Super Macro Brothers: the Weigh-In

I’ve been reading up on Macro photography quite a bit lately. Well, that’s not quite true… I’ve been thinking of buying a proper macro lens for several days—the Tokina 100mm f/2.8, specifically—and reading review after review and spec sheet after spec sheet, and in the process I decided to see how the macro rig (the 75-150mm E Series, reversed and extended) and the Super Macro brothers stack up against the real Macros…

So I took a bunch of pictures of a ruler.

*yawn*

And I got some pretty interesting results:

The D7000’s sensor measures 23.6mm by 15.6mm. (For Sanity, we’ll say 24×16. Also, from now on all measurements will be in millimeters unless otherwise noted.)

The macro lens I’m considering produces a 1:1 reproduction at 11″ (~4.5″ from the end of the lens).

Well, the 75-150mm f/3.5 gets close-ish:

    • Simply reversed, the 75-150 reproduces roughly 36.5 x 24.5 @ 14″ (6.75″), or 1:1.5.
    • Reversed and Extended, it reproduces 17 x 11 @ 13.75″ (3.75″), or ~1.5:1!

The 36-72mm, by contrast, does simultaneously better and worse:

    • Reversed, it reaches 13 x 9 @ 8″ (3″). ~1.75:1
    • Reversed and Extended, 7 x 4.5 @ 11″ (2″). 3.5:1!

This focusing distance is ludicrously small, and very difficult to work with. I had to move the entire set up all around to even focus on the ruler, as the depth of field becomes rather small.

Something interesting happens when they come together, though.

  • 75-150 mounted straight, 36-72 reversed, we get 5.5 x 3.75 @ 15″ (2″), or ~4.2:1
  • and both reversed yields 5.25 x 3.5 at the same 15″ from the sensor plane, or (slightly less than) 2″ from the front of the lens.

This is interesting to me. Why is there so little difference between two? It would seem that two reversed lenses would be better than one, yet it seems to matter very little whether the first lens is straight or not.

In fact, some vignetting happens when the 75-150 is on straight.

I’m sure there’s a mathematical explanation for this, but I’m not much of a mathematician. If you can help, let me know in the comments.

Now I want to get closer! Closer! How close can I get?* I don’t know, but the depth of field is going to be tiny when I get there! I can only hope the bokeh is pleasing…

*I’ll maybe get a bit closer in the next week or 10 days: I just ebayed a Nikkor 24mm f/2.8 ai and an EL-Nikkor 50mm f/2.8 photographic enlarging lens, and another set of extension tubes and some more reversing rings, and I’ll have another report when I get all that stuff played with. And I decided to hold off on the Tokina for awhile since I’m already getting to 4+:1 with the Super Macro Bros.

365.79 Ohne Titel (Sending Feelers Out Into The Void)

Leaving work today, I walked outside and the clouds… oh my, the clouds.

I pulled the D7000 out of the bag and started shooting.

I took the long way to the car.

D7000. Sigma 30mm f/1.4. ISO100, 1/8000th, f/1.4 (yes, I should’ve stopped down, way down. Oh well. By the time I realized it, I was getting ready to post this…).

365.78 Reversed Walkaround

Got home a bit early today, and so I took the reversed 75-150 for a walk around the apartments. This is the best shot I got, though I was shooting more to test the performance characteristics of a reversed 75-150mm E Series in the wild than to make a competent photo.

I tried to take some pictures of clouds, but to my surprise, clouds are only about 3/4 of the way to infinity, and it was very difficult to focus on them at f/8 with the rather diffuse and low-contrast light about. If I was smart, I would’ve switched to the live view. Alas.

D7000. 75-150mm f/3.5 E Series, Reversed. ISO1600 (lemme go change that before I forget, again), 1/4000th (AP mode), f/8, -2ev (because the D7000 likes to overexpose in AP mode, especially with non-CPU and non-Nikkor lenses, though I probably could’ve gotten away with -1ev, since I just added in full stop of exposure in post…).

365.77 Pool of Dreams

Question: Why is there a tilt-shift type effect going on here?

I’m probably going to take the 75-150mm E Series to the Arboretum for a meetup on Saturday, and I’m probably going to take it reversed, with ~30mm of extension tubes on the end as a sort of lens hood.

An interesting thing about reversing a zoom lens: you can focus to (with the 75-150) 1:1.5 at 16″ and you can also focus to infinity. But the depth of field is much narrower at all distances.

Anyway. I took this shot of the pool part of the fountain just to shoot something, and it was the last shot I took before I ran back inside.

Notice how the center is in relatively sharp focus, but the edges are beautifully soft.

Why is this?

Is it the curvature of the rear lens element? Is it something about the physics of light and reversing lenses? Is it something to do with the aperture (f/5.6 here: I was trying to shoot ants prior to this (with no success), and didn’t ever go back to 3.5)?

Leave a comment if you have any thoughts, or hit me up on the contact me page.

D7000. Nikon 75-150mm E Series, Reversed. ISO1600 (to give faster shutter speeds), 1/2000th (selected by the camera, AP mode), f/5.6.

365.74 Ohne Titel (but it needs a good one)

And another one that I want to see printed BIG. Oh what fun things you can make with a couple of flashlights and some coffee stirrer things that will one day become a gridspot for the SB700 (maybe later today, but probably not).

D7000, 75-150mm f/3.5 E Series, Reversed. ISO100, 1″, f/16.