Adapting Canon EOS to BH2 Trinocular.

[wmodavis]

I have waded into the quagmire (probably simpler than I think) of mounting a camera to a BH2 Trinocular head. I'm wondering about the Olympus MTV-3 or the OLYMPUS OM Photomicro Adapter L as possibilities.

One question arose from my reading of how-too articles. Does either the MTV-3 or the Adapter L actually contain any optics? Or are they just adapter tubes to provide the correct spacing?

Would one or the other be preferred (as in simpler, less expensive etc) as a solution?

For now the camera I have access to is a Canon EOS Rebel T4i and so since that is a borrowed one (my sons camera) I need a solution that would be most easily adapted to another camera when/if I get my own.

So could any Olympus BH2 trinocular gurus familiar with the MTV-3 or Adapter L venture some advice? I think possibly why I consider this a quagmire is because I know so little about it and what I read is confusing and feel sometimes like I'm reading Greek.

Bill

[mrsonchus]

Hi Bill, in my experience - and I've been through the hideously confusing experience myself - the camera-to-'scope arrangement is indeed as you suggest, a lot easier and more achievable that may at first be imagined.

I'm unfamiliar with the BH2-trinocular but have a look at my very recent post of the arrangement I now use with excellent results of a Canon EOS 1200D coupled to my 'scope's trinocular port and it's tethered (via USB) control using either the superb software 'EOS utility' supplied ('free' with cameras) by Canon and used with my Windows (7) laptop, or my newest setup, control via a 10" Andoid tablet entirely touchscreen, via an app that costs about £5 and works faultlessly for me.

Here's a link to my topic - viewtopic.php?f=9&t=3039

Hope it helps a little.

[wmodavis]

I had read your linked post John. Thanks for the reminder which caused me to read over it again.
Unfortunately my confidence at this point doesn't put me in a comfortable position to put my money down.
Some 'solutions' I've seen are pretty pricey.

You mention ".... a lot easier and more achievable that may at first be imagined." That is my suspicion as I said.

My definition of Hard & Easy are this....
HARD=You don't yet know how to do something.
EASY= You know how to do something.

I'm working on transitioning from one to the other so I can exclaim how easy it really is.

The quest goes on and maybe one day I'll post a picture.

[Crater Eddie]

Well put.
I hope to pick up a trinoc for my BH-2 some day in the not too distant future, so I'll keep an eye on this thread. Be sure to keep us posted.
CE

[wmodavis]

Will Do CE. -Though I was hoping you would have a solution to my dilemma.
Are you doing any photography now? Have to look back. But if so must be thru eyepiece.
Seems like the trinoc heads are pricey as solo item. Keep your eye out though.

[Crater Eddie]

I have done a bit of photography with my BH-2, but mostly through the eyepiece port with my cheap USB camera. I have also played around with a "straight through" photo tube that replaces the entire viewing head, also with the USB camera. That actually works pretty well, once you get accustomed to not having any eyepieces to look through.
The trinocs are indeed a bit spendy, that's why I don't have one yet.
CE

[carlh6902]

I don't know much about this, but I do know a little. The Photomicro L adapter mounts onto the BH2 trinocular port, and then requires an NFK photo projection lens to be put into it. Finally, the camera can be attached to the L adapter. Unless you're shooting with an Oly camera, you'll need to adapt from the Oly OM mount on the L adapter to whatever mount your camera requires. This can be a problem, depending on which camera you want to use. I use an OM to Canon EOS adapter, which works quite well to put an EOS camera on the scope, since it maintains the necessary distance from the NFK to the image sensor plane. Other camera mounts cannot always be adapted without adding additional distance, and this is undesirable as it leads to optical aberrations.

I should mention that all of the above applies to using a DSLR without a lens on the L adapter. The NFK magnification should be matched to the camera sensor size. This will be either an NFK 2.5 or 1.67. The 2.5x are readily found. The 1.67x are very rare and expensive.

The MTV-3 goes from the trinocular port to C-mount. It has a lens (0.3X, I believe) that can be omitted, but is likely needed, depending on the image sensor size in the camera.

Alan Wood's site gives much more detail on all of this.

Carl

[Hendo]

Hi Bill, not sure if you have yet managed to 'wade through the quagmire' given this thread is a couple of months old. For what it is worth, I've attached my Canon EOS 600D to the trinoc port of my very recently acquired and absolutely fantastic BH2 (BHS) scope and it really was very easy.

The BH2 came with an MTV-3 adapter and a 3.3x NFK relay lens but I don't have a c-mount adapter for my camera so I haven't tried that configuration yet.

However, I do have a 2x relay lens that I bought from Imaging Apparatus (through their ebay store) for my 600D which I have been happily using through the eyepiece ports of my Zeiss GSZ dissecting scope and my old Olympus model E compound scope. I found that this adapter also fits very nicely directly into the trinoc port of the BH2 (ie. without the MTV-3 adapter or the NFK relay lens) as the nose of the adapter slides in about an inch and it seems very stable sitting there. For me, not being physically attached is a bonus as it makes it very easy to swap the camera between my microscopes.

I should mention that the camera is not parfocal with the way I have it currently setup on the BH2 but that doesn't bother me in the least because the camera and EOS software work so well I rarely bother using the eyepieces when I am taking photos.

I am very happy with the camera/scope configuration and the images I have obtained so far, however, please bear in mind that I am an absolute beginner so my opinion probably doesn't count for much! I've attached a few photos to show the camera with adapter, how the camera fits into the trinoc port and a couple of example images I have taken with prepared slides. I have ordered a c-mount adapter for my 600D and will try out the MTV-3 attachment but I suspect the 3.3x NFK lens will make the magnification too high for the APS-C sensor - I'll let you know how it compares.

Anyhow, this is my first post on this forum and I hope this may be of some help to you and/or others that are considering a similar setup. As you say, this sort of thing is relatively easy....once you know what is required and what configuration works!

All the best,

Steve

[75RR]

I should mention that the camera is not parfocal with the way I have it currently setup on the BH2 but that doesn't bother me in the least because the camera and EOS software work so well I rarely bother using the eyepieces when I am taking photos.

I think you will find that it does make a difference - it is my understanding that one should always setup the microscope using the eyepieces, that is how it was designed for optimum imagery, and then go "over" to the camera/computer.

You should try to find a way to make the camera parfocal. See link for a homemade option:

viewforum.php?f=9

[Hendo]

Thanks for that 75RR - I have no doubts you are absolutely right!

I must admit that I was hesitant to put my original post up as I am just a beginner and didn't want to come across as if I were giving sage advice. I was just really happy with what I, as a complete newbie, was able to achieve straight away with what I believe to be a good secondhand microscope and a relatively cheap-ish camera/relay lens given this sort of thing can be very confusing for beginners. Particularly, those of us loathe to invest a lot of money without knowing for certain what specific configurations will work and what sort of minimum imaging standard one could reasonably expect to obtain.

Clearly, this is the start of a steep learning curve for myself and I will need to do some configuration tinkering to get the best results!

[75RR]

Hi Hendo, if you have not come across these links yet I think you will find it worth your while.

viewtopic.php?f=15&t=882

[c-krebs]

The top of the Olympus trinocular tube (on the BH-2 TR30 head) has a circular dovetail. While the "through hole" is the same diameter as the eyepiece tubes, the inner inner diameter of the dovetail section that juts up (about 10-15mm or so...guessing, didn't actually measure it) will not allow a "viewing eyepiece" to be placed into it and drop down far enough to be parfocal with the binocular eyepieces (the top part of the viewing eyepiece is too wide). The projection photoeyepieces that Olympus made to be used for photomicrography are the NFK series and they have a much narrower top section. So they drop right in and their tops fit perfectly within that circular dovetail. This places the NFK photoeyepiece in the proper location. Then, simplest way to attach a DSLR is with the Adapter L, which attaches to that dovetail.

The 2X adapter that Steve shows appears to work well for him, although it will not be parfocal with the viewing eyepieces since it can't set down far enough because of that dovetail. In his case it doesn't bother him since he is using a tethered Canon camera and works off of a screen.

I think you will find that it does make a difference - it is my understanding that one should always setup the microscope using the eyepieces, that is how it was designed for optimum imagery, and then go "over" to the camera/computer.

The "issue" that 75RR alludes to is that since the 2X adapter sits up higher than it really should (the length of the circular dovetail mount) you are increasing the tube length of the microscope. Not an ideal situation since it can introduce spherical aberration, but the effect this might have will vary greatly depending on the objectives used. For objectives with numerical apertures under about 0.50 (so nearly all 4X, 10X and 20X) you would be hard pressed to see any problem. With a 40/0.65 you might start to see something if you look for it. As the numerical apertures go higher the effect can become more serious. I really have never tried to see at what point it becomes objectional. I've included a graph at the end of this reply that gives some idea.

[Hendo]

Thanks for the links 75RR - there is some really informative stuff there.

Many thanks to you as well Charles. Your specific and clear explanation of the problem got me thinking about how I could improve my setup. Given I am just starting out, I really can't justify the cost of an NFK 1.67x lens (they cost as much as what I had paid for my BH2!!) and the OM adapter. However, I think I've found an easy work around that has enabled me to obtain parfocality using my current 'cheapish' relay lens.

The short version: I removed the top of the trinoc port and inverted it which has enabled the relay lens to be positioned where it needs to be for parfocality.

The longer version on the off chance anyone is interested: After removing and inverting the port, I put the three bolts back in and tightened them a few turns to hold the port in place and mounted the camera with the relay lens sitting nicely in the inverted port. The way the bolt holes are cast enabled plenty of vertical movement of the inverted port so I was able to raise and 'shim' the port until the correct height for parfocality was reached. It turns out my kid's lego bricks were the perfect shim height (~15mm) for my temporary 'proof of concept' mock up. I'll probably end up using PVC pipe to make a proper spacer and seal the gaps between the port sections.

I have included some pictures to show this engineering marvel. I've also included an image through one of the eyepiece tubes and then through the trinocular without changing focus. I think the end result looks ok, at least to my rookie eyes, and is certainly much cheaper!

Anyhow, this probably isn't anything new but I thought it might be useful for BH2 trinoc owners on a budget like myself.

My apologies for hijacking your thread Bill!

[75RR]

Love lego!

[Crater Eddie]

Nothing wrong with a bit of MacGyvering. Looks like you are getting a very usable image.
The NFK 1.67x photo eyepieces are horribly expensive when you can find them. You can, however, find the NFK 2.5x unit at very reasonable prices if you are patient. Its not as good a match as the 1.6x, but its workable.
CE

[Hendo]

Love lego!

Lego is definitely one of the perks when you have young kids!

The NFK 1.67x photo eyepieces are horribly expensive when you can find them. You can, however, find the NFK 2.5x unit at very reasonable prices if you are patient. Its not as good a match as the 1.6x, but its workable.
CE

I nearly fell over when I saw the asking price for the 1.67x.

As you say, the 2.5x seem to be a lot cheaper but the magnification is a bit of a pain with the aps-c sensor. Certainly an option down the track though as I am assuming the image quality would likely be better than my generic relay lens?

[Crater Eddie]

but the magnification is a bit of a pain with the aps-c sensor.

Try it with a Micro Four Thirds!
CE

[wmodavis]

Hendo - No apologies needed for hijacking IMO. I personally think it is good to bundle related stuff in one place. Makes it easier to locate for me.

I have gotten a bit detoured from progress on the photography thing but really like the ideas being thrown about here.