Which trinocular should I have for insect photo?

len · Post by **len** » Sun Mar 28, 2010 2:15 am

Hi,

I'm an amateur insect collector and I would like to ask your advice about which trinocular should I have to photo insects parts.
I don't know too much on microphotography but I want to take a good quality photos of object of about 0.2-3mm (mostly leg parts).
I had been reading the post and found lots of buzz words i.e. FD, BF... but I'm not sure which method will be the best for me.
Does anyone have experience with insect photos? Can you suggest a recommended model or what feature should I look for in the trinocular?

Thanks,
Len

len · Post by **len** » Sun Mar 28, 2010 9:48 am

Does anyone has experience with amscope?

I was found this cheap model http://store.amscope.com/t490a.html (there is also a DF model) is it worth buying or a total waste of money?

Thanks

g4lab · Post by **g4lab** » Sun Mar 28, 2010 9:57 am

The trinoc scope you linked to, appears to have a fixed trinocular prism.
That is not the one you probably want.
They are cheaper,but some of the light always is shot up the camera tube, and is wasted.

You want one with a lever or rod, that allows you to move the prism. When you shoot a picture, one side goes dark, and all the light goes up the camera tube.

Fixed prisms have a use, if you need to watch and photograph live critters, or other moving things. I presume your insects will be dead or anesthetized.

the Amscope is not a total waste of money. But you would find that most list members here would recommend trying to get a good used major brand scope probably an Olympus or a Nikon. Its an old saw that a fine used instrument is better than a cheapo new one. Usually,, almost always.

There have been many threads on this and related subjects. Search the archives and then come and ask more questions.

Gene

rjlittlefield · Post by **rjlittlefield** » Sun Mar 28, 2010 12:57 pm

g4lab wrote:some of the light always is shot up the camera tube, and is wasted.

Gene, do you happen to know what a typical split is on this type of head?

I'm thinking that if it's say 50/50, that's only one f-stop, which for almost all applications would be easily made up in longer exposure time.

--Rik

g4lab · Post by **g4lab** » Sun Mar 28, 2010 1:49 pm

I know of no standard, but 50-50 sounds right. I am not so worried about
the cameras portion of the light, but rather the reduced brightness and contrast in the visual tube.

In my Zeiss works I came across a peculiar fixed trinoc that sends 70 percent to the camera and the 30 to the viewer. The view through the
eyetubes was very dim. Probably not alot of call for that one which explains why it came our way.

The best solution IMO is a multi position prism slider where you can send 100% either to the camera or the viewer and an extra position that has either 50 50 or some other ratio. 80-20 and 70-30 are used commonly

The Wild M400 has 100-0 0-100 and 50-50. Best of all possible worlds.
When you send 100% to the camera the prism is entirely eliminated from the optical path.

rjlittlefield · Post by **rjlittlefield** » Sun Mar 28, 2010 2:14 pm

Thanks -- good stuff to think about.

--Rik

len · Post by **len** » Sun Mar 28, 2010 2:26 pm

Thanks g4lab,

The description of "simultaneous viewing" is written only on the T490 so I think the other models http://www.amscope.com/Trinocular.html are 100-0 0-100 as you sugested.
What about my original question do you think DF will work better for me than BF?

Thanks,
Len

rjlittlefield · Post by **rjlittlefield** » Sun Mar 28, 2010 2:47 pm

len, getting back to your original question...

Most insect parts are pretty opaque unless they have been cleared and mounted in microscope slides.

Traditional microscope lighting will not work well with these subjects. In BF (brightfield), light is beamed through the specimen from behind. Many insect parts will be too thick for light to get through, and what does get through will not correspond to what you would normally see. In DF (darkfield), light is beamed from behind but off to the side, so that the microscope only sees light that was deflected by the specimen. Same problems there.

Most likely, what you need is front-lighting. Within the confines of a microscope frame, this can be done with fiber optic illumination, often aided by the addition of a diffuser made from half a pingpong ball or something similar of paper. Pictures taken using these setups will be found in the Photography Through the Microscope image gallery.

Front lighting and high magnification can also be obtained in open setups, using a microscope objective mounted on bellows with a DSLR. Pictures taken using these setups are posted in Technical and Studio Photography -- Macro and Close-up.

All of these topics are much covered in the forums -- insects and parts of insects are some of our favorite subjects. See the recent posts by NikonUser, for example.

One more thing I have not seen mentioned so far in this thread is that you will need to use focus stacking to get decent depth of field with such small subjects. Again, there is a lot of information in the forum archives, but feel free to ask if you have trouble finding it or interpreting what you find.

--Rik

Charles Krebs · Post by **Charles Krebs** » Mon Mar 29, 2010 9:36 am

Rik and Gene,

FWIW... the Olympus BH-2 trinoc head slider has 3 positions (view/camera)... 100/0 and 20/80 and 0/100. My older BHA head has two: 100/0 and (pretty sure) 20/80.

My Nikon stereo splits it 50/50.

One other trinocular thought. If you are working with live, or moving, subjects it really becomes essential to have some sort of split that allows you to view and photograph simultaneously.

len · Post by **len** » Tue Mar 30, 2010 10:28 am

Ok
So I need trinoc head of 100-0, 0-100 to get best result. How do I get front lighting for opaque object? The lens should be very close to the object so I guess it'll be difficult to put light source directly from above? or does some of the trinoc support this method?

Len

update: I found this http://cgi.ebay.com/Olympus-BHM-Metallu ... 19bb1f73bd an Olympus BHM Metallurgical Trinocular would something like this could be better for me than BH-2 or BHA ?

rjlittlefield · Post by **rjlittlefield** » Tue Mar 30, 2010 11:56 am

len wrote:Ok
So I need trinoc head of 100-0, 0-100 to get best result. How do I get front lighting for opaque object? The lens should be very close to the object so I guess it'll be difficult to put light source directly from above? or does some of the trinoc support this method?

Len

update: I found this http://cgi.ebay.com/Olympus-BHM-Metallu ... 19bb1f73bd an Olympus BHM Metallurgical Trinocular would something like this could be better for me than BH-2 or BHA ?

That scope appears to be using "episcopic illumination", which means that illumination is beamed down through the objective. It is an elegant method that is particularly good for looking at polished metal surfaces that cannot be illuminated any other way. I don't know prices terribly well, but I'd be surprised to see that scope last long at that price.

Another method of illumination involves a simple "light tent" wrapped around the objective of an ordinary scope. The example shown below is using half a pingpong ball and a dual-head fiber optic illuminator. This method provides a lot of flexibility for adjusting the orientation and harshness/softness of the illumination. If you're mainly interested in documenting anatomy, then a Kleenex tissue for diffusion and any sort of light or electronic flash directed against it will probably do the job.

The two methods are not mutually exclusive. You could certainly use episcopic illumination when that's appropriate, and wrap a light tent when it's not, or even use both at the same time.

Here is an illustration of the light tent approach. The subject is a carpet beetle; the field diameter is about 1.8 mm.

See HERE and HERE for discussion of shooting the same subject with the same objective on bellows. For this subject, there is no advantage to objective-on-bellows, and actually the bellows setup is acting just like a big ugly 'scope. For other subjects the bellows setup has significant advantages because of more flexibility for illumination.

--Rik

Tesselator · Post by **Tesselator** » Tue Mar 30, 2010 12:04 pm

I have what is now called the Eclipse 80i scope with 3-way lighting (100, 100, 100) and a mercury-vapor light source + halogen I think. It does the front lighting thing as one of the three ways. I dunno about that specific scope you linked to but on mine it's just awesome for photographing opaque objects and surfaces!

This just to say that if you're photographing opaques through the scope then front lighting is definitely one very good way to go! It looks to me like the system you linked is halogen but that's only a guess. I think halogen alone is pretty good but I dunno much about the wavelength sensitivity of your camera's sensor (or film?) nor what halogen produces by itself. It's on the net I suppose tho. Isn't everything these days?

BTW, I dunno about in the USA but in Japan where I live the Olympus BHM from about 2001 goes for between $400 and $700.

You might also wanna have a look at this article: http://www.microscopy-uk.org.uk/mag/art ... edepi.html for LED conversion.

g4lab · Post by **g4lab** » Tue Mar 30, 2010 12:14 pm

One other trinocular thought. If you are working with live, or moving, subjects it really becomes essential to have some sort of split that allows you to view and photograph simultaneously.

I always say, that the split prism is there ,so that you can snap the picture, when the little critter is sticking his tongue out at you, or showing his hiney.

rjlittlefield · Post by **rjlittlefield** » Tue Mar 30, 2010 12:20 pm

Tesselator wrote:what halogen produces by itself

The quality of light from halogen illuminators is quite good. The bulbs are black-body radiators just like normal incandescents. The "color temperature" may be a little higher or lower, depending on bulb type and brightness setting. The spectrum is smooth and continuous, without spikes, bumps, or dropouts like you'll find in mercury vapor, fluorescent, and LED illuminators.

--Rik

Tesselator · Post by **Tesselator** » Tue Mar 30, 2010 1:34 pm

You include LEDs in that list too? I dunno anything but I've noticed lots of photographers and some microscope users praising LED lighting - so I thought it was capable of a full, continuous and smooth spectral emission. No?

Here's the lamp from an earlier Olympus BHM microscope I just snapped. I guess this is the same bulb in the one the OP linked to. They're pretty cheap to replace and last a pretty long time. They can also be unattenuated up brighter than you would probably ever want.