Exercise: tungsten and Fluorescent lighting and digital cameras

It seems that the aim of this exercise is to get us to start appreciating the colour of light and learning how to tackle difficult lighting environments where one is faced with different coloured light sources, like daylight and tungsten, for instance.

Before starting this exercise I would like to point out that since 2009 incandescent tungsten lamps have been undergoing a phasing out period and are  now exceptionally rare... you will still find them in homes but less so as more and more homeowners are obliged to use energy saver fluorescent bulbs as substitutes. The photos I took where with fluorescents bulbs but the same principles apply. I have also taken a photo where both light bulbs were being used and it's interesting to see the difference in colour between fluorescent and tungsten bulbs. the fluorescent, as you can see are more turquoise, or blue green biased.

f 7.1; 1/250 ISO800

I did originally compose a still life as suggested making use of internal and external lighting and was going to use a set of 3 images as suggested, but yesterday I was photographing my cousin's sons 3rd birthday party and by chance took a photograph of the entertainer against a window (almost contre jour, but not quite) and because of the heavy snow, it accentuated the different colours between indoor and outside lighting. I have used the same photo here and altered the white balance setting in Lightroom instead. The photo was shot in RAW so effectively it allows me to create 3 different images as though they were taken 3 times at different WB  settings, but this is the same image with the WB changes made Lightroom.

Image 1: WB set manually in camera using a custom setting by taking a photo of a white card:

You can see from the photo that while the camera has adjusted the colour setting of the internal light to give a white light effect, outside everything appears blue, despite the eye registering it as white

Image 2: WB set in LR4 to daylight:

This time round you will notice that while outside appears natural, everything inside has taken on a golden hue

Image 3: WB set to Fluorescent:

This WB setting almost fixes the colour issues but doesn't remove the blue outside.

Image 4:  WB set to Auto

This setting, strangely enough, is no worse than the fluorescent setting and there is little difference between auto and fluorescent! Although I tend to avoid automatic WB  settings clearly in this instance it has worked satisfactorily.

What I chose to do, in this instance was use the custom setting and then in LR4 desaturate the blues to remove the blue from outside, as you can see below. It has left the outside looking desaturated of colour but that's not necessarily bad and avoids what's going on outside competing with the subject for the viewer's attention

In conclusion, relying on the camera's built in WB settings may not always be a bad thing especially in tricky lighting situations where you won't necessarily be able to accurately capture the colour range because the dynamics are too wide for the camera. In these instances, it is still best to use a custom setting but if you have to, using auto WB can still be useful and no worse than one of the other camera settings.

Exercise: Weather and rain

Part 1: Photographing same view in shade and sun

Foliage

f6.3; 1/320; ISO200

 

f7.1; 1/200; ISO200
 





The picture above on the left was taken with the sun behind cloud cover. It was late in the day but because the sun was behind clouds there are few clues within the photo to indicate the time of day. the colours appear dull and listless and despite a wider aperture the photo is not bright relative to the one taken when the sun was out (on the right). The photo on the right was taken about 30 minutes later. Looking at the foliage you can see it is more vibrant and glowing. I had to stop down the aperture and shutter speed setting for the sunlit photo in order to avoid blowing the highlights. Both photos have their merits. it is certainly easier to avoid blowing highlights   (as you will see in the next set) when the light is diffused through the clouds however this does leave the photos feeling dull and lacking in contrast and dynamic range.

 

 

Olive Tree



f6.3; 1/160 ISO 200

f7.1; 1/100; ISO200





This next set is a good example when one can use overcast days to great advantage. The olive tree is growing in a shaded area of the garden (sunlight is only striking the top leaves). The photo on the right's dynamic range  is too much for the camera which cannot compensate for both shadows and highlights. The photo on the left, however, was taken when the sun was behind cloud cover and you can immediately see the difference in the dynamic range... shadows are lighter, whilst highlights are not as bright. the tree is more evenly lit. Again these photos were taken less than 30 minutes apart, yet the presence of cloud cover has produced a completely different and altogether more pleasing photo.

 

Tumbling ruins

f6.3; 1/640; ISO 200

f7.1; 1/320 ISO 200





Again, these two photographs show the difference sunlight has on capturing an image. The one on the right was taken in sunlight which has created harsh shadows but has lit up and brought out the colours in the stone. The one on the left is cooler but it is easier to make out the detail in areas which would be cast into deep shade if the sun were out.

 

 

 

2. Part 2: Overcast days and detail.






Pietralia Sottana: f8; 1/160; ISO100

Hobbit hole: f11; 1/40; ISO100

Etna: f8; 1/500; ISO100

I took all three pictures on the same day. An overcast day which eventually brightened up in the late afternoon. Each in their own right take advantage of shadowless light in different ways:

1. Petralia Sottana: Areas that would ordinarily be cast in deep shadow are clearly visible. Although not identifiable, the sun would have been low on the horizon (winter sun) and to the left of the frame which would have meant that anything that fell to the right of a building would be cast in shadow;
2. Hobbit hole:   The vegetation in this photo is easily distinguishable not only by the colours but also because the diffused light lights up the darker areas and again avoids creating deep shadows, which would otherwise have been present at this time of day;
3. Etna: This photo shows the blue cast that is captured under a cloudy sky, though note the brighter yellow hues from the sun breaking through the clouds and striking Mount Etna.

 

 

3. Rain:

 

f4.0; 1/640; ISO800

Rain! or more precisely a fine misty rain which has produced a photo where visibility is limited to a couple of hundred yards and distant objects blend into each other. The effect has a somewhat ethereal quality.



Judging Colour Temperature (Part 1 and 2)

The aim of this exercise was to get us to start thinking about the white balance (WB) setting on the camera and how this can be used to "colour" the photograph. This is a useful exercise if you shoot predominantly in jpeg format as you let the camera do the work and the thinking at the time of shooting. If, however, you prefer to use RAW files, then it should be noted that white balance settings can be adjusted post shooting at the processing stage. To maximise the learning of this exercise I have accordingly used jpgs taken by the camera (as opposed to my usual habit of shooting RAW)

 

I have combined the 2 parts of the exercise into a combined exercise. The brief was to take initially 3 photos with a WB daylight setting at different times and/or locations: one in full sunlight, one in shade and one at a time of the day when the sun was close to the horizon- I chose sunset). The second part of the exercise was to alter the WB setting to "shade" and then Automatic and then identify and assess the different colour temperatures.

 

As mentioned above, I have combined the 2 parts of the exercise and have arranged the photographs in 3 separate sections: Full sun; shade and sunset. Within in each section the photos will be set out according to their respective WB settings of  custom (my own based on setting the WB using a white card in situ), auto, daylight and shade. I would add that I used spot metering and set the camera's picture style to "portrait" mode. I used a canon 5D mkii and the 100mm L macro lens. I shot in Aperture Priority mode and the settings are set out in each picture.

Full Sunlight





WB: Custom; f 11.0; shutter speed:1/250; ISO 100
I used my own custom setting for the white balance in this shot.  You can see that skin tones appear natural and fairly neutral. I deliberately chose a light terracotta background which easily changes colour to orange or pink depending on the WB setting. In custom mode the background colour is reflected accurately but skin tones appear  less accurate than expected (it seems that they have a yellowish tinge and this may well be due to the colour of the light at the time of day) and perhaps not the most flattering; and due to the time of shooting (around midday) the photo is very contrasty and shadows appear harsh and unflattering. The light also makes it difficult for the subject to keep their eyes fully open.

 

WB: Auto; f 11.0; shutter speed:1/250; ISO 100
Using Auto WB setting in full sunlight has produced a softer picture but the colour rendition is not accurate. Skin tones appear washed out and the background has been rendered less accurately and has taken on a more salmon colour. again due to the time of day the photo has harsh contrasts and the subject's hair colour is subtly different from the custom WB. 

 WB: Daylight; f 11.0; shutter speed: 1/320 ISO 100

The daylight setting has rendered the colours slightly more accurately than Auto WB but they are still biased towards a red/ pinkish hue. Again the hair colour is subtly different from the custom WB setting but the background colour appears the most accurate  in hue, even above the custom WB setting which had rendered tones slightly yellow.

 

 

  

WB: Shade; f11.0; shutter speed: 1/200 ISO 100

The shade setting has created a photograph with the least contrast of the 4 but has given the photograph a distinct orange hue. this can be seen in the skin tones and particularly in the hair as it now appears ginger.

In full sunlight the best setting to use appears to be the camera's daylight setting. even using a custom WB setting has created difficulties with the colours being biased towards yellow. Auto WB is biased towards red and the Shade setting towards orange.

Shade

WB: Shade; f 11.0; shutter speed: 1/20; ISO 100

Colours appear accurate and somewhat richer. Contrast in shade is less pronounced and harsh shadows are minimised.

WB: Daylight;  f 11.0; shutter speed: 1/20; ISO 100

Daylight setting in shade whilst still rendering colours well, tends to  bias towards the red creating an unrealistic pink skin tone.

WB: Auto;  f 11.0; shutter speed: 1/20; ISO 100

similarly to daylight setting in shade, auto WB is biased towards the red end of the spectrum and it too creates unnatural skin tones.   

WB: Custom;  f 11.0; shutter speed: 1/20; ISO 100

On this occasion the custom WB setting has rendered colour much the same as the shade WB setting. colours appear accurate and natural if somewhat less saturated than the shade setting.

Sunset

 

 

WB: Auto; f 11.0; shutter speed: 0.3 sec (hence the blurring) ISO 100

unfortunately this shot suffers from blurring due to camera shake. the shutter speed was too low and whilst the image is accurately exposed it is blurred. Blurring aside the colour rendition of Auto WB can still be assessed.  This set of photographs was taken at sunset  and the colour of light at this time of day is rich in reds and oranges. Nevertheless, the auto WB has not rendered the colours satisfactorily. It is biased towards red (what you would expect at this time of day) but it gives no indication that this is a photo taken at sunset. there is no golden glow and areas in shadow appear unnaturally red and the background is decidedly pink!

WB: custom; f 11.0; shutter speed: 1/6 ISO 100

Of the 4 photographs this appears to be the best setting. The colours appear realistic and natural and there is a definite sense that the photo has been taken at sunset. Skin tones are rich and vibrant and the background is rendered accurately.

 

WB: Daylight; f 11.0; shutter speed 1/6; ISO 100

The daylight WB setting has worked well and there is little difference between this and the custom WB setting except that perhaps the colours do not appear as rich  and highlights are perhaps brighter. Again, skin tones are accurate and the background is the right colour.

WB: Shade; f 11.0; shutter speed: 1/4; ISO 100

The Shade setting at this time of day is almost as inadequate as the auto setting. It does not reproduce the colour at the time of day and as with the auto setting the colours are biased towards red under these lighting conditions (interestingly this is not the case in  the other light conditions where Shade WB setting was biased towards orange). Skin tones appear unnatural and unrealistic in the circumstances. The background whilst not pink is till too salmon compared to how it is rendered by the custom and daylight WB settings.

 

In conclusion then this exercise has made it apparent that  the WB setting of a digital camera is crucial to rendering colours accurately and is one of the factors influencing the subtle messages that you want your photo to make (like mood; ambience and emotion). There is no single setting that will work all the time and it is for this reason that I tend to use a custom setting. However, in the absence of a white (or grey) card as a rule of thumb, the auto WB setting should be avoided and you should take into account the lighting conditions at the time of shooting and choose  the appropriate setting, i.e daylight in daylight shooting irrespective of time of day and  shade WB  in shady conditions.

Chapter 4 Exercise 2 Higher and lower ISO


The objective of this exercise was to get us thinking about using different ISO settings and to consider when it would be appropriate to move away from the usual ISO100 setting. I remember as an 18 year old snapper being fascinated by the Kodak film adverts for different ISO films  and thinking it would liberate me from those dreaded flash guns... ISO 400 was, alas, not enough to avoid flash in night photography! I did however, stumble across ISO1600 in 1994 in Italy and took some amazing shots in the Sistine chapel. These were taken without flash and it was absolutely amazing when I saw them once they had been developed. I also learnt that taking photos outside with such an high ISO led to very grainy pictures lacking in contrast. Here are some of the pictures.

The night photo along with the photos from the Sistine chapel allowed me to take the photos hand held without the use of flash and because thee was no sunlight, the grain usually associated with fast film was almost imperceptible. The daylight photo atop the Cupola tells a different story... it appears washed out, faded and the grain is very evident. Obviously not an ideal combination! Fast forward almost 20 years and we now have high ISO settings at the flick of a switch on our cameras. What hasn't changed though is that the higher the ISO setting, the more you have to compromise in terms of picture quality as image noise is introduced into the image.

For this exercise I took approximately 36 images at different settings (I am only loading a third of them). I decided to use a still life subject  and increase ISO and aperture but maintain the shutter value constant at 1 second. I wanted to use different aperture settings to accentuate depth of field and of course the narrower the aperture, the longer the shutter would have to stay open. By increasing ISO and aperture values  you can gauge how the three values interact and the compromises you have to make depending on what you are trying to achieve. For instance a narrow aperture at say f/11 or f/16 will give the greatest depth of field and maintain sharpness into the photo... but a small aperture also means longer shutter speeds (or higher ISO values) each bringing their own difficulties... long shutter speeds make it impossible to shoot hand held. A tripod is the order of the day. High ISO  however creates noise... which is not quite as romantic as film grain.. in fact colour noise is probably the single most frustrating aspect of a photograph which usually ends up confining the photograph to the "cutting floor".

 

f/4.0: This is a fairly wide aperture setting and as such creates a shallow depth of field. The photos are all focused on the nutmeg and in the f/4.0 sets focus sharpness has already softened by the first orange half and by the second the image is sufficiently blurred to not be able to make out the segments within the orange. You will notice that image noise is very well controlled  even if you view an enlarged section of the wine bottle. As the aperture is wide and the image is well exposed at ISO 100 there is no need to increase ISO to brighten the image. As you can see an increase in ISO by up to 4 stops only brightens the image and even if you only increase the ISO to 200 the image becomes overexposed. In order to maintain the same depth of field I would have to decrease the length of time that the shutter stay open. As ISO is increased progressively by 4 stops, to maintain the same exposure level at this depth of field with increasing ISO settings I would have to decrease the opening times of the shutters from 1 second by a stop for every full stop increase in ISO, i.e. ISO 200 would only need a 0.5 sec shutter speed; ISO 400 would only need 0.25 sec shutter speed; ISO 800 would need 0.125 and  ISO 1600 would need a maximum shutter speed of 0.06 second or 1/10



ISO 100; Shutter speed 1". This photo is well exposed.

ISO 200; Shutter speed 1"

 

 

ISO 800; Shutter speed 1"

 

 

ISO 1600; shutter speed 1"

 

f/11: Aperture settings between f/11 and f/16 are considered the best aperture width for full frame cameras and which point they will capture the greater field of depth within an image before diffraction starts to soften image sharpness and so I decided to use these settings for the still life. In contrast to f/4.0 you will see that f/11 the depth of the focus now included the nutmeg, the  first half orange and the cinnamon stick. The wine bottle and the steel ring however, are not sharply in focus but they are certainly clearer than at f/4.0.  You will also notice that due the decreased size of the aperture letting less light in the image at ISO 100 is very dark. So dark in fact that the gold writing on the bottle cannot be made out so while the image has  a greater depth of sharpness and no discernible image noise it is far too dark and underexposed.  The right exposure only being achieved at about ISO 800 and by which point image noise has started to creep into the image in the form of colour noise that can be seen in the darker shades of the photo like the wine bottle.  The noise is still well controlled but is the black is no longer pure. This noise differs from the noise of fast image film noise which is more of a grain and can add a pleasing effect. This noise however does not have the same effect.



ISO 100; Shutter speed 1"



ISO 200; Shutter speed 1"



ISO 400; Shutter speed 1"

ISO 1600; Shutter speed 1"

f/16: The best  aperture setting for details and depth of sharpness should be a landscape photographers default "go to" setting, certainly if they are using a standard 35mm equivalent DSLR.  But unless you are taking the photo in bright conditions ISO 100 with it's guaranteed of no image noise is useless. The photographs below are yet again staged at progressively higher ISO settings maintaining aperture and shutter values constant. Realistically, the only image that is usable in the set below is the one at ISO 1600 and again, this is far too high an ISO to realistically produce noise free images. Depth of field, however, is phenomenal. Most of the photo has been captured with maximum sharpness and while the noise is well contained, it is still visible in the blacks and detracts from the image.  



ISO 100; Shutter speed 1"

ISO 200; Shutter speed 1"

ISO 400; Shutter speed 1"

ISO 800; Shutter speed 1"

ISO 1600; Shutter speed 1"

Conclusion
Ensuring an image is  well exposed and not unnecessarily distracting the ideal ISO setting to use would be a low ISO setting and a narrow aperture in instances where you want a sharpness throughout the image. This combination, however makes it difficult to take hand held photographs without rendering images useless on the grounds of a lack of sharpness caused by camera shake. Unless you are able to use a tripod the only way around this is to alter the ISO and aperture setting so that hand held shots are taken at a speed fast enough to overcome camera shake. If, on the other hand you wanted to isolate a subject and maintain only the subject in focus then you would aim for a wide aperture and as low an ISO as possible. This combination would facilitate using lower ISO settings because the wider aperture would allow more light to reach the sensor.

Whatever the settings, there arecompromises that you would have to consider and accommodate to the environment that you are photographing in. For instance, if the subject is sporting related and require a fast shutter speed above depth of field you would have to widen the aperture, thereby reducing depth of field and but increasing the amount of light that reaches the sensor and thereby ensuring that the photo remains bright. For a lot of sporting and wildlife photographs a shallow depth of field is ideal in that it will isolate the subject very effectively so this may not be too bad a compromise, whereas increasing ISO will introduce noise to a photograph which will detract rather than enhance the image. What then the lot of  the landscape photographer? A steady hand or a tripod would probably be the best option. If the ultimate goal is to maximise depth of field then aperture needs to remain narrow and ISO should not be taken beyond a setting of 400, possibly 800.

 






Chapter 4: Light

Exercise 1

 

I've uploaded a few bracketed photos along with their final high dynamic range or HDR image to illustrate the difficulties cameras have with dynamic range. the HDR is courtesy of Photoshop as I'e lost my photomatix key.. I have to say Photoshop has come a long way in this regard . Somewhat more realistic and it gives you more 'useable' control over how to manipulate the image... less gaudiness, so to speak. For whatever reason HDR remains an emotive issue. However I do believe it has a place in photography and I suspect that over the coming years the debate will settle down and much like the debate over whether colour photographs could ever be considered art now seems a non sequitor, so too HDR will take it's place in photography as a legitimate processing tool in photo production.

 

The first photo is in the courtyard at the British Museum. this is a composite of 7 exposures (I took one photograph in RAW format and then created 7 DNG images in Photoshop ranging from -3EV to +3EV and combined the 7 images using the Automate function in Photoshop. technically not a bracketing exercise but with similar results. the resulting image has captured the full range of details but this shortcut method is not without pitfalls: because the images combined are artificially created by exploiting the EV tool in Adobe Camera Raw, digital noise can be problematic and this can be seen in the shadows of the windows in the central building. I suspect that if I had contained the process to a maximum of 3or 4 images closer in EV say -1, 0, 1 and 2EV  the total difference in range between them would not have picked up on the noise but it is nevertheless a god example of what can be achieved by combining a number of image of different exposure values.



 

 

The next set of photographs  were taken in Girona in the Cathedral. I used a tripod and took 3 separate photographs using my camera's bracketed exposure function. the images were then combined in Photoshop to produce the top image.  You will see that despite the high ISO, digital noise is well contained and the final image produces a pleasing mixture of lights and darks across a broad range of light. looking at the actual photographs that were taken in situ none of the 3 could be said to provide an accurate reflection of the detail in subject matter. The photograph containing details in the shadows has blown highlights... this is easily seen the histogram where the graph is skewed to the right. the opposite can be said for photograph containing details in the highlights (the dark photograph). That photograph has virtually no detail in the shadows. but the highlights are well defined and not blown. The histogram for that photograph was skewed to the left showing a loss of details in the shadows. The photograph in the middle, whilst capturing a good range of detail, somehow feels flat and still suffers from clipped highlights- the same can not be said of the combined photograph though.. it really does feel like you are there, taking in all the details of the scene.

HDR Composite of chapel in the Cathedral of Girona, Spain 

 

 

f5.6; Shutter 1/13; ISO 3200 EV:-2

f5.6; Shutter 0.3sec, ISO 3200 EV 0

f5.6; Shutter 1.6 sec ISO 3200 EV +2