Ant Dairy Farm

So I have this palm tree that is infected with lice. It's apparently very common here, and does not interfere with the plant. As you may or may not know, some ants "milk" these lice. I have no idea how they milk them, so I set up my rig and waited to see if I could get a pic of them milking. Alas, after an hour in the sweltering heat I gave up. I did, however, get some nice pics anyway. Here's one:



I know Asher would be asking for all the details , so here they are:

Canon 1D MkIII, Canon 100mm 2.8 macro on 68mm extension tube, shot at closest focus. Lighting with Canon MT-24EX at 1:4 ratio, manual mode 1/160 f13 ISO 100.

Comments and critique, as always, welcome.

Hello Kris,

Quite an interesting image, I like the overall texture of the background. Even at the expense of sharpness, if it were me, I would have stopped down much further (at least f/22, or even down to f/32) because I feel the depth of field in this image makes it feel a bit "uneasy" - either shallower (i.e. maybe taking a "portrait" of the ant's head) or otherwise deeper (getting as much in focus as possible).

I know diffraction at f/32 kills an image, but I find with some aggressive sharpening, the images still look very worthwhile, especially at small web resolution.

I am also loving my Canon 100mm Macro, and I recently got myself an MR-14 "ring lite" (I like the portability compared to the monster that is the MT-24 "twin lite"). I have a question - if you say you used 68mm extension tube, is this by any change the set of three Soligor tubes, stacked?

I am seriously considering getting that set, and I would love some first-hand impressions: Do you get vignetting on the 1DMIII with the 100mm macro? What is the build quality like? (Do you find it lets in more dust, a real problem for me in Macro shots with tiny apertures) etc.

thanks, and it's always amazing to me to see close-ups of the head of an ant - it has a distinctly different "personality" to most other insects, I find.

Hi Dawid,

Thanks for commenting! Yeah, the DOF vs diffraction limit is a constant struggle. Sometimes I break the barrier, but most of the time I tend to stay below, or at least around the limit. Rarely do I go as small as f/22 though. In landscape photography there are some who prefer to focus at infinity and have everything slightly OOF, others prefer using the hyperfocal distance in order to get the most in focus. It is kind of the same thing with macro, I suppose. I normally prefer to have a shallower DOF with sharp focus than more DOF but everything becoming slightly "OOF" due to the diffraction limit.

In this case I think I could have done two things better: slightly smaller aperture and focused a bit further out. As you can see, the foreground is sharper than the background. I think I could have focused to get the background sharp enough for the ant's head to stay focused.

I have another image from this shoot which is more of a portrait type shot. I post it later.

Regarding the extension tubes. I hadn't heard of the Soligor tubes, but a quick search seems to indicate that it is the same as what I used: a set of three (12, 20, 36mm) Kenko tubes. Judging from the pictures of the Soligor, it wouldn't surprise me if it is manufactured by the same people.
The picture above is uncropped, and not processed wrt vignetting. I have never seen any vignetting caused by the three tubes stacked. Build quality seems OK. At first you may think it is a bit rickety, but everything seems to stay in place well enough As for dust, I've never really thought about it. I can't see how it would not cause more dust, seeing as there are gaps between the tubes. However, there is so much dust where I live that it hardly makes a difference. But the MkIII is fantastic when it comes to dust. After some two months with it, with numerous lens changes, and a lot of time with the macro+tubes, I only have one spot on the sensor that the cleaning has not taken care of.

Hi Kris, Nice shot.

Are you sure they are Lice and not Aphids that the ants are milking?

Here's the other one.




Will, I honestly don't know. I know aphids are colloquially called plant lice, but I was simply told by the gardener that it was lice. But do these look like aphids to you? I mean, I've seen them crawl around other plants (in other countries) and these look nothing like it, and they don't move Are they aphid eggs? Some sort of pupa?

There is so much I want to learn about entomology!

Kris,

Well done, and handheld as well.

KrisCarnmarker said:

I normally prefer to have a shallower DOF with sharp focus than more DOF but everything becoming slightly "OOF" due to the diffraction limit.

Click to expand...

I agree with that choice/trade-off, I'd also rather have at least something 'in focus' than nothing (although small web compatible images can trick us into an enhanced DOF and sharpness perception). Macro photography unfortunately also means having to deal with shallow DOF (and motion blur), especially as the magnification factor gets higher and higher.

The total Depth of Field in macro photography will increase proportionally with aperture, but so does diffraction. At f/13, as used by Kris, the diffraction spot diameter is 17.6 micron, i.e. more than twice the 7.2 micron sensel spacing of the 1D MkIII. At f/22 the diffraction spot diameter is 29.8 micon, or more than 4 sensels regardless of focus.

The only way to visually 'compensate' for diffraction losses, is by proper downsampling of the output file size, in the case of the Mark III to approx. 1458x972 pixels for uncompromised quality. For many purposes, that's too much of a concession. Kris' current f/13 concession would limit the optimal file size to something like 2120x1413 pixels, maybe a bit larger with agressive but visible sharpening.

Of course when the goal is to produce images only fit to be used in web publishing, we can get away with a lot, but if prints may need to be made we won't have that option.

Bart