A 135 g, 3× zoom that frames like 23-69 mm, opens to f/3.5 only at the wide end, focuses to 13 cm, and has optical stabilisation but no weather sealing. Bought with the body it is nearly free — and that is the right way to judge it.
15-45 mm f/3.5-5.6 135 g ⌀52 mm 0.24× max
The numbers that matter
| Spec | Value | What it means for you |
|---|---|---|
| Focal length | 15-45 mm (23-69 mm equivalent) | Wide enough for interiors, long enough for portraits |
| Max aperture | f/3.5 at 15 mm, f/5.6 at 45 mm | Zooming in costs 1 1/3 stops of light |
| Min aperture | f/22 | Avoid past f/11; diffraction softens the frame |
| Aperture blades | 7, rounded | Sun stars render as 14 points, not 18 |
| Min focus distance | 13 cm wide, 35 cm tele | The wide end is a surprisingly capable close-up tool |
| Max magnification | 0.24× at wide | Not macro, but close enough for food and detail |
| Optics | 10 elements in 9 groups, 3 aspherical, 2 ED | Genuinely good glass for the price class |
| Filter thread | 52 mm | Cheap filters. A protective one is optional; a hood is more useful |
| Weight | 135 g | The camera stays pocketable in a coat |
| Length | 44.2 mm retracted, 65.2 mm at 15 mm, 62.1 mm at 45 mm | It is longer at the wide end — yes, really |
| Stabilisation | OIS, about 3.0 EV | Your only stabilisation; the body has none |
| Weather sealing | None | No “WR” in the name and no published rating. Keep it dry. |
| Mount | X mount, plastic bayonet | Fine in normal use; do not hang weight off it |
Three corrections to things you will read elsewhere
- Seven aperture blades, not nine. Fujifilm states “7 (rounded diaphragm opening)” on both spec pages and in the printed manual.
- Two rings, not one. A front focus ring (8 mm wide) and a rear zoom ring (13 mm). Most owners never discover the front one.
- Minimum focus is 13 cm, not 5 cm. One widely-syndicated review page prints 5 cm; it is wrong.
Two things Fujifilm does not publish
There is no official aperture-versus-focal-length table for this lens. Only the endpoints are documented (f/3.5 at 15 mm, f/5.6 at 45 mm), with an independent test recording f/4.5 at 28 mm. Nobody publishes the exact focal lengths where it steps. You can build your own table in two minutes, and the exercise teaches you what “variable aperture” means better than any explanation.
Also unpublished: how long the lens takes to extend and be ready after power-on. If you want that number, time it yourself five times and take the median.
Assignment: build your own aperture ramp card
- A mode, aperture set to the widest available value.
- Zoom slowly from 15 mm to 45 mm, watching the aperture readout.
- Write down the focal length at each moment the f-number changes.
Keep that card. It tells you exactly where zooming in starts costing you light, and it is the single most common invisible cause of blurry indoor photographs on a kit lens.