My Vanox AH journey (was: Olympus BH-NIC DIC with Nikon CF long-barrel optics?)

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viktor j nilsson
Posts: 423
Joined: Fri Mar 01, 2013 1:43 am
Location: Lund, Sweden

Re: Olympus BH-NIC DIC with Nikon CF long-barrel optics?

Post by viktor j nilsson »

Today I finally had ten minutes to spare, and tried making some thumbscrews for the condenser centering mechanism. It uses a 4mm x 0.5mm pitch thread, which is a finer pitch than the normal M4 thread. And they need to be fairly long, as the substage area is very crowded on the Vanox AH.

The minor diameter of a M5 screw, however, is very close to the major diameter of a 4mm screw. So I bought some ugly M5x30mm thumbscrews locally and a M5x0.5 die from China to try to re-thread them. I put the M5 screw into the chuck of my screwdriver and rotated it against a file until the threads almost disappeared. It was then very easy to cut new 4mmx0.5 threads with the die. Unfortunately the head of the ugly thumbscrew was too big to fit my screwdriver, so I had to grab it by the threads, which caused it to bend a little bit (I manually filed down the threads on the part that had been held by the drill chuck). The thumbscrew did work on the microscope, however, so I consider it a success. I've now bought some prettier ones from China to make the final version. Glad to have made a tiny bit of progress in between work and parental duties.

viktor j nilsson
Posts: 423
Joined: Fri Mar 01, 2013 1:43 am
Location: Lund, Sweden

Re: Olympus BH-NIC DIC with Nikon CF long-barrel optics?

Post by viktor j nilsson »

René wrote:
Fri Aug 28, 2020 4:26 am
Satisfied, Viktor?

Greetings, René
The beast keeps evolving!
I now have a full set of short-barrel PlanApos for the Vanox AH:

Image

In the front, all the PlanApo's: 4x 0.16, 10x 0.32, 20x 0.65, 40x 0.95 and 100x 1.30
In the back: a FL100x 1.30 (oil), a Apo40x 1.00 (silicone oil) and a FL100x 1.30 (silicone oil).
Missing in the image is a Apo40x 0.85 that I forgot I had. :oops:

The short-barrel PlanApos are really quite good. I recently tested them against my Nikon CF Fluors (10,20,40) and CFN PlanApo (20x) using the correct eyepieces. Need to make some more careful comparisons before I say anything definitive, but the differences are not that big -- and the Nikon Fluors and PlanApos are really really good. I am starting to gravitate toward keeping the Olympus SB objectives and selling off at least some of my Nikons. The photo setup is so nice and clean with the original objectives (and they were so cheap!) that I can't really see myself using anything else on this scope now that I have a full set. The SB 40x 0.95 PlanApo in particular is absolutely amazing - it crushes the CF Fluor 40x 0.85. It was also quite a bargain at $43! It would cost me almost as much as I paid for ALL the SB PlanApos to get the Nikon CF 40x 0.95 PlanApo. The only Nikon objective that I feel that I would really miss is my CF Fluor 40x 1.30.

At first, I was not pleased with the DIC effect I got with the 10x SB PlanApo. The SB 10x Plan achromat gives great DIC with a very even background (the system was made for this objective), but the 10x PlanApo showed a very poor DIC effect with the 10x prism, with a very strong black band covring just 25% of the FOV. DIC with the 20x PlanApo was quite even but rather weak with the 40x prism. This made me very sad, as I was getting great DIC at 10x and 20x with my DIY system. I rarely use 100x. So basically, I only had good DIC at a single magnification that I regularly use: 40x.

But then I decided to do a bit of DIY on the AH-NIC condenser. I opened it up, removed the phase rings, and put in three different DIC prisms from the Nikon Optiphot Epi-DIC unit that I have been using for my DIY setup.

Image

After I took the picture, I added a third Nikon prism, so I now have a condenser with six different Nomarski prisms. In the end, I attached them with double-sided tape.

The result? Pretty amazing. I tried all different orientations in combination with all different objectives. One prism gives nearly perfect DIC with the 10x PlanApo, and another prism gives great DIC with the 20x PlanApo. I am not getting quite as dark background at maximum exctinction as with the 10x planachro, but a very even mid-grey tone. So now I suddenly have almost perfect DIC at 10x, 20x, 40x, and 100x.

Will try to post some pictures eventually.

René
Posts: 467
Joined: Sun Oct 08, 2006 4:22 am

Re: My Vanox AH journey (was: Olympus BH-NIC DIC with Nikon CF long-barrel optics?)

Post by René »

Sounds great Victor!
My most used lens is a 25x/0.6 Leitz SW with the 40xdic prism, and as you find it is not perfect. But by lowering the condenser slightly (and opening the field iris more), I find it performs satisfactory.

Regards, René

wowjl
Posts: 16
Joined: Fri Apr 08, 2022 12:49 am

Re: My Vanox AH journey (was: Olympus BH-NIC DIC with Nikon CF long-barrel optics?)

Post by wowjl »

PeteM wrote:
Thu Jun 11, 2020 5:23 pm

I machined a bottom condenser dovetail (pix attached) so it would fit an Olympus BHS
Can you describe it in detail?

Sincere wowjl

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