From about 1:5 to 1:1 AF isn't useful because focusing is accomplished by timing the shutter to your natural bobbing and swaying. At those high magnifications 1mm of head, torso, or hand movement throws the subject out of focus - even at small apertures. The other way to accomplish focus is on a tripod with either bellows or a set of macro-rails and here again AF is hardly needed nor at all handy to have. Sure, focus on something a meter away (not macro) and AF is a style choice and very handy to some people - but you already have that covered with your 75/1.8 which has better IQ and bokeh anyway.
When manually focusing via the focus ring a large to very large throw is desirable. FBW is the last thing you want for making super tiny adjustments at high magnifications. The Oly 60/2.8 has a pretty good FBW as FBW goes but that still isn't good enough in some situations.
2) Micro-contrast (MC
Up there with focusing mechanisms MC is one of the more critical aspects when considering macro lenses. It's important in normal lenses too but much more-so in a macro. Why? Well, a couple of reasons:
a) Framing doesn't happen in the same way with macro so to achieve aesthetic framing you usually need to crop.
b) Working distance and magnification almost never come together ideally for the subject you wish to capture so you will be SEVERELY cropping most of your images.
With so much cropping going on the MC details become hyper-critical even for many shots you will only post to the web - at web-sized scales. Of course just as it is with any non-macro lens MC becomes less and less important as one scales the images down in size. If I were to score MC across the various macro lenses I've tried the Oly 60/2.8 would get a 7.8 or 8 out of 10 which is pretty average-ish and nothing exceptional or spectacular.
3) Working Distance (WD
Working Distance is different from Minimum Focusing Distance (MFD
) in that WD is the distance from the tip of the lens (be it the front element or the filter thread ring) and the focus plane when the lens is set to it's MFD. MFD is the distance from the sensor plane to the focus plane at it's nearest setting. Subject Distance which Olympus marks on this lens's barrel, is also measured from the imaging (sensor or film) plane. WD is a critical factor for two primary reasons:
a) The intrusion factor - where getting too close to your subjects upsets them or causes them to panic and leave the scene, and
b) The Lighting triangle conspiracy - where it becomes increasingly difficult to properly light the subject the closer you get to it.
The WD ranges for 1:1 captures work out to:
- 0.1cm ~ 5cm: nearly impossible. You have to invent your own lighting system.
- 5cm ~ 10cm: very difficult. Some specialized diffused ring flashes can work OK-ishly.
- 10cm ~ 15cm: Almost comfortable. Commercial and DIY lighting is easy-ish and available$.
- 15cm ~ 20cm: Yes! Nice. Even natural lighting can be used and diffused artificial lighting systems really shine (pun intended) at these distances!
- 20cm ~ 30cm: Great for lighting but at these lengths camera stabilization begins to become quite a major issue (even with most tripods) - especially on the far end of that range.
The WD for the Olympus 60mm f/2.8 Macro lens is 7.6cm by my crude measurement and 8.2cm according to Olympus
. The discrepancy between us may be that they measured from somewhere on the front element and I measured from the edge of the filter thread ring. Unfortunately we can not believe any of the reviews we read for this measurement as it seems even some well established sites are publishing reviews from authors who don't know what WD is nor how to measure it - very discouraging - even more discouraging is that they also don't understand magnification ratios and how to measure them - lame!
Either way 8.2cm or 7.6cm, you can see that it falls into the range of "very difficult" to light and too close for comfort to most of the living mobile subjects that are fun to shoot and who hang around in the likely locations. MFD is also somewhat important as that places our head&shoulders at a distance from the more aware insects and living creatures able to detect or assess our large body mass in proximity to themselves. A reasonable MFD for many critters starts right around 50cm. The Olympus 60/2.8 is around 20cm which again is too close for a lot of stuff.
I've pretty much already said or at least inferred, the important bits about how the lens itself affects lighting or the lighting you're able to use with it. Lighting itself is a huge subject as I'm sure you know, and variables only multiply when we begin to discuss photomacography or photomicrography. I won't try rewriting or even paraphrasing any of the books out there on the subject but the gist of it is that a strong very diffuse light source radiating from the front/top onto the subject is the most desirable in achieving that gorgeous "macro look" we see so many images posted with. You can check out sites like www.photomacrography.net :: Index
or threads like Post Your Set Up! - FM Forums
in order to see and read about some of the solutions people far better than myself have come up with.