random tidbits.

FinishLynx Camera Rapid Alignment Method

April 5, 2010 on 3:42 pm | In FinishLynx FAT System | Comments Off

If you use a FinishLynx 2000 Camera for track and field or some other fully automatic timing function you know that getting proper alignment on the camera is half of the battle.

I have a great solution — you can make your own or for $85 I’ll make you one and ship one to you saving you hours on alignment. Tired of using a plumb bob, three friends and stretching a string across the track as you keep telling athletes to stop, look out, get out of the way? We often set ours up as we do contract finish line timing for track and field in Michigan. So we are doing a complete alignment in most instances (unlike static site work where people permanently mark mounting information).

Here is what we do:

1. Use a scope for aiming/aligning the camera with the plane of the finish line: I have made an accessory for aiming my camera, a rifle scope that easily slips on and off of the camera. If you would like me to make one for you I will for $85, with free shipping in the continental US and about a week to make it (email don at htmlfixit dot com and I’ll send you paypal payment information). It is a simple idea really.

I made an inverted u-shaped saddle that fits snugly over the top of my camera. It is made from sheet metal and it slips cleanly on top of my camera. To the top of that I have mounted aluminum mounting blocks that can be adjusted side to side for initial sighting. Then on the aluminum mounting blocks I mounted an inexpensive rifle scope. How does it work?

a) I just use my eyes to get the camera near to the plane of the finish … as near as I can figure with the naked eye. You should be within a few inches in most cases just by sighting down the camera as you shift left and right.

b) I set horizontal level — I’ve usually got it close with the level that is built into the tripod, but I look down the scope, and pan up and down until the horizontal cross hairs are on a lane line. If I am aligned horizontally (side to side) then the cross hair should be exactly on the lane line. I will later recheck this after moving onto the plane of the finish line, but it is helpful to be horizontally level to begin.

c) I set the plane of the finish line — the the scope has a vertical cross hair and when I pan my camera head up and down, the vertical cross hair should stay cleanly on the finish line if I am in the plane. If it goes off of the finish line as I go up and down, I shift the camera left or right until I can pan fully up and down without the cross hair going off of the finish line. When I am in the right place, then you can see the cross hair stay in the middle of the finish line as you pan up and down.

d) since I have moved the tripod slightly (I don’t have an adjustable head yet), I recheck my horizontal alignment by repeating step b) which will require a very minor adjustment if any.

It is really that simple and I needed nobody to help me. I didn’t need to look at my computer screen to align it, or talk back and forth with a computer operator in the press box. I do of course now check that I have the white finish picture that I desired.

2. Next we work on our lane settings:

a) Make sure you have black squares where lane lines intersect with the finish line: tip – someone suggested black shoe polish which I now use to paint/retouch the squares between lanes if they are not present or faded. Some use tape and others black cardboard squares, but I find flat black shoe polish seems to work. When I look at the computer shot from the camera and black squares are present, I see clean lane across the screen. I can then drag the lane markers up and down so that they match which helps with rapid evaluation.

b) Check picture to be sure we have all lanes at chest level — I have someone run back and forth zig zag while watching the computer screen – capture mode works best and make sure that I have all lanes from foot to head and that I have the lane lines set correctly along the edge of my screen. This is the only time I need help and often you can do it with traffic on the track if necessary. Tip: be sure you have a solid background to the top of the picture behind the finish line or you will get people walking back and forth and that will frustrate your auto-crop — it won’t crop where it sees action at head level behind lane 8 or 9. Pan up or down until you have what you need.

3. Adjust gain and focus (follow the cryptic directions in the FinishLynx manual) using Automatic Gain Adjustment outdoors for changing lighting and not using it indoors when lighting is stable.

4. Test the sensor with a quick blow to be sure we have starts.

You should be good to go.

Just as an aside: where I got the idea — my friends Tim and Andy at MSU use a green laser to align their camera. They hold it to the side of the camera while panning up and down … as the camera is about 4″ wide from center of lens to side of camera, the green laser should be four inches off the line as you pan up and down … I then toyed with the idea of mounting a green laser dead center with a saddle, then I priced green lasers and they cost more than my entire set-up — and don’t have the horizontal cross hair feature of a scope. So from their great idea and my cheapness, this idea was born. If you want one, just let me know and we’ll fabricate it for you.