Olympus OM Zuiko 35mm f/2

Introduction

Like its slower, f/2.8 version, Olympus OM 35mm f/2 was manufactured by Olympus up until 2002 at which point it was replaced by Four Thirds lenses specifically designed for the new generation of digital SLRs. While manufacturing for the lens discontinued some time ago, the lens is commonly available on used markets, with good copies of the lens fetching ~US$200 (as of March 2008).

Olympus OM 35mm f/2 is a classical manual lens with fully manual focusing and aperture control. The optical construction of the lens is made of 8 elements in 7 groups. Like most of Olympus OM lenses, the 35mm f/2 variant is pretty light and compact, measuring 42 x 60mm (1.65 x 2.36in) and weighing only 240g (8.46oz). The build construction of the lens is superb - another common characteristic of the OM series lenses of that time. The barrel is all metal, as is the aperture ring, which is located in front of the lens. The focus ring is fully rubberized for comfortable grip and moves very smoothly. The minimum focusing distance is 30cm and the minimum supported aperture is f/16 (the aperture ring is moving in half f-stop increments). The lens accepts 49mm screw-in type filters.

While Olympus changed the mount system for its new SLR cameras, they also released an adapter that conveniently allows owners of OM lenses to use their favorite primes and zooms on the modern Four Thirds systems, albeit in a fully manual mode. This as well as other OM lenses are also easily adaptable to a number of other SLR cameras, including both APS-C and FF bodies from Canon.

Image

Since the lens was originally developed for conventional 35mm cameras, when used on an APS-C body with 1.6x crop factor, the field of view of the lens will be similar to that of a 56mm lens on a full frame body, while when used on a Four Thirds system, its field of view will resemble a 70mm prime.

 

Summary
Lens Composition 8 elements in 7 groups
Angular Field 63 degrees
Minimum Focus 30cm/0.98ft
Focusing Action MF
f-stop Scale f/2-f/16, manual
Filter Size 49mm
Lens Hood N/A
Weight 240g/8.46oz
Dimensions 42x60mm/1.65x2.36"
Lens Case N/A

 

Field Tests

Olympus OM Zuiko 35mm f/2 showed rather weak performance at wide apertures, where resolution was clearly lagging on both APS-C as well as FF cameras. Center image quality was a little bit better then borders, but the emphasis here is on 'a little bit'. Unfortunately, visual image quality improved rather slowly with stopped down apertures - by f/4 quality was just getting to an acceptable level.

 

ISO 400, 1/125, f/2, 35mm (Canon 5D)
ISO 400, 1/125, f/2, 35mm (Canon 5D)

 

Olympus OM Zuiko 35mm f/2 produced pretty round out-of-focus highlights when shot with wide open aperture. Unfortunately, highlights carried distinct bright edging, which is common among lenses over-corrected for spherical aberration. Contrast transitions in near and far OOF areas remained more or less smooth, but the lens showed minor level of double-edging around blurred background objects.

 

Vignetting @ f/2 - full frame vs 1.6x crop (35mm)
Vignetting @ f/2 - full frame vs 1.6x crop (35mm)

 

The lens showed pretty noticeable vignetting on a full frame body at f/2. Vignetting actually continues to persist even once you start stopping down the lens and does not go away completely until f/5.6. Disappointing. On an APS-C body, the lens handled vignetting much better, obviously due to the smaller frame coverage of a cropped sensor. Still, while not as pronounced as with a FF body, the lens did show very minor vignetting on an APS-C body at f/2.

The lens carried a rather low amount of contrast at wider apertures, which made images look washed out and 'lifeless'. Contrast does not improve until the lens is stopped down to about f/8. The lens also produced pretty heavy halation (axial CA) with wide open apertures. Notice well defined haloes around bright white tree flowers in the first image in the image gallery. Color fringing (lateral CA) was present as well, predominantly around corners. The lens also fell prone to pretty heavy flare at wider apertures and aperture ghosting with smaller aperture levels. All that somewhat surprising for a multi-coated lens. Finally, OM Zuiko 35mm f/2 showed minor degree of barrel distortion.

 

ISO 100, 1/1000, f/2, 35mm (100% crop)
ISO 100, 1/1000, f/2, 35mm (100% crop)

 

Lab Tests

Please note that MTF50 results for APS-C and Full-Frame cameras as well as cameras from different manufacturers are not cross-comparable despite the same normalized [0:1] range used to report results for all types of cameras.

 

Four Thirds: Coming soon...

 

Canon APS-C: Image resolution was somewhat of a mixed bag with Olympus OM 35mm f/2. The lens showed rather weak performance at f/2, both in the center as well as around borders. Quality improves once stopped down to f/2.8 where the center quality is already pretty good and border quality is quite decent as well. But the lens shines in the f/4-f/11 range with ever slightly better overall results at f/8. At its peak (f/8) the lens is capable of delivering outstanding 19in prints and you can get pretty decent quality 24in prints in the entire f/4-f/11 aperture range. Conclusion? Performance in the f/4-f/11 range is pretty much what you would expect from a solid wide angle prime. Quality at f/2 is disappointing though. Can't say that this is unusual though - majority of wide angle lenses show some weakness at their widest aperture settings.

 

MTF50 (Line Width/Inch on the Print) @ 35mm
MTF50 (Line Width/Inch on the Print) @ 35mm

 

Normalized raw MTF50 @ 35mm
Normalized raw MTF50 @ 35mm

 

The lens showed decent handling on chromatic aberration in the center, where CA was hovering around ~0.4px, which can be considered pretty low. Unfortunately, CA around borders was much higher, averaging ~1.2px at f/2 and  ~1px at f/2.8, and then slowly dropping to a more manageable ~0.7px by f/11.

 

Chromatic Aberration (APS-C) @ 35mm
Chromatic Aberration (APS-C) @ 35mm

Here are 100% crops comparing images taken with Canon Digital Rebel XTi at f/2 and f/8.

 

Image borders @ 35mm (100% crop): f/2 vs f/8
Image borders @ 35mm (100% crop): f/2 vs f/8

 

Canon FF: Olympus OM Zuiko 35mm f/2 did not produce any miracles on a full frame Canon 5D, and performance at f/2 was as mediocre as on an APS-C camera. However, while image quality in the center improves once stopped down to f/2.8 (and remains on a consistently high level throughout the rest of the aperture range), border performance lags quite noticeably and does not get to really good levels until f/4, with f/2.8 being sort of a transition point - overall performance here is not spectacular (due to border weakness), but is not quite terrible either. Conclusion? This is not what I expected from the lens - performance is still pretty good in the f/4-f/11 range, but border weakness at f/2 and f/2.8 is a bit disappointing.

 

Normalized raw MTF50 @ 35mm
Normalized raw MTF50 @ 35mm

 

The lens handled with chromatic aberration a bit better on a full frame body. CA in the center averaged ~0.3px across the frame, while CA around borders hovered around ~0.9px at f/2 and at ~0.7px throughout the rest of the aperture range.

 

Chromatic Aberration (FF) @ 35mm
Chromatic Aberration (FF) @ 35mm

 

Here are 100% crops comparing images taken with a full frame Canon 5D at f/2 and f/8.

 

Image borders @ 35mm (100% crop): f/2 vs f/8
Image borders @ 35mm (100% crop): f/2 vs f/8

Alternatives

As mentioned earlier, Olympus used to manufacture another variant of the 35mm prime - OM 35mm f/2.8. Both of the 35mm lenses offer very similar characteristics, but obviously vary in price. For slightly wider angle, you might want to consider three other OM primes - OM 28mm f/2, OM 28mm f/2.8 and OM 28mm f/3.5. If you're looking for some alternative glassw, then consider Carl Zeiss Distagon T* 35mm f/2.8 or its faster version Carl Zeiss Distagon T* 35mm f/1.4, both of which were manufactured in the now defunct Contax/Yashica mount. The latest edition of Carl Zeiss Distagon T* 35mm f/2 is currently available in ZF/ZK (Nikon/Pentax) mounts and is also worth exploring. Alternatively, check out Leica's Elmarit-R 35mm f/2.8, Summicron-R 35mm f/2 and Elmarit-R 28mm f/2.8. For a side by side comparison of a number of popular 35mm primes, including Olympus OM 35mm f/2, you might also want to check out the 35mm Challenge.

 

Recommendation

Olumpus OM Zuiko 35mm f/2 does not quite live to the expectations. Resolution-wise, the lens is not necessarily a bad performer - f/2 is the weakest spot, but quality improves with stopped down aperture and is quite decent from f/4 through f/11 on both APS-C as well as FF cameras. So where does the lens disappoint? Primarily in handling of various artifacts. Axial and lateral CA, vignetting as well as low levels of contrast make this lens rather hard to use effectively at wider apertures. This is what makes it so hard to make a clear cut decision on this lens - if you are willing to accept the idea of shooting at smaller apertures, then this lens might be a possible option for you. The idea is certainly quite appealing considering its relatively low price. On the other hand, if you only care about smaller apertures, then you might as well consider other, slower 35mm lenses.