LONG POST WARNING!
First I will lay out my needs and desires and explain my experiences to this point:
~ I want to take photos of small living things outdoors that often move - either on their own or with the environment.
~ Normally, I have little need or ability to be closer than 1 1/2 to 2 feet from my subjects - it scares them off or they fill too much of the view. When I do need to be that close and closer, I realize a tripod, flash and MF are needed.
~ I would like, in fact not theory, to have a fast lens aperture available in order to use higher shutter speeds.
~ My hands shake more than they used to - especially when I am trying to get closer to my subjects and I get a bit tense. Effective OS/IS would be great.
~ I am trying to break away from my tripod addiction a bit to bring more spontaneity and candidness to my style.
~ Effective AF would be great. I can easily use the USM to fine-tune but need AF to get me in the ball-park!
How I am working now:
~ To attempt to get what I want above, my current setup is a Canon 7D, 70-200 2.8 II, 1.4 or 2x III TCs, 580 flash w/diffuser.
~ Current MFD distance is just shy of 4'
~ Max magnification w/2x is about .42 (1:2.4)
~ Resulting IQ is OK but I am hoping for a simpler and lighter outfit that would give me me true macro if I should desire it and the ability avoid the TCs if my subjects allow me to get closer - the 70-200 combo not allowing a great magnification w/o TCs.
I decided to get the Sigma 2.8 macro OS:
~ Great reviews.
~ Extra working distance of the 150mm (vs 100mm)
~ Tripod ring
~ Ability to accept Canon converters (which I already have)
Got the lens last week. Tried shooting with 7D and T3i, with and without 1.4 mkII converter, single point, AI Servo & Single Shot, with and without tripod.
1) The AF seems to be very hit and miss as to when it actually operates at all. Sometimes it works as expected, reasonably fast and accurate. Much of the time though, it will not AF at all and I have to shut down power to the body and/or switch the lens from AF to MF back to AF and/or move the focus ring near the focus point before the AF actually actuates. It feels almost as if the focus "gets stuck" at a point and simply turns itself off at random times and has to be "re-set" in order to work. It is much more frequent when using the Canon 1.4 converter but happens as well with the bare lens.
2) The second issue may or may not be related to #1. No matter what I do, the lens will not actuate AF at all when closer than about 2 feet to my subject. I have tried all 3 distance pre-sets, AF to MF to AF (like above) and total re-sets without success. I know that at "true" macro distances the AF is normally slower but what I have is a lens that simply doesn't try! It is like the challenge detailed above except that AF will never work - no matter what I do.
Had some folks tell me the above is not normal behavior so I called Sigma. They listened to my concerns as well as a converter question:
~ The AF would regularly have no action whatsoever - under many conditions.
~ The AF would not function at all with distance limiter set on 0.38-0.53m position.
~ Amazon's packaging was, in my opinion, unsatisfactory.
~ Would either Canon converter cause any issues with the lens?
The tech support answer was:
~ Neither AF action that I was experiencing was normal. He suggested possibly firmware, but I have the latest version and he agreed "it must be out of adjustment."
~ He was upset at Amazon packaging and said that "the shipping could easily have thrown the OS out of alignment". He said "the OS is a floating element in the lens and sensitive to jostling and bumps" (I always thought that OS/IS was a motor gyro within the lens rather than an "element" but whatever).
~ Re: converters he said, "the lens is a f/2.8, it should function and AF fine across the board with either converter on the 7D body."
He suggested that I either send it to Sigma for calibration or deal with the vendor (Amazon). I chose to deal with Amazon.
Amazon was great. They agreed to:
~ Send me a new lens.
~ Give it to me at the current listed price (lower than I paid).
~ Overnight ship it.
~ Package the lens better. I really hit them hard on this one, using Sigma's own dissatisfaction as my lever.
In the meantime decided to drop my manhood and go ahead and RTFM. I am much enlightened by their write-up (and realize that their tech obviously hadn't read the manual).
The manual states:
~ The macro "light fall=off" phenomenon. Focus Distance vs F/stop Chart - At 1.65m the aperture is diminished to f/3.2, at 0.4m = f/5.4, and at 0.38 (MFD) aperture has darkened to = f/5.8!! The
If I am interpreting this data correctly, what it tells me is that the body doesn't really want to AF at all when the MFD is approached. Once I add the 1.4X converter the aperture goes to f/8.1, well under the AF range of the 7D. In fact, if I asses the data logically, anything under about 0.64m with the converter brings the aperture slower than f/5.6 thus not allowing AF with the 7D.
~ It states under "ABOUT TELE CONVERTERS" (their upper case shouting):
"With 1.4x APO Tele Converter, AF can operate between infinity and 0.53m. If the distance scale is between 0.38 and 0.53, only MF is available"
~ "When attaching the APO Tele Converters, the Focus Limiter will not function even if the position of the switch is changed."
~ "When attaching the 2.0X Tele Converter, it can be used in manual focus only"
~ several references to making sure to turn OS OFF when removing lens and when turning body OFF or risk damaging the lens!
Those last warnings scared me even more than the f/stop and AF surprises!
After reading the above, I realized that perhaps the original lens was working as designed! I am in a quandary as to what direction to take.
~ I cannot truly utilize the lens at f/2.8 at any distance closer than 1.65m.
~ I cannot use AF with any converters at, practically speaking, any distance less than about a meter.
~ The OS is not particularly effective at any of the macro distances (gleaned from internet postings/reviews)
Why have this lens as opposed to the non OS version or the Canon 100L (or even the older 100USM)? As I mentioned above, the reasons for this model over the others were: f/2.8, longer working distance (5"!), takes converters, OS/IS and AF. Seems like with what I know now, for my style, the only real advantage is the closer working distance and that is marginal at 5". Not to mention I could lose a bunch of weight (Sigma = 1lb 3oz heavier than Canon 100L ) in the lens and $$ gain to my pocketbook!
Do I go back to my existing equipment and methodology, keep this lens (one of them) and learn to live with its limitations as a macro OR move on to something else?
What are my options that could best meet my needs? Seems as though all three macros (Sig 150, 100 & 100 L) have many of the same limitations re: focus speed, AF ability and loss of light. Canon 300 f/4 has 5' MFD.
Does the Canon 100L have effective enough IS at close distances to help me?
Does the Canon 100L with (third party) converters (esp 1.4) AF at closer distances?
I really want to find the best method of getting the these shots! Without AF I am in sad shape. It is heavy enough that I need two hands to hold it (being both short and heavy make it very difficult for me to hand-hold AND totally MF) - my old eyes really need the AF help. And ... my shaky old hands could use effective OS as well but I understand I'm not to expect too much in that arena up close.
One hope was to also be able to use it with my Canon 2x mk III converter but I don't even dare try it with the erratic operation bare and with the 1.4!
I have also not tried Live View since it normally does not work well with what and how I shoot - butterflies & dragonflies.
I am fully aware that to get "true" macro I am going to need a "true" macro lens; but if that normally entails a tripod, MF and a dedicated flash - why bother getting a lens that has AF (that doesn't work) and OS/IS (that needs to be turned off on a tripod)?
Quite objectively, photos taken with my 70-200 2.8 II w/2x converter (400mm) from its MFD (< 4') have nearly as much IQ as the ones I was getting with the 150 + 1.4 from 2 - 3 feet - my original "sweet working distance". As it turns out, that 2 - 3 feet is the closest I can get with the Sigma macro and AND have dependable AF & OS! The advantage of moving in to about 2' would be to fill the frame more with my subject. I am feeling somewhat lost and bewildered by this whole experience and may just send both copies back to Amazon and begin anew.
Thanks for hanging in there with this long communique.
Thoughts and opinions are most welcome,