Procedure for using projection eyepieces

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Procedure for using projection eyepieces

Post by ChrisR »

I have an Olympus CH trinoc, and the Nikon one pictured.

Both have 2.5x PEs.
I have a couple of noname microscope adapters.
What do I need, to achieve parfocality? (Nikon body)

I can't "just try it" at the moment due to access difficulties.

Image

I do have an adapter with tube(s) a close enough fit in the Nikon head that the thumbscrew nicely grips it.
I assume it's just a matter of getting the height right (and centering). How far is the eyepiece likely to need to be, from the sensor?

I don't know what this: http://www.labx.com/item/nikon-camera-l ... tor/614681 is for, exactly. ??

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Post by Charles Krebs »

Chris,

The top of your trinocular tube accepts a "sleeve" that is about 42mm in diameter. This was fitted at the base of their photomicrography system cameras, as seen below.

Image

At one time I tried to get a couple of these as "parts" from Nikon but was not able to do so (they don't have any). I am not aware of any other readily available Nikon-made camera adapter that has this sleeve, although they may well exist. You can find an adapter that would fit at places like LMSCOPE, or Diagnostic Images/Spot Imaging. But these solutions can cost quite a bit. (see http://webstore.diaginc.com/PA1-12A-35m ... a1-12a.htm ). You should be able to put something together that will work just fine for under $50.

One very accessible and inexpensive thing that can work (I've done it) is an old Ihagee/Exakta extension tube. (for example see Ebay 381261224400 or 301490771239 and many others).
These have an outside diameter of 41.5mm. The longest tube can be used. These are a bit too "sloppy" when inserted into the trinoc head port, but a single layer of tape, or some thin metal foil will provide a snug fit. It is quite stable and tight when the locking screw is turned in.

Then you need to add additional tubing so that it positions the camera at the correct height above your 2.5X CF photo-projection lens. I don't remember off-hand what that distance is (something like 5 to 6 inches?)... you can get a rough idea by just holding the camera above the trinocular port when a subject is in focus in the binocular tubes.

Ideally you would have some fine up/down adjustment so you can match the focus in the camera to that of the eyepieces ("parfocal"), but if you can get it very close with fixed tubes you can probably adjust that by how deeply to slip it into the trinoc head. (For my DIY adapters I usually add some sort of helical or variable length T-mount tube in order to make that fine adjustment.) You will then obviously need to have a camera mount at the top. It might be pretty easy to add on some of those cheap Chinese extension tubes and thus get the needed height and whatever camera mount you want. (Remember, unless you are using a D810, you will need to use electronic flash or very long exposures with a Nikon body to avoid mechanical vibration issues).

The key is to get a tube that fits nicely into the trinoc head. After that it is pretty easy to come up with something that will work. (I know that 42mm is a common tube or pipe size in Europe. But not here, so I do not know if it would fit.) If you have a decent collection of various tubes and rings it isn't hard to do.

I can't see what the LabX piece is that you referenced. It appears to have an "F" mount on one side but I can't make out the other side. In any event, it will not get the camera high enough by itself, and there are many less expensive ways to get the male Nikon mount.

(I really like to be able to rotate the camera easily as well. You may get a few ideas from this post: http://www.photomacrography.net/forum/v ... hp?t=13924 . The components used bumped the cost up, but it was still far less than most other new, "third party" options.)

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Post by Pau »

Once you have the camera adapter to set parfocality take a look to the eyepieces: I see that both CFW eyepieces are focusable and their focus position do matter a lot: if you don't need eyeglasses for long distance be careful to set them to zero before parfocalizing the camera (or regulate to your actual diopter need if to be used without the eyeglasses), if not, despite being able to parfocalise the camera, the microscope objectives won't be parfocal between them (and if not intended to work with several objectives the dioptric regulation can be useful to fine tune the camera parfocality)
Pau

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Post by ChrisR »

Thanks Charlie. Same deal with the Olympus I imagine - put the lower part of a general purpose 'scope adapter onto the tube, then drop the NFK in, and add whatever it takes? My Oly trinoc is a CH version, so has a standard (I think) microscope tube not the wider one.

The "closely fitting" tube I was referring to above, was one from these, so it seems I'm there. One ring (upper left) goes to 42x1mm male.
Image

I take your point about rotating the camera. I don't know if it would wobble too much, but if the inserted tube's grip ring happens to be resting on the top of the trinoc, it can be rotated there?



The "pipe" suggestion is intriguing. Both plastic and copper pipe are standard at 42mm o/d, and there are some fittings which could yield a flange.

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Post by ChrisR »

Regarding the eyepieces - thanks Pau.
The eye relief seems good so I expect I'll be using it with glasses.

Perhaps I'll take some parts off so I can play with them. I can't move the whole thing about, it weighs more than I do.

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Post by Alan Wood »

Chris

For the Olympus FK and NFK photo eyepieces, the distance from the bottom of the wider top section to the sensor plane should be 150.0 mm.

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Post by ChrisR »

It's this one - so 150 from B, approx?
Image

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Post by Alan Wood »

Sorry, I meant 150.0 mm from the bottom of the wide part of the photo eyepiece, as shown in the photo below:

Image

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Post by ChrisR »

Ah, got it, thanks.

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Post by NikonUser »

?? so what is the "125" printed on the eyepiece
NU.
student of entomology
Quote – Holmes on ‘Entomology’
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No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
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Nikon camera, lenses and objectives
Olympus microscope and objectives

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Post by Alan Wood »

NikonUser asked:
?? so what is the "125" printed on the eyepiece
Olympus literature refers to 125 mm as the projection distance.

If you measure 125 mm down from the film plane, you arrive at a point a few millimetres above the FK or NFK eyepiece, presumably the location of the exit pupil.

Alan Wood

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Post by ChrisR »

Back with the Nikon finite, there are no tube-length affecting optics in the incident lighting attachment I have, so the camera adapter does need to have an adjustable length.
Image

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Post by Charles Krebs »

Chris,
there are no tube-length affecting optics in the incident lighting attachment I have,
Don't forget, your MM was intended to be used with 210mm finite objectives. So there is no need for optics to compensate for the additional 50mm or so of extension your vertical illuminator adds.
so the camera adapter does need to have an adjustable length
The camera tube that you need to add on your trinocular tube can be a fixed length... if you knew exactly what length was required. :wink:
But having one with some degree of adjustment is desirable since it will allow you to easily get the camera parfocal with the eyepieces.

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Post by silasthecat »

I would use the old Nikon UFX system and convert it to digital camera use. see the thread below. If you have a Nikon camera, it should be easy to achieve parfocality I would think.

http://photomacrography.net/forum/viewt ... highlight=

https://www.dropbox.com/sh/lyu71ao2ylir ... LNz-a?dl=0

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Post by Charles Krebs »

I would use the old Nikon UFX system and convert it to digital camera use
This is a good way to go if you have a vibration prone camera. I have a couple of these systems boxed away in storage but I have not been tempted to use them because of the need for the "double" release... first the DSLR... (then a brief delay for vibrations to dampen)... then the Nikon UFX shutter. No big deal with inanimate subjects or prepared slides. But if you are going to use flash and are chasing around live critters you often want no delay (or the least possible delay) when you need to take the picture.

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