Wide field, large aperture primes for m43.

Nearly all my lens acquisitions are predicated by a specific photo shoot opportunity.   The need to shoot candid portraits of people at an office Christmas party and at a ballroom dancing gala initiated my first foray into large aperture prime lenses.    These in particular were of a semi telephoto focal length since I would be separated by some distance from my subjects by either the dance floor or to remain innocuous and catch them in a relaxed, natural pose.

I had an altogether different scenario at the recent Toronto International Auto Show where I wanted to shoot some rare and beautiful collector cars, and where there would be enormous crowds and photo ugly stanchions cordoning off the vehicles.  Here, a wide field, short focal length prime would be needed in order to place the camera just inside the barriers to remove most of the crowds and yet be able to frame most if not all of the automobile.  Although I don’t strictly need a large aperture prime since I would be needing a much broader focal plane to keep all the design details of the entire car in focus, as a camera gear head I always want the biggest lens!

Olympus has recently released its 17mm f/1.2 Pro lens and by all accounts its image quality is exceptional.  And so is the price at $1200 USD, but to be fair it is very difficult to design and manufacture a short focal length lens that is well corrected right to the corners wide open.  Another option could be the 12mm Leica f/1.4 and although it costs $1300, it’s been around for so long that there are many used examples available.

Sigma Canada was once again very generous and offered to loan me two of their competing lenses.  The 16mm f/1.4 designed specifically for the Sony E mount and m43 and the 20mm f/1.4 for full frame cameras in EF mount.  I intended to use my Metabones Speedbooster Ultra 0.71x focal reducer with the latter lens so that it would operate as a 14mm f/1.0 lens.  The 16mm Sigma retails for about $450 and the 20mm for twice that.  I also managed to purchase a used 20mm off eBay for the actual price of $400, which happened to be an unusually good price even by eBay standards.

Having neither the Zuiko 17mm or the Leica 12mm to compare the Sigma lenses with, I chose what I had at hand.  The Leica 15mm f/1.7 and the older Leica 25 mm f/1.4 for 43rds mount.

The MTF tests were performed in the same manner as past blog entries.  For new readers, the results do not reflect absolute MTF values since I’m having difficulty with the software when it renders curves with values greater than 1!!!    However, the curves are still useful when comparing the relative performance of a number of lenses tested under identical conditions.  MTF10 curves are in red, MTF30 are shown in green.

The take away conclusion is that the Sigma 16mm is as good as both Leica lenses but the Sigma 20mm with Metabones Speedbooster performs better than all of the lenses even wide open at f/1.0!

But how does this hybrid system work in real life?  All images were taken with tripod using the E-M1.2 50MP high resolution mode, ISO1600  1/60th s, f/4.

1949 Delahaye Type 175 Drophead Coupe

In closing, it’s pretty obvious that lenses get bigger and heavier the faster they get.  What’s not obvious is that there appears to be a fairly predictable and linear relationship between aperture size and lens size.   I graphed the weight and volume data for the tested lenses (Sigma 20mm f/1.4 with the Metabones focal reducer attached) as well as five other m43 lenses in the same focal length region.  Namely, the Leica 12mm f/1.4, the Olympus 12mm f/2, the Olympus 17mm f/1.2, the Olympus 17mm f/1.8 and the Panasonic 14mm f/2.5.

There is a logarithmic linear relationship between mass and volume of a lens and its maximum aperture.

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