jj99c2

I am looking for tips using a bullet camera for recording DE events. I purchased the AutoXCam -- now Hoyt Technologies - http://www.hoyttech.com/. I used the included suction cup mount in the rear window of my 996. It held fine for the entire day (I had it tethered just in case).

The problem was the shots of the inside of the car came out looking great but everything through the windshield was signficantly over exposed -- so that you can hardly see the road/cones/etc. It was a slightly overcast day as well. The attached picture shows an example. Since its a bullet camera there are no exposure adjustments to make. Does anyone have any tips for getting better results? I might try a polarized filter or just move the camera further forward so that its only taking a shot out the windshield. I like the current location b/c I can see my hands, feet, tach, etc. Any tips appreciated.

Specs on the bullet camera:

Camera Specifications:
Image Sensor
High Resolution, 1/3" DSP CCD (Sony EX-View HAD)
Effective Pixels 768(H) x 494(V)
H. Resolution 480 TV Lines
Min. Illumination 0.1 Lux at 2.0
Video output 1.0Vp-p Composite. 75 Ohms
S/N Ratio More than 50 dB
BLC Automatic
Shutter Speed 1/60.1/100,000 sec
Gamma Correction R=0.45
White Balance 2100.K .8200.K Auto
Gain Control 4dB~30dB Auto
Smear effect 0.005%
MTBF 80,000 hrs
Power Source DC12V (Tolerance: 8V~15V)
Operating Current 130mA
Lens 3.6mm (92 Deg)
Operating temp 14°F~122°F (-10°C~50°C)
Humidity Within 90% RH
Dimensions 0.82" (Dia) x 3.0" (L) (21mm x 76mm)
Weight (approx) 220 grams
Cable Length: 5', Signal: RCA, Power: 2.1mm Coax

BrokeAss

A polarizing filter is going to help, but the brightness differences between the interior and exterior are just too great. What pogram do you edit your video in? You might be able to apply a digital brightness filter to the entire clip.

That's a great looking camera angle - where did you mount the camera?
...and where can we watch some in car footage?

Jean

My guess is that the camera picks up a weighted average for the luminosity, therefore will either underexpose the interior or overexpose the exterior. You will need to change the angle of the camera to pick up predominantly the exterior if you want to have the right exposure, or, to get it closer to the front windscreen since it seems like a very wide angle lens.. However at the risk of getting a dark interior.

jj99c2

Thanks for the feedback. I will try mounting closer to the windscreen for the next run -- having an all black interior probably makes the exposure range to great.

C4 Guy - I mounted it at the top of the glass for the back window. Its a small suction mount and the camera is only about 4" long. I would post some videos but the screen shot is actually one of the best shots -- mostly everythign outside the window is washed out in the video so it wouldn't be worth watching. I edit in Adobe Premier -- I tried the contrast/brightness adjustments but it didn't really improve at all.

BrianKeithSmith

mount it to your helmet!!!!

Now that would be cool!

Brian

APKhaos

You should talk to Hoyt about this. I'm fairly sure you should be able to adjust the aperture. There should be a way to do it because I'm seeing video shot with in-car bullet cams that expose very nicely. The Sony Ex-View HAD is a very nice CCD.

Take a look at this clip from Cory Friedman's Autometrics Motorsport GT3 Cup . It's perfectly exposed both inside the car and out.

RICHVIZZ951

Polarized filter will help, but if you turn the exposure on the camera from auto to manual, than decrease the exposure to about 25%. It may make the image in the viewfinder look real dark, but the video should look good outside of the car. By experimenting you can probably find the ideal setting in abour 30 minutes. Good luck.

Mike A.

Tony,
You're right, that is a well exposed image of both inside and outside of Cory's car.
Do know for sure that he is using a Sony Ex-View? I have an Ex-View with 94 degree view and I don't have the same results as Cory. The view out the windshield is washed out, but the view inside is good. I don't see an aperature adjustment on the camera.
Mike

APKhaos

Not sure. I'll ask & let you know.

mskala

I have the exact same camera (0.1Lux Sony) from them and even though
it hasn't been a problem where I've used it, I've seen others with the same
overexposure issue and have done some tests myself showing the problem
also.

I believe you would have the same problem with any of the bullet cameras
in this type of environment (half dark/half bright field area), but with many
other cameras the sensitivity is lower (1.0Lux on one of my other cameras)
so you won't see the overexposure, you'll see it dark inside the car.

Like others said, you can move it to where the field doesn't have much of a
dark area. I've tested mine by placing layers of window tint in front of it,
but the camera compensates and the picture will still be overexposed (in
the extreme of filtering the light, the dark areas will be grainy, too).

If you want to run it in that same position, you will need a filter that you can
place just across the top half, and that will allow you to get the right
exposure.

None of my autocross videos have had this problem, probably because I
live in an area that's not too sunny, and I usually run with the roof off the
914 which keeps the whole area brighter.

Hope this helps,
Mark S.
'70 914-6
In-car picture-in-picture

jj99c2

Thanks for all the feedback. I sent the picture/note to Hoyt and will follow up if I get a good tip.

I don't believe the exposure settings on the video camera have any effect when using the inputs for a bullet camera. Can anyone confirm? I am on travel and can't check the manual (Canon ZR50).

APKhaos - that GT3 video is great - even with a black interior. I wonder what he is doing differently?

touf

I mount my bullet camera on my tow hook on the front bumper. I used some foam to dampen vibrations and Tie wraps + Duct Tape to make sure it doesn t go anywhere.
I then run the cable into the trunk and where my camcorder is mounted very securely and used as a recording device.
The camera is a bullet camera I purchased in Singapore. It is a comoon security camera.
My next step is to buy a box that will allow me to plug in a 2nd camera so that I can have Pic in Pic.
The 2nd camera will be mounted inside the car.

Jean

jj99c2 please let us know what they tell you. Does this setup have the possibility at all of displaying RPMs, speed, G Forces, etc.. on the screen?

touf, do you have any short videos you could share (I am on dial-up). It would be interesting to see the angle of caption from the front tow hook.
Thanks

jj99c2

I heard back from AutoXcam and they had two suggestions. First is to move the camera forward so its more focused outside the window as many of you have suggested. The second idea is to remove the camera from the protective case -- they thought the lexan in the front might be reflecting the brighter light.

I will try both at my track events scheduled later this month and follow up.

thx John

Mike A.

I'm thinking that Cory is using the RaceCam system. I understand that it has a contrast adjustment on the camera.
For the Sony Ex-View cameras there is no such adjustment. I think moving it towards the windshield is the fix. Unfortunately you don't get to see the drivers hands, dashboard, etc. when you do this.
I ordered the PIP box from Hoyt and will use two cameras, one near the front and the other at the driver, or out the rear, or whatever. Just more toys to play with

Mike