Monday, October 29, 2012

Review: Yeenon 18-33mm Focusing Helicoid

If you read my blog for any length of time, you would know that I am a big fan of DIY lenses.  Projection lenses, enlarging lenses, odd ball lenses are my past time favourites, and all these lenses need a focusing helicoid, as the lenses themselves do not have a focus mechanism.  My first focusing helicoid was a converted Vivitar 2X Focusing macro teleconverter, which I wrote about it here. But, this home made helicoid is too thick (long) for wider angle lenses, so a thinner helicoid is needed.  I ordered two generic ones from eBay: a 12-17mm and a 17-32mm, which I covered here.  These two are widely available on eBay from many sellers, but they are essentially identical.  Typically they are selling for about $40 each, much cheaper than the time I bought mine. Sadly, they are very badly made.  Even when new, they have some play between the focusing and the mount. After only a few months of use, they have become wobbly, and pretty much unusable.  I did get a lot of use out of them, so it's not a total write-off.  I began searching for a better replacement, but couldn't force myself to forking out more than $100 for a different one.

There are basically four different makes of helicoids readily available on eBay.  They are: the generic ones that I bought and bad quality; one from Hawk Factory in Taiwan, which has good reviews, but at about $130; one sold by Fotodiox at $120, and the other, which I bought and I am reviewing, is a Yeenon 18-33mm, at $57 (free shipping if you offer to pay the asking price on eBay).  I chose the M42/52mm version, so that I can use it on NEX, Micro 4/3, and Canon EOS through the M42 adapter.

The Yeenon helicoid took exactly one month to arrive from China.  It came with a (relatively) nice box, and even a guarantee.  I could feel the difference in built quality as soon as I held it in my hand.  Much better than the generic ones I bought.  The Yeenon is slightly larger in diameter.  This has a negative effect on the NEX-5N, as the focusing ring touches my middle finger that grips the camera, while focusing. Also, there is still a very slight play between the focusing and the mount, just enough to feel it.  It's not a big deal, but nevertheless lessens the joy of using it. The focusing is relatively smooth, but a bit too much resistance.  I am sure with use, it will loosen up.

So far I have only used it for a week, but I enjoy it much more than the ones I had before.  It's not as good as the Vivitar 2X focusing helicoid, but very close.  I just hope that the build quality will hold up and last more than a few months.

The Yeenon 18-33mm helicoid. Click for larger

Face Off - Left Yeenon 18-33mm; right generic 12-17mm. Click for larger

Side by side. Click for larger

Intense colours - NEX-5N & Schneider-Kreuznach Componon-S 80mm f4. Click for larger.

Symphony of colours - NEX-5N & Schneider-Kreuznach Componon-S 80mm f4 @ f5.6


  1. Hallo Yu-Lin Chan,
    thank´s for your nice and helpfull comment on this helicoid. How did you fix it to the Nex? With glue to the opened C-Mount-Adapter? Or do you happily own a M42 Cutter? ;-)
    Does it work with the 50mm Rodagon to infinity?
    How many turns are needed for full hub of 15,5mm?
    I´m looking for a way to focus FD-lenses from 200 to 800 on a nex3 and I think, a helicoid with 3mm hub in a FD-Adapter will be helpfull. Do you have any idea if that is correct and how to manage it?
    Thanks a lot an best regards
    Jochen from Düsseldorf

    1. Hi Jochen, the c-mount to NEX adapter that I use for this helicoid has an inner 42mm thread. I just need to screw the two together. See this blog entry for more details on the c-mount adapter:

      As for the FD-NEX adapter, I haven't tried what you suggested, but there are PK-NEX adapter that has a built-in helicoid for close focusing, similar to the M-NEX adapter with built-in helicoid.

  2. Hrmm... What is the inside diameter of that Yeenon compared to the generic? The generic helicoids have internal flanges/baffles that I have to machine down for some of my lenses and it's an involved process to remove all the shavings. Also, have you disassembled it? I wonder if it's any harder/easier than the generic type.

    1. Not sure what you mean about the inner diameter. The opening to the lens side is 52mm, and the inside is probably a few millimeters wider. No I have not disassembled it.

  3. Hi Yu-Lin,

    I just came across your blog while searching on helicoids. How did the Yeenon helicoid hold up after 2 years? did the focusing loosen up a bit? Did any more play develop over time?

    I'm considering the Yeenon 27-61mm helicoid for a 645 negative copier/digitizer using a 50mm enlarger lens and a dslr. The whole contraption would be mounted vertically onto an enlarger head and the helicoid would have to carry the weight of the dslr (5Dmk2). Do you think that the helicoid would hold its "focus" when used like this?

    Menno from Ottawa

    1. Hi Menno,

      The Yeenon helicoid is holding up surprisingly well. The focusing is still pretty tight but I have gotten used to it. Also, the slight play has not gotten worse. Overall, I am very happy with it.

      I think the helicoid will be able to support the 5D II, as it's pretty much stationary and not a lot of movement. It's pretty well built and feels very strong in the hand. The slight stiffness is actually a plus for your application, as it won't move as easily. So, I think it's a good fit for you.

      If you buy from them on eBay, don't forget to negotiate a better price, or ask for free shipping.

      Good luck.

  4. Thanks for your reply Yu-Lin. That's useful info. I think that I'll put
    I like your blog, lots of interesting experiments. I'll be visiting more often.