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-   -   Helmet mounted VholdR camera - exposure issue (https://www.dvinfo.net/forum/open-dv-discussion/125168-helmet-mounted-vholdr-camera-exposure-issue.html)

Ian Stark July 2nd, 2008 07:51 AM

Helmet mounted VholdR camera - exposure issue
 
A friend has just bought a VholdR helmet mounted camera to use as he drives his classic Mustang at ridiculous speeds in the various Old Timers Grand Prix around Europe. He's aware that it's a budget device but he wants to see whether he will regularly use such a cam before investing in an upmarket model.

It seems that the VholdR has a non-user-adjustable exposure. Whether that means it has automatically adjusting exposure or whether it means it is fixed at a 'happy mid-point' I don't know, as I haven't seen or used the camera. I'm thinking that it is the former but I couldn't confirm that from the basic info on their website http://vholdr.com/.

He used the camera very successfully in an open top car where the footage was exposed well. However, when he used it in his own car, which has a hard top, the interior was perfectly exposed but the exterior was completely blown out. That's what leads me to believe it's auto-exposing.

Without being able to adjust the exposure manually, does anyone have any suggestions as to how he might use it successfully in the hardtop car?

Race rules dictate that he can't mount the camera externally or in headlight enclosures. It has to be helmet or rollbar mounted.

My first thought was to experiment with some small pieces of ND gel to drop the light getting to the CCD.

Any other suggestions welcomed.

Ian . . .

Ron Evans July 2nd, 2008 08:10 AM

The auto exposure is measuring the full scene level and is clearly exposing more for the interior. Move the camera closer to the windshield to get less interior. Putting ND gel will just raise the exposure level as it will still attempt to expose for the interior until it maxes out its gain. Shot will just getting more gain and grainy. Is there a roll bar close to the windshield?

Ron Evans

Ian Stark July 2nd, 2008 09:04 AM

Quote:

Originally Posted by Ron Evans (Post 902123)
Putting ND gel will just raise the exposure level as it will still attempt to expose for the interior until it maxes out its gain

Duh! Of course! What was I thinking??? I sheepishly beg other readers to take into account that I am having a bad day!

I'll go back to my friend and see what the possibility is of moving the camera closer to the windshield. Thanks for the suggestion!

Ian . . .


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