Algae Abstract Lately, I've been shooting a lot of long exposures, blue hour shots, lots of photos with low light and expansive areas of smooth color transitions in the sky, water, and the likes. As such, the only ISO my camera knew was 100. With anything over that, the noise becomes rather significant (on my camera).

The other day, I was in a local park with lots of small ponds. I didn't see any turtles on this visit, just lots of frogs jumping out of my way, and some birds. But at the end of the walk one of the ponds had a small area by the shore filled with algae. But it was not that boring solid layer of algae but rather a beautiful array of small algae patches and patterns. Not sure how the gaps happened but they were there and it looked beautiful.

By this time, it was rather late and light was low. Beautifully warm light from a low angle, but very little of it. For the photo on the right, I was at 200mm on my lens with a crop factor of 1.5, i.e. a full-frame equivalent of 300mm. Yet, all I could pull was f/7.1 at 1/45 sec. f/7.1 definitely did not provide sufficient depth of field for the whole frame since I was at a rather sharp angle to the water surface. And 1/45 sec. definitely did not provide enough motion stopping power. Even with the stabilization of the lens turned on, maybe the 1/45 was as stable as 1/200 sec. Maybe. But I was still at 300mm focal length, so 1/300 sec or faster would be ideal (without stabilization).

It was at this point that I took a few shots as a future reference and decided to come back another day with a tripod to be able to go to f/22 and mirror lockup.

Why did I not go to ISO 200, or 400? Not sure, I must admit. I attribute it to the strong habits I formed lately not to go past ISO 100. But would it have mattered for this scene? I doubt so. With so much texture, any little bit of noise would have easily disappeared. And 2 stops would have allowed be to add 1 to the f-stop and one to the shutter speed, better freezing the camera shake and providing a bit more depth of field. And I would have had a better photo right then and there.

Needless to say, when I returned two days later with my tripod handy and with cloudy skies to limit the glare off the water between the patches of algae, I did not find the pond as I wanted to. The overnight rain and wind pushed the algae together and it was the boring ugly solid layer of green slime. So, I still need to go back to get my sot, if it ever happens again. I think I've learned something though. The rules change based on the situation. While ISO 400 may not be a good idea with an expansive sky, it may be just fine with lots of texture.

Have fun!