Higher and lower sensitivity

January 2013

I decided to take some photos of our local town market. Having waited for cloudy weather and researched when local markets happen, I set out with my camera.  Disappointingly, there were not many stalls or customers. I think the time of year had something to do with it – a midweek market just after Christmas in the recession with shop closures happening weekly.The weather was cold and misty, and only just above freezing. I considered whether to retake the photos on a different day, but thought that because I could draw some learning from this exercise, I would just bear the ISO exercise in mind next time it was cloudy.

I took a couple of photos and a street views.

 
F11 1/8 ISO100 80mm   f11 1/30 ISO400 80mm   F11 1/60 ISO800 80mm

At ISO100 it was difficult to attain clear shots. People were blurred all the way through the scene because of the slow shutter speed. There are some shadows under people’s feet.

At ISO400, people are still motion blurred and it was difficult to handhold the camera because of the long shutter speed (although not as long as ISO100). The foreground is more in focus than at ISO100. There is some grain in the photo but it is acceptable.

By ISO800, the faces of people are still not crystal clear. There is less motion blur. I was able to handhold the camera. I think the graininess is still acceptable.



F11 1/8 ISO100 35mm  F11 1/30 ISO400 24mm F11 1/60 ISO800 28mm

 

At ISO100, the shadows are even and defined.There is motion blur as I was unable to handhold the camera at this shutter speed.  By ISO400, there is still movement of people. The shadow detail becomes grainier. By ISO800, the shadows are quite grainy.

In my opinion, increasing the ISO is an option to allow me to handhold the camera as there are times when using a tripod may not be practical. I think in portrait photography it is acceptable because I have seen photos on grainy paper and there are times when grain accentuates detail such as in black and white portraits. I think the subject matter is also important in the decision making process. For example, on my fungus photography morning in October 2012, I was unable to get into some nooks and crannies with a fully extended tripod. I increased the ISO to 400 and had acceptable results. At ISO800, the ISO made the photo appear grainy, and because the photo was taken with a lens that is 1:4macro, the graininess became apparent at 100% enlargement. (My fungi do not have much shadow detail as most of them were well hidden under the tree canopy.)

 
F4 1/45 ISO400                               F8 1/20 ISO800