Wednesday, 19 September 2007

Workshops Over For Another Year

Well the sun has set on another busy year of workshops and what a fun year it has been making a bunch of new friends from all over Australia and sharing in the passion of Nature Photography. I had a great year leading the groups in some wonderful locations all over South Australia for both private and public groups and I must say it has been great to get out and meet such enthusiastic people, passionate about nature and photography. Thanks again for making my work so fun.

In regards to next years courses we are in the final stages of finalizing the locations and dates at the moment with some courses going to be held interstate for the first time. Looking forward to exploring some great locations and making a bunch of new friends.

If you are interesting in being notified about the new courses then post a comment here with your email address. I won't moderate any comments with email address so don't worry, they won't go public. Otherwise send me an email and I will put you on the list so you are one of the first to know when the dates are set.




Tuesday, 18 September 2007

Sensor Sensitivity or ISO

The last piece in the exposure puzzle is sensitivity or ISO. This is the light gathering potential of the sensor. The higher the ISO set on the camera the less light needed to activate it allowing us to shoot in darker locations or allowing faster shutter speeds. The base ISO is usually 100 or 200, although some cameras will go as low as ISO 50. The sensitivities can be increased to 400, 800, or even 6400 on high-end digital SLRs. When increasing the sensitivity, the output of the sensor is amplified, so less light is needed. Unfortunately that also amplifies the undesired noise. This creates more noise in our images similar to larger grain when shooting faster speed film. It is similar to turning up the volume of a poor quality audio cassette recording. Doing so will not only amplify the music but also the hiss and crackle or background "noise". Improvements in sensor technology are steadily reducing the noise levels at higher ISOs, especially on higher-end cameras. And unlike conventional film cameras which require a change of film roll or the use of multiple bodies, digital cameras allow you to instantly and conveniently change the sensitivity depending on the circumstances. Read more...

Thursday, 13 September 2007

Shutter Speed

Shutterspeed determines how long the film or sensor is exposed to light. This is achieved by a mechanical shutter between the lens and the sensor which opens and closes for a period of time.A shutter speed of 1/60s will expose the sensor for 1/60th of a second.

Shutterspeeds are expressed in fractions of seconds, typically as (approximate) multiples of 1/2, so that each higher shutterspeed halves the exposure by halving the exposure time: 1/2s, 1/4s, 1/8s, 1/15s, 1/30s, 1/60s, 1/125s, 1/250s, 1/500s, etc. Long exposure shutterspeeds are expressed in seconds, e.g. 8s, 4s, 2s, 1s.

The optimal shutterspeed depends on the situation. A general rule of thumb is to shoot with a shutterspeed above the inverse of the focal length (1/focal length eg 1/200 for a 200mm lens) to avoid blurring due to camera shake. Below that speed a tripod or image stabilization is needed. If you want to "freeze" action, e.g. in action photography, you will typically need shutterspeeds of 1/250s or more. But not all action shots need high shutterspeeds. For instance, keeping a bird in flight in the center of the viewfinder by panning your camera at the same speed as the bird allows for lower shutterspeeds and has the benefit of creating a background with a motion blur suggesting movement and speed.

Wednesday, 12 September 2007

Lightroom Rocks

The more I use Lightroom the more I like it. I keep finding new ways to improve my images and speed-up my workflow.

I normally import Raw images using auto tone. I use this as a starting point and if I don't like it I can always hold down the Alt key which turns the Tone heading in the Basic panel into a reset button. Today I found out I don't even need to hold down the Alt key, just double click on any of the headings in the develop panels and it will reset that section of the panel. If it is just one setting I find I don't like I can reset it by double clicking on the slider handle.

Pretty cool, huh!

Photography Terminology Explained

Over the next few weeks I will explain some of the terms often used in photography starting with the basics and getting on to some of the more esoteric terms later on.

Today we will start with exposure. Exposure is the amount of light received by the film or sensor.This
is determined by your aperture, shutter speed and the sensitivity (ISO) of your film or sensor.

The first of these variables is aperture. The aperture refers to the size of the opening in the lens that controls the intensity of the light that hits the sensor and is controlled by a series of overlapping blades that work much like our pupil. It also controls the depth of field.

Successive apertures halve the amount of incoming light. To achieve this, the diaphragm reduces the aperture
diameter by a factor 1.4 (square root of 2) so that the aperture surface is halved each successive step as shown on this diagram.

Because of basic optical principles, the absolute aperture sizes and diameters depend on the focal length. For instance, a 25mm aperture diameter on a 100mm lens has the same effect as a 50mm aperture diameter on a 200mm lens. If you divide the aperture diameter by the focal length, you will arrive at 1/
4 in both cases, independent of the focal length. Expressing apertures as fractions of the focal length is more practical for photographers than using absolute aperture sizes. These "relative apertures" are called f-numbers or f-stops. On the lens barrel, the above 1/4 is written as f/4 or F4 or 1:4.

The next aperture will have a diameter which is 1.4 times smaller, so the f-stop after f/4 will be (f/4 x 1/1.4) or f/5.6. "Stopping down" the lens from f/4 to f/5.6 will halve the amount of incoming light, regardless of the focal length.

It is important to remember that f-numbers are fractions of the focal length, "higher" f-numbers represent smaller apertures.

Tuesday, 11 September 2007

The New Nikons

I have received quite a few emails now regarding my opinion on the new D3 and D300 cameras from Nikon. I haven't had a chance to shoot with one yet so I know about as much as everyone else from reading the info available on the interweb. While I am very interested in both cameras, they both offer some new tools and fixes that are going to revolutionize digital shooting, I won't be able to get my hands on one for a while. As soon as I do I will post a report on the new cameras and some settings to take advantage of all the new features.

Will I rush out and buy one? Well I am super interested in the D300. It incorporates the same 51-area autofocus system, 3-inch (diagonal), 920,000-dot rear LCD, Picture Control options, 14-bit A/D conversion, LiveView, HDMI video out, AF calibration adjustment, UDMA CompactFlash card support, real-time lateral chromatic aberration correction, Active D-Lighting, compatibility with the new WT-4/4A transmitter as the D3. But the full frame (FX) sensor on the D3 leaves me wondering. I loose some length when shooting wildlife and although my 12-24mm DX lens will work on the larger sensor it automatically switches the camera to high speed crop mode. Nikon is offering a new 14-24mm f2.8 lens that looks awesome but it weighs twice as much as the 12-24 and I am all for a light camera bag! Either way these cameras are good news for all digital photographers and will open up a whole new world of photographic possibilities. Oh well time to reaccess what goes in the camera bag.

Gluepot Workshop

Back from another workshop at Gluepot Reserve in The Murray Mallee and what a fun weekend it was. We had a great bunch of folk from all over Australia come down and spend some time at the reserve to get a better handle on their photography and expand their photographic vision.

I had a fantastic time, made a heap of new friends and look forward to catching up sometime in the future.

And the good news is I get to do it all again this weekend! I am back off again this weekend with another booked out workshop, this time concentrating on macro photography. Time to get down and dirty in that beautiful red dirt of the Mallee!

I will be sorting out dates for next years workshops soon so keep an eye out and book early, we have been totally booked out for the spring workshops this year.