Canon Powershot Sd890 Is
Megapixels vs f / stop?

Comparing Canon Powershot for a rich purse of the camera. SD890 has 10MP 37-185mm f/3.2-5.7 zoom. SD1100 has I have currently 8MP SLR f/2.8-4.9 so accustomed to good quality, but also as zoom. What is more important to produce better quality Photos?

Choose the SD1100. In the world of digital compact cameras with tiny sensors fewer pixels is better. Plus the SD1100 has a lens a little more fast.

Canon Powershot Sd890 Is

Can you change the shutter speed on the Canon powershot sd890 IS?

I am looking to doing some light graffiti testing

No, but you could try using the fireworks scene mode.

San Diego – Del Mar, 4th of July 2010 Fireworks – Part 1