Fossil Diatoms from Newport Beach

Frez · Post by **Frez** » Sun Dec 02, 2012 8:11 am

Hello everyone. The Newport Beach deposit has a good diversity of specimens and the occasional rarity. The Glyphodiscus stellatus was a nice find and something I had never seen. It was imaged in BF and Hoffman Modulation. HMC does not work well with most diatoms. In this case it reveals surface detail with naturally occurring height variations due to its shading ability. The Aulacodiscus affinis has nine out of ten perfect Rimoportulae and is a fine example.

The camera used is a Olympus DP-10 with an Optem .67 relay. The scope is an Olympus BHA. Stacking was done with either Helicon Focus or CombineZP.

Thanks and best of luck to all
Frez

Pau · Post by **Pau** » Sun Dec 02, 2012 10:43 am

Excellent images!

Jacek · Post by **Jacek** » Sun Dec 02, 2012 10:59 am

Beautiful, fifth picture which is a technique?

Frez · Post by **Frez** » Sun Dec 02, 2012 11:15 am

Jacek wrote:Beautiful, fifth picture which is a technique?

Hi Jacek. The technique is called Hoffman Modulation Contrast.
http://www.olympusmicro.com/primer/tech ... ffman.html

Thanks
Frez

Cactusdave · Post by **Cactusdave** » Sun Dec 02, 2012 1:28 pm

Classic pictures. Excellent halo-free stacking, crisp detail and clean backgrounds. The Olympus DP-10 was a highly innovative camera for its day and its modest pixel count is no disadvantage at these high magnifications.