I used a combination of low power to capture the entire Hydra using 2.5, 5X objectives and high power 40X, 63X objectives with DIC to capture the cnidoblasts. Below are some pictures - if you are interested in learning more about Hydra - see the article I just posted. http://www.canadiannaturephotographer.com/hydra.html - I have included links to PDFs of various research papers and online books.
Pictures:
1. Green Hydra Hydra viridissima
2. Brown Hydra - Darkfield Microscopy
3. Brown Hydra - tentacle showing cnidoblasts
4. DIC microscopy with 63X objective of 4 types of cnidoblasts
5. Hydra feeding on Daphnia Darkfield microscopy
6. Hydra with a copepod inside





