Apologies for the title, but this is what this post is about: snorkelling in one meter of water taking soft focus images. Low depth of field (DoF) results from a large (or wide) aperture (somewhat confusingly, to make the aperture larger you need to select a lower f-number on your camera). A wider aperture results in more light hitting the sensor, so it is something you’d do when taking photos under low light, but it can also be used for creative effects, as it results in only a thin slice of the image being in focus. This leaves cluttered backgrounds and foregrounds blurred out which makes for a more pleasing aesthetic effect. I used this technique for the photos above and below of a European Cowrie (Trivia monacha) (M43: f4, 1/160s, ISO100). Of course there is a trade-off: most of the subject is out of focus, so it is not a setting you would use for an ID shot that needs as much detail as possible. The golden rule is to keep the eye(s) in focus – something that worked slightly better in the second pic. Strangely, this snail has two pupils in its right eye! I have indicated the slice that is in focus in the second photo with a red line; the shell is 10-15mm in length.
While I was taking photo after photo of this snail, I was approached by several small Tompot Blennies. This species (as well as Common Blennies, but not so much Montagu’s Blennies) is very curious which is great for a photographer (although sometimes they come too close and you have to keep moving back). I used the same settings as above for the smallest individual (not longer than 4 cm). I noticed for the first time the blue spots on the dorsal fin (see first pic). I did not get THE photo but it was good practice. Finally, a close-up of a baby Topknot; although the aperture was smaller this time, the mouth is still not in focus. Sorry for all the photography talk if you are not into that, but at least I hope you enjoyed the pictures!
