Strange thing with 30D-400mm f/5.6

[Chrysophylax]

I have a canon 30D/400mmf/5.6 set up for birding and have noticed something strange, I mainly shoot in AV mode with it. But when I am in continuous mode, either standard or "H", there is a great difference between the photo's, not only in the exposure but file size as well. I shoot in Ljpeg, not raw. Is this a setting somewhere, either a custom function, or a standard setting? AFAIK I have not used any of the custom functions but on the top display I noticed a symbol, Cfn1. Any help would be appreciated. Neil.

[GYRob]

AV mode will ajust the exsposure as you shoot a burst if the subject or light changes or as you say follow a bird etc -This to will then afect the file size of the jpeg as its recording diffrent info onto the sensor.
Rob.

[Chrysophylax]

Thanks Rob, but I am also getting a large variation in the exposure even when taking still photo's, it's as if the camera is taking 3 different photo's at different exposure levels all after one another, IE: a 1 second 3 frame burst will produce a correctly exposed image, a slightly under-exposed image and a under-exposed image all after one another. You would think they would all be the same to a certain extent. I know I can sort it out with post processing, but I don't think I should have to. Thanks again. Neil.

[GYRob]

Thanks Rob, but I am also getting a large variation in the exposure even when taking still photo's, it's as if the camera is taking 3 different photo's at different exposure levels all after one another, IE: a 1 second 3 frame burst will produce a correctly exposed image, a slightly under-exposed image and a under-exposed image all after one another. You would think they would all be the same to a certain extent. I know I can sort it out with post processing, but I don't think I should have to. Thanks again. Neil.

ah that sound like you have exsposuer bracket set ? it takes 3 shots in a row at what ever you set the bracket too .
Rob.
eddit i dont have a 30 but its on page 94 in the manul just looked it up for ya :)
another eddit you should be able to reset the camra to default that should clear it and anything else thats set.

[carlj]

Neil, sounds like you've assigned exposure bracketting to a custom button. Can't comment on how Canon work, but would assume that pressing the c1 button would remove the cfn1 marker, and revert to AV single shot.

Carl

[Roy C]

I agree, you have got AEB set, just go to AEB in the menu and make sure there is only one underline (under the zero)

[JohnJos]

This certainly seems to be the case but AEB turns off on a 40D when you power down the camera. Does the 30D do the same?

[Chrysophylax]

I agree, you have got AEB set, just go to AEB in the menu and make sure there is only one underline (under the zero)

I have just checked the settings of the AEB there is only one underline but it is not under the zero, it's under the second marker to the left of the zero. I have tried to get it under the zero, but it won't move. Thanks for all the help guys. Neil.

Doh! Sorted now guys. I had knocked it down 2 thirds of stop when I took the last picture, all I had to do was look through the viewfinder, half depress the shutter and turn it back to the middle.
Sorry for being a numpty. Neil.

[JohnJos]

OK, but that's your exposure compensation (EC) setting not your auto-exposure bracketing (AEB) setting. AEB is turned on in the menus and its parameters are set using the custom functions. Like I said, the 40D manual says that AEB is turned off when you power off the camera (unless C.Fn I-4 is set to 1 in which case AEB does not turn off). I haven't verified that with my 40D but will tonight.

[Chrysophylax]

OK, but that's your exposure compensation (EC) setting not your auto-exposure bracketing (AEB) setting. AEB is turned on in the menus and its parameters are set using the custom functions. Like I said, the 40D manual says that AEB is turned off when you power off the camera (unless C.Fn I-4 is set to 1 in which case AEB does not turn off). I haven't verified that with my 40D but will tonight.

You are quite right John, it was set to CFn1 in custom functions, I have now disabled it. Thanks again. Neil.