MicrobeHunter.com Microscopy Forum

Hello,

Can anyone explain how the magnification changer works on the Olympus BH2 systems?

What type of lenses are we talking about? Is there a version with values < 1.0x? (It is even possible?)

On my case it is placed after the vertical illuminator (a BH2-MA, and I have MSPlan objectives), but I imagine it works also without, in a 160mm tube length configuration and biological objectives.

Thank you!

There's a sort of carousel inside, typically with achromat doublet lenses for the magnification and often a Bertrand lens. Not sure Olympus made one with something below a 1x magnification.

These made great sense in an era where film cameras ruled, and where users want to get the best possible images from the objectives at hand for publication images. They can also help extract the last bit of resolution from objectives, much as adding 15x eyepieces might.

They make a bit less sense, though still useful for viewing, when a digital camera, software, and monitor now give us the equivalent of a mag changer.

PeteM wrote: ↑

Mon Feb 05, 2024 2:08 am

There's a sort of carousel inside, typically with achromat doublet lenses for the magnification and often a Bertrand lens. Not sure Olympus made one with something below a 1x magnification.

Thank you for your insight!

So in theory, if I place an achromat doublet at the same position, I should see some magnification depending on the FL of this lens?

Maybe I can just unmount the magnification changer and try to check the FL of each lens so I can clone it?

I didn't think it was that simple.

PeteM wrote: ↑

Mon Feb 05, 2024 2:08 am

These made great sense in an era where film cameras ruled, and where users want to get the best possible images from the objectives at hand for publication images. They can also help extract the last bit of resolution from objectives, much as adding 15x eyepieces might.

They make a bit less sense, though still useful for viewing, when a digital camera, software, and monitor now give us the equivalent of a mag changer.

I use the 1.5x a lot with my current setup to compensate the low resolution of my camera (3MP), so I get smooth and clean images. I'd love to see what's possible with dezoom (if it's even possible) to do some tests with another camera (with an higher resolution, but a sensor relatively small so not the ideal combination).

onilink_ wrote: ↑

Sun Feb 04, 2024 10:48 pm

Is there a version with values < 1.0x? (It is even possible?)

No, but it is possible. I have seen an off-brand BX (u-ca) one with 0.5x.

Macro_Cosmos wrote: ↑

Tue Feb 20, 2024 2:58 am

onilink_ wrote: ↑

Sun Feb 04, 2024 10:48 pm

Is there a version with values < 1.0x? (It is even possible?)

No, but it is possible. I have seen an off-brand BX (u-ca) one with 0.5x.

Thanks! It's good to know.