Low light autofocus issue

[Solareyez]

I shoot alot of events, parties and weddings. So this is a huge problem for me right now. For some reason my Canon 10D is having is having a hard time focusing in low light situations, where as before it would. As of now I am having to manually focus in low light and in almost no light, which is just impossible. I switched out the lenses, to see if it was the lens. It's not. I believe it may be my Canon 550 EX. I was told to clean the sensor with an eraser. Has this happened to anyone else? If so, any solutions?:confused:

[Eagle]

Does the 10D have a CF to turn the AF assist beam off? And if so, did you turn it off? Have you tried it with the onboard flash and not the 550?

[Curtis N]

Clean the sensor with an eraser? The camera's image sensor? Let's put a hold on that idea before you ruin your camera. The image sensor isn't involved in the autofocus process.

More information needed with regard to your autofocus issues. If you are using a 550EX flash, its AF assist light should enable you to pretty much focus on anything within range. Have you verified that the AF assist light is working?

[Eagle]

As for the eraser thing; I hope he was told to clean the hotshoe and flash contacts and just said sensor by mistake.

[Mark_Cohran]

As for the eraser thing; I hope he was told to clean the hotshoe and flash contacts and just said sensor by mistake.

Is the flash not throwing the red focus assist grid? If not, then cleaning the contacts might help - but it will be a go/no go kind of thing. The flash will either display the grid or not.

Cleaning the contacts will not, however, direcly help in the AF process. The flash assists in that process by displaying the grid so the camera's AF system has something lock onto in low light.