Diatom - Arachnoidiscus sp.

[hkv]

Further tests of the 60X water immersion. Here is what I believe is a Arachnoidiscus sp. Correct me if I am wrong. I am by no means an expert on diatom identification...

60X objective:



Crop of 60X with more details:

[75RR]

Beautiful image and amazing resolution.
Must have missed the announcement on the purchase of that objective: details please :)

[zzffnn]

Very nice!

[hkv]

Beautiful image and amazing resolution.
Must have missed the announcement on the purchase of that objective: details please

Hi 75RR, well here is the link so you can catch up on the new investment

viewtopic.php?f=6&t=4783

[JimT]

I would say it is a good investment. Great detail.

[KurtM]

I can go with Arachnodiscus. You know where the name comes from, right? Because it resembles a classic (orb weaver) spider web? But I'm no expert either (and I doubt anyone else around here will agree to be called that as well, ha ha).

VERY nice images coming out of that lens, still amazed at the flagella thing (see referred thread link).

I'd like to see you zero in on those aerolae, or whatever you call features like those, with the 100x lens. I suspect there's a world of micro pores going on in there ... ... and would sure love to see 'em.

[mrsonchus]

Fabulous images - the best diatom images I've ever seen - no contest!

[Johann]

Wow - resolution is amazing - I'm thinking of getting one of these objectives myself!

On a side note, what camera do you use and how is it connected to your Olympus?

[hkv]

I can go with Arachnodiscus. You know where the name comes from, right? Because it resembles a classic (orb weaver) spider web? But I'm no expert either (and I doubt anyone else around here will agree to be called that as well, ha ha).

VERY nice images coming out of that lens, still amazed at the flagella thing (see referred thread link).

I'd like to see you zero in on those aerolae, or whatever you call features like those, with the 100x lens. I suspect there's a world of micro pores going on in there ... ... and would sure love to see 'em.

Thanks Kurt for the explanation! Let's see when I find time and motivation to mess with the oil. Would be a nice comparison though! Oil objectives loose resolution quickly if the subject is not very close to the cover glass. Therefore, many diatoms are mounted directly on the cover glass. Water immersion is not that sensitive and resolution does not degrade even if the subject has sunken down into the medium.

[hkv]

Fabulous images - the best diatom images I've ever seen - no contest!

Thanks for looking!

Wow - resolution is amazing - I'm thinking of getting one of these objectives myself!

On a side note, what camera do you use and how is it connected to your Olympus?

Yes, you will not be disappointed I think.

I use a Canon 6D with the U-SPT and PE2.5X. On top is the Olympus Photoadapter L with a OM to EOS adapter.

[zzffnn]

Water immersion is not that sensitive and resolution does not degrade even if the subject has sunken down into the medium.

I think hkv was too lazy to specify what happens to resolution/contrast with what types of medium.

With aqueous medium with refractive index around 1.33, water objective can indeed image deeper than oil objective.

With resinous (oily) medium with RI around 1.51, water objective will actually image shallower than oil objective. With diatoms mounted in high RI medium, oil objective actually works better.

Water immersion objective is also more sensitive, compared to oil immersion objective, with regards to cover slip thickness, especially in applications such as phase contrast.

[hkv]

Water immersion is not that sensitive and resolution does not degrade even if the subject has sunken down into the medium.

I think hkv was too lazy to specify what happens to resolution/contrast with what types of medium.

With aqueous medium with refractive index around 1.33, water objective can indeed image deeper than oil objective.

With resinous (oily) medium with RI around 1.51, water objective will actually image shallower than oil objective. With diatoms mounted in high RI medium, oil objective actually works better.

Water immersion objective is also more sensitive, compared to oil immersion objective, with regards to cover slip thickness, especially in applications such as phase contrast.

Yes! You are right. And in 95% of the cases I use water as the mounting medium as most critters I enjoy looking at live in water.

[mrsonchus]

Now then!
This is exactly why I always read the posts of these top fellows here - the above exchange between hk' and zz' re water vs oil immersion objective characteristics with regard to coverslip distance from subject, mounting medium RI and the respective RI of oil and water has in so very few words taught me an awful lot of very useful information with which to tailor my own use of oil and water immersion objectives. Thanks chaps - very useful input from you both.

The perfection of the images is stunning - I really have to tear my eyes from them - they are the best I've seen - superb!

JB

[hkv]

A few more. Unknown to me.

60x:

''

Crop:

[mrsonchus]

Simply beautiful image, the geometry is wondrous!
John B

[billbillt]

Superb quality and stunning!...

BillT

[KurtM]

Let's see when I find time and motivation to mess with the oil. Would be a nice comparison though! Oil objectives loose resolution quickly if the subject is not very close to the cover glass. Therefore, many diatoms are mounted directly on the cover glass.

Depositing diatoms on the cover slip is (or ought to be) standard practice for making permanent slides. I don't know about the pros, but a few of us amateur mounters are known to have taken to final curing our slides upside-down in order to further encourage the frustules to hug the cover slip. As diatoms are often used to test the resolution of microscope optics, we want our slides to work well with whatever objective any microscopist may dial in.

Beautiful new images!! So, wonder if you could offer a word or two on the slide? Who made it, and what mounting medium?

[hkv]

Thank you all for your kind comments and appreciation!

The slide I used for this was from a slide labelled "Diatoms" and came with the Zeiss Jena Sedival that I purchased last spring. I have no idea who made the slide and its history, but it could be Klaus Kemp. I also got several officially marked Klaus Kemp slides as part of that deal.

[gekko]

Excellent images (all of them) and superb details and resolution. And beautiful too

[RudiV]

This is a really beautiful set of images hkv! I think I need a water immersion lens!

Thanks for sharing,
Rudi