Extend your UV-Nikkor (or any longer UV-capable lens)

[nfoto]

I'm grounded these days because of harsh winter conditions outside. Lots and lots of snow and temperatures that on occasion drop well below -30C. Add strong polar winds and you have the perfect recipe for a fatal asthma attack if I would be foolish enough to venture outside.

 

Instead I was browsing some UV captures and was reminded of a nice DIY project completed a few years ago. Time to share the details.

 

The basic assumption is that you have a UV-capable lens and would like it to be "longer". The lens in question might be a UV-Nikkor 105mm f/4.5, or any old 105/135mm lens with decent UV transmission.  To the latter end I purchased some dirt cheap Petri 135mm f/3.5 lenses and with these came a Petri 2X teleconverter. In a flash of insight I realised the TC 2X easily could be rebuilt so as to fit my UV-Nikkor to make it a 210mm UV lens. That is, if the TC transmitted any useful amount of UV. A quick test with a Nemo torch indicated tons of UV passed through the TC. Not surprisingly as the opticals apparently is a simple 4 element design with almost uncoated glass inside.

 

Building the TC was very simple. I just removed the optics and put it into a suitable short extension ring with F mount either side, since I was going to use the contraption on various F cameras.  For those interested, the Nikon E2 or FC rings are perfect, but doubtless more options exist. I kept the mounting barrel for the TC so as to be able to relocate the elements back and forth to get infinity focus -- at first try the master lens + TC was badly off infinity.

 

So that is the story. I got a "new" UV lens for approx. $5.

 

Here is the finished TC, to which I added a bespoke CPU chip while I was fiddling around with the parts anyway. It sits in an FC  ring, however the E2 ring would do equally well and wouldn't require adding a male F bayonet at its rear end (the FC ends in a C-mount).

 

Front view,

 

Rear view, show the internal focusing unit from the original Petri TC, plus the CPU contacts.

 

 

Finally, UV-Nikkors with and without TC !!

 

 

All of this would be of no use if the combination didn't work well for UV. The adorable harbinger of spring, Tussialgo farfara, comes to assist in resolving the question.

 

First, the "native" UV-Nikkor on my modified Nikon D3200 camera with internal Baader-U filter. Daylight, just standard UV processing through Photo Ninja.

 

Then, with the TC-2X added, same processing,

 

(photos not taken on the same day, but conditions otherwise as similar as it gets in a field test)

 

So, the TC works. With the TC, the final exposure is reduced by just a little more than 2 stops, so adding the TC incur about 1/3 EV additional light loss apart from the 2EV by the TC principle on its own.

 

Building the TC took me about 1 hour, including some Dremel work to get parts to fit on the inside.

[Wayne Harridge]

I wonder if anyone has tested any "off the shelf" nikon mount TCs, they seem to be readily available at low cost.  Perhaps the Nikkor TCs wouldn't be so good due to "better" coatings.

 

[nfoto]

Some examples from a field test later, comparing Noflexar 35mm f/3.5, UV-Nikkor 105mm f/4.5, and UV-Nikkor 105mm + TC2X= 210mm f/9. All with my Nikon D3200,  built-in Baader-U,  and standard UV processing in Photo Ninja. The motif is a restored fishing village on the souther coastline of Norway. Taken in early May thus little in terms of flowers.

 

First,  Noflexar 35/3.5

 

UV-nikkor 105/4.5,

 

and finally, the UV-Nikkor + TC2X,

 

 

 

I find the outcome quite acceptable.

[nfoto]

As to Wayne's question, I can confirm the standard Nikon TC models "steal" a lot of UV. Not surprisingly given their much better coatings and more complex optical design, compared to the simplistic Petri unit.

 

In fact, the observation above was what made me consider the old Petri TC in the first place.

[colinbm]

Looking pretty good Birna.

[lukaszgryglicki]

Nice, I'm always looking for the opposite, the widest possible UV-lens, currently it is my UV5035BK2 quartz lens used on GFX sensor - this gives about 40mm full frame equivalent.

 

[Doug A]

Impressive project and results. The sharpest 200mm UV results I've seen. Do you think this would work well with an old metal body Nikon EL-Nikkor 80mm lens? I'd love to have a lens sharper than my Meyer Tele-Megor 180. 

Thanks for sharing,

Doug A

[Stefano]

22 minutes ago, lukaszgryglicki said:

Nice, I'm always looking for the opposite, the widest possible UV-lens, currently it is my UV5035BK2 quartz lens used on GFX sensor - this gives about 40mm full frame equivalent.

Not to go off-topic, but did you read this topic? You might ask them about information on their lenses.

[nfoto]

53 minutes ago, Doug A said:

Impressive project and results. The sharpest 200mm UV results I've seen. Do you think this would work well with an old metal body Nikon EL-Nikkor 80mm lens? I'd love to have a lens sharper than my Meyer Tele-Megor 180. 

Thanks for sharing,

Doug A

 

As I do have the 80mm f/5.6 EL-Nikkor, I might give the combination a try. However, my Tele-Megor 180/5.5 isn't that bad for UV. See below,

 

 

Compared to the better UV solutions, rendition is lacking in utmost clarity due to residual chromatic aberrations. Plus using it on a bellows for close-ups requires significant bellows draw.

[colinbm]

@nfoto are there no older Nikon 2x TC that will work as good in UVA ?

[nfoto]

Not to my knowledge. I have tried the oldest TC-14A, B, and C, plus TC-16, TC-2/200 and Tc-301.

[colinbm]

Thanks Birna

[Andrea B.]

Lofoten rorbuer?