Sunday, April 11, 2010

Project 39; Using faster film and higher sensitivity.


Here is a photo taken at iso 100, the second shot is a cropped detail of the blue sky to compare with the second photo taken at high iso.


This photo on the left is taken at iso 1600. The photo on the right is a crop to show detail of the sky. The noise can be seen clearly.






Two shots taken at iso 100 and 400. Both at f11 but to get an average exposure at iso 100 I had to shoot at 1/15th sec and as a result the image shows camera shake.



ISO 1600 ISO 400 ISO 100
F 11 1/50th sec F11 1/6th sec F 4 1/8th sec

The three shots above were taken handheld in low light. In the right hand photo looking at the steps at the back there are signs of camera shake. It may also be poor depth of field. The image is not sharp and there is some cyan fringing near the top.

In the middle shot the steps are reasonably sharp and the depth of field is better. I cannot see evidence of camera shake but I would be surprised if there wasn't any. Again there is a red/cyan fringe near the top. I also cannot see ant noise.

In the left hand shot there is a real noise problem in the shadows of the steps.

This is a series of shots taken in low light at 100 ISO. To achieve the depth of field I wanted I needed to use a small aperture like F14. However the shutter speed needed is 1/20 second. This is obviously too slow for hand held and the second shot shows an enlargement of 1 part of the photo. The blurring from camera shake can be seen here.

This is a little faster at 1/15 second. The enlargement shows that there is less camera shake but now you can see movement for example in the hands of the man standing on the step.

Same here, and again you can see the movement here in this mans foot. I think its important to realise that this effect can be used creatively too and in some situations may be desirable.
Personally speaking when I find myself in low light situations like this one I always push up the ISO. I feel that I would rather have a small amount of noise that can be dealt with post processing than end up with blurred and unsharp picture that are very hard to fix afterwards.

The above photos were taken at ISO 100. The day was dull and rainy and I was surprised at the low lighting levels. It proved impossible to get a photo without camera shake because of the low shutter speed and also the depth of field possible was very shallow.

The above were taken at ISO 800. The depth of field possible was better, F8.0 as opposed to F 5.6. Still movement blur though but now no camera shake.

The above were taken at ISO 1000. Good depth of field, no camera shake but still some movement blur. Very little difference between the shutter speeds possible with ISO 800 and ISO 1000.

Project 38; Measuring the intensity of light.


Here is the graph for an overcast, cloudy day. The month is April. Springtime.
The camera was set at 1/125 sec and iso 100. I used an 18% grey card.
Please excuse the poor graphing. I feel from the experience of recording during a day like this that the lighting is going to be a little unpredictable. Note the double peaks.



So here we have a clear day. More predictable, note the gradual rise then a plateau before the decline. At the moment, the sun is behind a mountain ridge until about 8.45 am and then dips behind another at about 5 pm.

I can imagine how as the seasons progress the sun will rise earlier. the plateau in summer would be longer and the decline more gradual.
In winter it would be the opposite.