TAOP Part 4: Light – Ex 2: Higher and lower sensitivity (Project – The Intensity of Light)Posted: October 3, 2011
Part 4 : Light
Project – The Intensity of Light
Exercise 2 : Higher and lower sensitivity
The first two images were taken with my Ricoh GDR 3 compact camera on a day with an overcast sky. I went to a small shopping centre in a village near to where I live.
No. 1: ISO 200 f/5 at 1/500
No. 2: ISO 800 f/7.1 at 1/1000
At 100% there was obviously much more noise/graininess at ISO 800 particularly on the CCTV cameras; car number plates and the Waitrose sign in the distance. This is a small camera which produces a jpeg at approximately 15” x 11”. Noise would be very noticeable at ISO 800 if the jpeg was expanded.
The next ten photographs were taken with my Canon 500D DSLR, using my 15-85mm EFS lens. Again it was a cloudy day.
No. 3: f/11 ISO 100 at 1/250 – lens at 24mm focal length
No. 4: f/11 ISO 800 at 1/20000
I chose this roundabout because of the mix of dark and light tones and moving cars. At ISO 800 there is very noticeable graininess at 100% but I had to look much harder to see this at 25%. At ISO 100 the shutter speed was still sufficient to freeze the motion of the car but I can see some motion blur on the bonnet.
No. 5: f/11 ISO 100 @ 1/25 lens at 70mm
No. 6: f/11 ISO 800 @ 1/250 lens at 70mm
There seems to be more depth of colour in No. 6 but the foliage in the background looks more blurred and I can see the noise on the road particularly.. The shutter speed of No. 5 is decidedly low for the size of the lens when handheld, which it was.
No. 7: f/11 ISO 100 @1/100 Lens at 63mm
No. 8: f11 ISO 800 @ 1/800 Lens at 63mm
I can’t see a large difference at 100% between the two here
No. 9: f/11 ISO 100 @ 1/100 Lens at 44mm
No. 10: f/11 ISO 80@ 1/800 Lens 44mm
Looking hard, at 100% , I can see that the wording is less clear on No. 10.
No. 11: f/8 ISO 100 @ 1/800 Lens at 19mm
No. 12: f/8 ISO 800 Lens at 19mm
I can’t really see any difference in texture between these two.
Canon DSLR with EF135mm F/2L USM lens
I decided to do something different, and more interesting to me this time. I don’t know why but, even though, we’re told to be as creative as we would like, I always seem to descend into ordinariness when I’m doing these exercises. Maybe I’m hoping that some magic will occur as a result of completing them and what was banal will turn into something beautiful.
I have this new lens (bought via Ebay) which can be wonderfully sharp. However, it’s quite heavy handheld and does not have image stabilization. Both these factors mean that I do have to keep up the shutter speed if I hand-hold but it’s been another technical challenge to me to work out the different combinations of shutter speed, aperture and ISO.
It was a beautiful, sunny day so I thought I’d take the lens a walk along with our two dogs and off we went to the Common. Sun and trees mean shadows and dappled light. Add to that two dogs who have creamy coats and black muzzles and rarely stay still (except with heads down) searching out pine cones, bits of bark and other fascinating objects!
No. 13: f/5 @1/50 ISO 400
Dora standing still! I used evaluative metering, hoping that this would cope the best with the cream, black and brown.The aperture was right but, even though I increased the ISO to 400, the speed was too slow and this shows in her face. There was some improvement through sharpening etc but her face is still slightly blurred.
No. 14: f/3.2 @1/200 ISO 400
I used centre-=weighted metering on Digby. To see if it would cope with the contrasts better than evaluative. Auto exposure mode gave a shutter speed at 1/200 and ISO at 400. On preview I could see flashing on Digby’s coat so I reduced the exposure by -0.33. His head was in shadow so there is less definition but I was able to improve this somewhat in editing.
No. 15: f/2.2 @1/200 ISO 100
Lady in red walking through the dappled light. Auto exposure gave a fast enough speed with a low ISO setting but, again, exposure was reduced by -0.33 to take account of her hair. There was still highlight clipping on her dog though.
A higher ISO setting does lead to marked graininess, even with a small size image, when using a smaller compact camera. On the whole, I need a higher ISO setting to give a suitable shutter speed when I use my 135mm lens hand-held. That applies with dappled light/shade but would be less necessary with a more even brightness.
I need to inject more creativity into my exercises because when I do I feel more pleased with the results.
10th October 2011