This is the next installment in my series of Quick Tips for photographers. This one is an oldie but a goodie…

Sometimes your camera will be confused by the lighting conditions around it. In those cases it’s always a good idea to have a feeling for a good starting point for what the correct exposure settings to use will be.

Way back in the olden days (before histograms and light meters were built into the camera), photographers had to do this in their heads, and they had to do it all the time. They developed lots of rules of thumb to help. Here’s one that you can used to determine the correct exposure on a bright sunny day.

The Sunny 16 Rule

On a bright sunny day, if you set your aperture (or F-stop) to f/16, then the shutter speed required to get a good exposure will simply be 1 / ISO.

Some modifiers for this rule:

• If you are at a white sandy beach or shooting in snow then you may need to stop down by 1 stop to cut glare and reflections.
• If your background is darker or there are important areas of the scene in the shade then you may need to open up by 1 stop to fill in the shadows.
• You may have to “salt to taste” to get an exposure that matches your creative expectation!

NOTE – If you need a refresher on Aperture, F-stop, Stop Down, or Open Up, then check out my earlier post on Apertures and F-stops.

For the Advanced Class

f/16 at 1/ISO should be considered to be your starting point, and you can always add salt to taste if you want to change the look of the image (Tip – use the histogram on your LCD to check your exposure). You can also use that exposure information to calculate a whole series of equivalent exposures depending on the creative decisions you want to make.

For example, if you want to blur the background then you might want to use f/2.8 instead of f/16. In this case you simply need to figure out how many full stops brighter f/2.8 is than f/16, and then take away that much light be increasing the shutter speed or decreasing the ISO.

Every time you move either the Aperture, the Shutter, or the ISO from one of the standard settings in the table above to the adjacent setting to the left of it, you are “Stopping Down” your exposure by 1 full stop, which means you will use half the light of the previous setting. As you move to the right you “Open Up” by 1 full stop, which means you will get twice as much light. If you Stop Down the aperture by one stop, then you must Open Up the Shutter or the ISO by one stop in order to maintain the equivalent exposure.

A practical example: Moving from f/16 to f/2.8 is 5 full stops more light. To achieve an equivalent exposure you would have to take away 5 stops. You could do that by Stopping Down the ISO or the Shutter. Changing the ISO from 3200 down to 100, or increasing the Shutter Speed from 1/4 sec up to 1/125th sec are equivalent moves.

NOTE – Modern cameras allow many more choices for Aperture, Shutter, and ISO. They generally allow adjustments in half, third, or even quarter stops. It is very important that you understand how much you have to change to affect your exposure by a full stop! And as always, practice makes perfect!

This is the next installment in my series of Quick Tips for photographers.

New photographers often get confused about terms like Wider Aperture, smaller F-stop, Stopping Down, and Opening Up. So here is a series of explanations for what some of these terms mean.

The thing is, photographers that know this stuff just know it, and they don’t even have to think about it. When a new person comes onto the scene and they hear terms like Stop Down, Open Up, Fast Glass, and Maximum Aperture, they often have no idea what language is being spoken. It’s really not obvious what any of these terms mean, and it can be very confusing to figure it out unless someone explains it clearly and simply.

Here are some key points to remember:

• A small F-stop means a large aperture.
• A large F-stop means a small aperture.
• Large apertures (small F-stops) let in more light than small apertures, so you can use faster shutter speeds to get the same exposure.
• “Stopping Down” means to use a smaller aperture, which is a higher F-stop.
• “Opening Up” means to use a larger aperture, which is a smaller F-stop.
• “Fast Glass” means using lenses with a very low f-stop (such as f/2.8 or smaller) which let in lots of light. More light means faster shutter speeds, hence the term Fast Glass. Fast glass is good.
• “Maximum Aperture” means the largest aperture, or smallest F-stop, that a lens is capable of. See “Fast Glass” to figure out why this is important.

This can be very hard to remember until you’ve used your camera so much that it just comes natural to you and you don’t even have to think about it. For many people, simply memorizing the table above will be enough to make this all work flawlessly!

More Detail for the Advanced Class

For some people it helps to think about what the numbers mean. If you don’t want to know, just stop right here, and go back and finish memorizing the terms above!

The F-stop is really just a ratio between the size of the lens opening (called the aperture) and the focal length of the lens you are using. The size of the aperture is simply the focal length divided by the F-stop number.

The important part is that no matter what lens you are using, if you divide the focal length by 4, you will get a larger number than if you divide by 16; this means that at f/4 you will have a much larger aperture than at f/16, and therefore the lens will let in much more light at f/4 than at f/16.

For example, if you are using a 100 mm lens:
- At f/4 the size of the aperture is 100/4 = 25 mm
- at f/16 the size of the aperture is 100/16 = 6.25 mm

You can see that the aperture at f/4 is significantly bigger than at f/16, and therefore the lens will let in way more light at a smaller F-stop.

In a widely anticipated announcement, Canon has provided a firmware update (to version 1.1.0) for the brand new Canon EOS 7D.

This update includes all previous firmware updates, and a new fix for an odd ghosting issue that was widely Twittered and Blogged about last week.

The update “Corrects a phenomenon that in images captured by continuous shooting, and under certain conditions, barely noticeable traces of the immediately preceding frame may be visible. This phenomenon is not noticeable in an image with optimal exposure. The phenomenon may become more noticeable if a retouching process such as level compensation is applied to emphasize the image.”

I’m definitely taking it as a positive sign that Canon jumped all over this issue and provided a fix so quickly! They have been exuding a much better, more customer friendly, attitude about this sort of thing recently. It seems that they have really taken it to heart after being lambasted so soundly for the past couple of years after repeatedly denying that there was an issue with the autofocus system on the 1D Mark III for months (or it seemed like months anyway)! I really don’t know if there was an issue or not, but the customer base certainly perceived that there was, therefore Canon had to do something. And they should have done it faster. Hopefully this is the start of something new!

For more information about how to confirm whether you need this fix or not, head on over to the official Canon web page for the firmware update. You can download the necessary files and see detailed instructions on how to install it.

I have long been a fan of the website The-Digital-Picture.com as a fantastic source for in useful review of Canon cameras, lenses, and accessories. The reviews presented are the perfect length to provide an great overview of the equipment, without requiring hours of reading to get the idea. Each review also provides a brief comparison to closely related equipment with a discussion of why the buyer might want to choose one over the other.

For example, Canon has three wide-angle zoom lenses that, on the surface, have very similar specifications (EF 16-35mm f/2.8L, EF 17-40mm f/4L, EF-S 17-55mm f/2.8 IS, EF-S 18-55mm f/3.5-5.6 IS); however, even though their focal length ranges are similar, these lenses are all extremely different have have very different target markets. The reviews for each of these lenses includes discussion about some (but not necessarily all) of the related lenses. This information is gold and it becomes very easy to narrow in on a couple of the lenses as the likely preferred options.

The site has recently been updated with a brand new Lens Specifications and Measurements comparison tool that allows you to directly compare lenses to easily see the differences in height, weight, diameter, and many other physical properties. In the past it has been very difficult to get this kind of information at all, never mind finding it in one place. Finding it usually required wading through multiple review sites, online retailers, and the Canon website.

If you are a Canon shooter and you haven’t been to The-Digital-Picture.com, you should go there right now!

This will be the third and final article in an ongoing series I’ve been writing about the recently announced Canon EOS 7D. As I have previously mentioned, I am very excited about the 7D because it looks like it will be a very impressive camera. The features it brings to the Canon camera lineup will only get better and more exciting as newer cameras are released. The competition between Canon and Nikon over the last couple of years has been fierce and it seems that Canon regained their lead with the 5D Mark II and now the 7D extends that margin. Competition has been very good for our industry and I have no doubt that Nikon will reply shortly…

I really like the look of the 7D; however, I have also stated that I probably won’t buy one. Here are a few reasons why I might consider buying the 7D after all:

1. The Hype: Canon fans around the world are very excited about this camera. I haven’t seen hype like this for a camera since the Nikon D3 was released. That was the first time in a long time that Nikon had sent a camera out that was really competetive with anything Canon had, and the Nikon users were on fire for months afterwards. Sure the 5D Mark II release was exciting, but everybody knew it was coming. In many ways the 7D trumps the 5D and it has tongues wagging all over the interwebs.
2. The Timing: In a perfect world I would wait for the pending expected successor to the 1D Mark III (presumably the 1D Mark IV) to be released, but nobody knows for sure when that will be. The pundits on the rumour sites are pointing to a spring 2010 release. I can probably wait that long, but I definitely don’t want to wait until fall 2010.
3. Improved Autofocus: I am becoming increasingly disappointed with the autofocus performance of my 40D, especially in lower light situations. The new 19 point AF system on the 7D looks amazing and I can only assume that it will be vastly better than the technology built into the 40D.
4. High ISO Performance: I used to be an absolute nut about image noise, taking my shooting to such extreme lengths to avoid ISO 400 even, never mind taking it up to ISO 800. I’m much better now and I actually use ISO 800 all the time; however, I’m really looking forward to having a new camera that has a useful ISO 1600. From the test images I’ve seen and the reports that I’ve read, the ISO performance of the 7D is very good.
5. 1.6x Crop Factor Sensor: There are lots of things to love about full frame cameras like the 5D (most notably the low image noise, the extreme wide angle field of view, and the beautiful bokeh), but crop sensor cameras have one thing that really trumps all of that for me: longer equivalent focal length. I mainly shoot birds and wildlife and for that purpose focal length is king. At this time I simply can’t afford (or justify) to buy the 500mm f/4L, 600mm f/4L, or 800mm f/5.6L Super Telephoto lenses that I really want. For now I would really prefer to stick with a crop sensor camera. Hopefully the 1D Mark IV will stick with the APS-H (1.3x) format currently in use in the 1D Mark III which would be an acceptable trade-off for me between the 1x of the full frame sensors and the 1.6x of the APS-C sensors.

I’m ready to buy a camera right now, but I really want the next camera in Canon’s professional 1D series. Hopefully that release will come soon, but if it doesn’t then the Canon EOS 7D is a very tempting piece of equipment. It will be interesting to see what the reviews are like as the production models start to actually appear in the wild.