P = Manual focus with connection chip with the box.

Should a half victory be considered more like a half failure???

You know well that I particularly appreciate challenges, lost causes, impossible missions and other catastrophic states when it comes to photographic equipment…

Well, on this one, I’m at the top, although…

I also like deals, which was the case for this Nikkor 500mm f/4 P.

I had been warned of his condition, a dive and stay in relatively fresh water, but undoubtedly murky.

The focusing mechanism is so simple that it still worked, but the interior was full of brown slime, and in particular the lenses were in poor condition.

There are two huge lenses at the front that were easily removed.

A third, the most degraded, is held by the front part of the barrel.

This is blocked by three needle screws. unscrewable.

Optimistic, remove those screws, drill bits and Dremel…

Until then, I was confident, but, IMPOSSIBLE to unscrew this part before…

I tried everything, alcohol, nail polish remover, heating, and even WD40, IMPOSSIBLE!!!

I set aside this part and moved on to the rear part, bay and diaph.

The rear lens is also easily removed and the aperture can be reached.

“Misery of misery”!!!

Full of silt, particularly rough, and a small guide partially cleared.

Complete disassembly, very heavy cleaning, repair of the guide, reassembly,

The aperture is stained by its stay in immersion, but works.

Deep cleaning of the rear part, reassembly. Test, the chip still works, the aperture is very responsive.

That’s done !

Okay, so, what about these internal lenses???

From the rear, I managed to unscrew the central group (still foggy), that of the focuser, but, logically, it is dismantled from the front, it goes inside…

There, a lot of manipulations, tinkering, improvisations and so on.

(thanks to Ste Bidouille) for being able to roughly clean the front lens from the inside, and the two accessible lenses of the central group.

The ideal is to be able to dismantle the barrel beforehand to do a good complete job, it’s not easy…

To make a conclusion:
After having tried everything (so much so that my wrists hurt from twisting in all directions to clean the internal lenses), I put together this pretty black granite baseball bat of… 3Kg

The few test photos clearly show that it’s not “at the top”, but it makes images, which was unthinkable at the start…

I am optimistic, I keep hoping, that one day (or rather the other), I will succeed in dismantling the front block and giving a better appearance to the lens.