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 Fujifilm X-T1 IR and Pentax X90 side-by-side from the front, back and top in their relative dimensions. Fujifilm X-T1 IR has external dimensions of 129 x 90 x 47 mm (5.08 x 3.54 x 1.85″) and weighs 440 g (0.97 lb / 15.52 oz) (including batteries). Pentax X90 has external dimensions of 111 x 85 x 110 mm (4.37 x 3.35 x 4.33″) and weighs 428 g (0.94 lb / 15.10 oz) (including batteries).
Below you can see the front view size comparison of Fujifilm X-T1 IR and Pentax X90. Pentax X90 is 18mm narrower and 5mm shorter than Fujifilm X-T1 IR but it is also 63mm thicker. As you can tell, actually this is not a fair size comparison since Pentax X90 has a built-in lens but Fujifilm X-T1 IR doesn't. Once you put a lens on X-T1 IR, its thickness will increase significantly.
Here is the back view size comparison of Fujifilm X-T1 IR and Pentax X90.
Now lets look at the top view comparison of Fujifilm X-T1 IR and Pentax X90.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Pentax X90 is 12g lighter than the Fujifilm X-T1 IR but we don't think this will make a significant difference.
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 X-T1 IR, the total kit will weigh much higher.
With its weather sealed body, we believe that X-T1 IR has a big advantage over X90 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Fujifilm X-T1 IR's 3" LCD screen is slightly larger than Pentax X90's 2.7" screen.
In addition to the size advantage, Fujifilm X-T1 IR 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, Pentax X90 has a fixed type screen which provides less flexibility in shooting positions compared to X-T1 IR.