Blog has been on a bit of a hiatus through other commitments but hopefully is back to being regular now. Our last session was the club Christmas party and a good time and a few quid raised for club coffers means that it was a success. A record was probably set for unflattering-photographs-of-club-members-whilst-sober but it was all in a good cause. Our thanks to Myk for running a very enjoyable evening.
The programme in the new year is full of promise too, underpinning the aim of the club to be one where we learn together rather than one where blokes (it always is blokes) stand around, sucking the air through clenched teeth, fiddling with the string in their cardigan pockets whilst moaning about things not being as they used to be in the good old days.
Like any skill we learn as much, arguably more, by not getting it quite right and keeping a balanced and critical eye. Use the judges’ opinions and try them out. Critique the result for yourself and compare it to your original. Use the clubs internal online presence (sorry members only) to try out others opinions. Use a buddy group, use external sites that offer critiques (thick skin sometimes required). There are lots of options.
Try something new. Christmas is rapidly becoming the one time in the year many photographers decide to try out bokeh. Everything to do with the Christmas Tree lights. Bokeh is an example of making the most out of something you can’t change. In this case, the laws of physics, branch optics.
If you look at the world through your camera phone, most of it is in focus most of the time, even though the lens aperture is usually pretty wide. Think of the situations cameras are used in phones for the most part and keeping things still enough not to blur means a wide aperture is a good idea to keep shutter speeds up. This is because of the depth of field relative to the size of the sensor you are using for capture. Basically F2 on your camera phone is roughly F11 on a full frame (35mm) sensor in terms of depth of field and camera phones use wide angle lenses (compare further). Note that is not an expression of the amount of light transmitted, only the area we find acceptably sharp. It also means, practically, that, mostly, bokeh effects on camera phones are software rather than optically driven. This is by the by for most users.
You can, at least in theory, construct bokeh on any lens (tougher on a fish eye, but possible). The term bokeh is Japanese and an art term for the aesthetic qualities of out of focus light. It can also, given the right context mean senility or mental fuzziness, apparently, but that too is by the by. The keys to successfully taking a bokeh photograph are pretty straight forward. Paying attention to the basics of composition is as important as always. The effect may be out of focus but the subject must be in focus. Maybe obvious, maybe not, but essential nonetheless. Get as close to your subject as possible, framing is important and only having one subject is as important as ever it is.
The largest aperture on your chosen lens is also a given if you want to maximise the effect. Prime lenses are probably better than zooms as they tend to have larger maximum apertures. F2 is more convenient for this than F3.5 which is better than f5.6 in that the depth of field is less for any given sensor size the wider the aperture set at a fixed focal length. But as with everything kit wise the one you’ve got is the best for the job.
The other key is the separation between background and subject (and, of course, having some light in the background!). The larger this gap is the larger the bokeh effect will be. Of course the Christmas tree isn’t likely to have a lot of room behind, nonetheless the effect is still obtainable, though colour balance can be tricky. If you are at macro distances then the effect on the background can still be striking, though of course through a more restricted field of view. That includes the use of lenses and extension tubes, just bear in mind depth of field is extremely shallow.
The shape of the bokeh is determined by the number of leaves that go up to making the iris. Cheaper lenses tend towards having five or six blades to the iris, more expensive lenses 9 or more (and in between). The more blades the more circular the bokeh appears. The other factor is the placement of the blades, straight or rounded making for hard edged or circular smooth points. You pays your money and you takes your choice.
And that is pretty much all there is to it. It can be done indoors and out. It can be done in different light levels. It’s a simple technique that makes the most of a physical necessity. It can be one point or many depending on light source(s). Straight forward and quite striking. Try it.
Club Social with photo-booth and a bokeh table this week, the last of 2016. So we will talk a little bit about Bokeh before completing our examination of light modifiers, in particular the “hard” modifiers (that’s about the quality of the light not the difficulty of use), and wish you all the best till next year.
Bokeh is, I have a lingering suspicion, the best of , if not exactly a bad, then at least, an unavoidable, thing. It is points of light rendered by a lens in the area beyond the zone of acceptable focus. It has, by association, a certain dream like quality. Whether that association with bleary eyes is as the result of a blow to the head, strong liquor, watching too many ’60’s films, recently arising from a deep sleep or a biological need for spectacles I leave to the individual imagination and circumstances. That’s not the sort of explanation I am trying to provide. That’s between you, your conscience and the likelihood of your significant other cracking your alibi.
The shallower the depth of field the greater the area of view that will be out of focus. Bokeh occurs at the point where single light sources lose their shape and become mini suns or circular (sort of) shapes of light. The term is Japanese, meaning blurred or something that approximates to that. It is the product of lens design which in itself is limited by the laws of physics.
That blurred area, behind the subject in focus, is formed by circular pools of light where the light has spread out rather than been brought to focus. The patterns formed are diffraction patterns whose edges assume the shape of the lens aperture in the diaphragm through which they pass.
The shape (and number) of the diaphragm blades will impact in the shape of the blobs in the background. The size and smoothness are regulated by light source, focal length, aperture and the diaphragm and what constitutes “good” bokeh is purely a matter of personal taste.
We started last post to talk about light modifiers, specifically “soft” modifiers. So that leaves the “hard” modifiers. Probably the thing to note first is that hard light is the default with flash/strobes (I am going to use the terms interchangeably). Flash is probably the first port of call for additional and controllable light for most photographers progressing through the hobby. There are a number of pro’s and cons in using it. On camera and off camera flash provide some of the same problems but generally off camera flash, that which uses a separate flash gun, is by far the more flexible option and the one we will be talking about here.
More specifically on camera flash is more likely to deliver red-eye, demonising your subjects, the light is harsh and direct and can only come from the direction of the camera. Built in flash is less powerful than off camera, separate units and you can’t always control the intensity of light you do have manually. That isn’t to say that built in flash doesn’t have its uses, just that those uses are relatively limited compared to the more modifiable off camera varieties.
All flash lighting needs modifying most of the time, and there are four basic types of hard modifiers:
- Reflectors – your common or garden light modifying accessory, bowl shaped, they have a single but important purpose, to cut down light spill – light that spills to the sides of (a bare) bulb in a strobe (not exclusively) and when using umbrellas or grids. Also below.
- Grids – Does what it says on the tin. Black tubes formed in a lattice work they are very effective in stopping scattered light rays coming from the (strobe) bulb, creating a thin, relatively soft beam of light, which arguably puts it into the soft category I know, but I think sits better in this list. The quality of light is determined by the density of the grid (the number of tubes in the grid), while the size of the beam (expressed in degrees) is determined by the thickness of the grid. The grid is regulated by gates acting as barn doors, movable flaps on each side which allow for finer, narrower, beam control.
- Snoot – is a cone which focuses light to create a very harsh, small beam of light. Can be rigid or flexible, allowing for some control.
- Beauty dish – A small reflector, (usually gold, silver, or white) is placed in front of the strobe / flash, while a bowl-shaped reflector is placed around the light source. This creates a very even, hard light with an extremely sharp drop-off. Used almost exclusively in portraiture, it is very useful as a key light.
These are not mutually exclusive pieces of equipment. They can be and should be mixed and matched according to the creative need. They don’t all have to be shop bought, DIY is always an option, but for the bought stuff the guiding principle, generally, is, you get what you pay for, especially when talking about longevity. This in itself can be a function of the frequency and conditions of use, however when starting out, certainly a look round e-bay or other on line shops will throw up some “bargains”. The bargain is what you feel the value of what you have is.
There are three other essential elements, not, I would put forward, necessarily directly under the heading of light modifiers as they don’t work directly on the source. These are: flags, scrims and bounces (reflectors).
- Flags block light. Bought flags tend to be black material, some are paper, stretched over a frame with a small handle to make it easier to place on a stand accurately. Black paper and tape will get you a similar effect to stop a white or light coloured wall from reflecting or for shading specularity in shiny objects. Their primary use is to control light spill and keep down highlights.
- Scrims are panels covered in diffusing cloth, placed where light needs softened locally. You have probably seen them on film and TV sets, spreading tent like over the actors, in order to provide a soft and even light.
- Reflectors, other than the ones that wrap around your light source, a.k.a bounces, or bounce cards, can be anything that will reflect enough light to be useful, but are usually white, silver or gold material stretched out on a frame. You are probably aware of the five sided reflectors that also have a black surface and an opaque white that can be used as a scrim. Mirrors are frequently used, especially small ones on product shots. They are usually a way of lightening shadows created by the key and other lights. The type of material determines the light’s quality and, and intensity is a product of the distance from the subject and the reflectivity of the surface used. The black on a five sided reflector, for instance, is used to reduce the amount of light going into the subject.
And that, as they say in the World of Onions, is Shallot for 2016. Happy New Year.
N E X T M E E T I N G
5th Jan 2017 19:30 – Editing Images: Bring your laptops and challenge your editing skills.
Bokeh is one of those words that have newcomers to photography scratching their heads! Their confusion is made worse by the way that the word is misused by many authors and bloggers who should know better.
The Japanese word “bokeh” is usually pronounced with bo as in bone and ke as in Kenneth, with equal stress on either syllable. It is often defined as the way a lens renders out-of-focus points of light. In general, some lenses render it in a more pleasing way than others.
OK, so what do we mean by “pleasing”? Well, you can easily spot “bad” bokeh. The out-of-focus areas of a picture will have a feeling that could be described as gritty, clumpy or wiry. These areas tend to draw the eye and detract from the picture, especially if they contain bright highlights or are in the foreground. Have a look at this or this. Warning – some of them may hurt the eyes.
“Good” bokeh on the other hand is often described as smooth or creamy. There is little to distract the eye from the parts of the image that are in focus. Out of focus highlights will be rendered smoothly without harsh edges. Often they will be circular, but will sometimes be a polygon whose number of sides depends on the lens diaphragm (frequently seven or nine-sided). Try some random examples – this or this or this.
The real problem with bad bokeh is that once you are aware of it, it draws the eye and can’t be ignored.
How can I get better bokeh?
There are articles and even books that imply that you can control bokeh. You can’t. What you can control is depth of focus, and anyone who has been on the Reflex beginner’s course will know how you can do that:
- Lens aperture
- Distance from the camera to the subject
- Distance from the subject to the background
If you are aware of the rules and are still suffering from bad bokeh, what can you do about it? Use a different lens! There are some well-known rules of thumb:
- Prime lenses usually give better bokeh than zoom lenses. Some zooms are really good for bokeh, but they tend to be large and expensive.
- So called superzooms (with a zoom ratio of 10x or so) will generally have bad bokeh.
- Very wide aperture lenses (e.g. F/1.2) can sometimes render very strange bokeh when wide open. They usually improve when stopped down but that rather destroys the point of them!
- You usually get what you pay for. Cheap primes like the well-known brand 50mm F/1.8 lenses often have poor bokeh. That’s not to say they are not worth buying but it’s worth bearing in mind.
- Mirror lenses have disastrously bad bokeh: highlights are rendered as bright doughnuts!
As always with rules of thumb, there will be exceptions…