Macro rock photography with the iPhone

A post by Chris RowanEarlier today Callan showcased a rather cool idea first dreamed up by fellow Scibling Alex Wild at Myrmecos: using a hand lens to shorten the focal length of the iPhone camera into the realms useful for macro photography. I had to try this out myself, so I grabbed the nearest interesting hand specimens* and got snapping. In the spirit of experimentation, I took pictures of the same field of view both with and without augmentation by the hand lens.
First up, a Neoproterozoic diamictite from Oman (part of the possible Snowball Earth sequences):


With hand lens

Without hand lens

Nodular hematite in a late Archean rock from South Africa:


With hand lens

Without hand lens

Another one from Oman: fibrous gypsum in a red siltstone unit.


With hand lens

Without hand lens

I’m rather impressed; returning to my earlier thoughts on the iPhone as a potential field tool, a case with a bracket to clip on a magnifying lens would be pretty darned useful for quickly recording lithologies. If said case added extra battery (like this one does) and some weather proofing, and perhaps a capacitive finger replacement a bit more elegant than a sausage, and it could be extremely darned useful. In the meantime, perhaps further experimentation might produce images worthy of inclusion in the upcoming Accretionary Wedge geo-imagery bonanza. Is anyone else experimenting with this?
*What? You don’t have random cool rocks just lying around in your flat? Or a hand lens? Strange people.

Categories: fieldwork, gifts and gadgets

Comments (8)

  1. DD says:

    Remarkable improvement, considering the convenience.

  2. Monado, FCD says:

    Neat. Must get hand lens. And 10x magnifier with light ring. And geologist’s hammer. And a little clear box for holding bugs in the field of view.

  3. Monado, FCD says:

    I used to see those iron ore pellets being shipped. I thought that the iron had been partially refined and formed into balls for shipping. (Hey, I was about 8.) I didn’t realize that they came from Very Old Rocks. Are they meteorite splash droplets?

  4. Lab Lemming says:

    Early in the Earth’s history (like the first 2 billion years or so), there was no oxygen in the atmosphere. When oxygen started getting more abundant, around 2.5 billion years ago, it started oxidizing ferrous iron to ferric iron (FeO + 1/2O2 -> Fe2O3.
    Ferrous iron is water soluble, ferric iron is not. So all the iron dissolved in the ocean precipitated. And that’s what formed a lot of the world’s major iron ore deposits.
    Note that this explanation has paved over a lot of important details, but it should get the big picture across.

  5. Silver Fox says:

    Monado, the iron you saw being shipped had been concentrated and then pelletized from iron ore. The little nodules above aren’t seen in all iron ore, often the ore is banded. Pelletizing is described here.

  6. Tim Eisele says:

    You were right the first time, the iron ore pellets that you see shipped are in fact made by grinding up ores, concentrating the iron oxide fraction, and then forming the pellets into balls that are fired to harden them. The similar appearance of the south african nodular hematite above is just a coincidence.
    (I spend a lot of time working with the iron mines around Lake Superior, that produce several million tons of iron ore concentrate pellets every year. So I’m rather intimately familiar with the process)

  7. Jeff says:

    During petrology class, instead of drawing the minerals, the professor let me use my digital camera to take snapshots of the thin sections. I pulled the rubber eye piece off of the scope and let the camera do the work. Worked like a charm.