A decade on – the Sigma 150mm f/2.8 EX DG IF HSM revisited – much more than a review.

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.

Robber fly (Engelepogon brunnipes) with prey...a grab shot just outside the kitchen door

This is the ‘go to’ lens for those close to home shots: a Robber fly (Engelepogon brunnipes) with prey – a grab shot just outside the kitchen door.

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.

I just want something I can pick up, not think too much about and use to record nature as I see it ‘close to home’: here a scarce swallowtail (Iphiclides podalirius) gets the Sigma 150mm f2.8 macro treatment.

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….

We get quite a few longhorn beetles from our log pile in summer. Here the facial view shows (Cerambyx scopolii)… which can give the unwary a painful nip.

Sharpness

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

  • Decent, off-axis lighting (natural via reflectors, LED or flash) to provide relief and create contrast,
  • Employ a rigid support to minimize vibration not only a tripod but a camera back as a giant bean-bag will do when working low down…and
  • To employ an understanding of how, as apertures get smaller, images can soften through diffraction even though depth of field increases.

It is a matter of compromise where art and science go hand in hand…

The choice of lenses is important in the way the background is rendered and the information you wish to convey: at the top the 15mm f/4 Laowa wide-angle macro gives a great deal of background detail whilst in the shot below the 150mm f/2.8mm Sigma isolates the striped hawkmoth (Hyles lineata). 

Handling

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.

To avoid specular reflections from the wing cases of some beetles I like to shoot on dull days with natural light – here the lens was used with camera on tripod at ISO 400 without flash

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 Aperture F22
Minimum Focusing Distance 38cm
Maximum Magnification 1:1
Filter Size 72mm
Dimensions Diameter 79.6mm X Length 137mm
Weight 895g

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:

http://www.imaging-resource.com/news/2013/09/11/understanding-bokeh-the-art-and-science-behind-the-beauty-of-blur-part-1

http://www.imaging-resource.com/news/2013/09/20/understanding-bokeh-the-art-and-science-behind-the-beauty-of-blur-part-2

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.

Lady's slipper (Cypripedium calceolus) . Photographed in the Camosciara Mts nr Pescasseroli, Abruzzo, Italy

When photographing the lady’s slipper orchid (Cypripedium calceolus) in the Italian Apennines I wanted to isolate it against a backlit white background…the Sigma 150mm f/2.8 serves me well for this kind of imagery, too.

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…

I am working a great deal with image stacking ‘in the field’ at the moment where combining images in a stack produces extraordinary depth of field with each image taken at around f/5.6 or f/8 to make use of the lens ‘sweet spot’ . This image shows the female flowers of hazel with tops of the male ‘catkins’ below.

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 …” .

This young fox came close to our car as we were parked in a nature reserve…the 150mm becomes a useful telephoto equivalent to a 225mm lens on APS-C

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.

This lens with its wide maximum aperture opened up new ways of working for me—a move toward soft backgrounds and shallow depth of field I thought I would never make.

Multipliers

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.

Image quality is barely affected with the x1.4 multiplier attached, and slight softening is only noticeable when you look hyper-critically at images where apertures are smaller than f/18 or so. Given the fact that the effective aperture is increased by a stop it is worth using.

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.

Harlequin ladybirds clustered in the corner of a bathroom , hibernating

Harlequin ladybirds (Harmonia axyridis) en masse clustered in the corner of a bathroom, hibernating…yet stirring when they felt the need to ‘poo’ as can be seen from the small dark flecks.

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 factorjust 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.

A deadnettle (Lamium garganicum) in evening light with shallow depth of field isolated against the undefined background…stacked image. The very soft background is attributable to the d-o-f at f/5.6….each of the images in the stack was made at this aperture

 

 

 

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