Pau, if there's any way to get the prescription data for your and Ferry's lenses I can try to ray trace it, at least crudely. Of course if its all working well you can figure out the actual magnification rather easily, so perhaps we don't need to bother. The only reason I used the 0.32X lens is tha...

...I don't have a 0.32X projection lens, but use an old Olympus 50 mm camera objective between the Eyepiece and my Canon 550D, which I changed for my Nikon D300 after reading a paper from Charles . It works excellent. I don't know how to calculate it, but I think it will be approx. the same: I use ...

Great!

Excellent images.
Was the leaf just inmersed in water between the slide and coverglass?

Rik, you're right, I was refering to ferrofluid, and it doesn't match well your images.
I never heard about this magnetic viewing film, a very interesting material.
Unfourtunately my children are too old, if not I would be now ordering some sheets

A magnetic fluid?
There is some kind of magnetic fluid used in scientific toys, I thin it's opaque, but never saw it so close

Section of the lens of an eye? --Rik YES! =D> At the end...it was for Optics lovers :D It is a microtome section of crystalline lens fibers, cells without nucleus and organelles filled with the protein crystallin. The diamater of the cells is about 5 micron. This is from an unknown mammal, and it's...

Dave, no feathers or scales are so important for us Clues reminder: - It's an optic material - The brown color isn't original. - If you are reading this post, you have it for sure. - ... I don't know about any insect reading the forum posts... - old (and useful) material, not directly related with m...

Yes, it isn't unusual, in particular with infinite corrected objectives like the Nikon CFI 10X 0.25 and Mitutoyos with tube lenses shorter than the specified 200mm. The main issue is the image circle coverage, so it only works if the image circle can fill the sensor with enough quality at reduced ma...

#2 is the same sample as #1 but taken with a 50X objective

Mitch, you get closer than others, but... I don't know about any insect reading the forum posts, despite they are usual models.

Well, it's Chritsmas time, but tires are not optical materials and because the magnification of the last one is about 75X on sensor...it would be a micro Santa

Excellent. You're doing wonders with this filter.

Charles, many thank for your answers.

No, it's a MUCH older (and useful) material, not directly related with monitors, but indirectly....

Not wood, it's an optical material (colorless and transparent). The brown color isn't original.

Follow the clues...