Problem with the Canon SX40's standard mode

[CGraco]

Hi!


I have Canon Powershot SX40 . And yes, i'm a newbie : )


Yesterday i tried to record a short video using the standard mode (the one with that little camera icon) , with a option that has this symbol -> * on it's highest level, in order to get a brighter image (sorry, i dont know what is the name of the option)


I have a little home studio with two softboxes and a white background. I noticed that when the recording starts and i'm not yet in front of the camera, the image gets all blurry. Once i'm in front of the camera, the image gets normal.


Alright...the thing is that in the middle of the recording, you get some parts of the video that get blurry again. Sometimes it's all normal...and other times the blur comes back, randomly.


I'm almost sure that it has to do with that * option that i use on high level to get a bright image.


What can i do about it? How can i configure the camera to get a image with high brightness, with out having this blur issue?


Thanks in advance for any feedback!

 

[AlexanderB]

Seems like camera autofocus is working that way. Not sure it is about brightness or something.

 

[KmH]

I have a little home studio with two softboxes and a white background. I noticed that when the recording starts and i'm not yet in front of the camera, the image gets all blurry. Once i'm in front of the camera, the image gets normal.

An understanding of how auto focus works will help. Understanding Camera Autofocus

Auto focus needs contrast to work. When the scene is all one color (white background) there are no edges to produce contrast, and the camera cannot focus.
When you walk into the scene there is then contrast the AF system can use to focus.

AF also needs sufficient light to work.
For making a still photograph, most digital cameras use phase-detection AF for it's accuracy. Phase-detection splits the image in 2 and compares the 2.
In Movie mode many P&S cameras can't use phase-detection and have to rely on the less accurate contrast-detection method of doing AF.
How Phase Detection Autofocus Works
Autofocus - Wikipedia, the free encyclopedia

SX40 HS User's Manual - http://gdlp01.c-wss.com/gds/0/0300005730/01/pssx40hs-cug-c-en-web.pdf
Go to pages 215 ans 216 in the Index of the User's Manual and review all the info about Focus that apply to your SX40.

 

[CGraco]

Dude thanks, many thanks!