fern spore capsules

[Charles Krebs]

25X (with 10X M SPlan) and 50X (with 20X M SPlan) on sensor. Olympus BHA with BH2-UMA vertical illuminator and NFK 2.5X photo-eyepiece. Brightfield with crossed polarizers to reduce glare.

[Craig Gerard]

Charlie,

The choice of objectives and photo-eyepiece. Was that due to working distance requirements and/or other additional factors?

Looking forward to seeing what happens next with these fern spores.


Craig

[Charles Krebs]

The choice was simply to get the composition I wanted.

I prefer to use the 1.67X NFK, but that is usually in the BHS stand. If I am going to take a number of shots with the BHA and epi illumination, I will switch it out. If, like in this case it is simply a single subject with a couple shots I'll sometimes just leave the 2.5X in, as I have done here.

[sonyalpha]

Amazing........these look animal rather that vegetable:

What wonderful colour and texture too:

sonyalpha

[discomorphella]

Spectacular. That's a great use of an epi illuminator. I must admit these remind me of the clutch of eggs from one of the Alien movies. Now I have to go and grab a fern from the woods, what species did you use?

Regards,

David

[Charles Krebs]

David,

Pretty sure this is a Western sword fern (Polystichum munitum). It is a different species than the "macro" shot I posted over in the "Technical and Studio" section. This time of year there are many fern species that offer very interesting shots of sori and the sporangia.

[Julian Brooks]

wow, the lighting on the second pic is spectacular. They remind me of cornish pasties, and somehow the pictures bring out the tangible living quality of these spores. Could you explain how crossing polarizers reduces glare, since the reflections from the surface will only go through one of them? Brilliant as ever.

Jules

[sonyalpha]

wow, the lighting on the second pic is spectacular. They remind me of cornish pasties, and somehow the pictures bring out the tangible living quality of these spores. Could you explain how crossing polarizers reduces glare, since the reflections from the surface will only go through one of them? Brilliant as ever.

Jules

Hi Jules,

Being a fellow Brit......I can see what you mean about looking like Cornish Pasties..............but....but........do our American cousins on here know what Cornish Pasties are???

P . S . If you don't know Google them:

sonyalpha

[Charles Krebs]

Jules,

Could you explain how crossing polarizers reduces glare, since the reflections from the surface will only go through one of them?

Because the subject is being illuminated by light that has already polarized.

The light illuminating the subject is polarized by "A" in the first diagram below. The image forming light reflected from the subject then passes through the second polarizer "B" ("analyzer") before reaching the sensor. Polarizer "A" has a rotating mount, so when rotated it controls the glare off the subject. Direct "epi" brightfield is a rather "static" direct frontal lighting, and sometimes it's tough to get pleasing effects. But without the polarizers the glare is really hard to deal with.




Light comes in at "5". Is polarized by pol "A". Hits half-mirror unit at "3", is reflected down onto subject. Light reflected from subject passes upward through pol "B" and on to eyepieces and camera.

[Ecki]

I have never seen it like this.

Chapeou, Charles!

[rjlittlefield]

Could you explain how crossing polarizers reduces glare, since the reflections from the surface will only go through one of them?

The key detail is that specular reflections retain whatever polarization the illumination had, while non-specular reflections do not. Hence the polarizer on the lens, crossed against the illumination, can almost completely kill specular reflections. while leaving mostly intact the rest of the image content. See http://www.photomacrography.net/forum/v ... php?t=3945 for full discussion.

--Rik

[Simon W]

Charles, as I trawl through the forums, I keep coming across your helpful posts, but more importantly, some pretty stunning images. I really loved this one of yours, the colours, focus, everything. Enough said.