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Old Mar 14, 2012, 12:15 PM   #11
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At the moment, I have been snapping my sons Rugby games, so I'd continue with outdoor field sports (rugby, football etc). I already know that it's difficult to capture all the action, so I set up camp where I think most of the action will be.
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Old Mar 14, 2012, 12:58 PM   #12
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Daytime or night games? If night under the lights, you're going to have problems.

I don't want to discourage you. IMO, out of those two choices, the Canon would serve very well for a lot of photography, and it's a more rugged camera design compared to the older D80 model. But, I'd make sure the warranty includes more specifics on time frame for replacement or refund.

But, If you're talking low light photos (night under the lights), you'll need a brighter (and longer) lens. Basically, the smaller the f/stop number, the wider the aperture opening. A lens like the 17-85mm would be super for most photos, with a focal range that's equivalent to a 27-136mm lens on a 35mm camera. It would probably be my "go to" lens for most of what I'd shoot. But, it's just too dim for use in lower light (you'd just end up with blurry photos, even if you could get relatively close to the action).

Basically, with a Canon dSLR like that, you'd multiply the focal length by 1.6 to see how it compares to the same focal length on a 35mm camera. For example, a 100mm lens would give you the same angle of view you'd have using a 160mm lens on a 35mm camera (100mm x 1.6 = 160mmm). That's because the APS-C size sensor in that Canon dSLR is smaller than 35mm film, so lenses appear to be "longer" on a camera using that size sensor. That 17-85mm is an f/4-5.6 lens, meaning that it's widest available aperture is f/4 at it's wide angle zoom setting, dropping off to a widest available aperture of only f/5.6 at it's longest zoom setting (when you zoom in to fill the frame more with distant subjects). f/5.6 is a relatively dim aperture if you need faster shutter speeds in borderline lighting, and that lens would give you the same angle of view you'd have using a 27-136mm lens on a 35mm camera (again. multiple the actual focal length by 1.6 to see how they compare). That's fine for daytime use, or indoors with a flash. But, for night use under stadium lights, f/5.6 is not bright enough. Even f/4 (the widest aperture you'd have at the 17mm end if you didn't zoom in any at all) is still too dim.

To put that into perspective, f/2.8 (which is the aperture setting a lens like the 70-200mm f/2.8 Sigma I mentioned that you might be able to find for around $800 can maintain) is exactly 4 times as bright as f/5.6, allowing shutter speeds 4 times as fast for the same lighting and ISO speed. Another benefit of a brighter lens is that your AF (Autofocus) sensors can "see" better. So, in dimmer lighting, a brighter lens can help your camera focus faster and track action better in lower light. Light is typically measured as EV for Exposure Value in Photography.

Aperture works similar to the pupils in your eyes, where you can open up the aperture iris wider to let in more light, or close it down to let in less light. If you let in more light with a wider aperture (smaller f/stop number), you can expose the film or sensor faster (allowing faster shutter speeds for proper exposure to help freeze rapid movement). I f you let in less light with a smaller opening (as in the widest aperture of f/5.6 you'd have with the lenses included with those kits if you zoom in much), it takes longer to expose the film or sensor for a given ISO speed setting, which means blur from subject movement in lower light.

Note that aperture is normally expressed as f/stop, which is a ratio between the focal length of the lens and the diameter of the aperture iris. So, smaller f/stop values represent a larger iris diameter. With a prime (non zoom) lens, you will see one aperture listed (the widest available). But, you can still use smaller apertures (represented by higher f/stop numbers). With a zoom lens, you usually see two apertures listed (the widest available aperture at wide angle zoom setting, and the largest available aperture at the full telephoto zoom position). When in between the widest and longest focal length of the lens, the largest available aperture will fall somewhere in between the apertures shown.

For use in lower light, a number of high quality zoom lenses like can maintain a constant aperture throughout their zoom range (with f/2.8 being the most common). So, you'll only see one aperture listed for this type of lens (the widest available, since you have that aperture available at all focal lengths supported if desired). That's the kind of lens you need for use in lower light for sports photos, so that you can get shutter speeds fast enough to reduce blur from subject movement.

But, you can still set a lens that can maintain f/2.8 through it's focal range to smaller apertures (higher f/stop numbers). For lower light, primes (fixed focal length versus zooms) can be found that are even brighter (smaller f/stop numbers), as in the Canon 85mm f/1.8 that I mentioned (which is more than 4 times as bright as that 17-85mm lens it's when zoomed into it's longer 85mm end).

When you vary the aperture, you're controlling the iris in the lens (which like a pupil in your eye, can be opened up to let in more light or closed down to let less light in). So, this impacts the shutter speeds you'll need for proper exposure (since more or less light is getting through to the sensor). Aperture also impacts Depth of Field.

The aperture scale in one stop increments (with larger than f/1 apertures possible but very rare in lenses) goes f/1.0, f/1.4, f/2.0, f/2.8, f/4.0, f/5.6, f/8.0, f/11, f/16, f/22... With each one stop move to a smaller aperture like going from f/2.8 to f/4 (represented by higher f/stop numbers), you will need shutter speeds twice as long for proper exposure for the same lighting and ISO speed (only half the light gets through compared to a one stop wider aperture opening).

ISO speed is how sensitive the film or sensor is to light and is the same thing as the older ASA rating for film. The higher the ISO speed, the faster you can expose it (each time you double the ISO speed, you can use shutter speeds twice as fast for the same lighting and aperture). Shutter Speed is how long the camera's shutter stays open to expose the film or sensor).

IOW, it all boils down to how sensitive the film or sensor is to light (which you control via the ISO or ASA speed of the film you use with film, or the ISO speed settings you use with digital), and how much light you need to let it see to "expose" the image (which you control via the aperture opening size and shutter speed).

The problem with low light sports is that the available light (even under stadium lights) is much dimmer to a camera than it appears to the human eye (as the human eye adjusts much better to light at that levels). So, you'll need a very bright lens (f/2.8 or brighter, which increases size, weight and cost), shooting at very high ISO speeds (e.g. ISO 3200) to prevent a lot of blur from subject movement for lower light sports (and indoor sports or sports under stadium lights at night is very low light to a camera).

But, the good news is that with a model like that Canon 40D kit with a 17-85mm f/4-5.6 lens, you'd have a really good camera body with a lens that has a very versatile focal range for most photos (landscapes, photos of friends and family, etc.), since it would have the same angle of view you'd normally get with a 27-136mm lens on a 35mm camera. For most of what I'd shoot (friends and family type images), that focal range would be ideal. More often than not, you'll find a 24-85mm lens on my camera for general purpose use, and that 17-85mm in the Canon kit you're looking at goes even wider (making it easier to get what you need to fit into the frame, since you can only back up so far in some conditions)

The bad news is that it's totally unsuitable for any type of low light sports. It's simply not bright enough, so you'd just end up with blurry photos because the shutter speeds needed for proper exposure would be too slow in dimmer lighting, even if the ISO speed was set to maximum setting of ISO 3200 (which will increase noise and/or loss of detail from Noise Reduction).

However, you don't have to buy all of your lenses at once. For example, you may want to buy an inexpensive 70-300mm f/4-5.6 lens for daytime sports use for now, then save up and buy a brighter lens (one that can maintain f2.8 throughout it's focal range) later on.

An external flash is also a good idea for use in dimmer environments (keeping flash range limitations in mind).
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Old Mar 14, 2012, 1:48 PM   #13
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OP, if you need a fast-focusing low-light action sports type of lens the Canon 100mm f/2.0 USM is easily within the financial reach of most amateurs.

There's also the Canon 135mm f/2.0, but this one's a bit more expensive!

Obviously, these lenses work very well in day-time, and they make fantastic portrait lens as well!
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Old Mar 14, 2012, 3:38 PM   #14
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Those lenses would be great for a lot of indoor sports. But, for outdoor sports in low light, a longer focal length is usually needed for a higher number of keepers.

I'm not much of a sports shooter. But, when I do need to shoot lower light sports indoors (versus something like Rugby like the OP is interested in shooting), my Minolta 100mm f/2 AF lens (I shoot with a Sony dsLR) is my "go to lens", and from time to time, I'll use my Minolta 135mm f/2.8 AF lens instead.

But, for a sport like Rugby (which requires a longer lens to get a higher percentage of keepers due to the size of the playing field), a longer lens like a 70-200mm f/2.8 (or longer if budget permits) is a more desirable option.

For example, I took a couple of Rugby photos that were used in our Sony A850 Review Samples (see the last photo in our second row after the ISO speed series, and the next one in the row below that) when zoomed all the way into 200mm with a Sony 70-200mm f/2.8G SSM lens, to "fill the frame" enough to get reasonable detail, and I was able to shoot from anywhere I wanted to. Most of the other photos from further away were just not suitable, and even the photos we did include in the review samples were "borderline". It's not easy to capture rapidly moving subjects, even in better light.

Now, perhaps that's an extreme example (since I was zoomed in so much I cut off part of one foot) But, you should see some of the photos that were taken from further away.

Night photos are an entirely different "ball game", as a camera's Autofocus is going to struggle more to lock on to the subject and stay with it during movement.

We have some members here that shoot a lot of sports, and my hat is off to them, as it's really hard to get a high percentage of keepers. As long as I've been using cameras, I'm still not very skilled at it. That type of shooting places a very high demand on the camera, lenses and photographer skill level needed to capture good images.

Now, that's not to say that you won't be able to get some keepers using a shorter lens. But, a camera's AF system doesn't work that well for tracking moving subjects unless your subject is filling a larger percentage of the frame.

So, it can be very difficult to get decent images of moving subjects without a lens that allows you to fill the frame more with your subject, and one that focuses quickly enough for the camera's AF algorithms to keep up with subject movement (and the lower the light level, the more problems you'll have in that area).

Here's a "sticky" thread on the subject of Lens Working Distances that includes some feedback from some of our sports shooters:

Lens working distances .

Now, the Sony A850 is a "full frame" model. But, most skilled sports shooters will tell you that working distances really don't change when you're using a camera with an APS-C size sensor. IOW, if you want the AF system to focus fast and track a moving subject (especially in lower light), you'll need a longer lens for typical outdoor sports (unless you're only interested in capturing the action close to where you're shooting from).
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