Extension Tubes With Laowa Lens - Question

First, the reason for the question... Just for fun, I thought I'd put some extension tubes on the Laowa 25mm x2.5-5 macro lens. They didn't fit. The reason is that this manual-everything lens has a plain bayonet mount - no electrical contacts, no screw drive, no coupling of any sort to the camera and, crucially, no slot for the stop-down coupler lever that is present in the extension tubes. The lack of a slot doesn't matter when mounting directly on the K3 (or, as far as I understand it, other DSLRs) as there is no lever.

And now the question... Is there a way of linking the lens to the camera via extension tubes? It must be (a) practical (no surgery on lens or tubes, please!); (b) cheap (this is just for fun, the resulting images might just be a mess of diffraction and aberrations ) and (c) easy (e.g. no searching the world for an obscure adapter only made in March 1974).

Hopefully, one of you good people who enjoys playing with old or unusual lenses might have an answer.

And finally... For info only (it won't help here), the Laowa can be mounted on a Q - the Q to K-mount adapter does not have a stop-down coupler lever (or indeed, much else at the lens end). But I don't know yet whether the results are worthwhile. And I don't have Q extension tubes .

Steve

Steve
Does the Laowa fit if a teleconverter is used? If so, could you try the extension tubes, ideally the 13mm one between camera body and converter?

Michael

Thanks, an interesting suggestion. I've just tried it with the 1.4TC and it works! Goodness knows what a TC that's optimised for long lenses will do with a short focal length lens that's optimised for short distance, high magnification. There's only one way to find out, though. A whole new area for tinkering and experimenting has opened up ... .

However, interesting as it is, it isn't quite what I was looking for because of the extra glass in the TC. So has anyone any other suggestions that do not involve extra glass? And please don't suggest removing the lens elements from the beautiful, precious, oh so useful 1.4TC .

Steve

Am I correct in assuming that the back of the Laowa is fouling the stop down couple lever? I have just been fiddling with my Jessops extension tubes and have come to the conclusion that the only way to achieve what you want is to remove the lever - not to be recommended, though. The alternative would be if a forum member can lend you a helicoid tube which does not have a stop down lever.

Michael

Yes, the Laowa doesn't have a slot for the lever to go into. I did wonder about removing the lever but decided against since it's only for an experiment and Murphy's Law says that when I want to put it back I won't be able to find it or, even worse, damage the tubes while removing it.

TBH, I was really surprised that there was nothing in my box of odds and ends that would do the job. I thought that what is in there would be able to connect anything to anything else. Unfortunately not.

Steve

How about you put the camera on a tripod with an extension tube, preferably the 13mm one, set a high iso - relatively high speed and hold the Laowa on the end of the extension tube and try a couple of shots on a pre-focussed subject. In theory you shouldn't get any light leak.

Michael

An interesting suggestion, but you presumably haven't had the pleasure of a close encounter with the lens... It is very specialised, only for ultra-macro. Depth of field is always much smaller than 1mm and the range of focus is very limited - approx 4-5cm from front of lens, not capable of focussing on anything further away. Hand-holding the lens against a tube would need to be accurate to about 1/50mm for it to have any validity and I doubt if that would be possible even with the camera mounted on my fairly solid macro rig.

Anyway, I've decided to spend a little bit of money and have ordered a cheap (£12) and very basic set of new tubes. As far as I can tell it has no levers or any other connectivity or communication between camera and lens, just bare tubes, so it should be possible to mount the lens. I'm not expecting much in the way of build quality, but it will hopefully be enough to decide whether to pursue tubes any further. If the results look good but the tubes don't seem up to regular use, there's always the option of buying an old and inexpensive but well made set and removing the obstructing lever. Frustratingly, there's a bug photographer whose website shows pretty good pictures taken with tubes attached to the Laowa which have pushed magnification to 9x. However, he uses Nikon and Olympus M4/3 cameras so presumably doesn't have to deal with an awkward lever.

Steve