as possible. I do this by aiming at a point as far away as possible. I know I'll still have to deal with the 9 inch parallax offset when it comes to stuff that's close-up, but for everything else, when I put my sight on a target, it should be accurate to about 9 inches.
quade
http://futurecam.com