My venerable Sigma 150mm f/2.8 EX DG IF HSM macro (to use its full, slip off the tongue, title) virtually lives on a Nikon D7100 body. For over a decade, it has seen heavy use and I am continually amazed by the detail I have been able to squeeze out of it.
There really cannot be a better endorsement than that from a confirmed macro fanatic whose search for sharpness is akin to a personal quest for the Holy Grail.
I first wrote a paen of praise for this lens first on the Pixiq blog and then on the Images from the Edge – blog both now, in the scheme of things, lost and gone. Clay Bolt and I set up Learn Macro with the express intention of collecting together material new and old on ‘macro’ in its widest senses (literally) and so I thought that this was a good time to take another look at this lens…a kind of 10th anniversary.
Sigma announced an upgraded version of the original 150mm f/2.8 EX DG IF HSM macro lens at Photokina 2010 which then became the Sigma 150mm f/2.8 EX DG OS HSM with an extra pair of letters added to the name to indicate that it incorporates Sigma’s patented optical stabilising (OS) system. A few months ago, during a week’s trip to the Sibillini, high in Italy’s Apennine mountains I was able to use this latest version extensively when fellow traveller Dr David Read wanted to try out another Sigma faithful (the superb 15mm f/2.8 rectangular fisheye) and I ‘generously’ agreed to a temporary swap.The latest version of the lens is clearly superior both in terms of speed of focus and the way it snaps positively into sharp focus. I don’t think I can resist for long and then my son will get another of his dad’s cast-offs.
For 35mm work (albeit on an APS-C sensor) the 150mm f/2.8mm macro is still my working ‘field lens’ of choice… On Micro 4/3, to which I am slowly migrating, I can also use it via an adapter as a ‘legacy’ lens but am currently in love with the Olympus 60mm f/2.8 for that format which has to be the sharpest macro lens I have ever owned. Olympus are microscope makers ‘par excellence’ and they know what they are doing with lenses. I still have a full set of their lens heads made for use with the OM series of film cameras. I can also lay my hands on a Sigma 180mm f/3.5, a Sigma 105mm f/2.8 and a Nikon 105mm f/2.8 which are all excellent lenses and yet, for use in the field, I use the Sigma 150mm with my Nikon equipment and the Olympus 60mm f/2.8 (120mm equivalent on full frame) with a Panasonic GH4. I suppose I have to admit to collecting macro lenses and I could add quite a number of others to the list….including two super-sharp optics from Laowa : the 15mm f/4 wide angle macro and the 60mm f/2.8 macro. Horses for courses and all that for this is both work and passion.
Photo magazine reviews always produce lots of charts of MTF (modulation transfer function) and quote figures with the slightest of differences to justify somewhat specious ranking in comparative reviews of macro lenses. Call me an old cynic (readily admitted) but I cannot escape the feeling that, with few exceptions, reviewers ‘talk the talk’, even ‘walk the walk’ but seldom take macro photos …anyone who did could get great pictures with any of today’s crop of dedicated ‘macro’ lenses. It is mostly down to technique not equipment – though the latter helps.
I certainly don’t have MTF equipment in my studio (it is cluttered enough anyway) but what I have to do is to make my lenses work for their living. I am fanatical about sharpness when I want it – examining all images at 100% and even (just for the hell of it) 200% in Lightroom 6 and later in Photoshop on a 27” iMac screen. I can then simply see how a lenses satisfies (or doesn’t) my highly unreasonable demands.
Conclusion as previously: the Sigma 150mm f/2.8 macro is superb and I know a whole bunch of pros who think the same.
If you want more then read on….
First, a word about sharpness – it is important to reiterate that this something that is entirely subjective but which gets lumped, confusingly, with resolution which, at least, can be measured and thus can have numbers attached to it…even if those numbers, in the hands of reviewers, sometimes become meaningless. To optimize the impression of sharpness (given a good lens) we need to add in
It is a matter of compromise where art and science go hand in hand…
On a Nikon D7100 body the Sigma 150mm macro is no more (or less) unwieldy than my Nikon 105mm f/2.8 VR macro. “Ah, but the latter has a vibration reduction system” I hear you say: Well, so does the new Sigma 150mm f/2.8, but Nikon states (and quite correctly) that this is not effective at subject distances of less than one metre: I have yet to learn where Sigma place the cut-off with the 150mm macro but with the latest version of this lens it did seem to function well at close quarters, perhaps because the longer focal length puts you that bit further from the subject. I have noticed, in practice, that the shuffling vibration of correction mechanisms (struggling to cope with vibration by laterally shifting a lens element) can slightly soften an image if you leave it switched on and move in too close. In Olympus and Panasonic MFT cameras vibration reduction actually seems to work in the macro realm when it is controlled via mirror movements.
I know that it seems a bit greedy (even excessive) having both the Nikon 105mm and the Sigma 150mm macros but I bought the Nikon first because it is an incredibly sharp lens (in this respect nothing to choose between it and the Sigma). However, I really need a tripod mounting ring when, in my work with flowers and insects, the ability to change from horizontal to vertical format swiftly is paramount. In fact, in my view, it is often a huge omission on any macro of 100mm focal length or more and it’s the clincher for me with this Sigma lens. I had SRB Griturn make an adapter for me to use with the Nikon.
In use, the Sigma 150mm f2.8 macro is quiet and reasonably fast to focus – the later model noticeably faster and it is advertised as an “IF HSM” lens (internal focusing, high speed motor). In fact, this was the first macro lens where I sometimes forgot to switch off the autofocus when I moving in to 1:1. If there is no breeze it does not ‘hunt’ and snaps in and out of focus with the limit set. I realise that things have moved on a bit in a decade and, for example, the Olympus 60mm macro I use with micro 4/3 ( the equivalent of a 120mm lens on 35mm) is much swifter in its autofocus response… also not so much metal and glass to move given its tiny size.
The original Sigma 150mm f/2.8 EX DG IF HSM versus the Sigma 150mm f/2.8 EX DG OS HSM specification
The later version new version boasts 3 (rather than 2) low dispersion glass elements and 19 elements in 13 groups…rather than 16 elements in 12. An optical stabilizer needs a separate lens group, moving at right angles to the optical axis… so my guess would be that this is where those three extra elements reside, one of which is low dispersion glass so as not to introduce aberrations to a design that works extremely well already. As mentioned previously, the latest version is noticeably faster and more precise in its autofocus mechanism – a boon in the field with skittish subjects.
|Lens Construction||16 Elements in 12 Groups|
|Angle of View||16.4 °|
|Number of Diaphragm Blades||9|
|Minimum Focusing Distance||38cm|
|Dimensions||Diameter 79.6mm X Length 137mm|
Backgrounds & Bokeh
A macro lens of longer focal length creates a background where everything is a soft blurr – great ‘bokeh’ as some might say. Incidentally, I have written extensively on Bokeh, what it means and the factors affecting it. There is an article in Wild Planet and another, in two parts, on The Imaging Resource – accessible through the links below:
Many macro lenses now boast a 7-9 blade diaphragm (with curved blades), making the aperture very nearly circular with no angular edges at higher f-numbers. Since an image on a sensor is really a series of tiny, overlapping diffraction patterns that take the shape of this aperture, the result ultimately looks better and smoother the closer the diffraction pattern centres approximate in shape to perfect circles.
In the past, photographers often overlooked the background and concentrated solely upon the foreground. However, the two go hand in hand and background often has a psychological input that creates the ‘feel’ for the image. For example, I love the background softness that one gets for plant portraits with the Sigma 150mm f/2.8 EX DG IF HSM lens since it effectively accentuates the foreground sharpness. But then, in turn, I also go for extreme wide-angle macro shots (there are numerous articles if you put ‘wide angle macro’ into the search facilty on Learn Macro) with lots of background detail, where a great sense of ‘place’ in a habitat and a maximum amount of peripheral information is conveyed.
As always in photography, there are different views and effects – all equally valid and part of the armory of techniques you can bring to bear and thus avoid getting locked into the same ‘vision’. Too many photographers, keen to follow trends and sometimes lacking in imagination, seem to feel there is only one way…whatever is currently fashionable. That is the way to cliché…
BELOW: This was first published as Part 2
So you are seriously thinking about the 150mm f/2.8 lens or, indeed, any dedicated ‘macro’ lens of longer focal length…180mm and 200mm What else might be useful to know… such things as what is available, how to boost magnification and optimise sharpness (via choice of aperture and control of vibration.
Here are some ideas for extending the effectiveness of this remarkable lens and also getting the best out of long-focal length macro lenses in general.
Convenience…Grab and Shoot
With the Sigma 150mm f/2.8 EX DG IF HSM on a D7100 body and Nikon R1C1 macro speedlight attached I can go ‘walk about’ several times in any day, especially when I am working on a book, tweaking images for agency submissions or when I am just desperate to get outside … every single day there is something worth photographing—bugs, flowers, moss. The camera plus the macroflash system sits close to hand on my desk ready for when Lois calls as she gardens: “There’s something out here …” .
Other long focus macro lenses.
I can comment from personal experience upon the Sigma 180mm f3.5 macro and the Nikon 200 mm, both excellent lenses: others, only by repute from friends who are Canon users, for example). I have owned (and happily used) the former and have borrowed the latter for extended periods. The Sigma 180mm f3.5 macro I passed to my son Rhodri, in a fit of generosity, who took it off to spend time in Amazonian rainforests and elsewhere in S America looking for the crawly things sensible people might avoid. ‘Pops’ lovingly felt the ‘son and heir’ needed a lens of long focal length both to get at shy life-forms and to keep his distance from the more venomous ones. It did nothing, however, to help avoid the angry scorpion in his boot in Peru…
I have borrowed and used a Nikon 200mm macro from time to time. It is a superb lens, that comes at a steep price and, in terms of quality of image, it offers me nothing that I cannot get already from my Sigma lenses. I am not one of those preoccupied with labels – what matters is a tool for the job. The Sigma lenses deliver and their macro lenses (and many others) are second to none. Several friends wax lyrical over the Nikon 200mm macro it and, if offered one, I would certainly not decline. It is worth pointing out that, on the Nikon 7100 the Sigma 150mm f/2.8 lens becomes the equivalent of a 225 mm on full-frame, thanks to the APS-C sensor crop factor of 1.5.
The 150mm f/2.8 really scores when used in conjunction with a Sigma x1.4 multiplier, becoming a 210mm f4 macro. This gives x1.4 maximum magnification on the camera sensor, but with the crop-factor of a DX sensor (eg 1.5) you can easily fill the frame with some tiny bugs for you now have a real macro-focusing telephoto of 315mm….35mm equivalent focal length. On micro 4/3 with one of my adaptors it becomes a whopping 420mm macro giving life-size on the sensor. I have not used this much..
In macro work, depth of field decreases with magnification (for a given aperture), and consequently you’d get shallower depth of field at the same aperture with the FX sensor and a subject occupying the same proportion of the viewfinder as on the DX camera. It’s one of those definite advantages of DX (and even smaller) sensor sizes when it comes to macro work—provided you want depth of field rather than shallow focus, that is.
When you use the x1.4 multiplier with the Sigma 150mm macro you get a magnified image and a safe working distance to allay the fears of any arachnophobes … in fact, you might find you like spiders after all.
NB. as lens magnification increased so the effective aperture gets smaller…at 1:1 the marked lens aperture of f/16 is in fact 2 stops smaller (f/32)…your metering system compensates for this but diffraction gets more pronounced as you look critically at images on screen. Another stop on top of this would take the effective aperture to f/45…. I always keep a mental tally of what the effective aperture is and make sure it is no smaller than f/22 or f/32
Diffraction is an important element in controlling sharpness. It is an inescapable property of light where wave fronts ‘spill’ around the edges of the diaphragm, spread out and the visual result is softened images. This is the source of that perennial battle between reducing aperture size to achieve increased depth of field and the wave nature of light where diffraction softens the image.
In practice, a tiny bit of post-production work can mitigate this softening: I go for smart sharpening or unsharp mask (USM) in Photoshop or, a combination of ‘sharpen’ and ‘detail’ with the Lightroom 3 sliders and a cut in ‘luminance’ to improve background … simplicity is all. I have found that judicious use of USM can seemingly compensate for about two stops of ‘degradation’ due to image softening: an empirical judgement and just my visual impression on an A3 print or on screen. Sharpness is about personal perception: the physical processes involved in diffraction and USM are utterly unconnected, after all
And, of course, you can also use an ‘optimum’ aperture where the so-called ‘sweet spot’ lies (usually f/5.6 to f/ll) and build up incredible depth of field with a composite from a succession of images using Helicon Focus™. I have been working with this for the past five years and more and it is amazing.
Use In the Field
I often use the multiplier both for shy or small insects: with a Nikon R1C1 macro speedlight at ISO 400 there is sufficient flash power to add a sparkle and to mix with ambient light (more in a future post about lighting set-ups both off-the peg and homemade) and still have a shutter speed of 1/250th sec. I have modified mine to place the flash heads much further off the optical axis and fitted them with bigger diffusers. By the way, this business of using the small flash heads off-axis is an important elements in creating the impression of sharpness with your precious and expensive macro lens because the angle of the incident light creates tiny shadows that enhance surface details …what we call ‘relief’… it is all about fooling the eye.
Dragonflies tend to be wary unless it is late in the day, just before sunset—with a tele macro lens such as this plus convertor you can be well outside the ‘zone of fear’ and get a pin-sharp portrait with a soft background.
The combination of 150mm macro, macroflash unit and camera can be hand held but might prove a bit unwieldy for some. Near the ground, I often just use a bean bag for support or the remarkable Novoflex Minipod. which, like everything that comes from the German engineering firm Novoflex, is superbly built—I often rest that on my camera backpack or use it as a chest-pod. Sometimes, a monopod is better than a tripod with insects at eye level and lower … you leave the unit partly extended with one section loose so by pushing down it gets to the height you want, then tighten, tilt forward to frame and focus.
Crop factor—just to clear up a misconception, again.
This seems a useful place to mention ‘crop factor’ in macro work. It’s the primary reason (taking out cost) that I like using a DX camera. It is better for getting frame-filling portraits of smaller subjects in the field. Some writers say that DX cameras ‘magnify’ an image compared to FX (full frame): this is a misleading, not to say inaccurate, statement.
A macro lens that boasts 1:1 or lifesize magnification produces that degree of enlargement on the sensor whatever camera is used with it. The DX camera simply takes a smaller portion of the image which is what you see when you look through the viewfinder. And the depth of field advantage has already been mentioned above.
When you ultimately compare A3 prints from a DX and FX camera used on the same subject with the lens set at 1:1 the image from the DX camera looks electronically ‘magnified’ only because a smaller part of the image has been enlarged to fill the print or computer screen. View the prints on a wall from normal distances (not in front of a screen with Photoshop at 200%) and differences of sharpness wouldn’t be discernible for two images taken at ISO 200. An on-screen quality difference between FX and DX becomes apparent to me from ISO 600 up because noise from the smaller sensor sites on a DX camera represents a greater proportion of the output than from the larger ones on some FX sensors.
Whether it’s for books, web images or even large prints made with ON-1 Re-size (once known as Genuine Fractals) —this is an optic that has delivered again and again.