Wideangle closeup with 18-200VR and K-1 extension tube

Started Jul 18, 2011 | Discussions
_sem_ Veteran Member • Posts: 5,033
Wideangle closeup with 18-200VR and K-1 extension tube

After you got your first DSLR with a kit or superzoom lens, have you ever wandered what happened to that wide-angle macro mode you had on your old P&S? You surely didn't love the short working distance and you likely preferred the subject isolation that comes with longer macro lenses. But now and then one likes the "deep focus" impression that comes with wideangle due to low relative blur of the background (although there is no more DoF technically).

Well, it so occurs that this is achievable with a short FL, 18mm on various DX zooms is just fine, and a very short extension tube, like the thinnest Nikon K-1 ring (5.8mm). Anything thicker likely won't work because the working distance gets too short; with the K-1 it is about 3 cm (these lenses may be also reversed but then you get into super-macro rather than close-up range).

Unfortunately the old K-1 is fully manual, with no aperture coupling etc. It fits current cameras fine, but it is very tight with electric contacts of AF lenses, so one should preferably shave off some metal if not sticking with pre-AF lenses. Regarding possible further modding for more convenient operation: there really isn't any room for adding electric connection as with Kenko auto tubes; one may be able to add a Dandelion chip for metering but there is very little space for mounting its support; one would have to extend the aperture lever of the lens to regain auto-aperture by the body but I'm not sure how this'd be done reversibly.

Some first-time samples... "Deepest" focus with the aperture almost closed, so bright light is required to get useful shutter time at base ISO. One should pay more attention to dust on the front element than I did And dust on your sensor may happen to be the only really sharp thing in your image at this aperture - so don't peep for sharpness cause there is none! You don't really need a sharp lens for deep-focus; resistance to flare and small physical size seem to be more field-relevant. Compared to a typical P&S: P&S requires less light for base ISO so is more handholdable; but modern Nikkors have much more DR at base ISO so fare better if playing with midday sunlight and pseudo-HDR (these are quick&dirty Picasa raw conversions).

If you want to reduce diffraction blur or get more light in, you need to stop down the aperture a bit by fixing the aperture lever with a piece of cardboard or rubber. But the deep-focus effect decreases. Samples at unspecified intermediate aperture...

subhrashis Forum Member • Posts: 66
Re: Wideangle closeup with 18-200VR and K-1 extension tube

Like the approach and the results- this technique has promise!

Is there room for any way to hold open the aperture... wedged in cardboard? you can experiment with a cheapie 18 55 if you have one.

{Edit, Sorry, didn't see the last bit of text where you already mentioned cardboard!}

Also seems to be a nice fate for those old uwa s from other mounts which lose infinity focus on F mount... maybe the extension of the adapter would suffice for mag!

pete_mb Regular Member • Posts: 226
Re: Wideangle closeup with 18-200VR and K-1 extension tube

I really like the idea of wide angle close up, and some of your shots are very nice in my opinion, despite less than perfect sharpness. It really gives a 3D look.

I'm considering buying the Kenko auto extension tubes - wouldn't this work just as well with the 12mm Kenko tube, and still give you electronic control of aperture?
--
Pete
http://peterbrockwell.zenfolio.com

OP _sem_ Veteran Member • Posts: 5,033
Re: Wideangle closeup with 18-200VR and K-1 extension tube

subhrashis wrote:

Also seems to be a nice fate for those old uwa s from other mounts which lose infinity focus on F mount... maybe the extension of the adapter would suffice for mag!

Those adaptors are dubbed "macro" simply because they lose infinity. Some work for "deep focus" when stopped down but some have too much inherent extension and blur background too much.

I've seen some folks have stripped mounts off in such case - then you're more flexible, can even make a tilt&shift.

OP _sem_ Veteran Member • Posts: 5,033
Re: Wideangle closeup with 18-200VR and K-1 extension tube

pete_mb wrote:

I'm considering buying the Kenko auto extension tubes - wouldn't this work just as well with the 12mm Kenko tube, and still give you electronic control of aperture?

No, 12mm is too much @18mm, the working distance is to short to be useful and the background is blurred too much. The extension is relative to the FL, so I guess 12mm is useful around 35mm. But it at 35mm it is even better to buy the Tokina 35mm macro Mind that zooms, particularly superzooms, tend not to always behave similarly as primes of the corresponding FL when on extension.

This effect is even intensified with a fish-eye lens, but 5.8mm is likely too much for DX fisheyes. One might use a flat ring dichtung for a spacer and handhold or tape the lens (careful not to damage the aperture mechanism!). Another workaround is to use an intermediate optical lens relay and a CCTV or cine UWA or fisheye lens - so that you can use a small-diameter lens that casts less shadows so it is easier to work at short distances. I've already tried with a CCTV fisheye which almost worked but I hit a couple of problems: I got vignetting in the relay (with three different kinds of relay), and my fisheye has no aperture control which is not good because stopping down in the relay makes vignetting worse. A camera with a shorter flange distance, such as a mFT, should be a better idea for this, except if you want the relay to increase distance of the shooter to the subject or perhaps insert a prism to shoot at angle.

http://www.koheisha.net/microwidelenz/musinomekakakukousei/e-musinomelensomonasystem.html

pete_mb Regular Member • Posts: 226
Re: Wideangle closeup with 18-200VR and K-1 extension tube

sem wrote:

pete_mb wrote:

I'm considering buying the Kenko auto extension tubes - wouldn't this work just as well with the 12mm Kenko tube, and still give you electronic control of aperture?

No, 12mm is too much @18mm, the working distance is to short to be useful and the background is blurred too much. The extension is relative to the FL, so I guess 12mm is useful around 35mm. But it at 35mm it is even better to buy the Tokina 35mm macro Mind that zooms, particularly superzooms, tend not to always behave similarly as primes of the corresponding FL when on extension.

Thanks, this is useful. I have the 35/1.8G and 85/1.8 so will be able to get some more 'classic' close-up shots with the tubes, but I wonder if my Sigma 17-50 OS set to around 24-28mm might give me some interesting wide-ish close-ups combined with the 12mm tube?

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OP _sem_ Veteran Member • Posts: 5,033
Re: Wideangle closeup with 18-200VR and K-1 extension tube

pete_mb wrote:

Thanks, this is useful. I have the 35/1.8G and 85/1.8 so will be able to get some more 'classic' close-up shots with the tubes, but I wonder if my Sigma 17-50 OS set to around 24-28mm might give me some interesting wide-ish close-ups combined with the 12mm tube?

Surely you can try...

pete_mb Regular Member • Posts: 226
Re: Wideangle closeup with 18-200VR and K-1 extension tube

sem wrote:

pete_mb wrote:

Thanks, this is useful. I have the 35/1.8G and 85/1.8 so will be able to get some more 'classic' close-up shots with the tubes, but I wonder if my Sigma 17-50 OS set to around 24-28mm might give me some interesting wide-ish close-ups combined with the 12mm tube?

Surely you can try...

As a cheaper experiment, I got some non-electronic tubes from ebay and tried them on an old 28mm Canon FD prime on my NEX-3 -- and I see exactly what you mean... Even with just the 12mm tube mounted, "infinity" focus on the 28mm was less than 2cm in front of the lens!

The effect is much more extreme than I'd imagined. With that in mind, I find it a shame that you can't get tubes of around 3-5mm in length, at least not without messing about and risking the AF contacts as you describe with the K-1.
--
Pete
http://peterbrockwell.zenfolio.com

OP _sem_ Veteran Member • Posts: 5,033
Re: Wideangle closeup with 18-200VR and K-1 extension tube

pete_mb wrote:

The effect is much more extreme than I'd imagined. With that in mind, I find it a shame that you can't get tubes of around 3-5mm in length, at least not without messing about and risking the AF contacts as you describe with the K-1.

Well it's the way F-mount is made, I guess thinner is not possible. Screw mounts are different...

I think the K-1 should be safe actually, just handle with care, and shave off a bit if you're not certain. Using a cardboard spacer ring and handholding is trickier (one must pay attention to the aperture mechanism, maybe another mechanical AIS coupling on the big cameras).

But the issue could be most conveniently solved by the lenses allowing some more close-focus-throw "overdrive". For instance there are certain AIS wide Nikkor primes which may be relatively easily modded to focus a bit closer than default (like default max magnification around 1:10, modded 1:6, default with K-1 1:3).

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