Macro Extenders – If You’re Tempted…

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I bought some macro extender tubes from eBay a couple of months ago. They seem to come in two flavours: those which have electronic contacts and those without. I went for the economy option because, including postage, I picked them up for about 10 quid.

As I’ve mentioned elsewhere, I’ve found TWIP to be a particularly useful resource, and there was a video podcast a month or so ago about what one of the presenters carries around in his camera bag. He happened to mention that he carries the extender tubes – albeit a posher variant than I bought, with contacts – and used them in conjunction with his 50mm F1.4, as it has very good optical performance. Having just bought the same lens, and just decided against buying a macro [for the time being], I thought it would be cheap, interesting experiment.

I’ve read around the subject, and the principal functional difference between the contact and non-contact varieties appears to be aperture control: in simple terms, the camera doesn’t know that a lens is attached, and shoots wide open. Metering still works though. 

Narrow depth of field appears to be an endemic problem with macro photography. Combining macro-style focussing distances with a lens that is defaulting to F1.4… Not good. I’ve completely written off trying to use the extenders on any subject that isn’t just flat, but completely parallel to the lens. I could try it with my 28-135, which is going to default to f3.5, but have made the assumption that the lower optical quality is going to exacerbate other problems, such as chromatic aberration. So, you’re faced with a problem of trying to use the extenders with the slowest lens that you have, which isn’t normally high on the list when you’re buying.

The real problem with the extenders is a serious drop-off in optical performance the further away from the centre of composition. This is about as good as I’ve been able to get:

This is with the shortest configuration of the tube, and with the lens focussing at infinity [an effective focus distance of about 15-20cm] – only about half of the 45cm default of the lens without the tube. The longer the extender config, and the shorter the focus on the lens, the worse the drop-off in performance.

Having tried this about half a dozen times on different subjects, I’ve pretty much written the extenders off. The next image is less cropped than the one above, and shows the drop-off more clearly. There’s also an almost text-book example of chromatic aberration, with the shifting of the colours of the string directly above the string ‘Deluxe’ towards blue:

Layers Experiment

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This is the first photo I’ve attempted to mix black and white with colour:

 

I’ve taken a couple of bites at it, most recently with a tablet [as in the input peripheral] which I’ve borrowed from someone from work. It’s probably not a bad shot to try to apply the technique to in terms of subject matter. It’s just that it betrays the shallow depth of field towards the top of the image. The original shot was at F4, 47mm on my 28-235mm zoom, and shot at ISO 200. I’ve used a couple of layers: the first is an adjustment layer -> Hues/Saturation, which I’ve reduced the saturation to -100. I’ve then created a second levels layer, and used that to increase the contrast a bit. Then back in the saturation layer, I’ve painted the colour back in.

Trip to Highgate Cemetry

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We had a fantastic afternoon going around Highgate [and Hampstead] today [bank holiday]. We took the paid tour around the west graveyard, a first for both my wife and myself [who’ve clocked up about 15 years of London living and working between us]. If you are ever in town, do it: It is fascinating. Learn about Victorian Londoners in the 1860s too poor to bury an elderly relative, whom they propped up in the corner of a house with 60 people living in it. They had this poor dead bloke in the living room for a fruity 8 weeks over the summer. Yum.

I was gutted as in the preamble, the spry lady who introduced the tour guide said, ‘no big cameras’. I asked her again on the way in and she said something along the lines of ‘be discreet, and sensitive to the fact that it’s an actively used graveyard.’ There are 180,000 people buried in both sections. This came out quite nicely:

though I ended up being pretty rapid, snatching photos with my 10-22mm. On the east side, where you have to take a photo of this:

 

[I’ll come back to this. The cropping is annoying: I can’t keep all of the text with the Big Man’s head in the right part of the image.] But I think this really says it all:

And a couple more: