[Ollie]

Hi all, I am about to show my lack of knowledge of camera settings in this post, but if you don't ask you don't learn, so here goes. I will add that this is the first DSLR I have owned previously being used to a Canon S2IS

All the questions relate to the 350D with a Sigma 70-300mm 1:4-5.6 APO DG lens and mostly being used at the maximum zoom for bird photography.

I am using the camera on Aperture priority mode on either F7.1 or F8.0 The camera has seven AF points and can be set to use automatic AF, ie all the AF points light red when focused or you can manually select just one AF point. Currently I have this set to a single centre AF point. Is this the best method?.

The camera also has three AF modes.One shot AF mode which according to the manual is suited for still objects, A1 Servo mode for moving objects and A1 Focus AF mode which switches automatically from One shot AF to A1 Servo mode if the subject starts moving. I am using one shot AF mode, is this the best for bird photos?.

Also I am currently using ISO 400. Am I correct in thinking that an ISO speed of 400 will give a slightly faster shutter speed than an ISO of 100 when used in Aperture value mode?. I know higher ISO speeds increase the camera's sensitivity to light but also tend to give a more grainy photo.

Sorry to have been so long winded, but I am flying in the dark a little with the DSLR and any help from anyone would be appreceated very much. I do use a tripod and/or a monopod recently purchased after good advice given here.

Thanks in advance. I probably won't be able to read any replies untill much later this evening as I have to go to work at lunch time.

Thanks
Ollie