Nikon Optiphot 66 Questions: Part 2

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Sure Squintsalot
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Nikon Optiphot 66 Questions: Part 2

#1 Post by Sure Squintsalot » Sat May 28, 2022 10:17 pm

On to the next part: Lighting and control!

Taking the base apart, I see nothing but mayhem:
Screenshot 2022-05-28 160749.jpg
Screenshot 2022-05-28 160749.jpg (208.46 KiB) Viewed 3934 times
I guess the lighting and stage control were strictly customized for wafer inspection.
All the same, whatever's left looks to be in decent shape: the dimmer switch doesn't grind, diaphragm, glass, and reflector are all smooth and clean, and even the fuse is still in its receiver, despite many of the connections being simply snipped off.

Might anyone have the wiring diagram for the optiphot line? I'd like to retrofit to LED lighting, but still use the rocker selector switch, dimmer, and base as much as possible.

Part 2 subsection 1:
The fine-focus wasn't working, so I took it apart and found the plastic reduction gear was split and unmoored to the focus shaft:
Screenshot 2022-05-28 162835.jpg
Screenshot 2022-05-28 162835.jpg (128.36 KiB) Viewed 3927 times
20 minutes of cleaning and some superglue and I saved $60 by not buying the kit. I guess broken fine-focus is a thing with these microscopes!

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Re: Nikon Optiphot 66 Questions: Part 2

#2 Post by blekenbleu » Thu Jun 02, 2022 6:15 pm

Might anyone have the wiring diagram for the optiphot line?

I never learned schematic generating software, but have a wiring list here:
https://blekenbleu.github.io/microscope ... ase-wiring
EPI Optiphot base wiring hacks may have been provoked by
12V for 100W universal vertical illuminator vs 6V for 20W diascopic base.

Rather than restoring original wiring, supposing 12V DC input,
consider eliminating that power resistor and either:
  • replacing 6V lamp with 12V lamp
  • installing a current-limiting buck converter, e.g.
https://www.amazon.com/dp/B078JTRHFC
.. replacing its 10-turn potentiometer with the Optiphot's control.

A current limiter makes subsequently replacing halogen lamp with LED a slam dunk.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#3 Post by Sure Squintsalot » Sat Jun 04, 2022 12:51 am

Thanks Blenkenbleu....conversion to 12v LED is certainly the plan. Would like to use existing plugs and dimmer switch, though.

Does your dimmer control both transmitted and epi lighting?

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Re: Nikon Optiphot 66 Questions: Part 2

#4 Post by blekenbleu » Sat Jun 04, 2022 8:12 am

Sure Squintsalot wrote:
Sat Jun 04, 2022 12:51 am
conversion to 12v LED is certainly the plan.
The original base provides 6V power by this connector:
Nikon6V.jpg
Nikon6V.jpg (44.66 KiB) Viewed 3820 times
Would like to use existing plugs and dimmer switch, though.
Understandable, but 12V 100W vertical illuminator uses a different connector:
Nikon12V.jpg
Nikon12V.jpg (52.14 KiB) Viewed 3820 times
There are some situations where both diascopic and episcopic illumination
may be wanted simultaneously...
Does your dimmer control both transmitted and epi lighting?
No, mine still have original Optiphot 6V power with 20W lamp for diascopic
but 12V power and lamp for episcopic.
The front control switched AC power,
but its potentiometer cannot directly control power,
instead controlling bias to the power transistor on the heat sink.
This linear 60Hz supply is much less efficient
than higher frequency PWM LED supplies.

For LED illumination, I use a 10W U`King B93 RGBW LED pin spot.
Resolution improves by using only e.g. green illumination.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#5 Post by Sure Squintsalot » Sat Jun 04, 2022 5:15 pm

I'll have to replace the potentiometer with some kind of PWM dimmer; shouldn't be too hard to find and modify it to fit.
I have a couple of high-end philips 12v LED bulbs on order. Those will also be re-jiggered to fit available space.
Now, to find the male version of this goofy electrical connector!
s-l1600.jpg
s-l1600.jpg (85.57 KiB) Viewed 3795 times

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Re: Nikon Optiphot 66 Questions: Part 2

#6 Post by blekenbleu » Sat Jun 04, 2022 5:54 pm

Sure Squintsalot wrote:
Sat Jun 04, 2022 5:15 pm
I have a couple of high-end philips 12v LED bulbs on order.
Beware that many LEDs set to work at 12V are non-dimmable.
Since the Nikon base includes frosted glass in the illumination path,
a multi-chip LED should work.
Nikon's mount limits G4 lamp height to < 23mm.
Now, to find the male version of this goofy electrical connector!
Nikon did not even standardize on that receptacle for 12VDC;
its regular Optiphot has a 2 prong receptacle used for 110VAC in the U.S.:
Image
It seems easier to replace it with a socket
compatible with many 12V supplies which have a 2.1 x 5.5 mm barrel plug,
e.g. https://www.amazon.com/dp/B07L4LNSJV
Image

Here is such a socket with 5A rating:
https://www.amazon.com/dp/B07FK6MMGH
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#7 Post by blekenbleu » Wed Jun 15, 2022 8:52 pm

Sure Squintsalot wrote:
Sat May 28, 2022 10:17 pm
Might anyone have the wiring diagram for the optiphot line? I'd like to retrofit to LED lighting, but still use the rocker selector switch, dimmer, and base as much as possible.
An Optiphot-66 diascopic base (6V 20W) turns out to be more similar to that for regular Labophots than Optiphots (12V 50W).
Here are more details, including images, for an unmolested Labophot base: https://lavinia.as.arizona.edu/~mtuell/ ... 20base.php
An Optiphot-1 base might fit into the Optiphot-66 casting, providing 12V at 50 Watts for either episcopic or diascopic work.
Sadly, distance from an Optiphot-1 50W lamp housing to substage field lens centerline is about 220mm,
where nearer 290mm is needed for a 50W lamp housing to clear an Opitphot-66 base casting.
Perhaps some optics from a universal vertical illuminator could be repurposed
for a 50W lamp housing with an Optphot-1 50W base under an Optiphot-66..?
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#8 Post by Sure Squintsalot » Fri Jun 17, 2022 3:57 am

Thanks Blekenbleu...

I've seen those U of A pages too and simply decided to completely circumvent the legacy system altogether. I see no point in restoring an inferior technology. However....

After extensively researching and finding the perfect 12V bulb, a Philips ExpertColor 95+CRI with a really good spectrum, I found that I could not dim the bulb without spending stupid money on a commercial (non-household) dimming system. Nonetheless, I slammed it in "just to see" and got some pretty good first light. I'll post photos after I find the patience to resize 30Mb photos to less than 50kb.

I was on the verge of pulling the trigger on my own LED+driver+lens+PS+dimmer/controller build, when someone was practically giving away a lab-grade LED system with controller and cables. So, now I'm waiting for that to arrive before getting back under the chassis. In the meantime I'm happy to have everything back together working, more or less, as I expected.

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Re: Nikon Optiphot 66 Questions: Part 2

#9 Post by blekenbleu » Fri Jun 17, 2022 11:27 am

Sure Squintsalot wrote:
Fri Jun 17, 2022 3:57 am
After extensively researching and finding the perfect 12V bulb, a Philips ExpertColor 95+CRI with a really good spectrum, I found that I could not dim the bulb without spending stupid money on a commercial (non-household) dimming system. Nonetheless, I slammed it in "just to see" and got some pretty good first light. I'll post photos after I find the patience to resize 30Mb photos to less than 50kb.
Thanks for identifying Philips' ExpertColor; I found this claim of
"over 94% identical to halogen light colour, compared to about 60% with standard LED lights"
https://www.electronicsweekly.com/blogs ... n-2017-05/:
Image
Having so highly optimized those LEDs for compatibility with existing commercial 12VAC dimmers is indeed disappointing.

I would like to see how MR16 was adapted to the Optiphot.
On Windows PCs, I find IrfanView Lanczos resampling expedient for image resizing,
with a good tradeoff between minimizing blur and sharpening artifacts.
https://www.irfanview.com/
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#10 Post by blekenbleu » Wed Jul 06, 2022 2:53 pm

Sure Squintsalot wrote:
Sat May 28, 2022 10:17 pm
On to the next part: Lighting and control!
...
I guess the lighting and stage control were strictly customized for wafer inspection.
Unlike regular Optiphots, Labophot (and Optiphot-66) diascopic base lacks provisions for Köhler filament alignment,
with a lamp diffuser buried in the base and without either lamp focus or alignment adjustments,
making them ideal candidates for LED upgrades.

Regular Optiphots also have a more elaborate field lens.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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Re: Nikon Optiphot 66 Questions: Part 2

#11 Post by Sure Squintsalot » Fri Jul 29, 2022 9:15 pm

So....here's how I threw in that Philipps LED light:

The LED has a built-in driver, relatively tight spread angle, and a quasi-fresnel front end. Luckily, it's about the same diameter as the frosted lens/heat shield assembly:
Screenshot 2022-07-29 145347.jpg
Screenshot 2022-07-29 145347.jpg (82.28 KiB) Viewed 3267 times
A dremel and some careful grinding made quick work of fitting the lamp into the holder:
Screenshot 2022-07-29 150333.jpg
Screenshot 2022-07-29 150333.jpg (86.33 KiB) Viewed 3267 times
Finding a holding mechanism was the hardest part. There's not a lot of room at that end of the base to accomodate the bulb, much less a "plumbers solution". Finally figured out how to fashion a couple of low-profile clips from some poster frame spring metal hardware:
Screenshot 2022-07-29 150927.jpg
Screenshot 2022-07-29 150927.jpg (59.1 KiB) Viewed 3267 times
Not done yet....that lamp still wasn't in the clear, and some of that microscope had to disappear. TGFD! (Thank God For Dremels):
Screenshot 2022-07-29 151206.jpg
Screenshot 2022-07-29 151206.jpg (91.45 KiB) Viewed 3267 times
And....there it is:
Screenshot 2022-07-29 151335.jpg
Screenshot 2022-07-29 151335.jpg (114 KiB) Viewed 3267 times

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Re: Nikon Optiphot 66 Questions: Part 2

#12 Post by Sure Squintsalot » Fri Jul 29, 2022 9:49 pm

A quick re-assembly and found "Musk Illumination": super bright and super white across the entire field of view. Here's the thermal test, 5 minutes at full power:
Screenshot 2022-07-29 151900.jpg
Screenshot 2022-07-29 151900.jpg (82.1 KiB) Viewed 3260 times
Some caveats about this LED lamp. Despite the excellent light quality: High CRI and brightness, I can't dim it. It's an industrial light made to be fitted in large numbers into high end hotel lobbies and product display cases. Dimmers for this light run in the hundreds of dollars and run off 220V/470V supply. Running them individually wasn't easy either; they take a 12VAC, 1amp wall wart. Not a 12VDC power supply of which there are billions on the planet right now, but 12VAC, of which there are less than a dozen in North America. So.....there's that.The reconnection to the EPI/DIA switch was easy enough, but the power supply doesn't really run the standard filament bulb very well, so I just use the switch for simple on/off of the diascopic illuminator:
Screenshot 2022-07-29 152309.jpg
Screenshot 2022-07-29 152309.jpg (117.39 KiB) Viewed 3260 times
Screenshot 2022-07-29 152440.jpg
Screenshot 2022-07-29 152440.jpg (53.23 KiB) Viewed 3260 times
Here's some first light images of some tight folding in a slate in crossed pols (L) and crossed pols with 1/4 wave plate (R), FOV= 2mm(?). Without the sub-stage condenser, you can really see how out of focus the edges get with these objectives:
Screenshot 2022-07-29 153900.jpg
Screenshot 2022-07-29 153900.jpg (165.74 KiB) Viewed 3260 times
It was hugely fun to look at thin sections I hadn't looked at in 40 years!
When used properly, with correct epi-illumination, the imaging is pretty top-notch. An early 90s era AMD CPU at 1000x:
Screenshot 2022-07-29 154444.jpg
Screenshot 2022-07-29 154444.jpg (221.47 KiB) Viewed 3260 times
Last edited by Sure Squintsalot on Sat Jul 30, 2022 12:47 am, edited 1 time in total.

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Re: Nikon Optiphot 66 Questions: Part 2

#13 Post by blekenbleu » Fri Jul 29, 2022 10:57 pm

Sure Squintsalot wrote:
Fri Jul 29, 2022 9:15 pm
they take a 12VAC, 1amp wall wart. Not a 12VDC power supply of which there are billions on the planet right now,
but 12VAC, of which there are less than a dozen in North America
I think that the Nikon UN transformer, which may be powering your EPI illuminator, has a 12VAC transformer.
Metaphot, Optiphot 1, 66; AO 10, 120, EPIStar, Cycloptic

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