Working with the Fuji Macro Extension Tubes
Mass Made Soul combines my love of vintage products with my love of photography, so here's a peak under the hood at more of the photographic side.
I use Fujifilm cameras (namely the X-T1) to take the photographs here at Mass Made Soul, and recently acquired one of Fuji's macro extension tubes to take close-up shots of the products we feature here. I thought I'd share some thoughts on the usage experience and image quality for those who might be weighing an extension tube (about $100) vs a dedicated macro lens (about $800).
In the past I had a macro lens for my old Pentax DSLR (the extremely good 35mm Limited), so I had a feel for how much I’d use such a lens. The Pentax macro was also usable as a general purpose normal (50mm equivalent) lens, but the extremely slow AF of Fuji’s 60mm macro didn’t make that a good option, and in any case that focal length I have covered with Fuji's 56mm. So I decided if I’m just going to get something specifically for macro then I will go the less expensive route for now and put my lens dollars to use elsewhere.
Fuji makes two extension tubes, the MCEX-11 and the MCEX-16, which are 11mm and 16mm respectively in how much they push the main lens out from the body (with the 16 having higher magnification and closer focus). Fuji vs. Fuji has this handy comparison page for the two tubes. I purchased the 11. All the photos here are taken with Fuji's 35mm f/1.4 lens, which goes closer than most of their other lenses that aren't wide angles (I don't like to use wide angles for this kind of work due to the distortion and how close I have to get to the product - see below about casting shadows...).
It’s a tight fit
I sprung for the official Fuji extension tube instead of getting an eBay cheap one because most of the 3rd-party brands seemed to have reviews about how loose they were. The Fuji is the opposite - it’s quite a tight fit indeed, especially between lens and tube, and I find I have to be slow and deliberate with both attaching and removing it. Removing it means depressing the small lever on the outside and then twisting off. The 35mm lens barrel doesn’t have much to hold on to as the focus and aperture rings both slide easily, so it can take a bit of work to get the tube off again. The plus side is there's absolutely no wobble between the lens and body.
I’ve found it easier to remove the tube once I’ve taken the lens+tube combo off the camera.
Narrow focus window
One thing to keep in mind is that with an extension tube you have a quite limited focus range that barely, if at all, overlaps with the focal range of the lens without the extension. Unlike a dedicated macro lens where you can also zoom out to infinity, the extension tubes give you a very narrow distance window in which to work - it doesn't just add on close-up range to the existing focus range. Since it is a bit tricky to attach/remove the tube and you can only use the lens for close-ups once the tube is attached, I try to batch my macro shots (say, of a particular product that I’m shooting). If you’re a landscape and nature photographer, you may not want to have that limitation (or just keep the tube attached to one lens while other lenses for everything else). Even then, it takes a while to learn how close you’re really going to need to be to make the extension tube work, and there are going to be cases where the ideal framing sits between the focus ranges of the lens by itself and the lens+tube.
Use manual focusing
I typically manual focus with the MCEX-11, using focus peaking, as I find this is more predictable than letting the camera focus itself when you need to be absolutely precise with such a narrow DOF. The X-T1’s brilliant EVF makes this really convenient with the mini magnified area. For macro work I find that focus peaking is easier than the split screen focus assist, which I often prefer for more general usage. Even so it can be challenging - in the shot belows you'll see that I didn't quite nail the focus on the front row of keys of the Olivetti Divisumma 18 calculator in the top photo but did get it right in the lower one.
This limited focus range can also make it challenging to get in close without casting a shadow. The 35mm allows me to get very close, but its normal focal length means I’m right on top of the object and can easily put it in shadow. The 56mm helps avoid that, but must be almost twice as far away and has a magnification of .29 instead of .47 for the 35mm.
In the shot below of the Olympus O-Product camera you'll see my shadow in the bottom left corner, which took some contorting to avoid.
Watch out for color fringing
At least with the 35mm attached I find it pretty easy to induce color fringing with the tube attached, easier than the lens by itself (and more than I’ve experienced before with a real macro lens). You have to be super careful about having enough depth of field, because if you don’t and there are areas of high contrast in the image, you’re likely to get color fringing. Here's an example of a close-up of a printed page (from our review of the book Ettore Sottsass). The blue rectangle at the top is 2" wide as printed on the page and you'll notice blue fringing around its edges, as well as of the blue circle. (There's also a bit of barrel distortion, but not as much as it might seem here, as this is a photo of a collage and the pieces aren't all lined up quite perpendicular.) To an extent these can be corrected in post (I use Lightroom), but they can get large enough in spread that LR doesn't fully correct them with its chromatic aberration tool.
I'm not a technical expert on this but I don't think this is chromatic aberration in the usual sense, I think its smearing caused by falling outside of the depth of field. Perhaps the page wasn't completely flat, but in macro work it quickly becomes apparent that you don't so much have a focal plane as a focal sphere - in this case I was shooting a flat plane but because the lens was so close to that plane (i.e. the page) things at the edges of frame actually get out of focus. Such gotchas are always an issue when doing macro photography and are not specific to these tubes, but I do find that it comes up more easily than I would expect with a dedicated macro lens, which are designed specifically for close up work and correcting some of these problems optically.
Having said that, the optical qualities of whatever lens you're pairing with the tube will be largely kept intact. Since I'm using the excellent 35mm f/1.4 that does a lovely job of softly rendering out-of-focus areas, that is still the case here even when relatively stopped down (f/6.4 in this example of the flash unit of the Olympus O-Product camera).
You’ll need a pouch
The tube doesn’t come with any kind of pouch or case, and the various protrusions of the tube are sharp-edged - not good to have kicking around loose in a gear bag. I keep mine in a microfiber sunglasses pouch, which doubles as a way of cleaning glass and surfaces.
Is it worth it?
For my purposes I’ve been satisfied with the purchase.
I’m glad I got the 11 rather than the 16, which would have meant an even closer working distance, which I don’t need. (You can also stack the tubes together to get super close…and you can even put a macro tube on the 60mm macro lens!) Down the road once my lens collection has become more complete, I will probably spring for a proper macro lens so that I gain the conveniences of the full focal range and less fiddling when swapping lenses. Perhaps the 120mm macro they have on their roadmap for 2016...