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 Panasonic LX100 II and Canon 1Ds MIII side-by-side from the front, back and top in their relative dimensions. Panasonic LX100 II has external dimensions of 115 x 66 x 64 mm (4.53 x 2.6 x 2.52″) and weighs 392 g (0.86 lb / 13.83 oz) (including batteries). Canon 1Ds MIII has external dimensions of 150 x 160 x 80 mm (5.91 x 6.3 x 3.15″) and weighs 1385 g (3.05 lb / 48.85 oz) (including batteries).
Below you can see the front-view size comparison of the Panasonic LX100 II and the Canon 1Ds MIII. Panasonic LX100 II is clearly the smaller of the two cameras. Its body is 35mm narrower, 94mm shorter and 16mm thinner than Canon 1Ds MIII. As you can tell, actually this is not a fair size comparison since Panasonic LX100 II has a built-in lens but Canon 1Ds MIII doesn't. Once you put a lens on 1Ds MIII, its thickness will increase significantly.
Here is the back view size comparison of the Panasonic LX100 II and Canon 1Ds MIII.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic LX100 II is significantly lighter (993g ) than the Canon 1Ds MIII 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 1Ds MIII, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the 1Ds MIII, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the LX100 II.
LCD Screen Size and Features
Panasonic LX100 II and Canon 1Ds MIII'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.