Sigma 120-300 F2.8 DG OS HSM | S
The first, and so far, the only lens in Sigma’s “Sports” class of their new Global Vision line, this is the fourth incarnation of their unique 120-300/f2.8 optic. Having used their original, film-oriented 120-300 for the past eight years (and having seen little reason to upgrade until now), I have been anxious to get this one into the field. I’ll be updating this page continually as I get more used to this lens and exploring its potential. [skip to what's new]
First and foremost, there’s that 120-300 focal length range coupled to the f2.8 wide aperture. No other lens on the planet has it. It’s very much like having a 70-200 and a 300 built into the same lens.
The ability to switch from a “tight” view to a wider perspective can be invaluable in field sports like football or soccer. Taking into account the 1.3x crop mode on the Nikon D7100, with which I shoot sports almost exclusively, I can cover a range of 240-600 at f2.8 with a single lens. Throw my Nikon D600 and 70-200 into the mix, and that range expands to 70-600 with just two cameras.
Sigma’s USB Dock is an amazing “smart lens cap” that allows for firmware updates to be made to their Global Vision line of lenses, and for some lenses (including the 120-300), it unlocks additional customization options. (Sigma Optimization Pro software, a free download, is required for use with the dock.)
This is an important addition for Sigma, as their lenses have been plagued by compatibility problems over the years – especially as Nikon has released new lenses. This has not been unique to Sigma lenses – most third-party lenses have some problems. (Back when I shot film on the Nikon F100, my Tamron 300/f2.8 would continuously hunt back and forth and never focus and required a $250 “re-chipping” to work with that body; while today, the old Tokina 20-35/f3.5-4.5 lens I acquired for use on my D600 has periodic issues conveying the correct aperture.) Rather than requiring users to ship lenses all the way back to Sigma to have firmware reprogrammed or chips replaced, users can now download firmware updates from Sigma and upgrade their lenses in the field.
For the 120-300, the USB Dock also unlocks customization features:
- Optical stabilizer. Three options – Dynamic View, Standard, and Moderate View – are provided for here. The descriptions contained in the software are not very clear, however. I’ve contacted Sigma to see if I can obtain a better explanation of these differences.
- Focus tuning. For zoom lenses like the 120-300, focus can be “fine tuned” at each of 4 focal lengths, for 4 different focus ranges. This gives an incredible amount of control over the lens’s focus characteristics. It also requires an incredible amount of testing, which I have not delved into just yet.
- Focus speed. This appears to be a very useful option indeed, giving you the option to bias the lens toward speed or accuracy from the default setting. According to Roger Cicala over at the LensRentals blog, there are measurable differences in the speed at which the lens focuses at the three different settings. I will be looking at this function over the next few weeks.
- Focus limiter. Three focus limiter settings are built in to the lens: full range, 10m to infinity, and close focus distance (1.5 – 2.5 m) to 10m. You can create your own custom range (though with questionable precision beyond 30m):
Mount Conversion Service
As with all Global Vision lenses, the 120-300 is eligible for Sigma’s Mount Conversion Service if you decide to change camera systems. I probably won’t be trying this any time soon…
Differences from Older Model
(Note: all comparisons are to the original 120-300/f2.8 model, which I acquired new in 2005, unless otherwise noted.)
Aside from the features described above pertaining to the USB Dock, there are substantial differences in construction that are noteworthy.
The lens has a smoother, “darker” finish overall that I find more pleasing than Sigma’s old “sandpaper” finish. It also appears less likely to pick up dirt. The lens hood is deeper, and lined with lightly ribbed rubber. A snap-on 105mm lens cap is also provided, versus the soft vinyl slip-on cover that came with the original version. All told, the new model gives a more polished look.
The new lens gives evidence of more solid construction in all respects. The detachable lens collar is of a completely different design, and is stronger and sturdier than the original collar. Thanks to Roger Cicala’s tear down of two lenses, we know the weather sealing of the new 120-300 is superior to the older models. I’m hopeful that, in addition to the obvious benefits of improved sealing, this may address one of the older model’s greatest weaknesses: failure of the AF motor. In the eight years I’ve owned my original model, I’ve twice had to send it to Sigma for replacement of the AF motor module. I’m hopeful that better protection from dust/dirt getting into the lens body will help protect the sensitive electronics in this module, since Roger’s tear down indicates few internal changes to the design.
On my first shoot with the lens, I faced some light rain. While hardly a test of the lens’s weather-sealing, there was no effect whatsoever under those conditions.
Major changes were made from the original lens’s 18 elements in 16 groups; the new 120-300 contains 23 elements in 18 groups. Two of the three “SLD” (low-dispersion) glass elements in the original design have been replaced by “FLD” elements, which Sigma claims have the optical properties of fluorite (the material that is behind the white finish on Canon lenses). Compared to the most recent OS version, the new model apparently maintains the same optical formula.
I have always been slightly hesitant to use the original model at f2.8 due to a loss of sharpness and contrast and increase in chromatic aberration. I’m pleased to note that while the new lens does perform slightly better stopped down, performance wide open is much improved.
Size and Weight
All that additional glass does come at a cost, and the weight has increased substantially from about 84 ounces to 120. The new lens is slightly bulkier, 4.8″ around as compared to 4.4″ and 11.5″ in length compared with 10.6″. Add about 4.3″ for the new lens hood, compared with about 2.9″ for the original.
In the Field
My first opportunity to use the news lens was during VMI’s fall football scrimmage. Overall I was pleased and noted an increase in performance over the venerable original model. Still, I noted room for improvement in AF accuracy, and will be looking closely at the lens’s customization features to nail this down.
This 35-yard TD catch was shot across the field, from the opposite sideline. Very nice detail and color at f2.8.
AF is definitely fast – the shot above was the pass being thrown by the QB around 3 seconds earlier. I was able to recompose and fire off an additional shot just prior to the catch, and AF locked on immediately. Note from the above photo of the QB, though, that the focus was slightly off – the sort of error that I’m hoping some fine-tuning will help eliminate.
First time out, I had a chance to shoot an evening football game at the small but reasonably well-lit Robbins Stadium at the University of Richmond. After the sun went down in the second half, I was shooting primarily at 1/1600 @ f2.8 with Auto ISO ranging in the 4000s and 5000s.
I also made two key adjustments on the D7100 – I changed Custom Setting a1 (AF-C priority) from release to focus, and switched from 21-point dynamic AF to 9-point. These definitely improved the number of “keepers” without any really noticeable effect on shooting speed. Although the D7100 manual suggests 21-point AF for “unpredictable” movement such as football, if you have good tracking skills and knowledge of the game (which I would hope I’ve acquired after 15 years of shooting sports), you can do a better job of following your subject than the camera. I have not yet delved into any of the AF tuning or customization options available on the lens through the USB Dock, because I wanted to ensure I had the best on-camera settings for the lens first.
In the dark, the AF responded very well, even when compounded with a periodic drizzle throughout the second half. I did notice some slight variation in results that make me think that the zone-by-zone AF Fine tuning offered by the USB Dock may be necessary, and I plan to perform such fine-tuning this week.
One of the most significant things I have discovered as I have shot more and more with this lens is that it has AF tuning “zones” for a reason.
Before I snapped my first photo, I fine-tuned AF through the camera – my usual procedure with a new lens – using the Datacolor SpyderLensCal – at something akin to minimum focus distance. That indicated a serious front focus problem, requiring a maximum +20 adjustment on the D7100. But when I got to the field and rough-checked this adjustment at distance, I found the adjustment was too strong, and I cut it in half to +10. After two outings like this and so-so results, on a hunch I zeroed out the adjustment and my results immediately improved. This improvement held for most situations, although results when the subject was very close (within 10-20m) lead me to believe there may be some adjustment needed in that zone. I think I now have informally gathered enough about the behavior of this lens to make use of Sigma’s Optimization Pro software meaningful. I plan to perform some adjustments this week.
Meanwhile…I really liked using this lens for soccer. Great reach and flexibility on the D7100.
AF Speed Optimization
With several events under my belt using this lens, I decided it was time to delve into some of the options available with the Sigma Optimization Pro software. Foremost among these was the AF Speed Setting which offered, in addition to the default AF speed, Motor Drive Speed Priority and Focus-Accuracy Priority. As one might expect, these settings correspond roughly to Nikon’s custom settings “Release Priority” and “Focus Priority.”
I shot most of this past Saturday’s football game between my VMI Keydets and the University of Virginia with the “Motor Drive Speed Priority” setting on the Sigma. And yes, you can tell the difference! Got lots of keepers in those tricky situations where you’re quickly moving from one subject to another, like during pass plays.
This 38-yard TD catch by Virginia’s Tim Smith was a remarkable enough play. The shot itself was even more gratifying as three seconds earlier, I was shooting quarterback David Watford 40-odd yards closer to my position on the sidelines.
I need a little more experience with the various combinations of settings to report on the effect of changing Nikon’s custom settings from Release Priority to Focus Priority, as well as the impact of the Focus-Accuracy Priority setting on the Sigma. In terms of absolute AF speed, however, Sigma’s Motor Drive Speed Priority does indeed make a difference.
More reports on the way!
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