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 Nikon P500 and Sigma SD1 Merrill side-by-side from the front, back and top in their relative dimensions. Nikon P500 has external dimensions of 116 x 84 x 10 mm (4.57 x 3.31 x 4.06″) and weighs 494 g (1.09 lb / 17.43 oz) (including batteries). Sigma SD1 Merrill has external dimensions of 146 x 113 x 80 mm (5.75 x 4.45 x 3.15″) and weighs 790 g (including batteries).
Below you can see the front view size comparison of Nikon P500 and Sigma SD1 Merrill. Nikon P500 is 30mm narrower and 29mm shorter than Sigma SD1 Merrill but it is also 23mm thicker. As you can tell, actually this is not a fair size comparison since Nikon P500 has a built-in lens but Sigma SD1 Merrill doesn't. Once you put a lens on SD1 Merrill, its thickness will increase significantly.
Here is the back view size comparison of Nikon P500 and Sigma SD1 Merrill.
Now lets look at the top view comparison of Nikon P500 and Sigma SD1 Merrill.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon P500 is significantly lighter (296g ) than the Sigma SD1 Merrill 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 SD1 Merrill, the total kit will weigh much higher.
Thanks to the weather sealed body of SD1 Merrill, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to P500.
LCD Screen Size and Features
Nikon P500 and Sigma SD1 Merrill's LCD screens has the same diagonal size of 3".
On the other hand, Nikon P500 features a Tilting screen
where you can change the angle of the screen to make it easier to shoot from waist or over the head levels whereas the Sigma SD1 Merrill has a fixed type screen which provides less flexibility in shooting positions compared to P500.