Heligon now converted

[rosko]

I recently bought this lens ''as Heligon''.

Heligon is mentioned anywhere on the lens. No focal distance, no aperture specified either.

# length : 95mm;

# Front glass diameter : 64mm;

# Rear glass diameter : 20mm

# Weight : 440gr.

The lens shows a 2 mm orange O-ring in the middle.

Nikon conversion under way.


Any clue of identification is welcome.

[charlie]

I've got both a 100mm f1.5 as well as a 100mm f1.6 and both of their rear elements are in the 30-35mm range. However with Heligon lenses the same lens can come in many different casings/mounts depending on which machine it is intended for use with, or so it would appear.

It certainly looks Heligon-ish, if any of the lens casings can be unmounted the identity may reveal itself (?), can the numbered part of the lens be removed?

At this point I would be less interested in what the lens designations are and more interested in how it works. If you hold it to the mount on your Nikon SLR how far is the focus distance?

[Jakov Minić]

I agree with Charlie.
Nice to know the focal length, much better to obtain good results 

[rosko]

Thanks Charlie for these informations. I tried to find out more about this lens on internet without success. Nothing shows this O-ring.

I didn't try to remove the numbered part as numerous holes around it suggest that it would require a specific tool.

much better to obtain good results 

Yes, I am more concerned too by the result indeed ! .

Anyway, I am not worry about the technical data of this piece of glass, as several specialists (included you!) will try it soon somewhere in Scotland ...


I am going to open a thread to show the Nikon conversion as the part is now machined. 

Cheers, Francis.

[Bjørn Rørslett]

The numbered holes are to lock focusing in an X-ray or other industrial machine. You set up the lens and found best focus, then clamped the lens down.

Some of the Heligons are designed for laser work. Hopeful your lens isn't among that crowd or you are in for some massive colour artefacts.

[rosko]

Hopeful your lens isn't among that crowd or you are in for some massive colour artefacts.

Thanks for these additional informations, Bjørn !

I made pictures to see how the lens behaves by comparison with the macro nikkor 55mm f/2,8 AIS.

The Heligon gives darker colours (I am not sure what colour artifacts are, though)

But it's obvious that the sharpness is really different... (in connection with the very thin DOF)

[Bjørn Rørslett]

You apparently don't have a laser optics, Francis .... These are corrected for a narrow wavelength range and if feed normal light will make images with colour fringes everywhere.

Now, it's time to explore the world in a Heligon-wise manner . Sheer image sharpness is not something one pursues with these lenses. They are very sharp when used correctly, but that is not the way we love to abuse them and even the slimmest mirrorless camera cannot put such lenses in a correct conjugate relationship anyway.

[rosko]

Now, it's time to explore the world in a Heligon-wise manner .

Conversion achieved !

I brought few ingredients to a mechanic turner :

# the lens;

# a Nikon bayonet taken from a cheap close-up ring.

I ask the mechanic to tap an aluminium sleeve inside threads to match existing ones on lens. I required him to make sure the rear glass does't protrude outside the sleeve.

Some pics to show the job:

[rosko]

I tried to change the title to avoid a new thread, but didn't work, never mind !

Error ! now it works !

[rosko]

Now 2 pics to shows how  this lens performs...

The next images will be posted in the dedicated thread.

[Jakov Minić]

Francis, the pink one is magical

[Hugh_3170]

I agree.  It looks like a thistle flower.

Francis, thanks for sharing the details of how you achieved the conversion.  It is always nice to see how others tackle these challenges.

Francis, the pink one is magical

[John Geerts]

Lots of colourful effects in the first one, Francis.

The pink one, is ...  very sweet 

[rosko]

Thanks everyone for your nice comments.

I have many more picture to post, but I cannot find the dedicated thread.

Perhaps Jakov (who started the thread if I remenber well) could give some help ?

Here, a portait of my Df mated with the Heligon.

[Akira]

The mechanic turner did a very neat job!  The test images look pretty.  Congrats on the new purchase finally!