Guide: About intentional and unintentional blurring

[zoossh]

Please do not post in this thread in order to maintain a clean and efficient platform.

Status: 2009 Jan 03, still editing and re-verifying old information

Summary: About blurring due to motion

1. Camera-Subject motion
1.1 Handshake versus subject motion
1.2 Desired motion versus unwanted motion.
1.3 Intentional subject blurring
1.4 Panning

2. Unintentional blurring
2.1 Unintentional blurring and the reasons to it
2.2 How to deal with unintentional blurring?
2.3 Focusing: Getting the right focus on static frame
2.4 Focusing: Anticipation and planning for dynamic frame
2.5 Avoiding handshake: Increasing stability and handheld techniques
2.6 Avoiding handshake & motion blur: Controlling of shutter duration
2.7 Camera: Vibration reduction mechanisms
2.8 Extra-Camera: Tripod and other tools for establishing firm support


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[zoossh]

1. Camera-Subject motion


1.3 Intentional subject motion blurring

Depending on your desired effects, blurring is not always bad. below is an example of subject motion blur, intended. the girl in the picture is meant to supplement the colors of the background, so in a way, the background becomes the subject, and the subject becomes the background.

1.4 Panning

Panning is a technique that is used to keep the moving subject relatively sharp with the background in motion blur, by following the moving subject with your body & camera via a smooth rotation and steady hand.

This is a reversal of a typical shot of a moving subject.

If the camera remains static, it will capture a static background in focus and sharp, and the moving subject will of course be blurred with its trail captured depending on the shutter duration. If the shutter duration is very short, there will be neglieable movement in the frame to be noticed, as what we call freeze. And if the shutter duration is prolonged to an extent that the movement is noticeable, that is motion blur.

Panning on the other hand, make use of our coordination ability to keep the moving subject constantly at the same location of the frame as we move the camera body. The ability to coordinate the fixation of the subject at the same spot determines the sharpness of the moving subject. The shutter duration also cannot be too long as it will increase the chance of mis-coordination leading to erractic blurring. The concept is similar to handshake. The static background which will not move together with the moving camera, on the other hand, will appear to "move". This is similar to you sitting on the bus, looking at the surroundings out of the window move backwards as the bus move forward.

There is no big secret except practice and talent (some people just have better hands). The only thing is to understand if the subject is moving too fast for you, eg. if the subject moves towards or away from you, it changes size rapidly, and if the subject is very near to you or the focal length is long tele with the subject magnified, any movement of the subject will represent large magnitude of movement caught on the sensor.

Bryan Peterson mentioned in his book that the shutter duration can be set to approximately 1/60 to 1/30 secs. This should give you sufficient control over the sharpness of the moving subject as well as the ability to blur the background. Of course, the same principle applies, the sharpness of the subject depends on the subject's velocity with respect to your position, the magnitude of the subject to the frame which depends on the focal length, and your ability to follow it within an acceptable shutter duration, while the blurring of the background depends on how long the shutter duration is.

Due to the difficulty of shooting something that runs tangential or oblique to you secondary to the fact that the subject changes size, most panning occurs on distant subject that runs coronal to you, mostly horizontally from left to right or right to left, maybe with or without a slope. A vertical shot is less common as anything that drops with gravity at free fall is too fast for us to pan. At closer distances, due to a larger angle of movement, one can possibly capture a curve of the background.

Fish vendors driving around with their loads at Keelung's Kanzihding Fish Market, taken about 3-5m from the vehicle.
11mm (x1.5), ISO 400, f/4.2, 1/4 sec, EV-0, AF-S.

A low ISO will help to reducing the shutter duration in a bright condition. However, it is too bright, and the smallest aperture size is already applied, then a polariser or an ND will be required. A low light condition is usually less of a problem for panning as compared to static shots, because the themes for panning shots usually demands less of the crystal sharp shot of the subject. If one pans smoothly, the subject should be relatively sharp. However, if the shutter duration drops too low despite of the highest possible or acceptable ISO and the largest aperture, then flash may be required.

The purpose of panning is somewhat similar to the purpose of bokeh in narrow DOF. Both emphasize the pattern of the background and isolates the subject, one stressing motion, whereas the other stresses depth. The former produces streaks while the latter produces blobs. As such, having suitable colorful and simple background is common ground to both. A single color background is aesthetically useless for both techniques.

This technique is best done at a later stage, and not for beginners. Too much emphasis made on producing good panning without reflex actions on subject choice, colors and compositions will not give good photos, although when i first took up a course on basic photography, everyone seems so excited about panning.

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[zoossh]

2. Unintentional blurring and dealing with it


2.1 Unintentional blurring and the reasons to it

Blurring is unforunately a very generalised term. Over here, we discussed about unintentional blurring - blurring that can spoil a picture.

A newbie will often ask the same question - why is my pictures blurred? is it becos there is something wrong with my lens and my camera body? would it help for me to upgrade my equipments? well, equipments does help to improve some conditions, but if the bottleneck is not being resolved, those costs does very little help.

These unintentional blurring may be either generalised or focal or even peripheral, and may be perceptional to different people.

The most common reasons are
1. out of focus shorter than the minimal focusing distance
2. wrong focus (unintentional focus)
3. handshake due to techniques or low light/long durations that cannot be coped on handheld
4. unexpected movement of subject (unintentional motion blur)
5. small depth of field (unintentional limited DOF, less often as large aperture lens and macro photography are less used by newbies)

6. lack of contrast*
7. flare or unwanted reflections*
8. harsh flash*
9. blooming*
10. dirt or condensation on lens frontal element or filter*
11. vignetting (unintentional vignetting)*

* factor 6 to 11 are not exactly blurring but may affect either sharpness or clarity, often focally and multi-focally, and may be described as "blurring" by some newbies.

lousy failed pictures served as good teaching material

1.5x 48mm, evaluative metering, ISO 1600, no exposure compensation, aperture priority, f/4.8, 1/5secs

1. the foot shows there is relative sharpness compared to the rest of the pictures, because it is close to the coronal plane of focus (the squatting lady's face) and because the foot being static components on the ground showing no or little movement, appears to be relatively sharp. this illustrate the point that subject movement is just as important as, if not more than, the problem of photographer's handshake. It is however not sharp enough by itself because with low lighting and not using tripod, my handheld ability using 1/5secs at 48mm (x1.5) focal length using the largest aperture size available (f/4.8 at that focal length) and the highest ISO available in my Nikon D50, is still not steady enough to avoid subject movement even in the more static component.

2. the face is where the focus is correctly applied. however, an expected turning movement is too fast for the fastest duration the system gave at that time (without flash). This ruin the picture as the focus on the eyes of a face is the single most important factor to a picture's success.

3. hand (terminal portions of the limbs) movement is an allowed photographic component and may even give a sense of motion. If the face is sharp while the hands in this picture remained in motion blur, this photograph will make it.

4. the blurring (softness) of the people behind is neither that of handshake nor subject movement. it is a natural effect of shallow depth of field. given that the aperture size is pushed to the max to give maximum light capture, the depth of field is relatively shallow but acceptably appropriate. at f/4.8, these people are just less than 10m from the lady squatting down, they are blur enough to bring attention to the lady in the front but still sufficient to show their own forms and activities.

5. timing isn't always a luxury. but if i can afford to wait for the young ladies to turn back and able to catch their side profile while the lady in front remained facing me, it would be great. however, the main thing is that the lady's face in front is simply not sharp, thus a gone case already. and in the end, none of the pictures in this scenario eventually works because struggling with low light without flash means that the fastest light capturing ability of my system has to cope with whatever subject movement can afford me to. in this instance, it didn't give me a chance to. and that's life of a newbie who does not yet use flash - you got to accept that there are some situations that you just cannot get the pictures right.

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[zoossh]

2. Unintentional blurring and dealing with it


2.2 How to deal with unintentional blurring?

First of all, you have to understand what causes the blurring.

If you wanna ask in the forum why is your picture blurred, do 2 things first,
1. show your picture, post it. see this, reply is fast and spot on
2. show your settings.

The most common causes of blurring are already listed above in b).
But broadly categorising, there are mainly 2 reasons.

1. not in focus (usually not/not always dependent on light)
2. insufficient shutter speed (dependent on light)



2.3 Focusing: Getting the right focus on static frame

In order to get the focusing portion right, you need to understand

1. how to get the subject in focus
2. how to get sufficient depth of field


1a. how to get the subject in focus
- have a subject of interest that you are keen to make it sharp
- lock focus on the subject
- view it on your viewfinder to know that the subject is sharp
- remember to on the beeping sound of the focus lock
- fully pressed the shutter release only after you hear the beeping sound
- practise the workflow such as recommended here

1b. if you have difficulty achieving the focus lock, check the following
a. did you set any camera settings that gives shutter release control to other modes, such as the remote?
b. did you set the lens settings that inhibit electronic autofocus connection between lens/body, such as the Nikkor AF D 50mm f/1.8 which have to be set to the largest aperture marking?
c. check online or your manual to see what is your minimum focusing distance. if the minimum focusing distance for your lens is 1m, you must stand at least 1m away from the subject to make the subject able to be focused on.
d. could your camera body or lens be spoilt? change lens to check. or change situation to check.
e. could it the subject is too dark or monotonous, lacking tonal contrast, that the autofocus mechanism cannot find the focus? try manual focus or look at another subject that is at the same distance, lock focus and reframe. As quoted by theRBK, "to get the focus off something at roughly the same distance as the subject is only necessary when a) you can't get a good focus lock on the subject, or b) you are shooting through glass which might affect the focus of the camera...so in these cases, you get the camera to focus at something that is roughly the same distance as your subject, then you shift the camera to your subject..."



2. how to get sufficient depth of field
- in order to get sufficient area to be sharp, this depends on your subject and preference, e.g. for face, at least the eyes and nose must be sharp; for food, at least the the important area in the dish must be sharp; for event, at least the face of 1 person must be sharp.
- one can push the aperture to the largest to achieve the best bokeh, but need to learn from reviewing and experience on how much to cut back to achieve sufficient depth of field, which is achieved by reducing the aperture size.
- consider choosing another angle of shooting to most of the subject at roughly the same distance from you, e.g. going on top of the food to shoot.


for example, this is done at a shallow depth of field at f/2.8, but everything is sharp becos the depth of field required is very small.

Comparatively, food if shot at an angle will have a requirement for a wider depth of field, requiring a smaller aperture. For this picture, only a small area of the food is sharp whereas the rest quickly fade into bokeh. This is suboptimal. A larger area of focus is preferred.

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[zoossh]

2. Unintentional blurring and dealing with it


2.4 Focusing: Anticipation and planning for dynamic frame

Much of the photographic opportunities is by chance, but very often surprise elements turn up some of the best photos. However, in much consistencies, you need to be at the right place at the right time, with the right angle and right preset, becos some of the events are fast moving and disappear by the time you are ready to act on it.

Failure to do so, means either you are not at the location at that time, or if you are there, you are hurried into a situation with a poor composition and blurred due to improper focusing, and lack of time to preset appropriate settings and control your composure to avoid handshake.

Therefore planning where you should stand, how you should position yourself, at what focal length should you frame your picture, at what settings are you going to set your camera at, is another art form by itself. For example, someone shooting a squirrel may have take much effort to camouflage himself at one hidden corner, a wedding photographer securing his position when the champage is to be popped, or an sports photographer anticipating the movement of the athlete. All this takes understanding of your subject, and even static subjects like buildings and scenaries changes with the time of the day, and with seasons. And with this understanding, you will preset your estimated ISO, aperture size and shutter duration, priority mode & metering mode & exposure compensation, as well as focusing mode.

Of note, a key technical factor in shooting with anticipation is pre-setting your focus of a fast moving object. Anticipate where the object is going to be, set your focus and exposure, lock it or set focusing to manual mode, and wait for the subject to turn up at that location. This is important especially when the camera & body is not able to establish auto-focus fast enough to enable shutter release. And if you are doing panning and trust your continuous focusing mode (AF-C) or automatic focusing mode (AF-A), then the preset focus may not be required.

Timing can be based on anticipated moments of activity and subject position, and also by anticipated ambient lighting which can differ from places to places. In Singapore, generally the time between 645 to 745pm is where the colors can transit from bland white/pale blue to dark blue/reddish-brown, with variable colors in between. This varies widely especially at places at the extreme north and south at different seasons - your sunrise may be at 3am or 7am.

Remember one point, many factors make or break a picture. You need to get your subject relatively sharp, that is the first and foremost. Subsequently is the angle of perspective which if exaggerated, cannot be easily replicated by post processing. Next, many things will be affected by the lighting from colors to tones to contrast to exposure to details to zones to shutter duration and resultant duration related matters, hence get the timing right, you won half the battle. I cannot emphasize this part more.

Read this about timing from Ken Rockwell.



2.5 Avoiding handshake: Increasing stability and handheld techniques

with regards to the body
1. broad base with centre of body weight kept low, e.g. one leg forward, one leg back, or kneeling instead of squatting
2. gain support for body by leaning to the body

with regards to the arms
1. keep the arms close at the side of the body, avoid excessive winging while keeping your posture comfortable.
2. gain support for the arms if the body is leaning on a inclination, e.g. bend forward. Do not lean forward without resting for your elbow.

with regards to the face & camera body
1. keep the camera body close to the eyes and the nose.
2. loop the neck strap on the camera body on the arm and pull taut to gain further support.

with regards to breathing
1. control the pace of the breathing, snap on expiration or between breaths

with regards to pressing the shutter release button
1. control pressure, do not jerk
2. use a timer, or cable, or remote, if not handheld

Nikonians have a good reading on it.

There are many ways of handling the tools based on the above concepts.

Joe McNally have also demonstrated a few methods best suited for right hander and left eye focus, which is to say the camera will be nearer to the left shoulder, thereby allowing the elbow to maintain a relatively neutral positions at the side without bending inwards. He took a sideway stance, gain support with the left shoulder, allow a downward directing left elbow and also suggest a double right handed grip. You got to see the video to learn and practise on your own. I tried it out and feel that i got to modify his method for more comfort and stability for myself, but it really works. I find that with two hand handing on the side, i tend to wobble the camera, but instead of wrapping my left hand over my right hand, i put it partially across my right hand while still supporting the base of the lens.



2.6 Avoiding handshake & motion blur: Controlling of shutter duration

The common teaching is to ensure that the shutter duration does not exceed your handheld ability to avoid handshake. And this ability changes with the situation. You may be able to hold it steadily at 1/8 seconds, but not necessarily so when you have to hold it vertically. Or that you may do it well at standing, but when you squat or kneel and bend down, you may not be able to handle 1/30 seconds well. Or do it after jogging for a 100m, perhaps not so well too. It also depend on whether you are holding a light short lens or a heavy long lens. So afterall, the shutter duration depends as much as your varying handheld ability.

Assuming a consistent handheld ability of a common man, and assuming the similar conversion factor of 1.5 to 1.6 for most DSLR sensors, a general shutter duration guideline on shooting a static object, would be dependent on the focal length.

shutter duration < 1/focal length
If shooting at 200mm, aim to have 1/250 seconds or faster.
If shooting at 10mm, aim to have 1/15 seconds or faster.

The assumption made is of a common man, so some people will cope better than the above rule, whereas some will not. The conversion factor for some smaller sensors may also be larger, thereby amplifying the effect of handshake requiring a faster shutter duration. And of cos, if your subject is an animal or a human being, he may move, at various speed, hence the shutter duration may or may not be able to fixate into a static image. Hence the above rule should only be used as a general guideline and further adapted based on personal experience.

Fair handheld techniques is required to reproduce the above guideline. Good handheld techniques, good monopod techniques and the use of VR will help to push the limit a bit. Tripod will push the limit significantly. And tripod with good tripod techniques will push the limit by a lot, and equipped with cable release or remote control to reduce or eliminate the shake caused by shutter release button almost complete it. Perhaps the last part is mirror lockup.

As far as the shutter duration control, it can be done on PASM modes to various degree. Either you alter the aperture, ISO and EV on programmed or AP mode while observing the resultant shutter duration to be appropriate, or you switch to SP and manual to have active control of the shutter duration.



2.7 Camera: Vibration reduction mechanisms

Manufacturers have designed some physical mechanism within the camera body and the lens to allow the image to be focused more correctly onto the sensor with the effect of the handshake reduced. These various mechanisms only help to decrease the handshake effect to a certain magnitude, and if handshake is bad, the blurring will still be present and evident, but less.

They comes in different names.

VR: Nikon Vibration Reduction
IS: Canon Image Stabilisation
SSS: Sony Super Steady Shot
OS: Sigma Optical Stabilizer
SR: Pentax Shake Reduction

Of all, my personal favorite term is VR, not because i uses nikon, but the term describe the mechanism most directly aptly. Of all, I find SSS most awkward and corny. But what i didn't like is each brand comes up with different terms that meant the same thing.

Not everyone will find the effect evident, especially when their handshake is severe or that the shutter duration they take is often too long for the vibration reduction mechanism to work effectively. When users find that their pictures are variably blurred still, that does not mean that the VR is not working, more often it is because handshake is a variable thing in some people, and sometimes they can handle may a 1/15 and sometimes they cannot, and different times, different focal length may be within or outside of their handheld ability with or without VR.

Moreover, the vibration reduction mechanism works only for a few stops and is only meant to complement good handheld technique and monopod use and definitely cannot replace the use of tripod.

By the way, some compact manufacturers have used higher ISO settings to pass off as "image stabilization" mechanism. Here's an article from dpreview on this issue.

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[zoossh]

2. Unintentional blurring and dealing with it


2.8 Extra-Camera: Tripod and other tools for establishing firm support


Purpose of using extra support
The main purpose of using extra support is to replace our hand, arm and body as a platform, and to reduce the likelihood of handshake.

Depending on the lighting condition and the resultant shutter duration, the degree of support needed may increase or decrease. Before consideration of any external support equipments, one should understand his or her own photographic habits first, that means what lens and what focal length you tend to shoot, what aperture and ISO do you set for various situations, what is the resultant shutter duration that you tend to get difficulty handling handshake. Then after that, one can consider what kind of external support he or she needs.

Tripod v.s. handheld
azone

One advantage of using tripod is you have the luxury to use lower ISO settings. One advantage of handholding is you have the flexibity of speed and composition.

When do you consider using a tripod?
The problem with using tripods is that it is definitely heavy, and requires time to set up, hence limiting mobility and increasing time to set up, interfering with your attention using your eyes to visualise and worst of all, missing the fleeting moments. Hence tripods are basically meant for static, e.g. landscape/achitecture/still life or anticipated movements. It is used in very low light situations where shutter duration is long out of no choice, or whenever shutter duration is deliberately made long to smooth out waterfall and coastal shots, or to catch star trails or light trails.

The advantage of tripod over the monopod, gorillapod
1. provides more stability

The advantage of tripod over monopod
2. allows hand free control of the camera

The advantage of tripod over gorillapod, bean bag, mini tripod
3. provides a raised platform to our eye level and does not require any poles or fences

In terms of weight and ease of use, the others win tripod flat down, but when it comes to very low light situations, all except bean bag would not be able to achieve the kind of stability a tripod can potentially achieve. However, bean bag requires a raised platform, and requires beans or sand to fill it up esp if you do not carry them around.

Ken Rockwell propose avoid using tripod except for "at night or when you need long shutter speeds of about 1/60 or slower."


Tips in using tripods include
1. use a shorter height as much as possible and comfortable
2. avoid using the central rod if possible
3. extend the thicker upper segments first
4. use extra weight to increase stability if you dun find it troublesome
5. secure the tripod on hard stable grounds
6. watch out for tripod leg and shadow affecting your shot esp in ultra wide angles


Things to look out for when choosing tripods

1. judge by weight v.s. price, with resultant stability and value for money
- remember dun ask for recommendations for something steady, light and cheap: you can only get 2 out of 3 at most.
- weight required to support your setup depends on the situation you are in. choose something heavier if you are likely to be in crowded places with little bumps or in windy places, choose something lighter if you are always in non windy situations on concrete ground. manufacturer may provide estimations for maximum load, but the most reliable means is to bring your camera with your heaviest longest lens at your longest focal length, and try it out, making allowances depending on what you are likely to upgrade to. stability can't be asked, it is highly subjective.
- consider how heavy you can carry. for most common people, anything more than 2kg is heavy, and depending on build and fitness, any tripod of varying weight can be heavy after prolonged carrying.
- material of light weight tripods are usually carbon fiber (CF: not compact flash in this instance) or mag fiber (MF).
- for a decently good tripod, budget is from $300 above. for a decent tripod, about $100-$300. for a cheap tripod, $30-$100 will do.

2. note the segments, minimum length, and maximum height with and without central rod extension
- usually tripods can be kept to 3-4 segments,
- the lesser the segments, the more stable it is and it is also more easy to keep,
- but the lesser the segments, the longer it is when kept, and depending on how you carry your tripod, it can be troublesome to keep in your bag
- the maximum height with and without the central rod, determines on how comfortable you set your eye level at.

3. check the tip and the locking part of the legs
- to see if the tip of the legs are steady on the grounds
- to see if it is easy to lock and unlock the segments.

4. check the angle the legs can open till and the resultant lowest height it can get down to
- especially if you want to achieve a low angle shot on tripod.

5. do note that the tripod head may or may not be included. usually most come separately except for the cheaper ones, just like DSLR body and lens, so that you can get the best for both. do note that in order to attach the tripod head to the tripod body, the screw size should be compatible. most are 3/8", such as my manfrotto and gitzo. some others such as PPCP have another size. do check it out.

6. again asking about recommendations?
- well typical advice is to get a gitzo or manfrotto if you can afford
- for others, consider slik, giottos and feisol
- a locally brought in brand (design not known to belong to which country), PPCP, is affordable <$200 and have relatively good review.



Other modes

Monopod gives much more flexibility and can be used to aid lower light situations on the street.
How to use the monopod and a discussion on it.

Clockunder
Why do you want to use a monopod instead of a tripod?

Monopod is most useful for covering events where it's a little crowded and you're using a heavy lens or when you need to trek a lot (such as in the jungle or mountains) where weight is a major consideration..... Why are you thinking of getting a monopod? A monopod may not solve the problem which causes you to think about getting one.

Mini tripods (table top types) and gorillapod are smaller tripods that is used for compacts and require a raised platform to be put on to reach eye level. Google for more information. There is a gorillapod discussion - go to the product listing and search in cs for more discussion.

Bean bags are good and compact, if you do have things to fill them up with. This is commonly used in wide life shoots to help stabilise the camera in the hides. It can be adapted for other uses, provided you can find a raised platform to reach your desired angle.

Neck strap does not gives a hand free control, but it aids in securing your stance. Try to taut it around your elbow. I will see if i can find a picture to link here.

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