Sigma 105mm f/2.8 EX DG Medium Telephoto Macro Lens for Olympus and Panasonic SLR Cameras

I've been holding out for the long-awaited Olympus 100mm prime, which is on the lens "Road Map", projected for 2008, then 2009. But when it was not officially announced at PMA this year, I decided it was high time to try this Sigma.

I recently bought the Sigma 30, and have been thrilled (I gave that 4 stars but I would give it 5 in retrospect). Fast lenses provide such great artistic control over backgrounds, once you get used to them the slow (but otherwise good) kit lenses do not go on the camera very much.

It is well built, a pleasure to use. It focuses fairly fast on my E-510, although if it "misses", and if you don't have the Limit switch turned on, it will focus all the way in to macro and back out, which takes an age. Focusing speed seems to be affected by battery state - especially in poor light - and a battery in its last 1/3 will focus noticeably slower.

The front element is buried down almost in a tunnel - the included hood is quite unnecessary. This piece of glass is also surprisingly small. Photo geeks like to show off big lenses with big glass - it looks expensive because it IS expensive - and it is a little surprising that the advertized length and speed could be accommodated with a physically small piece of glass.

I haven often read on photo forums where photo beginners want pictures of their kids playing little league indoors, like basketball. This would be a great lens for this - and quite affordable, too.

Speed is everything for indoors action shots. The Sigma is pretty fast at f/2.8. The roughly equivalent Olympus kit lens is the 40-150 f/4-5.6, which you will note gets slower as the zoom goes out. At 105mm, it will be about 1.5 stops (=2^1.5 = approx 3x) slower than the Sigma. For indoor shooting, all else being equal, if you have 1/30th on the kit lens, you will see 1/60th or even 1/100th on the Sigma. The Sigma will shoot much superior pictures for this subject.

On a four-thirds camera, 105mm is a bit longer than a classic portrait length. You will be standing about 10 feet away from the subject for head shots, and 20ft or even 40ft for body shots depending on whether it is a child or adult. However, it shoots crisp portraits in the modern style - if you want any of the old-fashioned but often flattering blooms or other distortions of old lenses, check out M42 screw-type lenses and adapters on ebay, or use Photoshop.

The bonus is the macro feature. This was not a selling point for me at the time, but having used it, there is a lot of nature's art that reveals its beauty up close. Small buds breaking into flower, blades of grass, small insects, interesting surface textures, these are easy subjects to enhance your enjoyment of the hobby.

The Sigma 105mm has received praises for many systems, and in some instances these rave remarks are rightly due. The lens is an excellent value with a good build and super sharp optics. However there are many quirks with the lens that often get overlooked. The auto-focus performance is worse than lackluster and switching from auto to manual focus is a bit tiresome. The build is good, but the design provisions for the lens hood and cap are disappointing coming from a manufacturer with so many years of experience.

The Sigma EX series of lenses are the top grade lenses within their lineup. Being such, the lens comes nicely finished in its matte black and gold decor with a very well made, padded, zip-up lens pouch. The lens itself has a nice heft, but is not overburdening and should fit quite comfortably on most cameras. One of the best, and most often used with macro, features is the mechanical manual focusing. This is much nicer to use than the focus-by-wire on other Four-Thirds lens brands and provides a solid and tactile feel when focussing. The glass is exceptionally sharp, bringing detail to a photo you would not have thought possible. And of course being a Four-Thirds mount, that 105mm focal length acts like a 210mm making for a very nice telephoto prime and gives excellent magnification for use as a macro lens.

But all of these bonuses come at a cost. To be such a nicely finished lens, I found the build could have been better in two areas; the lens hood design, and the auto-focus switching procedure. It is nice that the hood has a provision to use 77mm filters, especially polarizers. But the hood, being a screew-in type, does not reverse for storage on the lens. To make it worse, there is not even a provision that allows the provided lens cap to snap in place while the lens hood is in use. This could have been easily allowed by protruding the threads used to mount the hood to the lens on the inside of the hood to give the cap something to attach to. A pretty big oversight in my book.

To switch between auto and manual focus on other lenses is straight forward. You flip a switch on the camera body or lens or shift the focussing collar. On the Sigma, you have to do ALL three. To gain proper manual focus, you have to change the setting on the camera body, flip the switch on the side of the lens, and shift the focussing collar if you don't want it turning under your hand. Now why couldn't Sigma do like Tamron and Tokina and make it so you only have to shift the focusing collar? I guess that makes too much sense.

The biggest performance disappointment is with the auto-focus itself. Especially with a 2.8 aperture, you would think this would make a nice telephoto for use in low light. But the auto-focus is not very sensitive, which I know is in part due to my camera. But my LEICA zoom can focus faster than this lens in low light. And even in bright light, the lens tends to jerk back and forth multiple times before the focus is confirmed. This is much worse than any Zuiko lenses I've tried. Also, if you want a sharp image, you had better use the central focus point. The camera tends to prefer the outer ones if you let it choose. And if it does, the pictures come out slightly out of focus. It isn't critical if you are printing small, but you can forget printing enlargements.

Overall this lens is a bit of a mixed bag. It is a quality optic at an excellent value, but it is far from perfect. I am pleased with the results when I remember to make adjustments in the way I use the camera-lens combination. If you can live with the issues that using this lens presents, then you will have a quality piece. But if you think any of these issues will be a problem for you, then you had best look to a different lens. I can only hope that Sigma will make some improvements on the design and functionality of this lens in the future. Then I could gladly give this lens an outstanding commendation.

I've owned this for over a month and have shot close to a thousand pics with it. It is fast - f2.8 - accurate and produces closeup shots with great detail.

It's also a great ''walk-about'' lens since it focuses from 12 inches to infinity. And the 105mm length (200 mm equivalent on a 35mm slr) is a great medium-telephoto length.

The unit is well built, solid and light enough to handhold. I own it in a 4/3 configuration (Olympus E-500 camera) and love the ability to switch from auto to manual in about 2 seconds, and to limit the auto focus to a limited range at the touch of a switch. I found that I can switch from auto to manual without looking, and love the large focus ring.

I use this coupled with the Olympus 25mm macro extension ring, and it produces amazing close shots. The lens itself is 1:1 and the extender boosts that considerably while retaining all my auto lens settings and capability.

I don't mind the matte finish, and love the fact that it doesn't generally need a lens shade because the front element is recessed quite a ways into the front of the housing.

I've been using some old Nikor and Sigma manual lenses from the 1970s, 80s and 90s, but they can be frustrating to open the aperture and focus and then stop down to shoot - especially with insects. By the time I open the aperture, focus and stop down they have often moved. And when a manual lens is stopped down to f/8 or f/11 it's too dark to see what's going on. The Sigma being coupled with my camera's electronics solves the dilemma and delivers bright views to the viewfinder.

You cannot preview the DOF, but a quick shot and chipmunking the viewfinder will show you what's going on.

I'd recommend this lens to anyone who is serious about macro work, and doesn't want to pack a ton-o-gear around with them. Being able to carry just the body, lens, and extender plus a tripod is enough gear to do some serious shooting.

I attach the olympus ring flash using the sigma hood (which comes with the camera) and a little duct tape. it works great.

Of all my Four-Thirds compatible lenses this has become a favorite. The Sigma is sharp, reasonably compact and features an actual manual focus mode. Yes, the 50-200mm Zuiko covers this range and is just as sharp, but this lens is much smaller and lighter than the Olympus lens and is, of course, a macro lens that focuses much closer than the Zuiko 50-200mm.

Despite being optimized for macro photography, this lens works quite well for general photography and has a bokeh that is a bit more pleasing than many of the admirably sharp Zuiko lenses. In macro operation the lens often gives a greater distance from the subject than the Zuiko 50mm macro lens does, but this lens is not (as far as I can tell) able to mount the Olympus ring flash for macro work so I use it strictly for outdoors and ambient light macro work (Edit: I have since purchased the Olympus twin flash and it works very well with this lens via an easily obtained step ring adapter.)

The build quality of the lens is not up to the level of the better Zuiko lenses and it is not a weather sealed lens but it is certainly of a higher quality than the Olympus kit lenses that normally ship with cameras like the E-410/510. It's also a higher quality lens than the inexpensive Sigma zoom lenses that have been available for Olympus and other Four-Thirds applications for some time now. I would say that it has a nice feel to it both in heft and in operation.

Due to optical designs that I do not pretend to understand the front element of this lens is remarkably deeply recessed into the lens housing. In fact, it's so deeply recessed that I don't feel the need to use the supplied screw on sun shade (which is a poor design in my opinion) nor do I feel the need to use a clear filter in order to protect the front element (it would be difficult to bang it on anything given how far from the front of the lens it is). One might view this as a money saver as well as a convenience but that's a very subjective opinion I do admit.

Finally, the lens features a fully manual focus mode that works very well but unlike the 'fly by wire' Olympus lenses that many are familiar with this lens requires that you throw a switch on the side of the lens housing in order to disengage the auto-focus motors. This is not terribly convenient, however with practice one certainly can train themselves to operate the switch without taking one's eye from the viewfinder.

To sum it up, I did not expect great things from this lens given that some of the Sigma lenses in the Four-Thirds mount have been a disappointment but I was pleasantly surprised by this lens. It is sharp at maximum aperture, it is moderately priced, it is an excellent macro lens, and it is a fine medium telephoto lens on top of it all. I can highly recommend this lens as a handy addition to any Four-Thirds DSLR camera kit provided weather & dust sealing is not required.