XL1 Gain Problem: Urgent Advice Requested
 

A few days ago my XL1 started showing a rapid Gain fluctuation between +12dB and +6dB while is was set to +12dB. Setting it to +6dB causes it to fluctuate between 0dB and +6dB. Every so often it will cease and stay on the proper setting.

Has anyone seen this problem? What's going on inside? Any miraculous way of fixing it? Canon service says send it in.

I'm in the middle of shooting a project and not excited by the thought of sending it away.

Hope someone can shed some light on my shedding of light problem.

Thanks for reading, hope you have some advice.

Cheers,

Paul Winterton
Vancouver, Canada

What exposure mode are you using?

- don

Because the gain setting is a mechanical switch, I suspect dirty contacts. Sometimes, if you rapidly switch back and forth through the settings, it will settle down. Most likely, it will either be remedied by contact cleaner or a switch replacement.

By dirty, I don't necessarily mean dirt. I'm referring to oxide that forms on the gold plating of the switch contacts and makes a poor, high resistance electrical connection. Like the stuff you see on your car's positive battery terminal.

The way most electronic circuits use a rotary switch to change ranges is to have a large semi circular contact which adds or subtracts resistors in parallel to go up or down a range. If the very edge of that contact is bad, the resistor at that point won't be added and the camera will revert to the previous range.


+0 ./\/\/\/\/\. /
+6 ./\/\/\/\/\. | O ----| Gain Select Switch
+12 ./\/\/\/\/\.


A crude drawing, but I hope it gets the point across.

For all of you who've had problems that seem unsolvable and then you realize the simplest of solutions.

I had forgotten that I set the white balance just prior to the problem occuring. I had set it on a "low light" white surface. Not realizing, I continued to shoot with the gain at +12dB. When the camera doesn't get enough light it can't reach the +12dB and drops back to the previous setting.

All I had to do was reset the white balance.

Oh boy, what a way to learn a lessson. And even Canon Service, didn't have an answer to my problem. I would have sent the camera to them and gotten it back in working order at $$$$$ repair cost.

Paul Winterton

Hey Paul, that's good to hear. I will definitely put that in my solutions box.

I really would have suspected impending switch failure. It's the nature of the beast. Mechanical things usually always fail before electronics.