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 Sony A35 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). Sony A35 has external dimensions of 124 x 92 x 85 mm (4.88 x 3.62 x 3.35″) and weighs 415 g (0.91 lb / 14.64 oz) (including batteries).
Below you can see the front-view size comparison of the Sigma DP3 Merrill and the Sony A35. Sigma DP3 Merrill is clearly the smaller of the two cameras. Its body is 2mm narrower, 25mm shorter and 1mm thinner than Sony A35. As you can tell, actually this is not a fair size comparison since Sigma DP3 Merrill has a built-in lens but Sony A35 doesn't. Once you put a lens on A35, its thickness will increase significantly.
Here is the back view size comparison of the Sigma DP3 Merrill and Sony A35.
Now lets look at the top view comparison of Sigma DP3 Merrill and Sony A35.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sigma DP3 Merrill is significantly lighter (85g ) than the Sony A35 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on A35, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Sigma DP3 Merrill nor Sony SLT-A35 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 Top DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Sigma DP3 Merrill and Sony A35'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.