Magazine reviews always produce lots of charts of MTF (modulation transfer function) and quote figures with the slightest of differences to justify specious ranking in a comparative review of macro lenses. Call me an old cynic (again) 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 the lenses.
young tree frogs that had freshly taken to the bushes were highly active on a sunny morning - a 150mm macro allowed me to get close enough without scaring them off. This one was just about to jump...
Fortunately, I don’t have MTF equipment in my studio (it is cluttered enough anyway) but what I 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 200% in Lightroom 2 and Photoshop CS4). I can then simply state how a lenses satisfies (or does not) my sometimes unreasonable demands: the 150mm f/2.8 macro is superb.
A word about sharpness might not go amiss for sharpness is something entirely subjective but it gets lumped confusingly with resolution (which we can measure) To optimize sharpness (given a good lens) we need to add in decent off-axis lighting to give relief, rigid support to minimize vibration and an understanding of how, as apertures get smaller, images soften through diffraction. It is a balancing act…more on this in weeks to come.
I use this lens with a Nikon D300 body where, in practice, it is no more (or less) unwieldy than the Nikon 105mm f/2.8 VR macro. “Ah, but the latter has a vibration reduction system” I hear you say: Nikon states (and quite correctly) that this is not useful at subject distances of less than one metre. I would go further and say that the vibration of the mechanism (as it struggles to cope with vibration by shifting a lens element) actually softens an image if you leave it switched on and move in too close.
The 150mm f/2.8 macro was used with a x1.4 converter at ground level to capture a pair of small skippers supping minerals from the edge of a watering hole
The Sigma 150mm f2.8 macro is whisper-quiet and fast to focus – it is advertised as an “IF HSM” lens (internal focusing, high speed motor). In fact, this is the first macro lens where I forget to switch off the autofocus automatically when I move in to 1:1. If there is no breeze it does not ‘hunt’ and snaps in and out of focus as long as one sets the limiter.
I have owned and used a Sigma 180mm f3.5 macro, too but, in a fit of generosity, passed it to my son Rhod: he is currently off spending time in rainforests (lucky so and so) looking for the crawly things sensible people might avoid. ‘Pops’ felt he needed a lens of long focal length both to get at shy life-forms and to keep his distance from the more venomous ones.
Backgrounds
A macro lens of longer focal length creates a background where everything is a soft blurr – ‘bokeh’ describes the ‘quality’ of this blurr (ugh – the pretension with which this Japanese term is ‘dropped’ by photographers irks me).
Many macro lenses now boast a 7-9 blade diaphragm because the aperture becomes very nearly circular with no angular edges at higher f-numbers. Since the image on the sensor is really a series of tiny overlapping diffraction patterns that are the shape of this aperture, the result ultimately looks better the closer these approximate to perfect circles.
that "OK Bokeh" soft background used to advantage with a wild delphinium flower
I love the background softness that one gets for plant portraits with this lens since it accentuates the foreground sharpness. But then, in its place I also love extreme wide-angle macro shots (that will be another article, soon) with lots of background detail and a great sense of ‘place’ in a habitat. Different views, equally valid and part of the armoury of techniques you can bring to bear and thus not get locked in the same ‘vision’
Multipliers
The 150mm f2.8 really scores when used in conjunction with a Sigma x1.4 multiplier, becoming a 210mm f4 macro (giving x1.4 maximum magnification on the camera sensor). Image quality is barely affected and then is only noticeable when you look critically at images where apertures are smaller than f/16. That is where diffraction starts to become an important element (in short, light wave fronts spill around the edges of the diaphragm, spread out and create softened images). This is the perennial battle between reducing aperture size to achieve increased depth of field and the laws of optics where diffraction softens the image. I use a x2 multiplier, too but notice a tiny bit of image softening.
the lense with a x1.4 converter allowed me to remain outside the cirlce of awareness and capture the whole emergence and wing-drying sequence of this common swallowtail
It is nothing you cannot ‘correct’ at the processing stage with a judicious touch of unsharp mask (USM). It can seemingly compensate for about two stops of ‘degradation’ due to image softening: an empirical judgement – just my visual impression on an A3 print. Sharpness is about perception after all: the physical processes involved in diffraction and USM are utterly unconnected.
And, of course, you can also use an optimum aperture where the so-called ‘sweet spot’ lies (f/8 or 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 year and will write a separate entry on the blog in this series. It is amazing.
In the Field
I often use the multiplier for shy or small insects with a Nikon R1C1 macroflash – 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 1/200th sec. The good thing about a macroflash unit such as this (or one you make yourself – to be covered soon) is that using the flash heads away from the axis of the lens gives ‘relief’. A ring flash provides almost axial lighting and can be very dull (unless you have a unit where the tubes are adjustable for intensity. This business of using the small flash heads off axis is one of the most important elements in creating the impression of sharpness because the angle of the incident light creates tiny shadows that enhance surface details…it is all about fooling the eye.
Crop factor – just to clear up a misconception
This seems a useful place to mention ‘crop factor’ in macro work. Its 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 statement. Sometime ago I made someone’s day – when they could ‘sneer’ at what they saw as my ‘ignorance’ in an article – much better than assuming that the word ‘apparent’ was removed by the editor. This time, no editor: I take full responsibility – publish and you will be damned (frequently!)
proof of the pudding - x2 converter, with crop factor of the DX format used to advantage to obtain a frame-filling shot of a horsefly (Tabanus bovinus). the tiny bit of image degradation was countered with a touch of USM...)
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.
When you ultimately compare A3 prints from a DX and FX camera used on the same subject with the lens set at 1:1 two cameras 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 becomes apparent to me from ISO 400 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
© Paul Harcourt Davies
150mm f2.8 macro - general lens specification
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Lens Construction |
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16 Elements in 12 Groups |
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Angle of View |
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16.4 degrees |
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Number of Diaphragm Blades |
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9 Blades |
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Minimum Aperture |
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F22 |
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Minimum Focusing Distance |
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38cm |
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Maximum Magnification |
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1:1 |
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Filter Size |
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72mm |
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Dimensions |
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Diameter 79.6mm X Length 137mm |
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Weight |
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895g |
Pingback: Niall Benvie. Paul Harcourt Davies. Andrew Parkinson. » Blog Archive » Macro Matters: my current favourite - the Sigma 150mm f/2.8 EX IF HSM macro
Cheers Paul, very useful!
Just one question – what kind of working distance do you get at 1:1? I’m guessing shorter than the theoretical due to the IF… but hopefully in that sweet spot where you aren’t disturbing the subject but still close enough for the macroflash to remain sufficiently off-axis?
Question is whether I need this more than a 10.5mm Nikkor…
Hello Adam,
Glad you found the comments of use – apologies if it precipitates a spending dilemma! Sigma quote 38cm from the sensor as the closest distance to the subject: I have it set up here on the desk and that figure is spot on. Perhaps more use is that it is 19cm from the lens front and the flash head I have just attached is, as near as damn it, 30º off-axis.
That horrid word “need’…as coincidence would have it I have been using a Sigma 10mm rectilinear fisheye for a while and getting ‘silly’ close-up shots since the subject is just 2cm from the lens front at maximum magnification of 1:3.3 (similar cost – perhaps a bit closer than the Nikon). It is super-sharp and I have just finished putting together a gadget to let me light close-ups. I hope to test it thoroughly this weekend and shall do a ‘post’ on the use of ultra-wides for ‘macro’ soon with this ‘device’. Watch this space, as they say! I have used a Sigma 10-20mm wide angle zoom for about three years now and love it – it goes close enough for most users (typically I want that bit extra and even the thinnest extension tube is impossible to use) but that lens, too, is incredibly sharp and great for groups of plants in those mountain landscapes you get to…
Many thanks Paul, that’s very useful. I’m a big fan of the wide approach too, so look forward to that post!
I spent a few days on the Grand Capucin this summer, which is a huge granite aiguille perched at about 3,500m on the Italian side of Mont Blanc (or should I say Bianco). I was really surprised at the amount of life surviving up there, plenty of Saxifrages and Moss Campion, plus Alpine Choughs and Wallcreepers, all way above the permanent snowline. Amazing.
Adam
I have only seen Gran Capucin in the distance. We take groups into the Adamello-Brenta region of the Dolomites where you can find granites on one side and dolomitic limestone on the other. The diversity of plants is amazing. It never ceases to amaze me how vibrant the life above the snowline is where everything has a desperation to squash life cycles into a few months. Dwarf alpines set against the mountain fastness…wonderful. We can get up to about 2,200m from home (Mt Terminillo) in about 2 hours – its an incredible escape in the heat with carpets of alpines, apollo butterflies, choughs…and that great to be alive feeling thrown in.
Paul,
I recently changed gear, and this article was very useful when choosing a macro lens, as you so obviously bought it to use in the field, which is what I do. Had it six months now, and so far so good, very good. By coincidence I picked up a second-hand copy of your book ‘Small Things Big’recently. I must say, as the owner of far too many macro/micro books, I think this one is an excellent mix of theory and practice.
Hi Mike,
Your comments on Small Things Big are appreciated…that title was not my choice. In the USA it came out published by Amphoto as Nature Photography Close-up. Amazon then offered both books together…which annoyed a few people who then gave it a single star. Something much more comprehensive is planned….watch this space.
Glad you liked the Sigma 150mm f/2.8 EX macro…pity I was not on a commission for the number that I now know have been sold.
best regards
Paul
Hi Paul,
the Amazon thing doesn’t surprise me when I consider some of the books it recommends for me!
Are you able to expand on the “something much more comprehensive”….
kind regards
Mike
Greetings Mike,
Early days – there is a Q&A book being prepared for Lark and also the first ebooks are almost ready to launch. More soon
best
Paul
Paul,
sounds intriguing, though I had to look up who Lark are. Funny, some of their titles, eg. B&W D P by Michael Freeman I have, but my version is an Ilex….same with some of the others. Interestingly I see that Ilex are doing e-book versions, which their website says are cheaper. It takes a Yorkshireman to spot that 6 chapters at £2.99 each is NOT cheaper than the £11.99 the same website says the printed book is. Ho hum.
Lastly, and keeping up the Yorkshire traditions…can I have your Tessovar?
best wishes
Hi Mike,
For some years Lark have handled the American editions of books for Ilex and others – including titles of mine for David and Charles. Essentially they are the photographic/crafts wing of Sterling Publishing (part of the Barnes & Noble empire). What distinguishes them for me is that their editors are intelligent articulate and professional – bloody miraculous. They are also straight in a contractual sense. Yep, another surprise!
That Tessovar is a much-prized item that took me years to find. I have not done as much with it as I should because it is not easy to focus (apertures vary from around f/45 – f/128) Coupling a D300 with its image intensifier on Live View has made a lot of difference. I have also made a focusing stand from an old microscope so I could utilise the fine-focus: there is a half-completed post on this item that I shall put up soon.
best
Paul
Regarding the Tessovar Paul, I assume you have the viewing telescope. If you get this parfocal with the image on the sensor, then you should be able to focus on that and then take the shot. To help, there was a magnifier for the viewing telescope too. Send me an e-mail if you need further details.
Mike
Hi Mike,
Thanks for your response – yes, I do have the telescope. I managed to get some bits of the original Zeiss literature, too from Peter Parks who had used them a lot at OSF. In fact it was working with Peter before I transferred to Italy that got me hooked on the Tessovar.
Currently, I have abandoned using the beam splitter and focusing eyepiece after a long time spent getting them parfocal. I now feed the output from the D300 to a mac laptop. You see the image break up if attempts are made to magnify too much but it works very well in accurately estimating focus!
Best for now
Paul
Hi Paul,
I see that Amazon are listing your new book, due in November. Looks good, though the idea of pre-ordering goes against the grain. I was in Waterstones today, and saw ‘Photographing the Microworld: The World Through a Photographer’s Eyes’
Svetlana Belorustseva (Author), Andrei Sochivko (Author), David Hefford (Translator) which I found very unimpressive I am afraid. The title drew me, but 5 minutes on the comfy seat upstairs in Waterstones was enough for me. Rather better seems ’100 Ways to Take Better Nature & Wildlife Photographs by Guy Edwardes. An interesting format/arrangement of a book that seems all the rage at the moment.
I wait in anticipation of your own offering later in the year, though November is not a month to get folk inspired to take their camera out, I don’t suppose you had a choice!
kind regards
Mike
PS. found your writing on another web-site (pixiq), with some good stuff their too. I hadn’t realised you got your Tessovar from my good friend and mentor Spike Walker!