MicrobeHunter.com Microscopy Forum

I've inherited a BH2 with a trinoc head. The trinoc head has an Olympus part U-PMTVC on it, which has a c-mount. There's an objective in it, marked
"NFK 3.3xL
125"

I'd like to take still color photos with this microscope. Is there a quick, easy way I can attach a 35mm digital camera body to this?
thanks

Alan Wood has all the information you are likely to need
... This is a good 'landing page'
http://alanwood.net/photography/olympus ... scope.html

MichaelG.

thanks, yes I saw that. It doesn't answer the question: can a c-mount be used to satisfactorily attach a 35mm camera?

cooperplace wrote:thanks, yes I saw that. It doesn't answer the question: can a c-mount be used to satisfactorily attach a 35mm camera?

A c-mount does not have the clear aperture to cover a 35mm frame, and its flange to image plane distance is shorter than of many 35mm cameras.
... So the short answer would be NO
[ depending, I suppose, on your definition of 'satifactorily attach' ]

A micro 4/3 camera would be a much more realistic proposition.

MichaelG.
.
P.S. What 35mm camera are you planning to use ?

cooperplace wrote: There's an objective in it, marked
"NFK 3.3xL
125"

No, that's a projection eyepiece not an objective
... May I suggest that you look again at Alan Wood's site.

MichaelG.

I use that very setup to project, essentially direct project as the NFK 3.3x and 0.3x lens in the U-PMTVC essentially cancel magnifications, onto the sensor of my Panasonic GH4 for 4K video. Since the GH4 is mirrorless, a C-mount adapter fits fine, and I get the necessary final corrections in the NFK eyepiece.

That is what I used to shoot this on a BHS: https://www.nikonsmallworld.com/galleri ... er-feeding

I used the same setup on a SZH stereo to shoot this: https://www.youtube.com/watch?v=OMNHuab9hKE

Mirrored cameras will need an Olympus Photomicro Adapter L, an easier to find Diagnostic Instruments PA1-10A, or another adapter of the same length and T-mount, along with a projection lens. Full frame takes an NFK 2.5x projection eyepiece, and APS-C sensors take the very pricey NFK 1.67x for optimal coverage. There are other adapters available, both with and without internal lenses that you can use to adapt the projection dimensions to your sensor. Understand each resolution on each sensor may have different dimensions. On my GH4 4K UHD and 4K DCI use different dimensions on the sensor. Look in your user guide to see the effects of different resolutions on the pixel dimensions used.

Tom

If you don't mind the look this is a very cheap and effective solution: viewtopic.php?f=12&t=7329
You'd want to get an nfk 2.5x eventually for full frame, but the 3.3 you already have would probably be just fine for the mean time it would just produce some cropping.

I have an Olympus CH with a BH-2 trinocular head. I have made a mount for Nikon F ( I use microscopy dedicated Nikon D200) but was not satisfied with it so have ordered one from an Ebay supplier in America, (newhopper (4872)). His price was US$59 with a 'make an offer' option. I got mine ordered for US$47 plus US$21 postage and ~US$12 customs. The total was AU$116. I thought this was OK because the supplier makes them up to suit the parfocal arrangement of the microscope. Although mine is probably not quite right given that it is a hybrid CH/BH-2.

Tom Jones wrote: ↑

Tue Apr 02, 2019 3:39 pm

I use that very setup to project, essentially direct project as the NFK 3.3x and 0.3x lens in the U-PMTVC essentially cancel magnifications, onto the sensor of my Panasonic GH4 for 4K video. Since the GH4 is mirrorless, a C-mount adapter fits fine, and I get the necessary final corrections in the NFK eyepiece.

Hi Tom.
Is this setup parfocal?
I got old Lumix g3, looks like the same sensor size
I want to replicate yours setup.
Thank you.

It can be. The U-PMTVC has screw threads that will allow you to adjust it's length a bit to make it parfocal. Adjust focus in the right eyepiece, match it with the left, then adjust the U-PMTVC (screw it in or out) until the camera focus matches what you see in the eyepieces. I use a -H focusing eyepiece on the right side to fine-tune it.

Tom

Tom Jones wrote: ↑

Sun Nov 10, 2019 9:48 pm

It can be. The U-PMTVC has screw threads that will allow you to adjust it's length a bit to make it parfocal. Adjust focus in the right eyepiece, match it with the left, then adjust the U-PMTVC (screw it in or out) until the camera focus matches what you see in the eyepieces. I use a -H focusing eyepiece on the right side to fine-tune it.

Tom

Thank you Tom for your respond.
I got all setup but Im having problem on focusing part.
My U-PMTVC screwed all in and picture looks almost sharp. It looks like a little more in and it will be perfect, but i cant adjust any more signs U-PMTVC already all in.

Do i missing somthing or mine microscope defective? (I got it from Craigslist)

I have access to the lathe machine. I can lower NFK lens a little but not sure if will be helpful.
Thank you.

Are you saying you cannot get the camera by itself in focus, or cannot get the camera focus and eyepiece focus to match?

If the camera image won't come into focus, something is wrong.

The flange distance is probably too long on your camera. (Sensor is too far inside the camera).

Some of the available micro 4/3 C-mount adapters don't like the flat top on the U-PMTVC and won't screw on completely before they bottom out. Mine just barely makes it.

That could make the adapter-camera sensor distance too long even with the adapter fully screwed together.

Tom Jones wrote: ↑

Thu Nov 21, 2019 8:17 am

Are you saying you cannot get the camera by itself in focus, or cannot get the camera focus and eyepiece focus to match?

If the camera image won't come into focus, something is wrong.

Yes , I can't get focus match.
I guess its an adapter.

Does your trinocular BH2 provide an intermediate ISO 38 mm photo port? I have seen references to a 38 mm clamp or dovetail, and was wondering if it is was one and the same.

If it is, I know a couple ISO to c-mount adapters that will (just) fully spin into most c-mount to micro four thirds thread adapters. (You have to bury the c-mount flange a little into the camera's to match its flange focal distance.) I also have one that won't.

jfiresto wrote: ↑

Fri Nov 22, 2019 11:31 am

Does your trinocular BH2 provide an intermediate ISO 38 mm photo port? I have seen references to a 38 mm clamp or dovetail, and was wondering if it is was one and the same.

If it is, I know a couple ISO to c-mount adapters that will (just) fully spin into most c-mount to micro four thirds thread adapters. (You have to bury the c-mount flange a little into the camera's to match its flange focal distance.) I also have one that won't.

Yes i do have 38mm dovetail port.
Im working with CAD software applications and I'm planing to recreate dovetail post with lite adjustments in demention and print on 3D printer.

Ok it works,
I make 3D printed version of dovetail with small modification.
I bring NFK lens lower by 5 millimeters and it allow me to adjust focus via U-PMTVC.
If anyone interested in 3d file let me know i will share.
Thank you everyone who try to help me.

Changing the position of the nfk projective is likely going to have some sort of optical consequence--raising it certainly does anyway.

I use this Fotodiox C-m4/3 adapter with the U-PMTVC for my BHS and SZH: https://www.adorama.com/fdcmft.html?gcl ... t4QAvD_BwE

It screws down flush against the PMTVC adapter, but works fine with the GH4. The adapter is even slightly unscrewed to adjust focus.

The Olympus "Photomicro Adapter L" has a fixed aperture at the bottom. Please, can anyone tell me or measure me the diameter of the aperture and the distance from the base of the adapter to the aperture?

I am in the process of building a phototube for my BH2 microscope and I have a lathe for this purpose.

Bnh wrote: ↑

Sun Jan 26, 2020 3:32 pm

The Olympus "Photomicro Adapter L" has a fixed aperture at the bottom. Please, can anyone tell me or measure me the diameter of the aperture and the distance from the base of the adapter to the aperture?

I am in the process of building a phototube for my BH2 microscope and I have a lathe for this purpose.

10mm diameter.

And 21mm from the base to the aperture

This is perfect with Nikon D3300 also 100% parfocal. Thank to Boss at dealcorner.com for the right tube and adapter and testing with D3300...

I am trying to stick an Olympus PE photo eyepiece into the dovetail on my BH2 head in order to take photos with UIS objectives (the NFK gives bad CA) and a DSLR. The problem, of course, is that the 24.8 mm PE doesn't fit inside the 23mm slot. I think Denny's idea of making a modified dovetail would be the most elegant solution.

Does anyone have an idea if I need to modify the length (height) of the BH2 dovetail to maintain parfocality with the PE? Or can I just let the PE sit in the dovetail at the same height as the NFK?

The U-SPT tube for the PE seems a bit longer than the chimney that sticks out of the BH2 head. I'm not sure whether this difference in height is because of differences in head optics or differences in the projection characteristics of the PE vs the NFK. If it is the former reason, then I should keep the BH2 dovetail height the same in order to make the PE compatible to the BH2 head. If the latter, then I have to adjust the BH2 dovetail height to adapt the BH2 head to the PE.

I would be grateful for any suggestions. In any case I will do some experimentation and report back.

To my understanding there is an additional telan lens required in the UIS- PE system somewhere?

You are right - thanks for the alert. Actually I already have a tube lens in my system that I failed to mention above. I have a vertical illuminator on my microscope that has a tube lens that converts it from 160mm to infinity. So I believe I won't need any additional lenses with the PE. Please correct me if I am mistaken!

The PE is an economical choice--they sometimes comr up very inexpensively. The u spt probably sits higher because the tube lens is in the dovetail of the head, requiring 180mm from that point, while in a BH2 infinity system the lens sits about 20mm lower below the head.
I imagine it would be easy to 3d print a replacement dovetail with a wider hole to bolt on after removing the existing dovetail, much like DennyNY's nice work above. That would also be very easy and relatively inexpensive to iterate.

I just noticed that the number "125" is printed on the PE 2.5x. Does anyone know what "125" refers to? Has it got something to do with how it modifies the tube length, or the position of the eyepiece with respect to the camera sensor plane or something?

I will look into a modified dovetail design.

According to Alan Wood, "The “125” that is marked on the FK, NFK and PE photo eyepieces indicates that they are designed to give optimum performance at a 125 mm projection distance."

http://www.alanwood.net/olympus/photo-eyepieces.html