Nikon DIC conversion

Paul92706 · Post by **Paul92706** » Wed Oct 04, 2017 10:00 pm

Hi guys i got a question, i recently bought a Nikon Optiphot Reflected DIC microscope. I want to convert to a Transmitted DIC. The Turret has the Slider DIC prisms mounted and also included are the Large Nikon BD 210/0 DIC objectives. i recently aquired a Nikon Nomarski condensor. I installed the condensor and all seemed to work fine except that the Nikon BD 40x and 100x objectives are Not clear and the Nikon BD 20x is beautifully clear.I am asuming they are not compatiable? Or are BD Objectives specifically for Reflected DiC? I was thinking maybe i can add a thread Adaptors for standard 160/- Dic objectives??i hope this all makes sense, my worries are i have to buy the extremly hard to find Nikon Intermediate tube for combining POL and Prism slider rotater. please help! Thank you

Pau · Post by **Pau** » Thu Oct 05, 2017 12:08 am

I have no direct experience with your Nikon equipment but usually reflected and transmitted DIC are not full compatible if compatible at all.
You have another problem: if you put 160 objectives you must remove the epiillumination system that provides the additional 50mm for 210 objectives, if not the objectives won't be parfocal and you'll get lots of spherical aberration destroying resolution of high NA objectives

I installed the condensor and all seemed to work fine except that the Nikon BD 40x and 100x objectives are Not clear and the Nikon BD 20x is beautifully clear

Do you refer to the DIC effect or to the image resolution?.
Beware of that BD and M objectives are to be used without cover glass. It doesn't matter up to NA 0.3-0.4 but spherical aberration quickly increases with the objective NA like the with the 40X and even more the 100X, did you test them with glass covered slides?

If you are able to get good DIC with your reflected light objective prisms you don't need the intermediate tube, you could put an analyzer inside the microscope head in most cases, this is not ideal but it works.

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 12:50 am

Hi pau thanks for feedback, what do you mean by removing epiillumination system, do you mean incident light tube? I refered to imAge resolution. Yes i mount Analyzer under head and works great. I ordered a objective thread M26 to M32 adaptor thread, you think this will be ok? I think it should be ok right? Oh i test without glass converslips of course. Thanks so much pau, i am not looking to spend More money i have spent to much already, i hope i can fix this problem.

abednego1995 · Post by **abednego1995** » Thu Oct 05, 2017 1:31 am

Plus, the DIC turret condenser for Optiphots would be of max NA of 1.35 or 1.40. The BD plan 40x would be NA0.65, the 100x 0.90. The nomarski prisms are NA matched, so even though the turret indications are 20,40,100x, they correspond with NAs of around 0.4, 0.65, 1.25 respectively. However, the turret condenser for Optiphots are made to go with a single translating objective Nomarski prism which has a continuous shear amount in the normal transmitted DIC setup.So... if the shear amount of the condenser turret prisms don't match the shear amount in your objective revolver, you're pretty much out of luck. Hope this helps.

Pau · Post by **Pau** » Thu Oct 05, 2017 3:52 am

Paul92706 wrote:I ordered a objective thread M26 to M32 adaptor thread, you think this will be ok? I think it should be ok right?

The normal Nikon CF non BD objectives have RMS mount (about 20.2mm), so it doesn't seem right.

Do you get transmitted light DIC with any of your objective/prism combinations?

what do you mean by removing epiillumination system, do you mean incident light tube?

Yes, I do, it's the same with other words.

Pau · Post by **Pau** » Thu Oct 05, 2017 4:01 am

abednego1995 wrote:Plus, the DIC turret condenser for Optiphots would be of max NA of 1.35 or 1.40. The BD plan 40x would be NA0.65, the 100x 0.90. The nomarski prisms are NA matched, so even though the turret indications are 20,40,100x, they correspond with NAs of around 0.4, 0.65, 1.25 respectively. However, the turret condenser for Optiphots are made to go with a single translating objective Nomarski prism which has a continuous shear amount in the normal transmitted DIC setup.So... if the shear amount of the condenser turret prisms don't match the shear amount in your objective revolver, you're pretty much out of luck. Hope this helps.

You're likely right at least partially.
Each objective DIC prism has a knurled knob to control shear and maybe it could be completed adding a rotatable 1/4 wave plate over the polarizer to add control shear (De Sénarmont system) like in modern Nikon DIC systems, but I never tested it.

JohnyM · Post by **JohnyM** » Thu Oct 05, 2017 5:02 am

It's for controlling bias retardation, not shear amount.

abednego1995 · Post by **abednego1995** » Thu Oct 05, 2017 6:15 am

JohnyM wrote:It's for controlling bias retardation, not shear amount.

Yup. translating the objective prism/ rotating the 1/4? plate only introduces retardation respective to E,O wave. So if the shear amount(angle) doesn't match between condenser and objective prisms, the interference plane winds up in unintended locations. The interference plane has to be at least under the analyzer(only guessing without proper knowledge in optics...am I right??)

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 7:54 am

abednego1995 wrote:Plus, the DIC turret condenser for Optiphots would be of max NA of 1.35 or 1.40. The BD plan 40x would be NA0.65, the 100x 0.90. The nomarski prisms are NA matched, so even though the turret indications are 20,40,100x, they correspond with NAs of around 0.4, 0.65, 1.25 respectively. However, the turret condenser for Optiphots are made to go with a single translating objective Nomarski prism which has a continuous shear amount in the normal transmitted DIC setup.So... if the shear amount of the condenser turret prisms don't match the shear amount in your objective revolver, you're pretty much out of luck. Hope this helps.

You are right, now the next problem is finding the right intermediate tube for that setup, these tubes are very very rare and hard to find, i see an Olympus Intermediate tube for DIC looks similar, would this work aswell?

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 7:56 am

Pau wrote:
Paul92706 wrote:I ordered a objective thread M26 to M32 adaptor thread, you think this will be ok? I think it should be ok right?
The normal Nikon CF non BD objectives have RMS mount (about 20.2mm), so it doesn't seem right.

Correct my apologies it is M20 to M26, the BD objectives have M26 RMS.

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 8:04 am

Pau wrote: Do you get transmitted light DIC with any of your objective/prism combinations?

Yes, i get transmitted light DIC, the problm is the image is very blurry on 100x and 40x is ok but but gives me a faded kind of image. the 20x works fine nice and sharp and DIC seems to be working great on this objective.

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 8:21 am

Hi guys, would this intermediate tube work? Seems rather large, where can i source the right Nomarski prism for this item?

JohnyM · Post by **JohnyM** » Thu Oct 05, 2017 8:36 am

where can i source the right Nomarski prism for this item?

Good luck with that!

Paul92706 · Post by **Paul92706** » Thu Oct 05, 2017 8:42 am

JohnyM wrote:
where can i source the right Nomarski prism for this item?
Good luck with that!

Ya looks like you can fit a harmonica! Hehe

JohnyM · Post by **JohnyM** » Thu Oct 05, 2017 9:29 am

You dont see those very often. Once i've had one for sale, if pictures gonna help you with your search, it looks like that:
http://www.photomacrography.net/forum/v ... f5d2090932

There are also other variants:
http://www.photomacrography.net/forum/v ... b264992935