Image Size & RSS Feed

Hi Guys. Basically, the images on my site don’t load up full size very quickly. Now i have assumed it is because of the size of the images rather than my hosting. Is there a plug in which will change the images in my media library so that they will be not take as long to load, whilst preserving the size if you see what i mean? As i am using light box to show a larger version, but they take ages to load.

Also, my Feed at Feedburner is not showing correctly. The images do not load and have an error, is there something i have done wrong? (This may be something for the feedburner support but i wanted to ask here first)

Thank you for any information you can give me. You can find my site at : http://www.samsmithphotography.co.uk

Thanks again