I decided to change up my ultrawide lens choice by trading out my Sigma 24mm f/2.8 for a Zuiko 24mm f/2.8. This isn’t really a comment on the Sigma’s quality as it is a pretty sharp lens, but the Zuiko just happens to be sharper (IE very, very sharp) and much smaller. The Sigma could go down to 1:4 reproduction size, but frankly that isn’t something I used much and a 12mm extension tube will allow the Zuiko to go down to about 1:2 as it is.
The 24/2.8 Zuiko is a very, very small lens. You really have to see it in person and hold it to really appreciate its tiny size. It comes in at 31mm in length, just a scant 6mm longer then the famous, or infamous depending on if you just emptied your wallet to buy one or not, Zuiko 40/2 pancake lens.
Beyond its 31mm in length the lens weighs 185g for the later multicoated versions and 180g for the earlier single coated versions (more on this in a moment). The lens takes 49mm filters just like almost all ‘slower’ Zuiko lenses. It has an F-stop range from 2.8 to 16 and can focus down to .25m (1:6.6 reproduction size). The field of view is 84 degrees on the diagonal and is definitely a nice step up from 28mm. If your widest lens before was 35mm then this lens will really wow you by just how wide it is.
I have been unable to confirm it, but since the later multicoated lenses weigh 185g compared to the earlier single coated lenses which weigh 180g this leads me to believe that there were changes to the lens through its life cycle. At a minimum the construction of the lens is different even if the optical design remained completely unchanged. Looking over a number of Zuiko repair diagrams, talking to some people who know what they are talking about and exploring some of Olympus’ literature it looks like a number of their lenses were redesigned over their life cycle. An example is the Zuiko 50mm f/1.4 which underwent at least 4 redesigns over its life that modified the optics, even though the formula remained the same (7 elements in 6 groups). The Zuiko 24/2.8 has at least mechanical changes if not also optical changes, though the number of elements and grouping remains unchanged from the earlier single coated version (8 elements in 7 groups).
Like most Zuiko lenses there is an early single coated version characterized by a chrome ring and/or H. Zuiko on the front of it. There was a ‘short’ production run multicoated version with an MC on the front and then the last version which only read Zuiko on the front and has the NMC coating (New MultiCoating? Nano MultiCoating???).
I haven’t had a chance to test the lens head to head with any others. My Sigma 24/2.8 started giving up the ghost as a very tiny amount of grease from the focusing mechanism migrated to the rear surface of one of the elements. It didn’t seem to impact optical quality at all, but in the interests of a fair test I didn’t/won’t compare them. I have had a chance to test the Zuiko 24/2.8 against itself.
The following series of tests was done tripod mounted using mirror lockup and used the apertures 2.8, 4, 5.6, 8 and 11 respectively. This is the final version of the Zuiko 24/2.8 (NMC coated). Most people claim that 2 stops down is a Zuiko lenses sharpest aperture, well in the case of the 24/2.8 that really is the case. 2.8 is just a little soft, not noticable in anything under an 8×12 certainly and probably not even then. f/4 sharpens up a little more and then f/5.6 is the sharpest sharing that title with f/8 and 11 all three of which are pretty much indistinguishable. Contrast also improves slightly from f/2.8 to f/4. Distortion is also very low with just a small amount of barrel distortion.
For the test I left ICE off so that sharpness wouldn’t be impacted and scanned the negatives on an Epson 4470 at 3200dpi, the images are 100% pixles. No color corrections and no USM applied.
The red highlighted areas are where the samples were taken from. The center area uses fairly low contrast text on the books and the right center crop uses fairly high contrast text on the book. Chromatic aberration is not particularly evident either. Click on the test pictures for the full size versions.
Right center: 2.8/4/5.6/8/11
A final parting crop from the f/2.8 picture of the toy train, not shaving sharp, but still quite good at f/2.8 (100% pixles).