Thursday, 27 September 2012

Contrast and Shadow fill

Exercise  - 11 photographs

The purpose of this exercise is to show the effect of different reflective surfaces on contrast and shadow fill in an image.

By creating a simple still life and placing a light source to one side and at a 90 degree angle to the camera various types of reflective surfaces are used to fill the shadows. Both shadow and highlights are required in an image to illustrate texture and reveal shape and contour.

Reference image.
No reflector - light source at 90 degrees.
The images below are placed in order of contrast with the highest contrast first.

Black "reflector"
Black reflector - opposite light source.
The image in the series with the highest contrast was taken with a matte black reflector opposite the light source. This has the effect of deepening the shadows by preventing any light being reflected back onto the scene.

White reflector.
White reflector at 3 feet.
With a white reflector placed opposite the light source 3 feet from the object the shadows are lightened when compared to the image with the black reflector. The image below shows the white reflector at 1.5 feet away from the object. Moving the reflector closer has only resulted in a marginal difference in lightening the shadows further.
White reflector at 1.5 feet.
Matt silver reflector
Matt silver reflector
Smooth shiny silver reflector
Smooth shiny silver reflector
Crinkled silver reflector
Crinkled silver reflector
As you would expect the silver reflector does a much better job of filling the shadows with the crinkled silver reflector being the most effective.

Diffused light source
Diffused light source 

In addition to the images showing the effects of various reflectors, diffusing the light source itself can also reduce contrast in an image.

The results are as I expected with the most efficient shadow fill being created by the crinkled silver reflector and the black "reflector" creating the highest contrast.

Whilst working on this exercise I remembered visiting Edward Weston's exhibition in Edinburgh and being amazed at the images on display. His black and white images are a great example of high contrast images and the use of shadow to create depth and form.

 http://www.edward-weston.com/index.htm


Assignment 4 - Thought and Ideas


Finally. My camera has been returned from repair and I can get stuck into assignment 4 properly.

The past few weeks I've been catching up on writing some posts for the exercises already completed for section 4 of my coursework. I love taking pictures. Anything and everything. I can't tell you how much I have missed having my camera.

In it's absence I've been trying to decide what the "object" should be that I need to photograph for this assignment. It's suggested something with colour, shape, form and texture should be used to demonstrate the effects of light and looking at other students work these objects are quite varied. Initially I had thought about using my daughter and took a few speculative photographs to see how this might work out.


Shape.
This is probably the best image in the series. I particularly like how there are still details in the shadow areas which suggests a 3 dimensional shape rather than a 2 dimensional silhouette. I have no experience of using studio lighting and although I had borrowed some professional lights, getting the correct angles and effects was harder on this scale than using a table top set up which is much easier to move around and position correctly. There are a few other images taken in candle light and outdoors which could be improved upon so I haven't completely set aside this as a possibility.

I don't see any point in taking the easy option when completing the assignments but I do have to consider the time constraints here and I certainly don't want to get bogged down by indecision the same way I did with assignment 3 - colour. A still life series would be so much more time efficient but I feel that would be the easier option for me. Do I want to make the compromise? Would I learn as much? Probably not but I fear this time around I will have to settle on the easier option or risk not completing this course. Finding a day when both my daughter and I are free at the same time is proving impossible in the next few weeks. As I am planning on continuing my studies with the OCA People and Places module perhaps portrait photography is something I can concentrate on then. For now I think I have to be realistic and find another suitable subject for the assignment.

Tuesday, 18 September 2012

Shiny Surfaces

Exercise  - 4-10 photographs

Depending on the object being photographed the reflected light will have an effect on the final image. Most surfaces reflect light as a combination of diffuse reflection, where the reflected light is scattered equally in all directions and direct reflection, where the reflected light bounces back at exactly the same angle as it is transmitted. It is important not to confuse diffuse transmission of light and diffuse reflection here.

Diffuse transmission - is diffusing the light source by use of a light tent or other translucent material. This has no effect on whether the reflection is diffuse.
Diffuse reflection - is light reflected from a subject.

Diffuse reflections are the same brightness no matter which angle we view them. Because shiny surfaces like polished metal transmit mainly direct reflection it is very difficult to photograph without seeing the light source as a "hot spot" in the metal. In my limited experience of photographing metal not only can you see the light source but also the entire surrounding area reflected in the surface.

For this exercise a shiny object is photographed from above firstly without any special "equipment" and then using some tracing paper in the shape of a cone and some experimentation in lighting angles to see what effect this can have.

This is the recommended "equipment". A shiny object, in this case an ice cream scoop, scissors, sellotape and some tracing paper.

 
 
You can see from the following reference photograph the common problems of shooting shiny objects.
Photographing a shiny object

The next two images show the use of the cobbled together paper cone which sits around both the object and the camera lens and effect of moving the light source.


Light source closer.
I suppose you could say the resulting images are marginally better with the paper cone, at least the reflection of the surroundings, camera and photographer have been removed. Moving the light source had little effect on the reflection nor did rotating the object. I expect the results would have been better if I had been able to get some proper white tracing paper and not had to use an alternative which has resulted in a colour cast on the images, or perhaps used a shiny object with a textured surface.

I can see in theory how this works but the exercise was a bit of a nightmare. Trying to construct the cone and secure it around the lens and also the object being photographed was really fiddly and time consuming. The tracing paper cone idea does result in less extraneous reflections from the surroundings but doesn't completely remove the view of the lens in the final image. I'm now left wondering how a professional would handle photographing this sort of surface and reminded why I try to avoid them.  

Monday, 17 September 2012

Personal Project.

I Like Your Style - Project

My personal project finally gets off the ground.

Despite still not having my camera returned from repair I have finally managed to add my first image to the personal project I have started alongside and as a continuation of my coursework.

I borrowed a friends camera and wandered around the streets of St Andrews on a mission to find the first image for my "I Like Your Style" project. I plucked up the courage to ask a young lady, who looked amazing, if I could take her picture as part of my coursework. Thankfully she agreed without any hesitation. I had previously set up my camera so that there would be no delay and took just one image.

It was a sunny evening with the sun quite low in the sky which has helped to add a warmth to the image. I used a little fill in flash as we were in the shade despite the sunshine.
 
I admit to feeling very apprehensive about approaching  the young lady but her reaction was delight rather than the suspicion I was expecting.  I remembered to give her a copy of my blog address so that she could see what I was working on but forgot in my haste to escape to ask her name. Luckily she has since contacted me to say how pleased she was at being asked for her picture and provided her details for my "I Like Your Style" page.
 
As a first encounter with photographing strangers in the street it went much better than I expected. I don't expect I will always be so lucky.
 
The points to remember for next time.

What worked well
  • Seize the moment and just ask. I know I'll regret it later if I don't.
  • Have my camera set up and ready to shoot straight away.
  • Remember to carry my camera at all times.

What didn't work so well
  • Try not to rush. Although people may be reluctant to stop because they are busy, once they have agreed remember not to waste the opportunity  - get a good picture and all the information you need. 

Tungsten and Flourescent Lighting - Part 1

Part 1 - Tungsten Lighting

For the first part of this exercise take 3 images composed indoors under tungsten lighting at dusk when the light levels indoors and out are approximately even. Take 1 image with the white balance (WB) set to auto, another at  daylight WB and the third set to tungsten WB. Compare the results.

Comparing the indoor tungsten to the outdoor lighting shows that tungsten lighting produces a warm yellow/orange colouring to a scene. The outdoor lighting appears blue in comparison. All 3 images were taken using spot metering and aperture f/5.6. ISO640 was used to increase the shutter speed and allow the images to be taken handheld.

Image 1 - Tungsten WB
Tungsten WB
The first of these 3 images was taken with the camera WB set to tungsten. Interestingly this recorded the colour temp of 3000 kelvin. This is lower than I expected as I believe tungsten light to be generally regarded as between 3200 and 3400 kelvin. However the scene has recorded much as I remember. The warm yellow colouring indoors created by the artificial light contrasting with the cooler outdoor light. Further reading on the kelvin scale in relation to tungsten lighting indicates that the colour temp of a tungsten light source can be anywhere between 2500k and 3500k depending on the wattage of the light source.

Image 2 - Auto WB
Auto WB
The second image shows an auto WB setting in camera. This recorded a colour temp of 3300 kelvin. Again the auto setting in camera has done a good job and recorded the scene quite accurately. There is only a subtle difference between the two images and I would say either are acceptable.

Image 3 - Daylight WB
Daylight WB
The final image in the series was taken on daylight WB. This recorded a colour temp of 5200 kelvin. This shows a much stronger yellow colour cast resulting in an unnatural colouring of the scene. The added yellow has resulted in the outdoor light moving from a blue tone towards green. If you concentrate on the window frames in the image which are actually white you can see how well the tungsten WB and auto WB in camera has dealt with the light conditions when compared to the daylight WB setting.

The results of this exercise show that both the tungsten and auto WB are fairly close in appearance and in this case either would have been acceptable with the daylight WB being the most inaccurate and giving a yellow/orange colour cast.