Keith and Joan's Gallery

Perfect exposure

admin — Wed, 28 Dec 2011 00:24:11 +0000

If you have your camera in green auto mode or aperture priority mode, your camera will make a decision about the exposure. Most times it will make a good decision however there are times when the light is tricky and you will want to decide for yourself.

First of all you need to choose a metering mode. This is the number of sensors the camera evaluates to come to a decision. In most DSLR cameras these modes are referred to as Multi-segment, Center-Weighted, and Spot.

Multi segment evaluates the entire scene, Center just the middle and spot just the point you aim at. In good light multi segment is OK most of the time. In some circumstances such as photographing surfers center is best so you get the face properly exposed. But when its dark and the light is highly variable like in a rainforest, you want spot to ensure you properly expose what you are trying to shoot. Rainforest light is very tricky and patches of sunlight breaking through the canopy will render multi segment unusable. Just saying.

Having made your metering mode decision and with your camera in manual mode, set the aperture and use the wheel to dial in exposure. On Sony cams, you compose, hold the shutter half way down, move the wheel until the exposure compensation meter is set to zero. That’s the one with plus and minus numbers and a zero in the middle. And that’s it. Perfect exposure.

The image below is a good example of a situation where highly variable light which would fool a cameras automated metering can be controlled easily using the manual technique described. This scene is evenly exposed and you can even see right into the pool at the bottom of the gully.

This technique may vary with other brands but check it out. On some cameras with a live view, you can see directly on the rear screen the effect of exposure settings. Its a useful technique to know and you’ll wonder why you haven’t done this before.

Click here for more information on exposure and metering.

The digital darkroom 1 – tools for post processing

admin — Thu, 22 Sep 2011 21:58:01 +0000

If you take a lot of images you’ll need to store them, sort them, edit them and have some way to retrieve the better ones when you need them.

This is going to require a computer of course. Setting aside the debate over which platform is “best” I’ll just talk about what works for me which is a PC with a big processor, a fair amount of RAM and a lot of hard disk space. In addition there is a NAS for archiving and two monitors. One monitor is dedicated to editing the other for a full size view of the image. This may seem extreme but is quite useful since I can always see the result of an edit without flicking between windows. The mouse has a variable resolution which makes it suitable for very fine edits. Its a gaming mouse, the fine control is standard on the better ones. “What about video cards?” I hear you ask. Well a fancy video card is not required. The expensive ones for gaming are all aimed at 3d graphics, not for image editing. Nonetheless if you plan to run two monitors, buy a card that supports multiple monitors.

Monitors need to be calibrated to show a true representation of colour for image fidelity. I use a colour target and manually adjust the monitor.The colour target has patches of colour which can be selected in Photoshop to identify how close they are to the true colour. Additionally skin tones and black, white and greyscales can be easily assessed. This is important for me because our prints are done using commercial equipment on professional paper so this ensures that what we see on screen is faithfully reproduced on the final print. If you are using the local mini lab this step is probably not required but if your prints come back with odd colour casts check the monitor.

Software used is Adobe Lightroom which is one of many packages available for image editing. This also catalogs images and maintains a database so if you have thousands of images you can easily find the ones you want so long as you took time to tag them when they were uploaded. Tagging involves adding keywords to describe your images which can be done in bulk with each upload. Its not a big task and should be something you do automatically. The learning curve for a tool like Lightroom requires some commitment but it is powerful and flexible and well worth the investment in time required to learn how to use it. Photoshop is also still used if major edits are required however Lightroom is where the bulk of editing takes place these days.

Lets take another look at image storage and archiving. On the computer Lightroom creates a catalog which is the image database as well as putting all the files neatly in a series of folders. This is great but what it the hard drive fails as they sometimes do? That’s where the NAS (Network Attached Storage) comes in. This is a device attached to the network where copies of the images and the catalog are kept. In case of disaster you can easily restore not just the images but the Lightroom database as well. Because there are many large files a gigabit LAN is in place to ensure file transfer is as fast as possible. It all works well enough but may be too extreme a solution for some folks.

So that’s a quick tour of the tools used for editing and image storage and archiving.

Macro Photography

admin — Mon, 12 Sep 2011 21:58:47 +0000

When the topic of macro photography is raised people often think of close ups of small objects. That’s quite true but macro photography strictly speaking refers to creating images where the subject is @ 1:1 on the film or sensor and this requires specialised equipment to achieve. To do this a macro lens is most commonly employed although extension tubes or diopters can also be used as well with regular lenses. And these days most lenses say “macro” on them somewhere but this refers to their ability to focus up close, not to produce a 1:1 image.

If you look at the image below left you can see the dew drops on the basil flower and the bee has good detail. However when this image is reproduced @ 1:1 (right) you can see clearly the detail of the bees eye. That’s a macro photo compared to a closeup.

The macro lens is typically a fast prime and a highly technical apparatus to use successfully. For a start depth of field is very shallow making a properly focused image had to achieve. Good light is required since as you adjust the lens to increase depth of field shutter speed is diminished and for small insects a high shutter speed is required. Overcoming these limitations requires a tripod and flash. Maybe a macro rail for micro adjustment of the camera position to compensate for shallow depth of field. And lots of patience. The setup below shows the macro lens (note the magnifications annotated on the top of the lens barrel) with the flash and diffuser side mounted. This has proven quite successful for static subjects like flowers and slow moving insects.

White Balance and Color Correction

admin — Sun, 11 Sep 2011 00:58:45 +0000

Digital cameras can sometimes exhibit a colour cast under certain conditions. Specifically shooting in the rainforest will produce images with a pronounced magenta cast as the camera tries to compensate for the light filtered by the trees under the rainforest canopy. In the image below you can see the effect on the right and the corrected image on the left.

Fortunately this is easily fixed in Lightroom or Photoshop so long as you have taken a reference image with a white balance card first. The white balance card is a neutral grey colour which is used to align the rgb components of the image and remove casts. I use a whibal for this purpose. In the image below you can see the magenta cast on my hand. The corrected image on the right has removed the cast and you can see the subtle shift in colour in the background as well.

Rather than explain all about it at length, the links have some good information.

Lighting for headshots

admin — Sat, 10 Sep 2011 22:44:40 +0000

I was asked recently to provide a headshot. No problem just step into my studio – except I don’t have one, what to do? I quickly set up at the kitchen table in front of a glass door looking out into the garden. A couple of issues arise, balancing indoor and outdoor light and not getting a reflection on the glass as well as properly lighting the subject. With an on cam flash options are limited, you will get hard light from the front only, a big reflection on the glass and the background will be quite dark. Using off cam flashes you can control the light giving a much better result.

Here I used two strobes off camera, one with a stofen pointing up and into a corner, the other pointing up at the ceiling from the other side with a small reflector to push some light forward. So point number one, no direct light.

The resulting image is reasonably evenly lit and there is balance in the foreground and background lighting. The glass has a small reflection from outside and if I were paying more attention I might have used a polariser to kill the reflection. Likewise there is a small shadow under the chin which a reflector at the front would have fixed but I’m not going to lose any sleep over that. I’ve used a 70-210 @ f4 at a distance of about 5 metres as well to be sufficiently distant from the shot and subdue the background which is nicely blurred. Had I used a wider angle from closer in the image might not have appeared as evenly lit and you would have seen all the junk on the table in the background quite clearly.

Now the interesting thing about this is how quickly it was to set up and test, maybe 5 minutes. No cables, no umbrellas. I am using Sony gear which inherits Minolta’s cleverness and their wireless flash system is pretty clever. All the flashes were set to wireless and the strobe on the cam was used to trigger them – that’s it. They can be test fired from the camera and the camera took care of ensuring proper exposure – brilliant.

Lens Filters

admin — Fri, 09 Sep 2011 23:48:57 +0000

Filters attach to the front of your lens and modify light entering your camera. The screw in type add some physical protection for the front lens element which is why you might see some folks with a UV filter permanently attached to their lens. Purists say this is not a good idea but personally I’ve not noticed any issues with having UV filters on all my lenses at all times. And certainly replacing a damaged filter is going to be cheaper than replacing a lens.

The filters you might commonly encounter:

UV which reduce haziness and can be left on the lens for protection against scratches and dirt,
circular polariser which cut down glare and can improve colour,
neutral density which decreases the amount of light entering the camera by set amounts. This is useful for creating a longer exposure on a bright day for example.

Another useful type is the split or graduated neutral density filter which is used for balancing the sky and foreground for sunrise/sunset shots. The shot below was used with a graduated neutral density filter to balance the sun and sky with the foreground. The ND grad filter is square and sits in a holder mounted to the lens. This link explains more about ND grads.

When buying filters you need to get them the right size for your camera lens. The lens should have a screw thread on the front and a number identifying the diameter in mm.

My tips:

Buy the best quality filters you can reasonably afford. Some specialist filter brands are insanely expensive so consider the more economical options before you decide if you need the deluxe models.
Buy the thinnest screw in filters you can. Thick filters can vignette or cause darkening around the edge of the image. Thinner filters decrease the likelihood of this happening.
Learn how to properly use your filters. Its easy to overdo the effect with the circular polariser so know how it works and how and when to use it properly.
When mounting a filter run a soft lead pencil around the thread and gently remove screw onto the lens. You might need to remove the filter and clean any debris from the lens and/or filter and refit. This stops the filter sticking to the lens because stuck filters are very hard to remove.

Its all about the light

admin — Wed, 17 Aug 2011 00:15:21 +0000

Experts agree to take really effective images you need to understand and be able to control light. From subtle sunset or sunrise light, to balancing indoor light, capturing captivating landscapes, macro photography, portraits and so on, the one constant element required for great shots is mastery of the light.

Sounds complex and it can be technical but there are a few things to keep in mind.

For ambient low light shots always use a tripod and the 2 second timer on your camera to avoid shaking the camera when exposing the shot. If you have a remote release, use that instead.
For shots outside, aim for soft even light like a lightly shaded position. Use the popup flash but with the flash dialed back to -1.7 ev. This provides a natural fill rather than over exposing with the flash. Check your camera user guide to find out how to do this.
For landscapes, target the time of day when the light is soft and even, sunrise and sunset. You’ll get some interesting colour as well.
If you use the flash a lot, get one or more external flashes. This requires a commitment because they aren’t cheap but will offer different creative opportunities.
Study the use and management of light. It makes all the difference to know how to control it and take advantage of it.

Sandgate at sunset, soft even light, good colour and the angle of the light has lit up the water.

Mt Warning Sunrise. Warm light on the peaks, soft even light in the valley below. The angle of the light is low as the sun pops over the horizon.

Three views of the Kurilpa Bridge on the same day showing the effect of the different light.

Links

Primer on light.

Strobist

Strobist Lighting 101

Taking better people photos

admin — Sun, 17 Jul 2011 22:25:26 +0000

When you take “people photos” there are some simple things you can do that will make better pictures.

My top tips:

Avoid distracting backgrounds. For example, don’t stand in front of windows (especially backlit windows) or busy backgrounds.
Use the flash especially outdoors but don’t have it cranked right up. If you have control over the flash, set it for -1.7 ev outdoors to provide gentle fill since you don’t want your shot to look like you nuked it with artificial light. Consider flash hotspots and reflections also and position accordingly.
Pose your subjects. If you can gently maneuver your subjects into a better pose for a shot you should do so. Tricky sometimes with kids and large groups but generally worth the effort. Formal portraits work better with subjects slightly side on to the camera. See the links below for more information.
Don’t even think about taking pictures of other people’s kids (OPK) without permission from the parents. No good can come from it. Even pictures of something else near OPK can cause a paranoid outraged over protective parent to appear at your side and rant at you. And that’s a bummer.

The image above has a full complement of elements to avoid, distracting background, bad light (strong sun, washed out background), no fill (shadows on the face and lack of detail), shot should have been lower, a little further back and closer to center so those seated were not looking up and moved to a shady area to improve the light. A little more thought might have made this a much better image.

Sometimes though you have to make do with what you have. In the shot above there was only one place to take this shot, shade was uneven and I only had the one small flash. It was a hot day as well and so a long session to get things perfect was out of the question.

Here I had a small room with dark light absorbing walls, a bunch of fellows in party mode so not too much time to work. I had to pile all the furniture in a corner to make room for everyone to fit and then stand on a table to get this one. Even then you can’t quite see everyone.

The links below are about posing for better shots. Kodak provide the user friendly guide and I have also included some more detailed information from a working studio photographer. All are useful techniques to know to improve your people shots. Click about on the linked websites for even more information and be amazed how proper posing can make a real difference.

Click here for some more ideas from Kodak.

More portrait guidelines.

Why Your Camera Lenses Do Matter

admin — Sat, 09 Jul 2011 01:32:17 +0000

Previously I explained why I think having an expensive camera body isn’t necessary. On the other hand, you should buy the best lenses you can afford simply because your lenses will outlast your camera body and can make a big difference to image quality. You will benefit from technology improvements in the camera body as you upgrade and so it just makes sense to be using the best lenses that you can afford and that are aligned with your own shooting requirements from the get go.

First though a primer on lenses. Essentially, there are two main types, prime and zooms. Primes are lenses of a fixed focal length whereas zooms have a variable focal length. Purists prefer primes for a range of reasons, mainly “sharpness” and speed. Here speed refers to the aperture, the ability of the lens to let in light. A fast lens may have an aperture of f2.8 or more (smaller number, bigger hole = more light = faster = bigger aperture). A fast lens can be an asset in low light but then you can nearly always use a flash anyway. Fast primes tend to be specialist tools and can be expensive.

Zooms are a better proposition for enthusiast photographers because you have a range of focal lengths available at your command in a single package. If you can’t get close, zoom in. If you need to shoot a group, go wide. Excellent. However, the zoom lens is not a master of a single focal length like the prime. Also a fast constant aperture zoom is going to be huge and expensive. Chances are you don’t need the deluxe model anyway so don’t worry too much about it.

Specialty macro lenses are typically fast primes that can create an image at up to 1:1 which is to say lifesize on the sensor for detailed closeups. Many modern lenses will say “macro” on them or suggest they have a macro capability. This refers to their ability to focus fairly closely, not their ability to fill an image frame at 1:1. So they may be OK for closeups but not true macro photography, an important distinction.

So what about focal length then? The link has some confusing maths and a technical explanation but in simple terms its the distance expressed in mm from the lens to the sensor plane. The smaller it is the wider the image you can capture. The bigger it is the further you can see. For example a 16mm lens focal length offers wide angle shooting whereas 300mm is a useful telezoom focal length for shoot birds and such. This link shows what the same scene looks like at different focal lengths.

For most of us shooting with APS-C sized sensors in our camera, it’s important to understand a few things. First, APS-C refers to the size of the sensor, 25.1 × 16.7mm which is smaller than a 35mm sensor. Obviously with a smaller frame it fits well inside the image circle of a 35mm lens which is what the lens and camera systems were originally designed for. This leads to the myth of 35mm equivalence in lens descriptions where lets say a lens of 300mm focal length is then said to be the equivalent of 450mm. It’s not. The focal length remains the same but the field of view certainly changes. Again some more complex math in the link, but some useful images as well to help explain. Anyway what this means is when you go to buy a lens, don’t be sucked in to thinking you have greater focal length because of the crop factor. You don’t. A 300mm lens is always going to have a focal length of 300mm, only the field of view changes.

Moving on, lenses come in about 3 grades of quality and performance. First kit lenses. These are the ones supplied with your camera when you buy it. You may get one covering the most useful focal lengths or two which together cover from about 28-300mm. These are usually plastic in construction with simple optical designs. They are not especially fast but for casual photographers are going to be perfectly adequate for most situations. The next step up are lenses which have better construction and superior optical design. They may not be particularly fast but will often suit the discerning enthusiast photographer. Finally there is the professional lens. These are fast, built like tanks to take the hammering of being used all day every day and are big and heavy as a result. They may have many buttons and switches to provide a high level of control. Needless to say they are expensive.

Which should you buy? If you have deep pockets, must have the best and have a strong back then clearly the pro lenses are for you. In some applications such as shooting birds and sport, it makes perfect sense to buy the best lens. However its not essential. My view is that once you understand the limitations of your kit lenses, consider the mid range offerings unless you have an application that absolutely requires a specialist lens. I am using the Sony 16-105 and find it meets my requirements as a useful general purpose lens quite nicely. It is certainly better than the lens it replaced, has a useful range of focal lengths and is small and light making it convenient and unobtrusive to use. I am using the Minolta 100-300 APO for longer focal lengths and it has proven to be an excellent workhorse and again light and unobtrusive. When you travel you will understand why “light and unobtrusive” are significant factors. The APO coatings deal with a problem of cheaper lenses, purple fringing which is the reason I bought it to replace the kit lens. Anyway with just these two lenses the bulk of shooting situations are covered and together these lenses represent an investment of much less than $1000-00. Your requirements may vary, but this mostly works pretty well for me.

Here’s an example of where a better lens might have helped. The osprey below left was a very long way away, the shot is not terribly sharp which is technique more than the lens. A better lens would have allowed me to use a bigger aperture for a faster shutter speed to compensate for poor technique and maybe a sharper pic. Maybe. As it turns out this lens works just fine most of the time. The next step up is a couple of thousand dollars as it happens, not worth it right now for the occasional missed shot.

Some lenses from the film era like Minolta’s Alpha mount lenses will work on DSLR cameras. While image quality can be good under ideal conditions it is worth noting they can come with issues. For example, modern lenses have sophisticated coatings not found on older lenses to combat CA and sensor reflections. Under certain conditions flare, ghosting and purple fringing may be evident, issues much better controlled in modern lenses. So while the old lenses are beautiful to behold and can produce magnificent images, be aware of their potential limitations. On top of this the original AF Minolta lenses have metal bodies making them very heavy and less than ideal for carrying on your back all day. Additionally, older lenses may be infested with fungus which attacks the glass and coatings and can be transferred to other lenses. Buying a lens with fungus is not something you want to have happen to you. Keep these things in mind when you contemplate acquiring an older second hand lens.

Finally, a topic that rages endlessly on internet photography discussions is the subject of sharpness. Unless you have a badly aligned or defective lens ultimate sharpness doesn’t matter which is why I didn’t think it important to discuss. Click here to read more.

Holiday Photography

admin — Sun, 03 Jul 2011 02:26:21 +0000

Journalist Nick Trend has a few words to say about travel photography. Apparently looking through the lens “interrupts the joy of discovery and ruins the moment for other travellers”. Really?

I recall a time a while back at Lady Macquaries Chair in Sydney. A number of photographers were set up there all watching the sunset and waiting for the light to turn. Then a bus load of tourists appeared and like like a flock of seagulls pushed past those already there, took their shots and were gone. Certainly they weren’t there long enough to enjoy the breeze, the boats, the sound and smells of the harbour or anything else that was going on at the time, aspects which for me make photography such an interesting past time.

This is what I saw, but since they were tripping up all over each other and with all the flashes were going off I expect they were surprised to later see only the sea wall, maybe the back of each others heads and not much else.

My tips for travel photography:

Don’t be in a rush, take your time, look for a good aspect and good light if you can. Remember why photography has been called “the art of seeing”.
Do take time to enjoy the experience, especially if its unlikely you’ll get back to the location or event.
If there is something particular that you wish to photograph, make time to do it away from the non photographers if time permits. Everyone wins.
Don’t be a nuisance to others.
Don’t pack the kitchen sink. Taking a portable kit will usually work out better than taking every lens you own.