MicrobeHunter.com Microscopy Forum

Hello!

I bought this wonderful Bausch and Lomb model VM349 off EBay just a week or so ago. It was made in 1944 and is in excellent condition; it came with it's original box, the manual, a blue filter and even a dark field filter as well as both 5x and 10x eyepieces. It also has a box to hold ten slides. The only trouble it has is the mechanical stage seems to be frozen on the horizontal axis, which I think should be repairable. Also, the 5x eyepiece seems to have some contaminates in the lens; possibly mold. But this isn't a huge issue at all.

I bought this scope for use in the field; I wanted something that was portable and didn't rely on electricity for the lighting. With the mirror, it can be used pretty much anywhere and I can quite easily fit a LED Mag Light in the box with it (and that provides more than enough light). So, I'm really quite happy with it and am very impressed by the excellent condition it is in for an instrument dating from 1944. I was also a bit surprised at how heavy the little guy is.

Just out of curiosity, what microscopes do you take with you into the field? Or, do you take any with you? I thought it would be nice to have so I could get an idea of what I'm collecting, especially if I'm hunting for a particular critter.

Hi Pat,
you've got a nice microscope there! With no optical surfaces between objective and eye it could actally offer a superior image to more modern microscopes. These horseshoe microscopes vary quite a bit in weight, I have a ROW mircroscope from the DDR and it is a true boat anchor, much heavier than it looks.

I regularly take a small microscope kit whith me for the family holiday. But my aim is always to stay much below size and weight of your boxed microscope.
I have a faible for field microscopes and even have built one based on a Lomo biolam nosepiece. I have a Swift FM-31 too. It is one of the few portable instruments that offers a 40:1 objective and a big field of view too. What I don't especially like is the flat built when in use. Holding it in hand, moving the specimen and focussing is difficult with just two hands. When using it bent down to a table I always hope to attract beautiful young women who try to rescue me from a heart attack.

There have been other objectives for it like LWD and PH, but I have no documentation of them and they must be scarce.

Among my field microscopes I have no clear favourite, they all have advantages and disadvantages. My home built "Biolamini" offers binocular viewing and full specification, but so equipped it is not really small anymore. The Zeiss Winkel and Meopta ones are nicer to use than the FM-31 but offer only up to 300x useful combined magnification. I have a Reichert one that is really small but has even lower magnification and a small field of view.
My russian filed microscope from 1939 is magnificently finished, like built by a jeweller, but it is a heavy beast.

There is a Nikon Nature Scope or so, a portable stereo microscope, but they are expensive and I don't have one.

What always increases the amount of luggage are the accessories, so the size and weight of the instrument looses importance.

Sometimes I think about a new field microscope design with wide field plan optics in a tiny package, but so far I haven't started building it.

Bob

Cell phone with a clip-on lens might be the most portable field scope around?

It seems to me, the reason for using a field scope if you are involved in a project, and unless one intends to set up a portable lab and stay for a while, is to triage samples, as a way to limit the number being transported back. If one has a portable lab , then presumably there are lots of components, so the portability of the scope need not be great. If one is just triaging samples, then the portability of the scope might need to be great but a sacrifice in image quality and magnification capability also acceptable. That's where the current gaggle of truly portable scopes sits. If one is just scoping around and has no further intention for the samples, it may or may not be important to have a scope of better quality in that case, so a really good assessment can be made in the field.
I'm kind of split between the two. I do triage samples but I also have fairly strict requirements on the quality of the instrument I am toting along because there are some fairly fine details that I am looking for. I also don't want to have to mess with immersion optics but I am considering water immersion for obvious reasons.
I'm still in the build a scope mode and have sorted out a dry 4 optic set on a very compact binocular stand 10X.30, 30X .55 58X .85 and 80X .90 but the attraction of having the potential of up to 1.33 with water immersion looms greatly. It is nice that some very small condensers were built in the past; condensers that thread into an R.M.S. mount and can be commandeered for such a project, cheaply.
I'll get around to posting about this eventually but that's where I am at.

apochronaut wrote:I'll get around to posting about this eventually but that's where I am at.

Hi Phil, take your time, but I'm looking forward to this!
Field microscopes are really an interesting topic and since there is little availabe new it is also rewarding to build something by yourself.

Bob

I picked up a Bausch and Lomb fiber-vue portable scope. It is a pretty simple design, with coacial illumination switchable to 'oblique' (just a bulb beside the objective). Downsides, it came with a 10x objective which is a bit much (and my generic 4x can't handle coaxial illumination), and the sample holder is pretty much fiber optic specific. Still, they sometimes go very cheap (there is one on eBay right now at 99 cents) so it may be worthy of further exploration.