
Introduction
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional is a compact, light-weight and weather-sealed ultra-wide-angle to straightforward zoom lens for the Micro 4 Thirds system.
That includes a 35mm equal focal vary of 16-50mm, the Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional gives a continuing most aperture of f/4 all through its zoom vary, plus quick and quiet auto focusing.
It has an optical formulation comprised of 16 parts organized in 10 teams, together with one DSA (Twin Tremendous Aspherical) aspect, one ED (extra-low dispersion) aspect, two aspherical ED parts, one Tremendous ED aspect, one HR (high-refractive index) aspect, one Tremendous HR aspect, and one HD aspect.
Different highlights embrace a minimal focusing distance of 23cm and a most magnification of 0.21x, with a ZERO (Zuiko Additional-low Reflection Optical) coating to manage aberrations, ghosting and flare and a Fluorine coating to guard towards mud, water droplets, grease, and filth.
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional lens is on the market now priced at £899.99 within the UK and $1099 within the US. The 8-25mm F4 is manufactured in Vietnam.
Ease of Use
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional is a weather-sealed wide-angle zoom lens with a devoted Micro 4 Thirds mount that’s fabricated from metallic, with a rubber seal across the mount. Communication between lens and digicam physique is offered via eleven electrical contacts.
Word nevertheless that with a view to take full benefit of the weatherproofing, you have to to mount it on a equally weather-sealed physique, like the brand new flagship OM System OM-1 digicam that we examined it with.

Tipping the scales at 411g and measuring 88.5mm in size and 77mm in diameter, the Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional is a compact and light-weight ultra-wide-angle to straightforward zoom lens.
When it is unlocked and zoomed out to 8mm, although, it does achieve one other 3cm in size. It is truly a bit of shorter in size when set to 25mm than at 8mm.
The OM System OM-1 used for this check is an excellent match for the lens, providing good stability, quick auto focus, and full environmental seals.


The M.Zuiko Digital ED 8-25mm F4.0 Professional lens may be very nicely constructed, absolutely dwelling as much as the PRO designation that Olympus have given it.
When it comes to options, the M.Zuiko Digital ED 8-25mm F4.0 Professional gives a lot of the similar controls provided by a few of the larger, quicker Olympus Professional lenses.


As with all Olympus M.Zuiko lenses, the 8-25mm F4.0 Professional doesn’t supply picture stabilisation. As an alternative that is offered by the digicam physique, on this occasion the frankly wonderful 5-axis system within the OM-1, which gives 7 stops of compensation when paired with this lens.
So whereas the dearth of in-lens picture stabilisation is a non-issue for Olympus digicam customers, house owners of different producers merchandise who do not supply in-camera picture stabilisation in a few of their cameras, like Panasonic, might wish to take into account a distinct lens.


With the 8-25mm lens connected to an OM-1 physique, focusing proved to be very fast in most conditions. This mixture is able to locking deal with a topic virtually immediately, even when alternating between shut and faraway topics.
In excessive low-light conditions chances are you’ll expertise a bit of focus searching on the lengthy finish, the place a lens with a quicker f/2.8 fixed aperture would assist keep away from this.



Guide focusing is finished in a standard vogue, with the adequately sized focus ring mechanically coupled to the transferring lens parts, though there are not any exhausting stops at both finish. Focusing is absolutely inner and the filter thread doesn’t rotate on focus.
There’s a reasonably sized focusing ring across the lens, which you should utilize when manually focusing the lens. You may snap again the focusing ring to vary from auto focus to guide focus in a particularly fast movement, snapping it again once more if you wish to swap again to utilizing autofocus. When within the guide focus place, you may see a number of focal distances are displayed in each meters and toes.



Slightly below the zoom ring on the base of the lens is a operate button, marked L-Fn, which could be customised by way of the digicam’s primary menu to manage numerous completely different actions. One helpful operate is depth of subject preview – this lets you see how your picture will have a look at the chosen when you maintain down the L-Fn button, and is especially helpful when working with slim apertures.
The Olympus M.ZUIKO Digital ED 12-45mm f/3.5-6.3 EZ lens contains a 72mm filter thread and a entrance bayonet for attaching the equipped LH‑76E petal-shaped lens hood, which twists into place to lock and launch it from the lens. The filter thread doesn’t rotate on focus, which is nice information for anybody intending to make use of a polariser or ND grads.






Focal Vary
The 8mm focal size gives an angle of view of 107 levels.

8mm
The 25mm focal size gives an angle of view of 47 levels.

25mm
Chromatic Aberrations
Chromatic aberrations, usually seen as purple or blue fringes alongside contrasty edges, should not an excessive amount of of an issue with the Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional lens, besides in areas of very excessive distinction.

8mm

25mm
Vignetting
With the lens set to its most aperture of f/4, there’s some gentle fall-off within the corners, requiring you to cease down by at the least 2 f-stops to fully stop it.

8mm

25mm
Distortion
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional does not exhibit an excessive amount of barrel or pincushion distortion, as you’ll be able to see within the pictures beneath.

8mm

25mm
Sunstars and Flare
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional is able to producing good sunstars when stopped-down to f/22, as proven beneath, though the lens is vulnerable to flare when capturing immediately into the solar, even with the equipped lens hood fitted.

8mm

25mm
Macro
The Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional will not be actually a macro lens, nevertheless it does supply a usefully shut focus level of 23cm / 9.05in throughout your entire zoom vary from the sensor airplane and a most magnification of 0.21x.






Bokeh
Bokeh is a phrase used for the out-of-focus areas of {a photograph}, and is normally described in qualitative phrases, comparable to clean / creamy / harsh and so forth.
Olympus have paid shut consideration to this facet of lens use, using a 7-segment diaphragm with rounded blades for pretty pleasing bokeh.
In our view, their efforts have been fairly profitable for an ultra-wide to straightforward zoom lens – see the examples beneath to guage for your self.










Sharpness
In an effort to present you the way sharp the Olympus M.Zuiko Digital ED 8-25mm F4.0 Professional lens is, we’re offering 100% crops on the next pages.