Hydra tentacle detail

[Olympusman]

A test comparing brightfield illumination and Universal Gradient Filter (UGF) illumination.
40x objective focus stacked in Zerene.

Brightfield



UGF

[vasselle]

Hello
Very nice photo

[Olympusman]

Vasselle,
Thanks for your kind comments for this and other posts.

[leonardturner]

Very nice illustration of these suckers, and clearly different detail in the second example. But my ignorance is exposed; what is UGF illumination?

[rjlittlefield]

what is UGF illumination?

Universal Gradient Filter. The standard reference is http://www.photomacrography.net/forum/v ... 5832#95832 and discussion in the thread that surrounds it, "Gradient Universal Filter - 'DIC', DF, OL effects".

I don't know if Olympusman is doing exactly what's described there, or something slightly different.

--Rik

[75RR]

Thanks for the info link rjlittlefield, was working on making some darkfield/oblique stops (on acetate) over the last few days, test version Mark 2 to be printed tomorrow. Have now made up some UGF on illustrator to test as well. This makes tomorrows trip to the copy shop that much more interesting.

[Olympusman]

I make my own UGF filters by shooting them with a 6X6 cm camera. I spray paint a foam core disc about 18 inches across so its half white and half black. Then I put a substage filter on the cameras ground glass to scale the disc for copy photography and shoot the disc on black and white film. When the film is processed I have a negative image which is half black and half clear. I then trim it to size for the substage filter holder on the condenser.
I have found that the results of UGF appear to be slightly crisper than straight bright field illumination, particularly with 20X and 40X objectives.

[RogelioMoreno]

Very nice details!

Rogelio