Sigma Corporation has been around since the early 1960s, always offering third party lenses with innovative design and prices designed to beat the OEM boys at their own game. Today, Sigma is no longer the upstart but part of the establishment by manufacturing their own critically respected (if not commercially) Foveon line of cameras. I have one of their DP2 Merrill compact cameras and while a pain to live with, can produce remarkable color images rivaling those from a medium format digital camera.
They are now so well integrated with the Japanese camera marques that it isn’t surprising that Sigma quietly performs a lot of subcontract work for them. Here’s an example of a Sigma lens patent for a 75mm f/1.8 lens that later became one of Olympus’ best performing m43 primes.
And despite gaining legitimacy, they haven’t forgotten their roots and insist on making lenses nobody else is brave enough to manufacture, like the monster 200-500 f/2.8 zoom!
We’re dealing with a slightly different league of Sigma monster and one I thought about acquiring for quite some time until the right eBay auction caught my eye and I caved – it’s the Sigma EX APO HSM 300-800 f/5.6 zoom.
This lens was available in early 2003 for MSRP of $5900 USD. In fifteen years the lens has depreciated 50%, but so has the purchasing power of the dollar. You can still buy essentially the exact same lens brand new for $8k. It still has 18 elements placed in 16 groups with 2 extra low dispersion elements and weighs about 13 lbs and is 25″ long with the shade afixed. In 2006 they added the DG designation for new optical coatings that reduce ghosting but otherwise nothing has changed. In the same year they also made the lens available in the 43rds mount and those rare birds do occasionally become available for resale but the Canon mounts fetch the best prices because of demand. Again, nobody offers a lens with such a versatile fixed aperture focal length range that is (relatively) affordable and light enough to actually use hand held for brief moments. My average is about 5 seconds and I did shoot the Moon successfully but you will need to invest in a gimbal head and monopod to use this lens on a consistent basis.
I also couldn’t wait to use my Metabones Speed Booster T Ultra and turn it into a 210-570mm f/4 zoom. Bring a few small primes and this beast and that’s all I need for an African safari photo adventure.
The following MTF curves were generated with the same setup I’ve used in the past but with a few interesting caveats. I boosted the ISO to 800 since the lens is slower and I wanted to minimize any blurring artefacts caused by lens shake. Just focusing induces the lens to shake and I have to fire with a remote USB shutter release to prevent all physical contact with the lens and typically wait 5s for the vibrations to vanish. This is only relevant to the slow (1/15s) shutter speeds I’m using for my interior lit targets and exterior daytime shots should not be affected at all. The lens has a minimum focusing distance of about 20 feet so for the shorter focal lengths (300mm and 210 with the Speed Booster) you need to use a 15mm spacer to attain focus and correctly frame the ISO12233 target. For my m43 brothers, you will need an EOS spacer with electronic contacts to keep the AF and aperture control working when using a Metabones Speed Booster since you can’t add a m43 spacer behind the focal reducer.
First column (top to bottom): 800mm f/5.6, 500mm f/5.6 & 300mm f/5.6 Second column (with Metabones Speed Booster T Ultra): 570mm f/4, 330mm f/4 & 210mm f/4 Third column: Zuiko 300mm f/4 Pro
Like most zoom lenses, the highest focal length tends to exhibit some loss of image quality but in this case the loss is minimal. With the Metabones Speed Booster you get sharpness at f/4 approaching the Zuiko 300mm f4 Pro. These are of course anecdotal findings and there is a wide variation of performance amongst these mass produced camera lenses but based on my personal experience, the Sigma 300-800 appears to be a winner!
All these images were taken at 800mm focal length f/5.6 and are uncropped using an Olympus E-M1.2 body and Metabones T adaptor. Also used, a very old Manfrotto monopod and a Chinese knockoff Wimberley gimbal head. Aiming the lens can be difficult so people often suggest finding the target at 300mm and zooming in. Since I have a lot of experience using telescopes, I found little difficulty working at 800mm, finding and tracking my living targets.
Jim Chung's Ramblings 