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Sigma 150mm f2.8 APO Macro DG EX HSM

Review Date: May 4, 2006 Recommend? yes | Price paid: $520.00 | Rating: 9 

Pros: Zero distortion, CA and vignetting (on 1.6x crop), small for 150mm, very well built, relatively inexpensive, tripod collar, hood and nice case included.
Slightly inaccurate autofocus.

When I decided to get a macro lens for my 350D, I had no idea how difficult it would be to choose the right one for a newbie like myself.

After many hours of "googling" and absorbing all info I could find on macro equipment, macro photography in general, tips and techniques etc., I realized that I really needed to complete some sort of questionnaire before taking any further steps. Here are the questions, my answers and my decisions based on those answers. I am sure many people will find this approach inconclusive, but I hope some will find it helpful, too.

Q: What is my budget?
A: One thousand USD.
D: Canon 180mm L good-bye. Especially considering the fact that I'll need more than just a lens.

Q: What would I like to photograph?
A: Live insects, arachnids, other arthropods. Most of them can be easily scared. And I definitely don't want to put them into fridge before shooting them.
D: Longer lenses look much more attractive, especially those with inner focusing systems. Not many of my potential subjects will tolerate close approach of an (extending) lens barrel.

Q: Do I need versatility from a "real" macro lens?
A: To an extent. I need infinity focus, other than that, I am not willing to sacrifice macro performance for anything else.
D: Canon MP-E 65mm is not for me.

Q: How important is AF?
A: I'd love to have accurate and fast AF. But manual focusing is the only good choice with real macro anyway.
D: Nothing focuses as fast as a genuine Canon lens on a Canon body Smile But since it's not that important, I can also look into third party lenses.

Q: What kind of lightning setup I am going to use?
A: Toughest of all questions. With macro, natural light can only be used in very limited circumstances. Since I don't have anything at the moment except built-in joke of a flash, I'd very much like to get something more versatile than a ring-type dedicated macro flash. Besides, if the lens is long, the ring type light is not going to be very effective. The hot-shoe mounted flash is going to be even less effective, but it can be moved forward on a bracket, which I will probably be able to make myself. I can also make, or buy, a diffuser or softbox. If I have no choice but to buy something I'd rather buy something that can serve more than one purpose. To have enough flexibility in adapting the light for different shooting situations, it has to be a powerful, but compact, flash gun with rotating zoom head.
D: 580EX with off-shoe cord 2 is the best I can think of. Expensive, but good from what I've heard.

Q: What other special accessories I am going to use when shooting macro?
A: Flash bracket -- definitely. If it is mounted on a tripod collar, it makes a very versatile lighting -- I can easily rotate the flash around optical axis. Filters -- likely, too.
D. Tripod collar is highly desirable. I'd also prefer a 67mm front barrel to use my existing set of filters. If no such thing exists -- the longer lens will be better because of lesser likehood of showing vignetting when coupled with a step-down adapter ring.

To summarize -- by answering these questions, I found myself looking for a long, optically uncompromising, inner-focusing macro lens with tripod collar, for 600 USD or less (considering the cost of other needed accessories). Thus, the list of available options became very short.

Sigma 150 mm matches all these criteria perfectly. Actually, for me it was a close call between Sigma 150mm and Canon 100mm with main advantage of the latter of being a Canon, but at the end the Sigma prevailed. All owners already know Sigma's advantages over Canon -- it's longer while being just as fast at F2.8 (which means it's more advanced optically), arguably better built, and, for the price, it comes with the tripod collar AND the hood, while Canon lacks both.

So I bought Sigma 150mm with 580EX and off-shoe cord 2 and 72/67mm ring adapter, and so spent my thousand.

Now, a month later, I feel I have made a good progress in putting it all together Smile and in learning how to shoot with it... It's quite different from what I am used to. Unfortunately, I didn't have much time to give this rig a good field (torture) test yet.

From what I've discovered about the lens so far:

Optically, it's very, very good. No distortion, no CA whatsoever -- this is just incredible. I admit -- this is my first prime lens, I am not used to such kind of luxury Smile But from what I heard -- many primes have issues with distortion and CA. I think I would be able to detect them in any lens... but, unless my eyes deceive me, I cannot imagine how ANY lens could be better in this regard. With my 1.6x crop factor on the sensor there's no visible vignetting either, of course. Sharpness is consistent across the frame. If the lens were shorter, making pixel-perfect panoramas of static objects would be very easy. It's just one thing that I don't like... When the aperture goes down to F16 and below, an abrupt decrease in sharpness occurs. While at F11 it's almost as sharp as at f5.6 (I found the sweet spot at about F5.0), F16 is very noticeably blurrier than f11, and F22 is QUITE blurry. Here's what I am talking about (animated GIF made from 100% crop):

I guess such loss of sharpness due to light interference is to be expected from any lens, but I've seen people making statements about how sharp this particular lens was at F22, so obviously I am a bit disappointed. With a powerful flash and diffuser, I have enough light to shoot at F22 and have a greater DOF, but with this kind of performance it makes very little sense in many cases because much of the sensor resolution would be lost. At F2.8, on the other hand, the lens perfomed much better than I expected. Unfortunatelly, with macro, wide open aperture is of no use for actual shooting -- though more light through the viewfinder and shallow DOF really help to focus on a subject.

About autofocusing... I don't want to follow the trend and start complaining about its speed, although it's admittedly slower than I expected. I guess it's still fast for a macro lens. It's accuracy I have issues with, and here I am talking about well lit environments. Quite strange, in many cases the AF is more accurate with close-ups than with distant objects. I would really prefer the opposite situation, since I am using MF with close-ups most of the time. The focusing ring is wide, smooth and a pleasure to use. The autofocus switch, however, is smaller than I would prefer and needs to be pushed hard to click. I often search for it while looking into the viewfinder... but maybe it's just a matter of practice.

All other physical aspects of the lens leave nothing to complain about -- it's very solid, yet small for a 150mm (which is important if you use it handheld). The tripod collar IS detachable, at least on my copy (some people say otherwise), you just have to turn the knob counterclockwise until it stops rotating, then pull. Very convenient.

I feel my post is getting too long Smile Thanks for your time reading this and sorry for my English.

Some final words.. Please don't get me wrong -- my complains are really minor and, after using this lens for a while, I feel how it's growing on me and I don't think I will part with it willingly in any foreseeable future. I am just learning how to use it, and such learning is a joy in itself. It really has opened a new world for me.

If you are interested, here are some examples (nothing to really brag about yet):

I hope to come up with something better in the future. If not, please blame the photographer, not the lens Smile