I am planning to buy a DSLR soon.
Before I zero in on the model, I want to know whether it is advisable to buy a kit (body + 18-55 lens) or not? OR should I go for the camera-body and the lens separately?
The answer is, unfortunately, depends.
First, what kit are we talking about? The 5D Mark II kit comes with the 24-105mm f4 IS L lens. The lens is roughly $1000 new, so selling it immediately, gives you discount on the body itself, so it absolutely makes sense to get the kit (unless you don't want to hassle with selling the lens). I bought the 5d2 kit, even though I already had a great copy of the 24-105 (I kept my original and sold the new one) However the 24-105 f4 IS L lens is a great general purpose zoom, so I would think twice before selling it. In kit your looking at, the 18-55mm Zoom lens isn't that all great of a lens. It works, but there are a number of drawbacks. The lens costs $170 new, but you will have a harder time selling that lens for that price.
Next, what is your budget? If you can afford a better lens, then you should buy a better lens. Lens are far more important than camera bodies. However, having no lens is way way way worse than having a "bad" lens. So if you need the 18-55mm range, and can't afford the step-up alternatives (or even the 3rd party alternatives), then get the kit lens.
Finally, what other goodies are you getting with the kit? If you search, you can find kits that also come with bags, memory cards, a filter, 2nd batteries, cleaners, etc. If you don't have these items already, they will add up quickly. Having them thrown into the kit will generally reduce your total cost.
The only time I would argue for not buying a kit is when you already own other lenses that cover the same focal range. If you are purchasing your first DSLR you should go ahead and get the kit. Even though the kit lenses have a bad reputation, it's been said that "99% of lenses are better than 99% of photographers", and the kit lens is going to be a great deal.
When I first did it, I bought a body and a separate zoom lens. If I were to do it again, I think I would do the same thing, but get a 50m prime lens.
Every camera company offers a 50m prime lens that is inexpensive, so it's a great buy when you are first starting out. The other reason is overload of information. When you first start out, the camera body has a bunch of settings and modes and options that are all new to you. You need time to figure them all out and to get comfortable with using the equipment. Keeping something in the equation of taking pictures simple, by having a prime lens instead of a zoom, helps you to focus (sorry no pun intended) your attention on the important parts.
Think about it this way: would you buy the kit lens if it was standalone? For example, if you needed a lens near the 18-55mm range, would you buy the kit version (which is generally of a fairly low build quality, fairly slow with a variable aperture) or would you buy something a bit more professional?
If you see no problems with the kit lens and would buy it standalone, get the kit. On the other hand if you'd probably opt for a different lens... don't get the kit and instead spend your money on what you really want.
I understand that you are talking about:
For that combination I believe it is worth buying the kit. The price difference is minimal and actually if you find that you want to change/upgrade the lens you will easily sell the 18-55IS for the price that will cover the difference.
Also Canon 18-55 IS is not such a bad lens optically and it also offers image stabilisation. The build quality is indeed not too good but it is definitely worth the price also the financial consequences of braking it are not too big neither.
Upgrade in the same focal range would be EF-S 17-55IS 2.8 but that is in completely different league in terms of price.
If I were you I would get the kit and 50mm 1.8 - the kit as a walk-around and simply to learn what focal range works for you best, the 50mm for portraits and photos in low light situations and also to find out if you really need a faster zoom with better optics.
Here are some reviews of the lenses I mentioned
Because of their price/performance ratio those are perfect lenses for the begginer and should work great on the 500D body that you are planning to buy
Note: This answer was originally written for a different question that was later merged with this one.
For only $50 difference getting the EF 18-55mm f/3.5-5.6 IS II with your T3i is a no-brainer. If you don't need it, you can sell it for a quick profit. The going rate for that lens used is about $80-100.
But if you are, as you say, new to the scene you need this lens if the only other option is a 50mm prime on a 1.6x crop body. This is because on a cropped-sensor camera, the 50mm lens will yield an angle of view similar to an 80mm lens on a film or full frame camera. There are just too many things at wider angles you need to try during the discovery phase of your development. There are some photographers who stay above 80mm almost all of the time. But for every one of them, I bet there are at least twenty who stay on the wide end of 80mm. Don't shortchange yourself by not exploring the possibilities of the wide to normal range of focal lengths as well as the telephoto end which traditionally begins at 70-80mm on a film or full frame body.
There is a viable third alternative: The Canon EF-S 55-250mm f/4-5.6 IS II. By going with the EF-S 55-250mm f/4-5.6 instead of the Tamron 70-300, you'll save enough to get both the kit lens and the EF 50mm f/1.8! That's what I would recommend for someone starting out with a T3i.
With a 50mm lens on the T3i, you're going to have to take most of those group photos outside unless you are in an awfully large room. You will find most residential homes or apartments too constraining. Individual portraits of a subject that can sit still long enough for you to focus will work inside.
Note: The subsequently introduced EF 50mm f/1.8 STM has pretty much corrected all of the shortcomings of the EF 50mm f/1.8 II listed below. It's still on the lower end for prime lenses in terms of optical quality. But as such, it holds its own compared to zoom lenses set at 50mm.
With the EF 50mm f/1.8 II you get optical quality that is very good compared to most zoom lenses that sell for less than about $2,000. But compared to prime lenses that sell for a quarter to a third of that, you give up a lot.
I guess you could make the argument that you could buy 3 nifty fifties before you paid for one EF 50mm f/1.4. Personally, I find that due to the speed of AF and ease of MF I use my f/1.4 a lot more than I did when my f/1.8 was in my bag. (Note: Since the introduction of the EF 50mm f/1.8 STM, you can get most of the advantages of the EF 50mm f/1.4 for the price of the old EF 50mm f/1.8 II)
As for why you could be just as well served on the T3i by the EF-S 55-250mm f/4-5.6 IS II for half the money compared to the Tamron 70-300 see my answer to Should I buy a Canon 55-250mm lens or 70-300mm for my Rebel T3i?. The Tamron and Canon 70-300 f/4-5.6 are comparable to each other optically, but so is the EF-S 55-250 and it costs half as much. If you ever wind up going full frame, you're going to want a better telephoto than either the Canon or Tamron 70-300 lenses.
It is nearly always a good idea to buy the kit. First of all, you may be able to find a kit with the lens you really want - the kits are not always just the 18-55mm lens. You also might find that the manufacturers discount a body + lens purchase pretty significantly. For example, right now Nikon is offering rebates of up to $400 with a body + lens purchase.
So I would first look and see if you can find the body + lens combination you would want anyway. Even if you can't find it, you may be able to find a package with another lens that you could sell to someone else (the 18-55mm might be a tough one to sell, since nearly everyone who wants it already has it)
Generally speaking, unless you are buying a high-end kit with a top of the line camera body, the bundled lenses (particularly 18-55mm lenses) that come with your entry-level camera bodies are not worth it. If you can find a kit that includes a reasonably decent mid-grade or top-grade lens, I would go for it. However, if your buying a kit that includes the bottom of the barrel lens (which the 18-55mm usually is), you are MUCH better off buying the body only, and saving for a more decent lens.
This might also be beneficial if you know the kind of photography work you wish to do, as 18mm is an ultra-wide focal length, and does not offer much unless you are looking to do a lot of landscape photography. A more useful focal range is 24-135, and any lens in that range will be much more useful from a general photography standpoint. The wide-normal lengths are useful for landscape, photojournalism, and other general forms of photography, while the 100mm and 135mm telephoto lengths are excellent for portraits and the like.
I usually dont get the kit lenses. They're not always the best quality. I feel like they're offered as a way to get people up and running with a new body, without having to buy other stuff.
If you find a kit that suits you, that is generally cheaper than buying the body and lens separately. If you buy them separately you get to choose whatever lens you want for the body.
Lenses in a kit (except for the most expensive cameras) is usually one of the cheapest models, and as they are sold in kits they can manufacture a lot of them at lower cost. So, you get a cheap lens, but at a good price.
Skipping the kit lens is a smart move. The focal range is similar to point and shoots and cellphones which is really convenient, but the kit lens will make you disappointed at the DSLR as it will feel exactly like a point and shoot, you could have gotten cheaper.
Primes are really good to get a real DSLR feel, where you can make thin DOF, shoot indoors without much light, make you think about your composition, etc. The 50mm 1.8 gives good images, but the AF is archaic (you can manual focus, though), and it has no weight and can fall appart - but it is really cheap. The 50mm 1.4 is a better buy, showing off Canon's great USM focus system.
If you want to shoot some wider shots there is a 28mm 1.8 prime, also with USM, or get a sigma/tamron 17-50mm F2.8 for your walkaround/party shots. You could consider Canon efs 55-250mm for your telezoom and free up funds for the "standard zoom".
It depends on your level of expertise in judging what lenses you need.
If you are a complete beginner who doesn't know what all those letters and numbers on the lens actually mean in practical shooting terms, and you're getting a entry-level dSLR body, then get the 18-55 kit lens (or if you're shooting four-thirds, 14-42 kit lens :-). Knowing what lens to get is kind of a chicken or the egg problem for a newb. To know what lenses you need, you need experience with lenses. But to have experience with lenses, you need a lens to shoot with.
While you will almost inevitably end up exchanging a cheap 18-55 kit in the future for something different, it will have the following advantages:
If you have enough experience with lenses to buy just the body and select your lenses à la carte, then you probably don't need to buy many lenses to go with the camera body at all, unless you're making the move from crop to full frame or swapping systems. You probably already have your most-needed lenses. At any rate, you probably don't need any advice on what type of lens to pick, possibly just advice on the finer points of difference between similar lenses.
If you have a friend who has enough experience with lenses to tell you what to buy, and enough imagination to guess correctly how/what you want to shoot and how much you want to spend, then maybe you can get away with picking a camera and a lens for yourself. But everybody's different, and a lot of folks are only really good at figuring out what works for them. And it's easy for online advisers to spend your money like it's water on $1000+ L (pro) lenses--it doesn't come out of their pocket.
Lenses are like tools in your toolbox. Carpenters, mechanics, and plumbers all have toolboxes, but fill them with very different tools. Photography is no different. What may be a kickass portrait lens for one person could be a not-quite-right landscape lens for someone else. What lenses you should be getting depends entirely on what and how you plan to shoot, and your budget.
Every lens has advantages and disadvantages.
Advantages of the 50mm f/1.8 compared to the 18-55:
Great optical quality
It will give you much more depth of field control
The autofocus is painfully slow
It's a fixed focal length (it takes more time to move yourself than to zoom)
50mm on a crop sensor is a little too tight, taking a group photo will be difficult or impossible in a small room
Basically the slower auto-focus and the need to position yourself (and sometimes your subject) rather than zoom will slow you down (or really teach you how to prepare and plan ahead), in exchange for this you get amazing image quality (compared to consumer zooms, the more expensive lenses tend to be better) and DOF
So, it all comes down to what you plan on doing, for posed portraits the 50mm is better is just about every way, for taking shots or running children the 18-55 is better.
Note: the Canon EF 40mm f/2.8 STM is just a little more expensive than the 50mm, it got some great reviews and should solve the main problems of the 50mm f/1.8 (the old autofocus and that it's a little too long on a crop sensor) - but I've never used one myself so I can't really tell you how it works
I have the 50mm f/1.8 and for my usage it's not a good fit, it mostly makes me wish I bought a 30mm or 35mm with a faster auto focus instead - but it is the cheapest way to experience what a fast lens can do and really see what you can get from a DSLR with a good lens that you can never get close to with a point and shoot.