At 266dpi and dimensions of 8.5" x 11", you would need an image with pixel dimensions of 2,261 x 2,926 (just multiplying the numbers together). Digital SLR cameras usually are a 3:2 proportions and a six megapixel camera would give you an image about 3000 x 2000 pixels so this would be just under what you would need. However, file size can usually be increased in programs like Photoshop with great results. I've made really high quality 16x24 prints with my 6mp DSLR, sized up to 240dpi.