Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Sigma DP3 Merrill and Casio EX-ZR400 side-by-side from the front, back and top in their relative dimensions. Sigma DP3 Merrill has external dimensions of 122 x 67 x 59 mm (4.8 x 2.64 x 2.32″) and weighs 330 g (0.73 lb / 11.64 oz) (including batteries). Casio EX-ZR400 has external dimensions of 105 x 59 x 29 mm (4.13 x 2.32 x 1.14″) and weighs 205 g (0.45 lb / 7.23 oz) (including batteries).
Below you can see the front-view size comparison of the Sigma DP3 Merrill and the Casio EX-ZR400. Casio EX-ZR400 is clearly the smaller of the two cameras. Its body is 17mm narrower, 8mm shorter and 55mm thinner than Sigma DP3 Merrill.
Here is the back view size comparison of the Sigma DP3 Merrill and Casio EX-ZR400.
Now lets look at the top view comparison of Sigma DP3 Merrill and Casio EX-ZR400.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Casio EX-ZR400 is significantly lighter (125g ) than the Sigma DP3 Merrill which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Sigma DP3 Merrill nor Casio Exilim EX-ZR400 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing
LCD Screen Size and Features
Sigma DP3 Merrill and Casio EX-ZR400's LCD screens have the same diagonal size of 3.00 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.