Friday, May 26, 2017

I want to see his hairy butt! TWSS, or extension tubes

There's going to be some camera jargon on today's blog, but if you're not a camera nerd you can skip that and dance from pretty picture to pretty picture.

To set the scene.
Once upon a time we rescued some hens and chicks from a neighbour that had torn up their garden. They did ok in our front, gradually getting buried. Then a few years ago Linda reorganized, and the hens and chicks ended up just beside the driveway, under the protection of the dread Alberta Rose. It's been doing pretty well.

The first good lens I bought was the Canon 100 mm F2.8L macro, and it's my go to lens for flower photos. I've had some stunning shots come out of it, showing me detail I'd never known existed. That got me hooked, and I wanted more. MORE! There is a specialty macro camera lens that will magnify 5 x. It's expensive just by itself, and buying that essentially commits you to buying macro rails to mount your camera on, a really sturdy tripod to mount the macro rails on, and some lighting. You'd need to budget about $2000 for all that, at least, depending on exactly what quality of rails you got.

Emphasis throughout all this is on sturdy. Even with my macro lens, the slightest movement of the subject or the camera will likely ruin the shot. The tolerances only get tighter as the magnification goes up.

I bought 3 extension tubes, since they come in a bundle. It includes 12 mm, 20 mm, and 56 mm, and they can be grouped together any way you like. These particular ones are by Kenko, and Jill at the Camera Store was happy to help get them, and discuss all the above related equipment with me.

My thinking at first was to mount the camera on the tripod, set up so I could add the various tubes and see what the effect was, without moving the camera. That didn't quite work out. Adding the extension tubes changes how your camera focuses, mainly by having to be between some fairly tight distances from the subject, and the range is really close to the subject.

Unless I say otherwise I have NOT cropped the photos to make it look closer. For my camera that's 6000x4000 px. Except for the last 4, these are pretty much the way they came out of the camera, with no sharpening or Lightroom tricks to make them look better.

Here's the first shot, just the 100 mm by itself. The sensor is about 67 cm from the focus point, and there's about 17 cm of lens and camera in front of that. I took the hood off the lens so as to get as much light on the sensor as possible. I can get quite a bit closer if I was doing a close up. The focus point is right near the centre of the big central flower. Even here you can see depth of field rendering the far flowers out of focus.


Just to give you a bit of perspective, the same grouping from a little later, shot from a slightly different angle, and slightly further away. As you see the later photos when you scroll down, keep in mind how small that central area is.

Adding a 12 mm tube doesn't change much. Still on the tripod, same position as the first photo.

The 20 mm tube, still on the tripod.

Then the 36 mm tube, but I had to move the tripod. There is no way it would focus that far away from the subject. The sensor ended up being about 40 cm from the subject. That means the front of the lens was about 19 cm (about 8 inches) from the plant, and that's the furthest away it would focus, and just barely. If I try this again, maybe I'll start with all the tubes on and take them off one by one.

Then of course, I had to try them all together, and had to move the tripod again. This was starting to get tricky, keeping the camera setup from shading the plant. Up till now I hadn't missed any shots. All were in focus, within the limits of depth of field. But that gets smaller as the magnification goes up. My camera was hunting for focus, shifting from place to place.

I messed up a bunch of shots trying to get in as close as I could. Mainly it was lighting, finding the right settings to get the exposure right. Once there I did an HDR shot, trying to get some detail in that hairy central patch. This has had my 'normal' tweaks, but isn't cropped. From the top of the image to the bottom of the image is about a cm in real life. Enjoy.

Some others, just for fun, shot with the 36 mm tube. This little flower is 5 mm (.196 of an inch) across. I can barely see the spots of orange with my eyes. This one is cropped, and has my normal processing.

In fact, because why not, here's that same flower without any crop at all.

I hadn't known ants had hairy butts. The peony bud it's on is about 1 cm across. This one is cropped. I'd told one of my buddies about this, and she got all excited. Maybe I'd worded the telling in a suggestive way.

Learnings so far:

  • Everything has to be absolutely still, even with settings tweaked so you have a fairly fast shutter speed. On the tripod I could get away with ISO 100, but those last three shots are hand held using ISO 1600 to get the shutter speed up. 
  • Lots of light. I was shooting at noon in direct sunlight for most of this. 
  • Focus is tricky, getting the camera in the sweet spot so it will focus. It's almost certainly much closer than what you've ever done before. Go with manual focus on the tripod is your only chance to compose the photo. Hand-held is spray and pray, hoping that something in the frame will be in focus.
  • Depth of field is a real issue. You can see in the above photos that the plane of focus is very thin, perhaps only a few mm with all the tubes on.
  • The detail you can get is amazing!
  • Be prepared to delete lots of shots. Of the 109 I took, I deleted 25 out of hand on the first pass through.

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