Saturday, 28 April 2012

An evening with Lee Miller

What a fantastic evening was had at the Bognor Regis camera club last Thursday. The invited speaker was Antony Penrose, son of the late Lee Miller and Roland Penrose. The talk centred around Lee's life and work, and what a life it was!

Antony's talk gave invaluable 'behind the scenes' information  which really helped to put the images into context. We learnt why Lee's career changed from model for vogue to photographer, about her move to Paris and involvement with Man Ray and the surrealist movement. We learnt about the discovery of 'solarisation' and then followed Lee from D Day to the liberation of the concentration camps, stopping of at Hitler's apartment on the way.

The evening included information about the Lee Miller archive and the steps taken to preserve her work and make it available for exhibitions around the world. 

But the final cherry on the cake was having my book 'The lives of Lee Miller', which accompanied the talk, signed by Antony Penrose!

Saturday, 21 April 2012

Scene dynamic range

When referring to dynamic range in a picture we are talking about the number of F stops between the darkest area and brightest highlight. If a scene we wish to capture exceeds the dynamic range of our camera we have to make a decision. Do we lose detail in the shadows or the highlights?

I have captured five scenes, each with different lighting and measured the brightest and darkest areas. These are shown on the sketch that accompanies each image.

Image 1. The park. F8 @ 1/80, 100 ISO, 50mm.
My notebook with the darkest and lightest metered values shown.
Image 1 (above).
The lighting for this shot was a clear bright day late afternoon about 4 o'clock. The shot was taken in the open although there are shadows from surrounding trees across the path.  The darkest area is the patch roughly in the centre of the picture. This metered at 1/15 @ F8. The lightest part is the sky in the top left. This metered at 1/800 @ F8. This is a 5 and 2/3's stop range. I have my camera set at 1/3 stop intervals. I would rate this as a fairly average dynamic range.

Image 2.
For this image I wanted to work with low contrasts. I set up a still life consisting of some glass vases which were placed on a piece of silver coloured card. I set this up in my conservatory which has a plastic roof and provides a very diffused lighting. The set-up was shot on a sunny day around mid day. The camera was tripod mounted.

Image 2, Glass. F11 @ 1/60, 100 ISO. 105mm.
The darkest and lightest areas.
I metered using the camera meter set to evaluative metering for the shot and changed to spot metering to measure the bright and dark areas. In this image there are not really any clearly defined highlights or dark areas. After metering several darker patches, I ended up using a reading from the middle of the frame for a highlight and from the dark edge of the right hand vase for the darkest area. The measurements were 1/80 @ F11 for the brightest part and 1/50 @ F11 for the darkest. The exposure range for this set-up is a mere 2/3 of a stop.

Friday, 6 April 2012

My camera's dynamic range

In this scene I have set up a shot where the camera is just short of highlight clipping on the white card. I have used evaluative metering to measure the whole scene. This has resulted in a somewhat darker scene than I would normally shoot.

Scene as shot. F22 1/125 Evaluative metering.

After taking the picture I measured exposure at various points. When using spot metering the card came in at 1/100 @ F22. The small difference could be the brightness of the sun changing between shooting the scene and measuring or due to the change in metering systems.

I picked several different points on the car based on how bright they appeared to the eye. The darkest area was the gap between the tyre and the wheel arch which measured 4 seconds at F22. The brightest part (after the card) was a patch of light on the reflective hub cap.

Exposure measurements taken at various points.
The total range from darkest to lightest runs from 4 seconds at F22 to 1/100 of a second at F22 - a range of 8 2/3 stops.

Below we can see what the darkest area of the image looks like if we ramp up the exposure. Digital noise is making it difficult to see the detail in the darkest area of the wheel arch (below).

Exposure ramped up to show digital noise competing with detail.
This exercise would suggest that my camera has a range of approximately 8 2/3 stops, although you could argue that it is slightly less as the darkest point is very noisy.