Olympus bx50 microscope

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Kadbrt
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Olympus bx50 microscope

#1 Post by Kadbrt » Sat Nov 07, 2020 3:55 am

Hello everyone, I have had a very cheap student microscope for about 5 years now and am finally looking to get something better - although I am on a fairly tight budget. I found an Olympus bx50 microscope with five objectives for $500 Usd and am extremely close to buying it. I would really love some input though to see if y’all think it would be a good fit for me.

My uses for it are as follows. First and foremost, I am going to be doing some citizen science research involving algae and mushrooms. This essentially just entails looking at fungal spores and checking the algae to ensure it is growing properly. Asides from this, I will mostly just be viewing and photographing pond samples for my own enjoyment.

My only worries with this scope is that it has a halogen bulb. My current microscope has an LED, so I am worried that a halogen would be dimmer or more yellow than I am used to. I’ve also heard that halogens will “sunburn” your eyes if you use the scope for too long, but I have no idea if this is true or not.

I am also looking to use darkfield as well. I am assuming it does, but for anyone who has a bx50, can you use darkfield with it? If so, what filters do you use for it? Do you guys think it would be smart to jump the gun on this, or would this scope not be what I am looking for? Thanks!

Scarodactyl
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Re: Olympus bx50 microscope

#2 Post by Scarodactyl » Sat Nov 07, 2020 4:07 am

That is quite inexpensive for this model. Accessories for these can be expensive, since they are more recent and widely used, but deals do pop up as well because they're prevalent enough that quite a few listings for parts end up on eBay.
Halogen bulbs are still the standard for high end microscopes because of the nice continuous spectrum they put out, though LEDs continue to improve as well.

BramHuntingNematodes
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Re: Olympus bx50 microscope

#3 Post by BramHuntingNematodes » Sat Nov 07, 2020 7:00 am

Halogen should be bright enough. They are more yellow, though this can be improved with filtering . I also put UV filters in front of all my light sources--its cheap and easy enough.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

Kadbrt
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Re: Olympus bx50 microscope

#4 Post by Kadbrt » Sat Nov 07, 2020 3:33 pm

Thanks for the responses
What type of uv filter do you use? Would you mind sending a link to it or to a similar one?
So then do halogens have the capability to cause eye damage if used for an extended time?

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ImperatorRex
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Re: Olympus bx50 microscope

#5 Post by ImperatorRex » Sat Nov 07, 2020 4:22 pm

The UV portion of the Halogen Lamp is quite small (see hyperlink below), also there are many glas lenses between light source and human eye.
More important is the IR Filter - and this is fitted by Olympus in the lamp housing.

https://www.mikroskopie-forum.de/index. ... #msg240689

Regards
Jochen

Tom Jones
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Re: Olympus bx50 microscope

#6 Post by Tom Jones » Sat Nov 07, 2020 4:52 pm

The BX-50 is an excellent microscope.

I don't know who mentioned the sunburned eyes, but they don't know what they're talking about. These microscopes are designed for research and clinical use where they are used for hours on end. I don't remember any of my colleagues in clinical labs complaining about sunburned eyes, and I've never seen research indicating it's a problem. I know it's never been a problem for me. If it was, you can bet all of the manufacturers would have dedicated UV filters in the light train. They don't, as they're unnecessary. Most of the time, you are not using anywhere near the full brightness available anyway. It's only necessary when using techniques like POL, darkfield and DIC that need a lot of light at high magnifications, and then most of the light doesn't make it though the system to your eyes. And most LED systems don't quite match the max light intensity of a 100W halogen. Even the 10W LED systems don't quite make it. But of you really want an LED you can find them. Do yourself a favor and try the halogen first.

You can do darkfield either with a patch stop you make (20x and lower) the patch stop in a universal condenser (still pretty much 20x and lower) , or the dedicated U-DCD dry, or U-DCW oil darkfield condensers. It will do gorgeous darkfield. I spent several days last year with a film maker friend shooting 4K video of my collection of arranged diatom slides. We were using her BX-51 which has the same optics as the BX-50, along with a U-DCD dry darkfield condenser. You can also set it up to do beautiful phase contrast as well. With a universal condenser you can use phase inserts (instead of the U-PCD dedicated phase condenser) or swap them out for DIC prisms. It can be set up as a polarizing microscope, or a DIC microscope. You can add fluorescense or vertical illumination.

It's a modern infinity corrected research microscope. You can set it up to do damn near anything you want. You can use inexpensive achromat objectives or hideously expensive super apochromats or something in between. It very easily adapts for photography.

Presuming the power supply works (and I'd get it repaired if it doesn't) the only justification I can think of for a LED setup is constant color temperature for video. The BX-50 even has a flip-in LBD daylight filter built into the frame if you like the bluer light. Personally I'm happier with the yellower halogen color, and adjusting color temperature for photography is so simple as to be a non-issue. I prefer it for normal viewing as well. I've used the newest Olympus LED scopes and find the light way too blue for my taste, even though Oly says it's perfectly balanced.

Olympus UIS/UIS2 (BX series) objectives are among the best made, easily available on Ebay, or from dealers, and Olympus will be happy to take your money if you want the latest and greatest available. Parts are available, service is available, all the bells and whistles are available.

At $500 it's a steal for the frame only if it's in good condition. Consider the objectives freebies. The parts aren't cheap by any means, but they're of very high quality. I've never seen delamination in an Oly lens either, unlike Zeiss, and the oil immersions lenses don't leak, unlike Nikon.

Aside from the fact I used BX microscopes for 15 years in clinical labs, I now own 3 BX-50's (set up for bright field, phase, DIC, darkfield) and a BX-60 set up for epi bright field, dark field and DIC. All are set up for still photography and video. Pricy setups, but I don't like swapping parts if I don't have to.

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Re: Olympus bx50 microscope

#7 Post by BramHuntingNematodes » Sat Nov 07, 2020 11:25 pm

I use UV filters only because my lights are all single die high intensity leds whose uv emission is not entirely certain to me. The advantage of halogen is not I think the flux or the color, either of which leds can do very well these days, but that the emission of halogen lamps is perfectly well known, the majority of professional and research microscopes designed with them in mind , the majority of historical research done with them or similar incandescent light sources, the ease of finding bulbs, and the familiarity of researchers with them. There's just really not many good reasons to not use halogen.

One issue is heat, which is a serious issue when using some ancient scopes but is going to be anticipated and the stand will be designed to isolate the heat from the user and sample in any scope since the eighties I guess.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

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mrsonchus
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Re: Olympus bx50 microscope

#8 Post by mrsonchus » Sun Nov 08, 2020 12:12 am

I use a 100W halogen BX50 every day without issue. Heat isn't a problem as, mentioned above, the design is perfectly able to accommodate the 100W at full volts. I however only routinely use the 'photo-setting' preset button, which puts the bulb to 9V I think - which is a std for photomicrography (at least pre-digital perhaps) which, together with other factors such as film and paper types allowed standardised results I suspect.

For other methods including darkfield, phase and polarisation, I use the full-on (12V) position. In both cases the built-in selectable ND filters are perfect for modifying brightness - I also have the Olympus filter holder that fits on the field-port that takes an additional 3 filters that are selectable - great for the use for example of an IF550 (green) filter with phase and monochromatic imaging. I leave the also built-in and selectable LBD filter in except when I need a large boost usually with polarisation, as it's (the LBD) use reduces brightness significantly but does give a nice balanced illumination that's not white but is a lot less yellow.

I imagine LED is already beginning to supersede halogen in new top-end 'scopes - at that level the charachteristics, consistency of the LED and comparability of results will be guaranteed and meaningful.
John B

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