Tuesday this week see's a re-cap on Macro and Close-up Photography.
Charlie Bruce will provide a reminder on the different types of equipment available which will be followed by a practical evening to practise, ask questions and get prepared ahead of the closing date for the Macro / Close-up competition approaching.
If you are coming along, remember your camera, tripod, macro gear such as lens, extension tubes, clip on adaptors (don't worry if you don't have any of these) and of course some props. Items with lots of small detail would be best and various scenes will be setup.
Remember flash guns or lights / torches to make sure you can get plenty of light onto your scenes also.
Look forward to seeing everyone and any new members who fancy coming along to see what we are all about!
In part one we covered off the Aperture control and what effect it has on Depth of Field.
In this post we will cover off the effects of the Shutter and ISO adjustment.
In the days of film photography, ISO referred to the speed of the film used. In simple terms, it classified the "sensitivity to light" rating of the film.
With digital photography, it is a common misconception that ISO still refers to sensitivity. Modern sensors are classed as ISO invariant with the ISO control adjusting the level of amplification applied to the electrical signals captured by the camera sensor. The higher the ISO capability of the camera generally means the electronic processing produces less noise which in turn leads to a cleaner image captured during low light photography. Many modern sensors are more than capable of producing excellent images beyond ISO 6400, going back ten years an image above ISO 1600 would almost have been classed as unusable by many.
Most digital cameras start with a base setting of ISO 100 which is designed to emulate the popular ISO 100 film, however modern cameras can sometimes go as low as ISO 50 with mobile devices such as the latest iPhones hitting ISO 20. These are the settings to use when capturing the brightest scenes as it lowers the level of signal amplification of the sensor to its minimum setting. As the amount of available light starts to decrease, increasing the ISO will ramp up the amplification of the signal processing electronics resulting in more of the detail being captured by the sensor becoming visible.
The image below shows the effect of ramping up the ISO, note that to maintain the same exposure the shutter speed has to be doubled with. each doubling of the ISO rating. You can see that by the time you reach ISO 12800, noise is becoming quite visible however the photography will be benefiting from a much higher shutter speed capable of freezing motion much better, hence introducing the important link to understand between ISO and Shutter control.
Put simply, to maintain a controlled depth of field (Aperture fixed in place) in differing lighting conditions you have two choices. Adjust the shutter or adjust the ISO. If you are capturing static objects, you can of course lengthen the shutter time keeping the ISO low, however if you have to photograph fast moving objects you have no choice but to shorten the shutter speed hence increasing the ISO to maintain the same exposure otherwise motion blur will be introduced.
Think of the shutter control as your "amount of motion" control:
From the image above it can clearly be seen that when photographing fast moving subjects, short shutter speeds are essential. Fast moving wildlife will require 1/1000s and greater, whereas landscapes can easily be 1/50 - 1/100.
As a general rule of thumb, if your lens focal length is 30mm, keep the shutter speed quicker than 1/30s to avoid blur due to camera shake. Equally, a 300mm focal length requires 1/300s to avoid blur unless using a tripod or a very steady hand!
The following image ties all 3 controls together into a single chart illustrating the effects of all three controls:
Hopefully now you will have a better understanding of the exposure triangle and which control to adjust to capture the image you are looking for.
Please do not hesitate to ask questions at a club night or drop through a message for further information. Lots of information is available online to help explain things further.
Remember to check out our post on night photography for sample settings and which controls to adjust to get different results.
Following on from the presentation given on Tuesday the 20th of November, the following blog will summarise the content presented including the suggested settings for getting started with the varying types of night photography covered.
As always, if anyone has any questions, please come and see me on a club night or drop me a message and I will be happy to explain further.
Thanks to everyone for coming along and hopefully it will serve as a useful reference ahead of the planned night outs.
The slides as presented are shown below:
The most important lesson for any photographer to learn is mastering the exposure triangle.
Understanding these three elements of control are the building blocks to producing the results you desire and understanding which to adjust to master the conditions you find yourself shooting in.
Aperture (Depth of Field)
Aperture controls the amount of light entering into the camera via the lens. Think of it compared to the Iris and Pupil of the human eye. In low light the iris dilates the pupil to let more more light into the retina, in harsh light it contracts the pupil to a pin hole to restrict the amount of light hitting the retina. The exact same is true of how a lens aperture effects the light hitting the camera sensor.
Aperture is expressed in terms of f-stop, also known as the speed of the lens, f-number or f-ratio. In simple terms, it is the ratio of the systems focal length to the diameter of the entrance pupil. The lower the value of the f-stop, the wider the diaphragm of the lens can open, hence allowing more light to hit the camera sensor. The higher the value of the f-stop, the narrower the diaphragm of the lens, hence allowing less light to hit the camera sensor.
This of course has a secondary effect on the image captured in regards to the depth of objects that are in clear focus vs those out of focus, known as Depth of Field.
Large apertures (small f-number) cause a narrow depth of field where the background can blur beautifully which is excellent for portraiture and wildlife photographs. Small (large f-number) apertures cause a much greater depth of field where objects near and far are in clear focus ideally suited for landscape photography. Mastering the art of controlling depth of field can lead to a large range of creativity in image capture.
The image below illustrates this, firstly showing the effect of a large aperture (f1.4 for example) and the narrow depth of field, the bottom image showing a small aperture (f8 for example) and the large depth of field it generates.
In the next blog post we will cover off shutter speed and ISO.
Tuesday night saw the club host a critique evening. The premise was simple, members could submit up to three images for critique by the panel before opening up to other members for additional comment.
The quality of the images submitted was truly astounding with some amazing images put forward by our newest members in addition to our experienced members. Genres ranging from "commercial", through "street" to "abstract" all featured and I'd like to thank all members for their contributions to making it a great evening.
Special thanks to Coreen for the organisation as always and our panelists, Eilidh and Caroline. Hopefully the comments have helped inspire new ideas and approaches to photography and post-processing techniques.
Next Tuesday sees a talk on night photography, look forward to seeing you there.
Do you have an interest in night photography? It truly is amazing what can be seen in the local area if you allow your eyes to adjust to the darkness and look up on a clear night. North Aberdeenshire is very fortunate to have lots of area with limited light pollution which makes it ideal as a location for venturing out and embracing the darkness, camera in hand.
CraigewanPG will be starting a series of night time excursions for members around the local area, 2 Friday evenings a month will be the aim, of course weather permitting as always. Techniques to be explored will include Astrophotography, Milky Way, Aurora, Light Trails and Light Painting. Perhaps we will have some wire wool spinning also for good measure.
If interested, why not come along and see the club, beginners through to experts welcome. Hopefully these events will be started by the end of November.
Darkness, “I’ve come to talk with you again” !
Welcome to the new public presence for Craigewan Photographic Group.
We are a Camera Club based in and around the Peterhead area, focusing on expanding learning for beginners and experts through to supporting community events wherever possible.
We meet at the Home Economics Department, Peterhead Academy every Tuesday Night at 7pm until the summer break where we run evening activities for practical hands on learning which are open to all. Additionally, during the season we run evening and weekend events focusing on specific topics to give hands on learning opportunities for all members.
Whether you are just getting started with an interest in photography or are a seasoned professional, it would be great to see you come along on a Tuesday night. Get in touch if you would like some more information and come and say Hi!