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 ZS1 and Nikon P90 side-by-side from the front, back and top in their relative dimensions. Panasonic ZS1 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 P90 has external dimensions of 83 x 114 x 99 mm (3.27 x 4.49 x 3.9″) and weighs 400 g (0.88 lb / 14.11 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS1 and Nikon P90. Panasonic ZS1 is 54mm shorter and 66mm thinner than Nikon P90 but it is also 20mm wider.
Here is the back view size comparison of Panasonic ZS1 and Nikon P90.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS1 is significantly lighter (171g ) than the Nikon P90 which may become a big advantage especially on long walking trips.
Unfortunately neither Panasonic Lumix DMC-ZS1 (Lumix DMC-TZ6) nor Nikon Coolpix P90 provides any type of weather sealing in their body, 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 Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Nikon P90's 3" LCD screen is slightly larger than Panasonic ZS1's 2.7" screen.
In addition to the size advantage, Nikon P90 LCD screen also has a Tilting feature
where you can change the angle of the screen to make it easier to shoot from waist or over the head levels. On the other hand, Panasonic ZS1 has a fixed type screen which provides less flexibility in shooting positions compared to P90.