TAOP Introduction Exercise 4 – Shutter Speeds

Exercise 4 – Shutter Speeds

I’ve set the camera up on a tripod and selected a small waterfall from a lake overflow sluice. I’ve composed the image to include part of the stream the water falls into as well as the fall itself as I‘ve feel this in an important part of the image to also demonstrate the effects of shutter speed on an image. I’ve set the camera to shutter priority so that aperture will be set by the camera as I slow the shutter speed from a fast starting place of 1/4000 second for the starting image.

I’ve resized all images to 800 pixels along their longest legth to help reduce file sizes being used for these exercises

Image 1 – 1/4000 second

I’m using a Nikon 28-105mm f/3.5-4.5 lens and the widest aperture limit had resulted in an underexposed image since the aperture couldn’t open any wider in response to the very fast shutter speed I’ve set. I’ve adjusted the exposure in Photoshop, as I’ll have to in some of the next images I’ll present in this set. At this speed the speed of the water is effectively frozen, which is apparent in the water droplets caught in mid-air

Image 2 – 1/3200 second

The water in the image is frozen static still at this shutter speed

Image 3 – 1/2000 second

The water in theimage remains frozen static still at this shutter speed

Image 4 – 1/600 second

The water in the image remains frozen still at this shutter speed, water droplets in mid air still appear static

Image 5 – 1/500 second

The water remains frozen still at this shutter speed, water droplets in mid air still appear static

Image 6 – 1/250 second

There is a hint of movement in the water; the water droplets compared to the previous images appear to have changed shape slightly.

Image 7 – 1/160 second

There is slightly more movement in the water at this shutter speed.

Image 8 – 1/60 second

The camera has set the aperture to a smaller size at f/5 to correctly expose the image as the shutter is opened longer. Movement in the image is starting to become more obvious as some water droplets have streaks and the water in the fall is staring to become smoother.

Image 9 – 1/40 second

The camera has amended the exposure again, this time to f/8 letting less light through the smaller aperture to attempt to maintain the correct exposure at the slower shutter speed. Movement in the water now is much greater; water droplets have longer movement trails and the falling water looking even smoother now.

Image 10 – 1/3 second

The aperture is now further reduced to f/25 to counter the longer shutter opening and the water is now beginning to take on a smoother and milky effect, particularly noticeable on the right of the image.

Image 11 – 0.80 second

The aperture again is made smaller at f/29 and the water is now beginning to look over exposed at this shutter speed of 0.80 seconds. The water at the bottom of the fall now appears as a complete blur

Image 12 – 1 second

At an exposure of 1 second the camera is no longer able to reduce the aperture past the lens maximum of f/29 and now the image is starting to become visibly over exposed

Slowest shutter speed before movement is visible

Based upon the images I’ve taken, the shutter speed at which movement becomes visible occurs between Image 5 with a shutter speed at 1/500^th second and Image 6 at 1/250^th second

Exercise Learnings

a)     In shutter priority the camera will automatically set the aperture to attempt to obtain the correct exposure

b)     In addition to learning a) there will be a maximum shutter speed for which the camera is able to select the widest aperture to correctly expose the image as there will also be a minimum shutter speed for which the camera is able to select the narrowest aperture. This will be impacted by lens minimum and maximum apertures, level of lighting in the scene being photographed

c)     Subject to the speed of movement of the subject being photographed, there will be a specific shutter speed for threshold at which movement of the subject can be detected in the image

d)     Creative use of shutter speed can be used when creating images to display movement or even to blur movement

e)     If the image visualised requires such a slow shutter speed that would likely result in an image being over-exposed because the lens is unable to use a narrower aperture then alternate methods could be used to reduce the light reaching the sensor. For example a polarising filter will reduce the amount of light reaching the sensor as can graduated filters or combinations of these. Searching Google reveals that there are lens screw on filters that allow an exposure reduction of up to 10 stops. Using these options, looking at Image 11, I could further increase the shutter speed to allow more movement of the water to be captured without overexposing the final image, as has started to happen in image 12

f)       There will be a link between shutter speed, aperture and filters light blocking abilities (measured as stops and/or 1/3 stops). I have seen in the earlier exercises that creative use of aperture and depth of fields can allow the photographer to direct the image viewer to an element of the photographer’s choosing.  Therefore the photographer through a series of calculations could determine the required light blocking required (measured as stops) should they wish to use a specific aperture and shutter speed combination. This would then determine the number of stops required of the filter, or filters in combination, required to create the image required and also ensure its correctly exposed.

Further Reflections and Experimentation

1. In googleing images of water, waterfalls, rivers, sea and waves etc in many cases there appears as a desire from photographers to capture water movement to the degree that the water appears milky, in effect a greater exaggeration of the images I started to create above using slower shutter speeds. As I found from image 12 onwards, light blocking filters are required to slow the shutter speed further and maintain exposure levels
2. Consider investment and experimentation with filters
3. Identify calculation charts confirming aperture / shutter speed / light stopping filter combinations. For example “Lee’s” filter website confirms shutter speed durations for specific apertures when using its 10 stop filter, known as the Big Stopper
4. This creative use of shutter speeds can also be used for creating movement in clouds and smoothing the effect of bodies of water such as lakes / ponds / seas where it may be impacted by wind and tide etc. This is an interesting area to experiment in.

TAOP Introduction Exercise 3 - Focus at different apertures

Exercise 3 - Focus at different apertures

I'm using a 28-105mm lens which has a minimum aperture of f/3.5
I've used a different set of subjects to the earlier exercise to make it more interesting in terms of images and my learning

Image 1:

I've positioned where I have 4 trees and have ensured the camera is at aperture priority. I've set the aperture to f/4.2 the widest aperture the lens will allow and have focused on the centre tree, the one leaning slightly left to right. The camera has selected 1/30 sec shutter speed, I'm on a tripod so will guarantee a sharper image than hand held

From this image the tree in front and behind the subject tree remain out of sharp focus, so is the foliage in front and behind though I do note the grass level with the tree is also in sharper focus. There is a gap of about 3-4 feet between the trees so clearly the depth of field at this focal length for this aperture is less than 6-8 feet.

Image 2:

I've set the aperture for this second image to f/9 and I note the camera has set a shutter speed of 1/8 second to get the same exposure. This is because the the aperture is now smaller letting in less light so the shutter will now stay open a bit longer to compensate. In this image for first tree, second and third trees are all in focus, as is the foliage between the first and third tree. This now suggests the depth of field at f/9 is at least equal to or greater than 6-8 feet and all 3 trees are in sharper focus, particularly the first and third which were not at the wider aperture. I think the depth of field is actually greater than this since the tree with ivy is now also in sharper focus which is at least 15 feet away. I suspect the depth of field stretches farther back

Image 3:

The aperture for this image is at the maximum of f/29. Whilst the depth of field appears similar to that at f/9 the image is distinctly softer than image 2. I think this is likely a result of using a zoom lens at its maximum aperture where the lens does not perform at its best. performing some on-line research when using a zoom lens lens aberrations can occur at their maximum and minimum apertures are are often best used 1 or 2 stops / aperture setting above / below their maximum to avoid these aberrations and ensure sharper focus for the depth of field required. However I also note that at an aperture of f/29 the camera has set a shutter speed of 1 second. Though the camera is on a tripod the could have been vibration / wind etc which may have contributed also to the softer focus

Exercise Learnings:

a) A wide aperture will give a narrow depth of field. This depth of field appears to be dependent on the focal length of the lens and the distance from subject to camera

b) Using a narrower aperture (larger f number) will require a longer shutter speed to expose the image correctly / the same as if using a wider aperture

c) Creative use of the depth of field (DOF) can be used when creating images, combined with manual focus the element in focus and the DOF can be well controlled (Exercise 2 demonstrated this using a set aperture)

d) DOF calculators can be bought to assist with DOF calculations. This can be very helpful in ensuring the image visualised is that created. I've identified this when looking to check my DOF estimates with actuals.

e) Zoom lenses will not always give the best image results when used at their minimum and maximum apertures

f) longer shutter speeds increase the risk of camera shake. In this instance I should have used a remote shutter release for all images on the tripod but particularly image 3

g) I think I should probably have used a different subject for this exercise to better demonstrate focus with different apertures. However I have learnt / reminded myself about some key aspects (as mentioned in the learnings above) so this exercise has proved valuable to me

The key in progressing through these exercises is not not only to learn aspects of photography but to put them into practise so to assist in creating the final image that one has visualised.



TAOP Introduction Exercise 2 - Focus with a set aperture

Exercise 2 - Focus with a set aperture

As always it pays to think in advance what you want to do and how in advance. Given the weather is hot I've selected bottles of lager as an apt set of subjects. I've lined them up in a row and positioned the tripod at a sharp angle to the row. I've set the camera up in portrait mode and have used a 50mm f1.8 lens. I shot a set of 3 images but in processing realised I had not factored correctly for the light background and dark room, this resulted in foreground correctly exposed and subjects underexposed else subjects correctly exposed and foreground over exposed. 

I decided to shoot in the opposite direction to avoid this issue and reset my subjects. Of course I had predicted this in advance then I could have avoided this error but that's what learning is all about, learn from your mistakes.


Image 1:

I've selected a wide aperture of f/2.2, whilst not its widest it is still wide enough to give a narrow depth of field for each subject, a lager bottle, which I have spaced 6 bottles out at about 3 inches between them. You'll not from my earlier post I realised I could set the same camera position for each subject without moving but could adjust the focus manually to bring each subject I wanted on sharp focus and thus the point of attention. Anything in front of this first bottle would also be out of sharp focus but the viewer would not see this from the image. The bottles behind the first are outside the apertures depth of field when manual focus is targeted at the first bottle. I notice the once the eye reaches the first bottle it tends to ignore those behind.


Image 2:

Adjusting the focus manually I've targeted the middle bottle as the subject of attention. The eye is drawn through the first 2 out of focus bottles to the 3rd bottle where the number "6" is seen as sharp, those immediately in front and behind are blurred and those at each end are blurred. This is because those bottles in front and behind are outside the depth of field for this aperture based upon the distance from camera to subject in focus. I notice here that the eye travels through the first 2 bottles before stopping at the middle bottle; looking at this image the row of bottles also "appears" longer than in image 1, though in reality it is the same distance.


Image 3:

Further adjusting the focus manually to select the last bottle in the row as the subject in focus I note how the eye is drawn through all the bottles. In this image there appears to be movement created in the image and I think this is created by the eye / imagined by the mind due to the blurring effect of those bottles in front.

Preferred Image
I prefer Image 2 since the eye is drawn through the first 2 bottles, it rests on the 3rd in the middle but then the eye moves on to notice those 3 remaining. The key to this for me is that this looks like a longer row of bottles. In addition the image is given depth as the eye moves through the image. The centre placement of focus gives a sense of balance to the image

From a creative perspective, in image 3 had I had a human hand at the end of the row, per my notes for image 3, the dynamic "movement" effect created could have been taken advantage of by giving the appearance of a waiting hand into which a bottle is sliding. Given the bottles are static this is an effect I will remember. 

Exercise leanings:
Elements I've learnt from this exercise:

a) a wide aperture can result in a small depth of field

b) the viewer's eye can be quickly taken to the subject in focus, and therefore exactly what the photographer wants the viewer to take notice of.

c) an image can be given depth by making the eye travel through the image

d) dynamic movement in a static image can be implied, especially if using diagonal lines

e) creative use of aperture and depth of field can give the photographer many creative opportunities in creating images

Of course if I think about this correctly, and I kick myself for not thinking straight away, I realise that I can mount the camera on the tripod to ensure I have a single shooting position, frame to keep all the subjects I want in the frame and then and then use manual focus to select the individual subject I want for the focus of each image.

Thinking about Excercise 2 " Focus" and what I will use as my subjects, bottles, plants, trees, utensils etc. Also if I will use a centre focus area or move the focus points; the latter would allow the camera to rermain fixed if say on the tripod, the former would require a half shutter depression to select the focus point and then a recompose...this may mean I don't get 3 identical frames

TAOP Introduction Exercise 1 - Focal length and angle of view

Exercise 1 - Focal length and angle of view

As my first exercise and given the activities required I've decided to take my position on my front drive and take an image across toward Eastbach Airfield.

This first image I've taken using a 28-105mm zoom lens. I've adjusted the lens focal length so I can get as near to having the image in my view finder that matches that I can see with my eye. This lens is attached to my Nikon D700 camera which is regraded as a full frame camera (full size sensor) as opposed to a crop sensor.

In this exercise I found that a lens focal length of 78mm best matched that of my eye. This image I've converted to a jpeg and resized it with a maximum length of 10 inches ready for my A4 print and resized to around 300kb to help with file downloads when viewing my blog. If anyone is able to recommend anything better that they use then please contact me via the blog, thanks.

Image 1: Focal Length at 78mm so that view finder view matches what my eye would naturally see. I've kept the the 4 foot metal railed fence in the image to give a sense of scale to those viewing my blog and looking at the images

Its a bright sunny day and clearly I've over exposed the sky. This is a great example why landscape photographers will often shoot in the golden hours and dawn and dusk since the sensor is unable to correctly expose both landscape and sky correctly. Having printed. I've printed this off at a4 size and gone back to my spot (advantages of using my drive as the camera position) and held the print. I'm holding this around 10 inches in front of my eyes so that the image on the paper matches that seen by eyes. I'm not sure what this distance means, perhaps its related to the distance between me and the subject of shooting and the focal length of the camera

Whilst the image captures a portion, say centre section of what I can see the camera clearly cant match the total view of what my eyes see, in a single image.

Image 2: Focal length at lens zoom maximum of 105mm

As the lens has "zoomed in" on the hill its clearly made it appear bigger in the frame. I am of course expecting to have to hold the A4 print further away from me so that the print matches the scene from my original camera standing position. Lets see...... well lucky I have long arms and I'm almost at full arms reach at about 20 or so inches holding the A4 print away until the image matches that seen by my eyes. Good job my lens is max'd out at 105mm as my arms would not be long enough to hold the A4 print far enough away for it to match the view my eyes would see.

Image 3: Focal length at lens zoom maximum of 28mm

The image is now at a wider view and I note in this image the sensor is better able to automatically the overall image exposure, which is unsurprising as this and the other images are almost shot into the sun as the shadow from the lamp post suggests the angle of the sun to my position. You will note I have a lens flare in centre top of the image however for this exercise I'm focused entirely on the learning element rather than any clone stamping adjustments. So before I go back out with the A4 print of this image I'm expecting the print to be brought much closer to my eyes....yep its 3-4 inches. With the wider view I can notice when comparing the image to my eyes' view there is a slightly bending of the image. This I know to be convergence of the car's body lines. Not noticeable to the viewer of this blog but it is when comparing my view to that captured by the lens. I also note at this wide view distance of subject has increased and elemnts visible in images 1 & 2, such as the basketball hoop backboard, is now no longer in view

Exercise Learning's
So what have I learnt, key elements as I see and  understand them:

a) a camera sensor using a lens at a focal length matching the view finder subject distance with that my eye sees does not maintain the angle of view my eyes can see. This is often why those great views seen on holidays and tourist destinations cannot be captured the  way we saw them. This can lead to disappointment if this isn't understood in advance

b) Using a longer focal length will result in a narrow field of view; there is also a compression of distance

c) Using a small focal length will result in a wider view, there can be an exaggeration of distance and there can be a creation of converging lines. In my final image the viewer may not see it but in Image 3 but when compared to my eye view line convergence is there along the lines of the car bodies.

d) Shooting into the sun with a wider lens the sensor appears better able to handle the dynamic range however I suspect this is simply down to, in this series of images, less greenery in the final image and less dynamic range that the sensor is attempting to capture. This is proven when view the histogram for each image, the first and second image show right hand highlight clipping, hence the over exposed sky. The 3rd image is able to reflect the light blues my eyes see but were not captured in images 1 & 2

e) Image exposure may need to be adjusted subject to the sensor captured scene based on lens focal length. However for this set of images I've kept it simple to focus on the exercise.

Today I start my first module the Art of Photography and my course work as just arrived. I have had and introductory conversation with my tutor so that he understands my aims, understands my current started and can hopefully better help me improve my photography since this is what this is all about.

I have bought Michael Freemans book "The Photographers Eye" last month which I have been reading. This nicely laid out and enables the points he makes come across well. Having reading through some of the course notes for the module the Art of Photography I can see that these tie in well so I must remember to read both to fully understand the point being made which no doubt will also aid my learning. Great, lets started!