Archive for July, 2009
Photo #8
Yet another photo from the Galapagos Islands. This time it’s a Marine Iguana.
The more I go over the photos from there the more I want to go back. Or to a new place. I need to go to Australia and New Zealand. I’ll get there…
Image Exposure – Part 2
In my previous post, I’ve explained about how the aperture and shutter speed affect the resulting image exposure. It’s all true. But not entirely. There is one last thing affecting the exposure:
ISO (or film sensitivity) affects the sensitivity of your “film”. I remember buying film for my old camera, having to choose between Kodak 100, 200 or 400. Completely unaware of the difference, I’d choose the cheaper one. The ISO determines the sensitivity of the sensor to light. The more sensitive (higher ISO), the brighter the image will be. This allows you to “push” beyond the limits dictated by aperture and shutter. I usually shoot at higher ISOs indoors or at night, or basically, when lighting is scarce.
My post of night photography shows a picture taken at night at 1/6 seconds at the maximum aperture f/4.5 and highest ISO settings: 1600. Had I used a lower setting, such as 800, I would have had to double the exposure time (since it’s half the film sensitivity). That photo at 1/3 of a second would have been quite blurry I guess.
Downside of high ISOs? Image noise. Lets compare the extremes: ISO 100 opposed to 1600:
 Bottle - ISO 100, 1/8 sec, f/5.6 |
 Bottle - ISO 1600, 1/125 sec, f/5.6 |
So we can photograph at the same settings at higher shutter speeds (or smaller aperture) at higher ISOs – but at a cost…
The last thing affecting the exposure, is EV compensation. You can manually brighten or darken your photo. Set the EV compensation to +1, -0.3, +2. Depends on what your camera allows. EV +1 means the image will be brighter by one factor (equivalent to doubling the exposure time, or the aperture size). You can also take a photo at auto bracketing. This will take 3 consecutive photos: one at regular exposure, one at negative EV compensation (underexposed) and the last at a positive EV comp (overexposed). I took a nice sample going to lunch the other day:
 EV compensation - normal |
 EV compensation - underexposed |
 EV compensation - overexposed |
My thanks to the two lovely models I met on the street. And that’s all I have to say about that…
Night time photography
Okay. I’ve been meaning to write part 2 of the image exposure piece, but last night I went to this sixties party. I’ve been struggling to take photos in the dark. I know I’ve written about it, but the camera has limits. Even with maximum aperture, you will have either use long exposure, or use a flash.
Now I won’t trouble you with all the crappy photos I took there. All my attempts of not using the flash resulted in a terribly shaky scene. Using an external flash would have been best I believe, but I’ve yet to acquire one. So I used the Lucille’s built in flash:
Danna blowing bubbles
This picture was shot at 1/6 seconds at maximum aperture (f/4.5… I also need new lens?).
I used a flash, but I was far away enough not to overexpose Danna. I also used a nice trick here: right after the flash fired I zoomed in, blurring the surroundings. Had she been moving, the photo would have been messed up, but slowly blowing bubbles made Danna quite static.
And the party itself? It wasn’t Woodstock but the beer was free 
Photo #7
I noticed my photo posts have been alternating between animals and people / other stuff.
So after the last photo post – it’s time for another animal:
Crab
This crab was eating from the greenish matter in front of him (or her, or however it works with crabs). I also have a nice video of it in action, but this photo turned out to be quite nice in my opinion.
Looking back, I must admit that touring in South America in general (and the Galapagos Islands especially) has been an amazing photographic experience. There’s nothing like taking the camera with you everywhere you go for a long period of time. It’s something you can’t quite do in the regular day to day routine. It is something I should do again soon…