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 ZS3 and Nikon D300S side-by-side from the front, back and top in their relative dimensions. Panasonic ZS3 has external dimensions of 103 x 60 x 33 mm (4.06 x 2.36 x 1.3″) and weighs 229 g (0.50 lb / 8.08 oz) (including batteries). Nikon D300S has external dimensions of 147 x 114 x 74 mm (5.79 x 4.49 x 2.91″) and weighs 938 g (2.07 lb / 33.09 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS3 and Nikon D300S. Panasonic ZS3 is clearly the smaller of the two cameras. Its body is 44mm narrower, 54mm shorter and 41mm thinner than Nikon D300S. As you can tell, actually this is not a fair size comparison since Panasonic ZS3 has a built-in lens but Nikon D300S doesn't. Once you put a lens on D300S, its thickness will increase significantly.
Here is the back view size comparison of Panasonic ZS3 and Nikon D300S.
Now lets look at the top view comparison of Panasonic ZS3 and Nikon D300S.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS3 is significantly lighter (709g ) than the Nikon D300S 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 D300S, the total kit will weigh much higher.
Thanks to the weather sealed body of D300S, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to ZS3.
LCD Screen Size and Features
Panasonic ZS3 and Nikon D300S'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.