Fitting a Vectis 80-240mm to the NEX

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OVER the past few days I’ve been looking at the NEX-5 and a range of lenses and optical systems. I’ve got adaptors for C-mount (16mm/TV/CCTV) lenses, Leica 39mm screw, Minolta MD and the LA-EA1 for Alpha A-mount. The NEX-5 has proved able to provide a surprisingly bright focusing image through a classic German microscope:

It also proved very competent with the Sigma 70-300mm f/4-5.6 OS lens, the adaptor providing power for the OS which is fully functional, and also for auto exposure, leaving only manual magnified focusing to tackle. The OS Sigma has an internal motor for focusing on Alpha, not screw drive though it sounds and feels like it. It’s not HSM and almost certainly won’t be friends with any AF enabling update of the NEX/Lens Mount Adaptor firmware.

One lens I have obtained a coupled of sample of to experiment with, even if it means dismantling one. That is the Minolta Vectis 80-240mm f/4.5-5.6 APO, a miniature version of the 100-300mm APO made for 35mm, in the APS Vectis mount. This mount is all-electronic like the Vectis, but probably very different in the voltages required and the command protocol. But who knows? Maybe an AE adaptor with power for manual focus might be possible.

Using a Zenith 39mm (Leica type SLR) thread T-mount the Vectis 80-240mm nearly focused OK attached to the Leica adaptor of the NEX, but the bayonet was only just able to fit in a doctored T-mount and the combination with the NEX Leica screw adaptor was clearly a little too thick.

Using a Leica thread lens reversing ring (don’t ask, from my box of miscellaneous old rings and things – 49mm filter to Leica screw!) and duct tape, I was able to fit one of my two 80-240mm APO guinea-pigs to the mount within 1mm or so of correct register (38mm). It’s only taped, but solid enough. I do not want to cement the bits together at this stage.

Effectively it’s got a Leica screw mount taped as close to the Vectis lens mount as anything will allow. There is plenty of room to make a proper Vectis adaptor, with or without contact arrays at both ends and a chip to convert the signals. Without that, the lens is stuck forever at full aperture. If power could be supplied to the correct pins to enable the focus-by-wire action, that would complete the job with this Vectis lens – but other Vectis lenses don’t even have a manual electronic focusing option. As it is, wrenching the front tube round focuses the lens. Just like it did when you were fitting or removing the lens hood, a frustrating rotating front unit.

As it stands, the 80-240mm Vectis APO f/4.5-5.6 is a really neat size of lens for the NEX and Sony could do far worse than remake this in an OS version for NEX. At full aperture, performance up to 200mm is very good but a familiar softness (like the 100-300mm APO D at 300mm etc) creeps in at 240mm. For 1996, the lens is pretty amazing.

80mm wide open, for original

240mm wide open –

Close focus at around 135mm wide open (because the lens can not be stopped down):

Around 100mm, same conditions apply:

And at 240mm close focus again:

This lens has some really good qualities, considering it is not even mounted correctly and is definitely not correctly set up for register, which alters the way the zoom/focus correction functions. It could no doubt be made to look better by picking a flat target and a medium distance, rather than homing in on garden close-ups with too much depth for the wide-open setting.

But the bokeh effects are not too bad, the point of focus is well defined, and the lens has few vices considering the imprecision of its mounting!

– David Kilpatrick


  • Hi David,
    I am considering adopting 400mm Reflex Vectis lens for my NEX, and I am wondering if you can manually focus it.
    It seems that there is a button MF/AF on the lens, close to the mount – I saw it once and now I cannot find ANY picture online to confirm this, nor any reference talking about this topic.
    Do you know if the button/switch is there at all, and if it is, can you actually leave it in manual zoom mode?
    Thanks in advance!

  • where did you get the T-adaptor for the microscope?? ive got a celesrton c90 and a T-adaptor/and a ring for an MD. i want to put my nex 5 on the telescope but i can’t find a ring for the new sony E mount how did you get it on the microscope??

    • The T-tube was made by SRB – now known as Griturn Ltd. Custom engineered. I do not use an E-mount ring, I use the A-mount adaptor on the body, and a regular Alpha ring.

  • The Super A lenses may have been very good; my Minolta 35 II Leica lenses were never all that good, but they were ten years before the Super A and lacked the same coatings. I have a 35mm f/3.5 lens unit taken from a 1950s rangefinder Minolta, might see if it can be tested on the NEX for fun.

  • minolta4me-kevin

    Hi not sure if the web links will work but should be able to cut and paste into browser and find these pages
    A quite remarkable merge of some of the oldest and most uncommon “breech” style lens and newest mirrorless technology – Quite why I stll do not know but I am going to
    try this one day. regards kevin

  • minolta4me-kevin

    Hi, just seen a web page that needed to be translated but appears to show Minolta Super A lens on a NEX ?
    At least that is what it seems to be showing, it’s not April 1st. is it ?

  • It does not seem to be doing any harm, but it’s not an elegant solution. I have two lenses to experiment with.

  • minolta4me-kevin

    Hi David,
    Apologies for not reading your explanation carefully enough, I misunderstood [language being a little open to interpretation, even if a dictionary is used ;-]
    On a couple of vectis zooms I have the front black “barrel”
    part extends when you zoom and indeed can be made to rotate.
    Not all the vectis zooms have that and I believe this is referred to in some vectis lens and camera instructions.
    Those being capable of “manual focus”. The few that do may then be feasible as candidates for a real adaptor and I will persevere with my efforts to interest a commercial manufacturer of specialist adaptors. As an aside is it doing any harm when you focus this way, the first time I experienced this was when “parking” a lens hood in reverse and the grinding noise made me think I had broken or was forcing something ?
    Worried of Cheadle……

  • You just turn the front unit, the zoom tube. It’s like the 100-300mm APO D and has a rotating front rim, that will focus it.

  • minolta4me-kevin

    Hi, still looking at this with some interest, but confused as to how you “focused” the lens. Surely the front ring is the zoom. As far as I can tell you can only manual focus when the lens in on a camera take it off my RD3000 or S-1 and the focus ring on a zoom or prime lens just rotates and seems to do nothing. Yes you can rotate the zoom ring but that is not focusing surely ? Anyone who can come up with a way to get extra use out of these veCtis lenses is going to be on a winner. As you say they are light, good quality and of a size more suited for the “APS” sized sensors, which have a sensor “similar” in size to the real APS… the near defunkt film format. regards kevin

  • minolta4me-kevin

    Hi, absolutely brilliant I am talking to a specialist adaptor manufacturer in Bedfordshire here in UK about the same subject. And would love to be able to use my full range of veCtis lenses on digital or 35mm bodies. Only way so far is use the APS film S-1 bodies or an early Minolta the RD3000 that I managed to get working.
    PS. ever hear of Heath Robinson, only joking 🙂 I really applaud your hands on approach. kevin

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