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 Nikon D700 and Panasonic ZS15 side-by-side from the front, back and top in their relative dimensions. Nikon D700 has external dimensions of 147 x 123 x 77 mm (5.79 x 4.84 x 3.03″) and weighs 1074 g (2.37 lb / 37.88 oz) (including batteries). Panasonic ZS15 has external dimensions of 105 x 58 x 33 mm (4.13 x 2.28 x 1.3″) and weighs 208 g (0.46 lb / 7.34 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D700 and the Panasonic ZS15. Panasonic ZS15 is clearly the smaller of the two cameras. Its body is 42mm narrower, 65mm shorter and 44mm thinner than Nikon D700. As you can tell, actually this is not a fair size comparison since Panasonic ZS15 has a built-in lens but Nikon D700 doesn't. Once you put a lens on D700, its thickness will increase significantly.
Here is the back view size comparison of the Nikon D700 and Panasonic ZS15.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS15 is significantly lighter (866g ) than the Nikon D700 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 D700, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the D700 has a big advantage over the ZS15 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon D700 and Panasonic ZS15'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.