My need for telephoto started at age fourteen when I would stalk tigers in the jungles of India with a Nikon FE and a 300mm Nikkor with a roll of 36 exposures Kodachrome 64 in the camera and if lucky, another roll in my pocket. All Manual Focus, no Image Stabilization, no LCD to check ‘playback’, no post processing to sharpen, adjust Chroma or contrast. No luxury of shooting in a burst mode, always being afraid of finishing the roll of film prematurely. Leopard with a cub on the tree feeding on a gazelle? Get exposure, focus, framing and press the shutter only when the moment seemed perfect as later cropping or even horizon straightening would be difficult.

As time passed I got busy making a career and started working full time with motion picture camera and stopped all still photography until fifteen odd years later when I bough a new camera, everything had changed. The new camera, a Canon 5D2, had great features available but came with a huge learning curve. Someone who got focus just by aligning two split images together had to learn how to select focus points, technique of center focus and recompose, servo focus, back button focus. Then histograms, sensor cleaning, micro adjustment…! Learning camera was not enough; I had to learn how to process photos myself – Photoshop is a different beast altogether.

The reason for this little background is for you to know how I marvel the advancement of technology and am not at all super critical of issues in equipment. I prefer to use the gear that I can afford and try to get the best results by overcoming the shortcomings of it.

About two years ago I was amongst the first ones to buy the Canon 200-400 f4 lens to replace my 300 f2.8 and 600 f4 (Both version 1). I have been travelling to Africa every year for wildlife photography and the zoom seemed to work better than carrying two lenses and getting the perfect composition quickly rather than having to put one camera down and pick up the other with appropriate lens. Things happen very fast in the bush (!) and zoom would work better. But I soon realized that I had an $11,000 lens sitting in the shelf for 20 days of use per year. Besides I was not thrilled that I had to switch a lever to engage the 1.4 extender to reach 600 mm. Sigma announced the 150-600 sports version for just $2000 and that got me thinking: slightly lighter, no lever to play with, whooping $7000 cheaper. I sold the 200-400 just two months before my scheduled February 2015 Kenya safari with the hope that I will buy the Sigma and take it along. I sold the 200-400 urgently thinking (stupidly) what if the Sigma turns out super and the price of the Canon lens falls? I preordered at all top stores – Adorama and BH photo included – but no luck and time was running out fast. I started questioning my timing of selling the 200-400 and nervousness started setting in. One fine morning I checked on Ebay and Samy’s Camera in LA was selling it. Turned out that they had only one copy and no one had preordered from them. Immediate buy! The lens arrived four days before my departure and after two endless days the AFMA settings looked like:

I have not done AFMA (Auto Focus Macro Adjustment) on any Sigma lens (or bought a 3^rd party lens) before so do not know if the calibration is extreme. I guess it does not matter, as long as makes the lens give sharp pictures. I find the AFMA process very tedious and error prone. I can never be sure if the settings I choose are correct and wish there was an absolute foolproof method. With the lens calibrated to the best of my ability I mounted it on my 1dc and never took it off for next two weeks on safari in Kenya. Here are some of the photos I took with this lens. (Right click and open in new window to see 1280 pixels wide shots.)

470mm @ f 6.3 1/500 ISO 200 (Full frame & 100% crop)

401mm @ f6.3 1/100 ISO 1600 (Full frame & 100% crop)

600mm @ f 6.3 1/200 ISO 400 (Full frame & 100% crop)

600mm @ f 6.3 1/320 ISO 1250 (Full Frame & 100% crop)

600mm @ f 6.3 1/200 ISO 500 (Full frame & 100% crop)

600mm @ f 6.3 1/160 ISO 1600 (Full Frame & 100% crop)

200mm @ f 6.3 1/50 ISO 2000 (Full frame & 100% crop)

300 @ f 6.3 1/1,000 ISO 1600 (Full frame & 100% crop)

600mm @ f 6.3 1/800 ISO 1250 (Full Frame & 100% crop)

600mm @ f 10 1/400 ISO 400 (Full Frame & 100% crop)

600mm @ f 6.3 1/125 ISO 3200 (Full Frame & 100% crop)

321mm @ f 6.3 1/320 ISO 400 ( Full Frame & 100% crop)

309 mm @ f 5.6 1/800 ISO 400 (Full Frame & 100% crop)

600mm @ f 6.3 1/125 ISO 500

On close examination of the results I find the pictures not as sharp as I would have liked. My shooting methods remain the same as before: Always on servo focus and careful placement of focus point, but on the same camera I got sharper – much sharper results from the Canon 200-400 demonstrated here. Shot at f4:

338mm @ f 4 1/800 ISO 400 (Full frame & 100% crop)

I did not find the above sharpness in any of the Sigma photos. At full frame the difference is not as noticeable as at 100% crop. Here each whisker is sharp! The MTF charts show that the Canon is indeed sharper. I am sure this does not come as a surprise to many. Sigma 35 mm A lens may be sharper than Canon’s 35 mm but when it comes to telephoto, Canon rules.

But was I doing anything wrong with AFMA? I decided to check sharpness using live view, tripod, IS off and such. Will I continue with this lens for my telephoto needs or replace with some other lens? Lets investigate together.

To compare the sharpness of the lens I tried to rent a 200-400 to compare with but did not find a single lens in Mumbai and so settled for another of Canon’s sharpest zoom: 70-200 mm f 2.8 Version 2.

The Sigma held up very well to the industry standard Canon zoom lens at 200 mm. Very reassuring.

Next I wanted to compare the Sigma at 200 mm v/s 600 mm at f5.6 and f11:

At 600 mm the lens looked much softer than 200 at full open f-stop. The lens becomes sharper at f 11 but the 600 mm sharpness full open prompted me to do another test and here are the new results:

This time around the results are a little better but 600 is again softer than 200. Not happy as I would generally not have enough light for f 11 where the lens looks much better at the long end:

Here the difference is much less – Remember we are looking at 100% crops and in actual life we will never zoom in so much. This is how it looks full frame:

At full frame the Sigma’s IQ at 200 mm and 600 mm seems identical for all practical purposes. (No contrast/sharpening enhancements applied.)

Auto Focus Performance: I found the lens to focus well and not hunt so much. Perhaps other lenses focus faster but this focuses fast enough and I never (never!) missed a single shot because of focusing or tracking speed, the few that were out of focus were operator error. Some other lenses I have used (Canon) focus much faster – here I could sometimes see the focusing (v/s instantaneous) but this never came in my way of catching action. The lens can be programmed for fast or more secure focus. I always want my photos to be in perfect focus and kept the settings to ‘Focus accuracy-priority’ instead of ‘Motor’s drive speed-priority. Besides the camera in use plays a huge factor in focus performance and the distinction between both becomes difficult to discern.

Image Stabilization Performance: In my previous telephoto lenses whenever I engaged the IS switch I could always feel the shake reducing. Interestingly enough I never felt the steadiness change on flicking the switch making me doubt if the IS was working or not. I made a test and was happy to see that I could hand hold the lens @ 600 mm and get sharp pictures at 1/40 shutter.

Handling: Zoom ring works both if rotated or pushed/pulled. I found it easier to zoom using the push/pull method but that is I, someone else may prefer to rotate. There is a convenient zoom lock provided which makes it possible to lock the lens at all focal length markings only. The handle to carry the lens is very badly designed. It has sharp edges and digs into the palm and the distance between the lens and the handle (tripod mount) is so less that knuckles keep scraping against the lens. I have average hands, wonder how bad it will be for people with larger hands!

Zoom Range: The 150-600mm zoom range is near ideal for wildlife photography. It falls a bit short for birds on full frame and sometimes too tight on crop sensors but this is the ideal zoom range to cover most situations in the bush. When on ‘off-road’ safari in most private game reservers and where the guides go off road when rangers are not watching 600mm prime lenses tend to be very tight. But when in strictly no off road situations – e.g. most of Kruger and Etosha National park 600mm can sometimes be bit short. So overall this is a brilliant zoom range. On a crop sensor this lens would be appropriate for distant bird photography as well.

F Stop: F5.6, the average opening of this lens is not too fast, but is this a matter of concern? Every passing year modern camera’s are delivering better and better IQ at higher ISO – with modern full frame camera delivering amazing quality un to 2500 ISO, a lens with f5.6 opening works fine. There is a period of about an hour early in the morning and late in evening when the f4 of Canon’s 200-400mm would be desirable but outside of that f5.6 is just fine. The f2.8 of a prime 400mm lens gives lot extra light and a shallow depth which is fantastic when required but lacks the zoom flexibility and the shallow depth can be (actually is) a big limiting factor when trying to get the entire animal in focus or when capturing wildlife behavior moments when more than one eye is required in focus. In my opinion the average f5.6 opening of the lens is not a problem as such. Do realize that f4 lens would be more expensive, larger and heavier.

The images from Kenya not being perfect could have been due to imperfect AFMA but I can never be sure. The live view tests I made seem to show improvement in sharpness but only marginally. At $2000 the lens is a bargain and can be used perfectly well to make impactful photos. If I ever get a paid assignment I will immediately swap this with the Canon 200-400. The upgrade would be for a combination of IQ, IS, AF and perhaps for mental security.

To get all details of lens: MTF charts, weight etc visit http://www.sigmaphoto.com/product/150-600mm-f5-63-dg-os-hsm-s

And of course wait for Bryan’s review at http://www.the-digital-picture.com/Reviews/Sigma-150-600mm-f-5-6.3-DG-OS-HSM-Sports-Lens.aspx

If you have any questions or comments, please let me know.

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