Beginner Tutorial – Aperture

I’d like to kick off with one of the more confusing components of any digital SLR camera, aperture. Aperture isn’t even really a feature of the camera: it’s a feature of the lens. It is a measurement of the opening in the lens. This opening allows light to pass through the lens – that light eventually strikes the digital sensor, which then captures an image. The aperture of a lens is never completely closed: it is always either narrow or wide open. Furthermore, aperture is a variable setting that can be adjusted by the photographer.

Back in the good old days of manual film SLR cameras, aperture was always set by turning a ring on the lens (right where it attached to the camera). Today, this mechanical system has been replaced with an electronic one.Many modern digital SLR lenses no longer include an aperture ring. This is because with a digital SLR, you set the aperture using the camera body: electronic contacts allow the camera to communicate with the lens so when you select an aperture on the camera, it adjusts the lens aperture accordingly.

If you do happen to have an older film lens that is compatible with your digital SLR, you will have to lock the aperture ring on the lens (this is often done by turning the ring to the narrowest lens aperture). Once the aperture ring is locked, then the camera will be able to communicate properly with the lens.

Now for the fun part: the aperture numbers themselves. Part of the fun is that in order for them to make sense, you have to think of aperture numbers as fractions, even though they aren’t displayed that way. Here’s why: the larger the aperture number, the smaller the opening in the lens. Aperture numbers follow a pretty typical scale, and you can always tell when an aperture number is being referenced because it starts with “f/”. The aperture scale goes something like this:

f/2.8, f/4.0, f/5.6, f/8, f/11, f/16, f/22

From left to right, the opening in the lens is getting progressively smaller. An aperture of f/2.8 means the lens is wide open, while at f/22 it is quite narrow. This is why thinking about apertures as fractional numbers might help (unless you’re really bad with fractions). For example, if you compared the fractions 1/4 and 1/22, 1/4 is the larger of the two and therefore represents a larger opening of the lens. This is enough aperture numerology for now. In the next post, I’ll tackle the issue of stops of light and will describe how the standard aperture scale can be broken down further.

By kind permission of Chris Roberts of

http://www.digital-slr-guide.com/

Beginner Tutorial – Aperture and Stops of Light

In the last post, I provided an introduction to aperture.

Here’s a quick summary of that information:

  • Aperture indicates whether the opening in your lens is wide open or narrow
  • Your digital SLR communicates with the lens via electronic contacts
  • You can control the width of the opening by changing the aperture setting from the camera
  • A small aperture number (2.8) represents a WIDE opening in the lens
  • A large aperture number (22) represents a NARROW opening in the lens
  • Aperture numbers follow a standard scale called f-stops.

The aperture f-stop scale looks like this:

f/2.8, f/4.0, f/5.6, f/8, f/11, f/16, f/22

Now, this particular scale shows each aperture number changing by something called a full stop of light. When the aperture changes by a full stop, the amount of light landing on the camera’s sensor is either doubled or halved.

Example:

  • f/2.8 lets in twice as much light as f/4.0
  • f/4.0 lets in half as much light as f/2.8

Once you realize that the lens aperture can be changed by full stops, a question arises: what about half stops? Yes, aperture numbers can also be broken down into a half-stop scale:

f/2.8, f/3.5, f/4.0, f/4.5, f/5.6, f/6.7, f/8.0, f/9.5, f/11, f/13, f/16

While a simple half-stop scale might make the most sense, most digital SLR cameras are actually set up by default to change aperture in third-stop increments:

f/2.8, f/3.2, f/3.5, f/4.0, f/4.5, f/5.0, f/5.6, f/6.3, f/7.1, f/8.0, f/9.0, f/10, f/11, f/13, f/14, f/16

Let’s take a quick break from the numbers and talk about HOW you actually change the lens aperture using a digital SLR camera.

  • First, you have to set the camera in a mode that allows you to change aperture – a good one to start with is “Aperture Priority” mode (often marked as “A” or “Av”)
  • In order to change the aperture value, you have to spin the main command dial which is located near the shutter release under your index finger

All main command dials don’t just spin freely: they “click”. Let’s say that your digital SLR is one of the many where aperture numbers are broken down into third-stops. Let’s also say that currently your aperture is set to f/8.0. Now, if you want to OPEN the lens by a full stop, you click the main command dial three times in one direction to go from f/8.0 to f/5.6. If you want to NARROW the aperture back down to f/8.0, you click the main command dial three times in the opposite direction.

The reason that you have to click three times is because of the third stops.

  • f/8.0 to f/7.1 = +1/3 stop of light
  • f/8.0 to f/6.3 = +2/3 stop of light
  • f/8.0 to f/5.6 = +1 full stop of light
  • f/5.6 to f/6.3 = -1/3 stop of light
  • f/5.6 to f/7.1 = -2/3 stop of light
  • f/5.6 to f/8.0 = -1 full stop of light

Before we wrap things up on aperture control, a word about customization: the factory default setting for most digital SLR cameras is to use a third-stop aperture scale. However, some cameras allow you to customize the scale and change from third-stops to half-stops if you so desire. Both work equally well, the third stop scale just provides you with a slightly finer level of aperture control.

By kind permission of Chris Roberts of

www.digital-slr-guide.com

Beginner Tutorial – Maximum Lens Aperture

In the past two posts, I’ve been talking about aperture, and how you’re able to control this setting on your digital SLR camera.

Here’s the high-level overview of aperture:

  • Aperture indicates whether the opening in your lens is wide open or narrow
  • Your digital SLR communicates with the lens via electronic contacts
  • You can control the width of the opening by changing the aperture setting from the camera
  • A small aperture number (2.8) represents a WIDE opening in the lens
  • A large aperture number (22) represents a NARROW opening in the lens
  • Aperture numbers follow a standard scale called f-stops
  • Changing an aperture value by a full stop either doubles or halves the amount of light passing through the lens
  • Aperture values can be changed in either half stop or third stop increments

Here’s the standard set of aperture numbers:

f/2.8, f/4.0, f/5.6, f/8, f/11, f/16, f/22

In this post I’m not going to go into as much detail about the aperture setting itself (that’s been pretty well covered) but instead I’ll explain why all lenses are not created equal, and how aperture comes into play.

There are two key points about lenses that are required to begin with:

  1. Virtually all lenses can be set to the same narrow aperture (f/36)
  2. Not all lenses can be set to the same wide aperture

When it comes to lenses, this second point is a limitation of some lenses and this limitation has a name: maximum aperture.

Let’s compare two lenses that are equivalent when it comes to focal length: both are 18-55mm zooms. Let’s say that lens A has a maximum aperture of f/4 while lens B has a maximum aperture of f/2.8. Now, BOTH lenses can be set to narrow apertures (anything between f/4 and f/36), but the f/2.8 lens can open up much wider than the f/4 lens. In fact, the lens with the f/2.8 maximum aperture can let in twice as much light as the lens with the f/4 maximum aperture.

The practical take-away here is that if you tend to enjoy taking photos in REALLY dim light (cloudy days, building interiors, etc.) then you’ll want to look for a lens with a very wide maximum aperture.

The most common aperture numbers that you’ll see on kit lenses are f/3.5 and f/5.6. The reason that there are two numbers is because the maximum aperture CHANGES depending upon the focal length of the lens. At 18mm the maximum aperture of a kit lens is a wide f/3.5, but if you zoom to 55mm that maximum aperture narrows down to f/5.6.

Now that you’ve got a better understanding of maximum aperture, let’s discuss why using the maximum aperture isn’t always such a good idea.

When it comes to image sharpness, lenses don’t perform as well at extreme apertures as they do with apertures in the middle of the range. Example: a 50mm lens set to f/2.8 or set to f/36 won’t capture images that are nearly a sharp as when you use apertures f/8 and f/11. Now, some lenses are better than others at maintaining sharpness throughout the entire aperture range – this is why they cost well over $1,000 USD.

For anyone who doesn’t have this type of budget for lenses, you’ll just have to live with the fact that your lens probably won’t be ultra-sharp at very wide and very narrow apertures. If you take photos with plenty of light, then you won’t have any problem using apertures between f/8 and f/16 all the time. However, if you enjoy taking shots in dim light, you’ll often find yourself using the maximum aperture of your lens.

When shots don’t turn out quite as sharp as you hoped for, maximum aperture can be one of the culprits.

By kind permission of Chris Roberts of

http://www.digital-slr-guide.com/

WCC Attendees Meet Members of Ivanhoe Photographic Society at Phillip Island Seminar

WCC members, Pete & Jill Myers, Vicki Moritz & Dave Sumner met up with Ivanhoe Photographic Society members Dianne, Jolanta, Cindy, Bernie & Barbara at the Phillip Island Camera Club’s Image Evaluation Seminar’s evening meal.

A great evening was had discussing clubs, memberships and what clubs should offer for their members.

As the evening went on it became more apparent that the Ivanhoe club was very similar in size to WCC. They were in the same position as WCC 18 months ago. They told us that although they had a great beginners course which was open to the public, the retention rate of converting students to members was very poor. We discussed newsletters and member communication, and of course with the help of modern technology such as the iPhone, WCC was able to not only show them our Blog and Galleries, we were also able to post this article whilst talking with them.

We showed them the monthly galleries, the critique gallery and the 4-Club gallery. Lin Richards our 4 club gallery was a guest speaker at the seminar, and spoke very positively about out WCC and our online galleries.

It was made apparent through this exchange of information that WCC had come a long way in the last 18 months giving the Ivanhoe members much to think of.

I like to think we successfully passed on some helpful hints and tips to help them with their club and its future, as well having a great night with some lovely people.


Cindy & Jolanta


Jill talking with Dianne.


Barbara & Bernie

A few quick notes from Vicki Moritz

Just adding a bit more to Dave’s information about the Philip Island weekend- as sadly Jill, Dave and Pete couldn’t make the Sunday sessions.

Adrian Smith presented information about what judges look for, and encouraged those present to think about becoming judges.

Portrait photography was presented by Jim Weatherill and Marg Huxtable showing their images and discussing various aspects of portrait photography (skip the expensive stuff, 2 bunnings lights are fine!)

After lunch Ron Cork and John Commin presented 2 different views of travel photography. It was entertaining watching Ron unpack his travel bag- 2 camera bodies, about 6 lenses, portable hard drive, tripods, bag for len changes, flash….over 12 kg. On the other hand John travels with one camera and two lenses!

I also spoke with the Ivanhoe Camera club group, it would be good to do something with them in the future.

Vicki

Click here http://pjmphoto.blogspot.com/ for a detailed description of the Anzac Day, weekend.

April’s Winners – Water’s Edge (where water meets the land)

Water’s Edge, was judged by our own Tuck Leong, he said that “The entries for April’s competition were of a high standard; unfortunately quite a few did not comply with the Month’s set subject – Water’s Edge”. Below are a the four winners from each of the categories, congratulations to Ron, Ross, Vicki and Warren.

A Grade PrintRon Weatherhead ” Water’s Edge ”

Tuck said, the winning print is a colourful yet simple composition of waves against rocks and a ramp leading into the water. The image reveals craftsmanship in the taking of the photograph and in the making of the print. Ron added, I took this photograph near Cape Conran in Gippsland. When I saw that the club’s competition was to be “Water’s Edge”, I thought that this image fitted the bill. I liked the colour of the rocks and the sea, the pier leading into the deep added perspective.

B Grade PrintVicki Moritz ‘Lough Derg’

Tuck said, a lovely print was presented of a row of blue boats amongst the reeds. The overall tones are harmonious with the saturated colour of the boats drawing attention to their position along the water’s edge. Vicki added, Lough Derg is a large body of water in Ireland along the Shannon River near Portumna. This pretty much typified the week of summer weather we experienced- I don’t think the boats were launched that week! It was taken with Canon 40D with EFS 17-85 f4 lens, handheld.

A Grade EDIRoss Garner ‘Tree and Lake’

Tuck said, the warm directional light revealed the organic form of the overhanging limbs of a tree against dark rippling water. Whilst the water’s edge is not visible, it is implied by the tree limbs leaning across the water.

B Grade EDIWarren Knower ‘Reflection’

Tuck said, the top image consists of a monochrome image with delicate tonality. The over-hanging branches traced a filigree design and reinforced by the strong graphic lines of the rush from the bank. Warren added, the photograph was taken one afternoon on a dreary winter’s day in the Queen Victoria Gardens. I find the reflections fascinating and along with the reeds they tend to disorientate the viewer on which way is up.

A still life – Definition

The WCC August competition subject is ‘Still Life’ and I have been approached on a couple of occasions to define what ‘Still Life’ actually means. Well it just happens that the Digital Photography + Design magazine had the very same question asked of them. Therefore I have used the same answer as they did to define what ‘Still Life’ is and you can find it as described below, published in the pages of Wikipedia.

A still life (plural still lifes [1]) is a work of art depicting mostly inanimate subject matter, typically commonplace objects which may be either natural (food, flowers, plants, rocks, or shells) or man-made (drinking glasses, books, vases, jewellery, coins, pipes, and so on) in an artificial setting. With origins in ancient times and most popular in Western art since the 17th century, still life paintings give the artist more leeway in the arrangement of design elements within a composition than do paintings of other types of subjects such as landscape or portraiture. Still life paintings, particularly before 1700, often contained religious and allegorical symbolism relating to the objects depicted. Some modern still life breaks the two-dimensional barrier and employs three-dimensional mixed media, and uses found objects, photography, computer graphics, as well as video and sound.

Courtesy of Wikipedia

An Explanation of the “4 CLUB” Competition

A brief but informative introduction to 4-Club from the WCC President, Pete Davies.

There are competitions being run outside of WCC’s monthly comp and lots of photography clubs get together and stage inter club competitions. Waverley is involved in one known as 4 Club, every six months (usually April and October) we join up with Berwick Viewfinders, Eastern Suburbs Photographic Society and Maroondah Photographic Society. The clubs take turns to host the event and Waverley does it in April during the odd number years and when Waverley is not hosting the 4 Club it receives a letter from the host club asking for entries.

We are invited to enter 6 colour, 6 monochrome and 6 digital prints. There is an individual medal given to the maker of the best entry in each class while all the scores are tallied up in each section and the top club in each section is awarded a trophy. Last time around Waverley won everything except for one trophy. Can we do it again? Come along and see.

When you see 4 Club Selection Night listed in the program bring along some prints and or digital for everybody to have a look at. General consensus decides which entries are chosen and we try to spread the entries between as many makers as possible. When we do host the 4 club comp we move into the Community Centre on the corner of Stephenson’s Road and Miller Crescent. If you look out of the kitchen window in Wadham House and across the car park you are looking at the Community Centre.

Please bring a plate of food with you and arrive early as we need some equipment carted across to the Community Centre.

As a final favour could I ask you all to make an effort to introduce yourselves to at least one person that you do not recognise? The whole point of these interclub comps is to get out there and share the love so to speak. Everybody there is there because they all share a common passion so why not spread it around?

Pete Davies WCC President

Rules Amendments for WCC Competitions

Just to follow up on the President’s email, here a re a few points from the new competition rules for 2009.

As you all should know by now there has been some changes to the competition rules (A and B grades, 2 entries instead of three) and now the committee have introduced a couple more.

The first and most significant change is to the deadline.

Instead of the competition entries being due at the 3rd Tuesday workshop night, they will now be due anytime up to the competition PRIOR to the one you are entering. For e.g. If you want to submit entries to the June competition, they would be due no later than the 5th May’s competition night.

Entries for the May competition are still due on the 21st of April, this change will come into effect for the June competition onwards.

The reason for this is that there are now more camera clubs than ever before, with more members than ever before (and increasing memberships at that) putting in more comp entries than ever before. The judges, whose numbers haven’t swelled accordingly, are being inundated with requests and are, quite simply, swamped. As a committee we felt that more time given to the judge could only be of benefit to all concerned. Until now Waverley have given the judge a week to 10 days to do their critiquing before coming in to the club. Adding two weeks to that not only releases a little of the pressure we place on Albert and Peter to collate all the entries as soon as possible but should result in more considered commentary from the judge, which is, after all, the point of the competition in the first place.

The second change is that from now you must submit a digital copy with every print that you enter.

The reason for this is that we will be using the back room for the judging and putting the prints up around the front room for perusal before the judging starts. It’s too much trouble to run between the rooms grabbing prints for the judge to comment on so we decided that we would display the digital copy of the print instead. One immediate benefit of doing it this way is that from now on everybody should be able to see the (digital) print. Reflections from the lights overhead will not be a problem.

The file naming covention will be almost the same as for the EDI comp – just put a P (for print) between WCC and your grade.
For example B graders will be: WCCPB-0609-25B-Title.

The third item is conformation of the new aggregate scoring system.

No longer will a judge be required to give a score out of 15 (except for 4 Club). Instead a judge will be asked to award as many merits and highly commended awards as the judge feels are warranted. The judge will be asked to nominate one entry from each of the four sections as the best of the month.

  • Every entry receiving a merit will get 2 aggregate points.
  • Every entry receiving a highly commended will get 3 aggregate points.
  • Each entry nominated as the best of the month will receive 1 extra aggregate point.

For the end of the year aggregate awards the winner will be the person in each section (A prints, B prints, A EDI and B EDI) with the most aggregate points.

In the event of a tie the winner will be the person who received the highest number of highly commendeds.

If things are still tied the winner will be the person who received the most nominations as the best of the month.

For the annual aggregate competition these aggregate points will reset to 0 at the start of each calendar year.

A person will be promoted to A grade once they have accumulated 30 aggregate points. This person does not have to accumulate all of these points in one calendar year. For promotion purposes a record will be kept of how many points a person has accrued since joining the club.

If a B grader accumulates enough aggregate points to be promoted to A grade before the July comp then that person shall immediately be promoted and shall carry over any aggregate points earned in that calendar year. If a B grader accumulates enough aggregate points to be promoted any time from the July comp onwards then that person’s promotion shall be held over until the start of the next calendar year.