Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Panasonic ZS7 and Sigma DP3 Merrill side-by-side from the front, back and top in their relative dimensions. Panasonic ZS7 has external dimensions of 103 x 60 x 33 mm (4.06 x 2.36 x 1.3″) and weighs 218 g (0.48 lb / 7.69 oz) (including batteries). 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).
Below you can see the front view size comparison of Panasonic ZS7 and Sigma DP3 Merrill. Panasonic ZS7 is clearly the smaller of the two cameras. Its body is 19mm narrower, 7mm shorter and 51mm thinner than Sigma DP3 Merrill.
Here is the back view size comparison of Panasonic ZS7 and Sigma DP3 Merrill.
Now lets look at the top view comparison of Panasonic ZS7 and Sigma DP3 Merrill.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS7 is significantly lighter (112g ) than the Sigma DP3 Merrill which may become a big advantage especially on long walking trips.
Unfortunately neither Panasonic Lumix DMC-ZS7 (Lumix DMC-TZ10) nor Sigma DP3 Merrill provides any type of weather sealing in their body, 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
Panasonic ZS7 and Sigma DP3 Merrill's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.