Possible/better to get new eyepiece for Olympus CHB?

[xioz]

G'day all,
First post, will probably have more then a few questions as I get into this hobby!

I picked up a Olympus CHB (monocular, mechanical stage, 3 objectives) at a pawnshop, and it looks like it was looked after, focus knobs move well etc. I have already bought a battery LED light source, slides, some optics, smartphone holder etc and started looking at water samples. Reading lots, found Alan Woods website etc.

I have three eyepieces now. I have only bought original Olympus eyepieces and attempted to clean them but it seems a lottery as to getting ones without damage. The P 5X is almost clean & bright, the Bi P7X is only OK with 4x & 10x objectives, and in general dirty & dim. And the original WF10X it came with has fungus marks on one side & is dirty and slightly dim.

Can you buy *new* well matched eyepieces for the Olympus CH standard objectives (DIN 160), or should I continue with the lottery of buying originals on ebay? I would like to get a 15X eyepiece to work with the 40X objective and smart phone holder for photos and videos until I know I am happy how much more to spend

Regards,
Malcolm

[Scarodactyl]

Have you tried cleaning them yet? Unlike objectives eyepieces can typically be disassembled and reassembled without much drama as long as you carefully document the order and orientation of each component.

[deBult]

Did send you a PM on a reliable Australian source of Olympus parts.

[xioz]

Hi Scarodactyl
Yes, several times with isopropyl & once with ethanol. I just tried again following Microbehunters video instructions. But it appears to be scratches and stain/fungus fogging parts of the lens. I can look through the eyepiece at a light and see the marks and they rotate unscrewing the top part of the eyepiece but they don't come off.
Am I just unlucky or is buying second hand optics off ebay just tricky?

[xioz]

Thanks deBult, I will definitely contact them!

[xioz]

Just an update, after having looked around what was available for new eyepieces online, I have opted for a 10X and a 12.5X eyepiece from AliExpress. I looked at microscope brands websites and Australian sites and such, but they didn't have many eyepieces and almost all of the ones they did have looked identical to the ones on AliExpress or eBay. I don't know whether there is any quality control when purchasing from a third party, but AliExpress were 10 times less expensive and had the largest range!

[Scarodactyl]

I don't know what the corrections are like on the BH series, but the BH2 really needs the matching correcting eyepieces to get good results. Third party ones are unlikely to match.

[viktor j nilsson]

The short-barrel BH series objectives are designed to project an image 16mm down the eyepiece tube, so the eyepieces are designed to pick up their image 16mm down the tube. This is quite different from the more recent standard of 10mm. This means that in theory, it's not a good idea to use the wrong eyepieces. In practice, though, it still works okay, especially if you don't really care about maximal image quality. But your objectives won't be parfocal.

[xioz]

Another update, I received two 10X eyepieces (one WF) ordered from AliExpress. Both are in great condition and are easier to fit into a smartphone adaptor as they don't have a lip on them like the original Olympus ones.
To my untrained eye, they are both better then the original Olympus 10X eyepiece, they appear sharp and don't have any false colours around objects. As well as being clearer, they don't have a yellow ring around the edges of the field of view which the original had, so less chromatic aberration I guess?

I tried testing whether they are parfocal, but all three seemed to be parfocal with 4X & 10X but not with the 40X (ie I sometimes used the coarse focus knob after switching to the 40X), but a microbe was not totally de-focused as to be invisible.

In any case, speed of switching between objectives and focusing again it a minor issue for this stage of the hobby for me.

[Scarodactyl]

The yellow ring is an indication that the originals are doing optical corrections to the image. Technically you're probably getting more aberrations with these new eyepieces (almost certainly) but if they're giving you a cleaner image without the damage of the others that could easily be balanced out. Your camera might be able to tell the difference better, though it will also be pretty sensitive to orientation which might exaggerate CA in one or the other. But that's an academic concern if the perceptual image quality is better, since that's all that matters in the end.

[xioz]

Interesting! Is it yellow because the common Olympus achromat objectives are corrected for red and blue?
So what would I look for to see aberration's? I was thinking seeing colour (Red & blue?) halo around objects, especially at higher mag or to the edges of the field.
The new eyepieces don't have any colour are the edges of the field of view that I have seen yet.