I'm looking at getting a Canon EOS T3 12.2 megapixel camera as my first DSLR (it's the only camera within my budget) and I have some questions about the lenses.

1. Do I need a dedicated lens for macro shots or is the included 18-55mm lens capable of macro?

2. I'm looking at getting another lens for airshows, but every single lens I look at, even the included 18-55mm lens, has an extremely narrow f-stop range. They're all around f/3.5-5.6. Comparing this with my old Petri MF-1 35mm camera which comes with an f/1.8-16 lens and has other available lenses that go all the way up to f/22, the Canon lenses seem inferior in this respect. Is the f/3.5-5.6 lens limited in any way? How would it compare with the lens on my Petri?

First, you can do some level of macro shooting with any lens, but there are dedicated macro lenses that will give you more capability.

As for the air show lenses and f-stops, the numbers you're seeing look like the widest they can achieve between fully zoomed out and fully zoomed in. In other words, if a 100-400 is f/4.5-5.6, that means the largest aperture you could get at 100mm is 4.5 and the largest you could get at 400mm is 5.6. It does not mean you can't go higher, though. I've shot at f/22 on my 100-400 f/4.5-5.6, and everything down to f/5.6. I just can't shoot at f/2.8 at all with that lens.

So f/3.5-5.6 is just the max aperture at certain focal lengths? Seems kind of stupid for them to list that without explaining what it means. The full aperture range would have been more helpful to me :p

correct, at 18mm it's 3.5, at 55mm it's 5.6

What exactly are you interested in for macro? I ask because some people think of macro differently than others.
The standard kit lens will be ok for flowers, but if you're looking for bugs then you're going to want a different macro lens.

by the way, just my opinion, but that is MORE than a capable first SLR. Get used to it, read the manual about 50 times, then you can worry about getting new lenses.

BTW, you mention airshows, my first airshow lens is a cheapy, but great starter zoom lens. Check out the Canon 55-250, you will find it for about $200...GOOD VALUE

I wouldn't be tempted by the 70-300, the quality is just not there.

I think the idea is that any lens can be stopped down by closing the aperture more, but they are more limited at the other end. It's easy to block light, but it's not easy to get more. That's why they list them with those numbers - they're the ones that can't be changed by adjusting the aperture, so you're stuck with those as your max.

To get more light in they'd have to have a larger diameter lens, which makes it tougher to get clear glass in that diameter, which then costs more. That's a big reason why a 100-400mm f/4.5-5.6 is ~$1600 and a 400mm 2.8 prime is over $6000. There's no way to get f/2.8 out of the 100-400, but both lenses, could be stopped down to f/22 or whatever just by closing the aperture more, so the max aperture size is one of the main limiting factors that distinguishes the lenses.

TheBigDog: Which 70-300 do you have? IIRC, there are quite a few 70-300s knocking about, including a DO, 1st gen IS and 'L' ones.

Jinro, if you *do* get an airshow lens, the 100-400L that Arthonon (and doubtless many others) have is one of the best non-exotic (i.e. marginally affordable) lens. Yes, I know, it's a grand and a bit, but if you want to shoot aircraft in flight, you might find 200mm a bit limiting unless you can get right up close, even on a cropped-sensor camera. Once you've been playing around a bit, you'll realise that glass is pretty damned expensive. It might not be a bad idea to find a place that rents lenses - that way you can figure out how you feel with different focal lengths without spending too much money.

On the side of macro, if you don't want a dedicated macro lens, you can purchase things called "extension tubes" which sacrifice infinity focus in order to allow the lens to focus closer. It's a cheap method of getting closer to macro distances, especially if macro isn't your primary focus. Only thing is that you (most likely) won't be able to achieve true 1:1 magnification with them, and due to the optics, you'll "lose" some light as well.

hey Gopher, you're correct on the 70-300's, there are 3 common (not too sure how common the DO lenses are). The basic 70-300 which is around $200, then there's a 70-300 with IS which I believe is about $600, then the one I have is the 70-300L (which is just phenomenal IMO).

The bottom end 70-300 is VERY slow, and VERY soft. The mid range IS model isn't too bad, but at its cost there are better options. I don't really know anything about the DO model, so can't really comment on it.

I started out with the 55-250, then eventually upgraded to the 100-400L which I shot for about 2 years. When the 70-300L came out I made the jump to it, and while I lost 100mm on the long end, I found that I gained much sharper images and the IS is just so good, I can't say enough about it. Of course for airshows you don't have much use for IS, but I found that (especially when shooting props or helos) it comes in handy for taxiing shots and panning to get good prop and background blur.

I actually just purchased the 400mm 5.6L, so I can't wait to get some shots with it this coming airshow season.

Feel free to check out some of my work, I'm still a long ways from being where I'd like to be, but I enjoy it so that's a plus

Flickr Page

Reading, PA 2011 Airshow

Atlantic City NJ 2011 Airshow

I'm getting more and more into macro shots, you'll see them on my flickr page too..

Flowers and random close-ups is about the most macro I need. I hate insects.

A grand-and-a-bit is outside my range right now; I'm saving that for an MM Stingray bass :p

I'm looking at the 75-300mm lens for airshows though. I tried taking my old Petri out to an airshow with a 200mm telephoto and I still ended up with lots of sky in my pictures, so I'm thinking I need at least 300mm. It looks to have good reviews, but as you guys said it's "slow". Does speed matter at all outside of low light conditions?

At the distances you'll be using it, not really in any practical manner without the judicious injection of lots of money.

"Slow" lenses just mean that you can't open it up to get in more light, so when the light falls, you have to boost ISO (sensor gain) or cope with slower shutter speeds, or not shoot at all. Everyone wants fast glass. Some can afford it. Fewer can justify it. Luckily, modern cameras are able to crank up the ISO, or sensor gain, quite a lot these days.

Aperture (or f-stop) also controls depth of field - larger apertures (like f/1.8) allow a lot of light in, and as a consequence of the way it works, gives a very shallow plane of focus. If you play around with your kit lens at max aperture with something on a table not far away, play around with different aperture settings to see what happens with the amount of the table photo in focus (as long as you're not looking straight down at it :o). At airshow distances, however, the depth of field is pretty large.

F-stops also have an effect on autofocus - cameras like lots of light, so you'll get faster AF response with "fast" lenses. AF still works at f/5.6, but obviously not quite as well, although at this point in time you probably won't be able to tell the difference. If you have an even slower lens, like something that is natively f/8, it will fail to AF at all - there simply isn't enough light hitting the AF sensor.
Don't confuse camera AF response with the actual speed of focusing though - they are two separate systems.
Also, don't worry about this stuff just yet.