Is it really useful to have a fast prime lens for portrait photography, considering a low budget? If it is, what about the Canon EF 50mm F1.8 II?
I have an entry level 18-55mm lens and a Canon 20D.
The 50 f/1.8 is outstanding value for money providing a very wide max aperture for portraiture compared to other lenses in the same price bracket.
I have the 1.4, but borrowed a 50 f/1.8 when my lens was being repaired. Although it was 2/3 of a stop slower and lacked an ultrasonic focus motor, wide open it was sharp, and can produce outstanding images in low light:
Other advantages are that it's very light, and stopped down one of the sharpest lenses in the whole range on account of it's simple construction. The lens tests on dpreview also reveal that wide open it's sharper than than the EF 50mm f/1.4 at f/1.8:
Definitely worth it. I use this lens very often. It's lightweight and may feel cheaply built, but it has excellent image quality and can't really be beat. Even the f/1.4, which is probably constructed better, doesn't seem to provide better quality.
I have the 18-55, 50/1.8 and 50/1.4 as well as the 20D - superseded by a 50D.
My personal rules have always been these: Get the very best glass you can afford. Get prime lenses first, zooms later. Get the fastest lens you can afford.
You will see a difference in sharpness, contrast and color going from the 18-55 to the 50/1.8. The 50/1.4 is better than the 1.8, but you may not be at the point where you will see or need the improvements the 1.4 offers.
BUT if you can only get one more lens in the near future, AND since you have the 18-55 AND you are starting out, you may want to expand your range first with another zoom, say a 70-200 before you start picking primes. The 70-200 is a great range for portraits.
Yes, prime lenses, especially Canon L's are significantly, sometimes vastly better than their zoom counterparts. They are also generally faster. BUT they are also expensive.
Once you have shot across the full range of 18-55 and 70-210 THEN pick the prime you want the most. I may be a 24mm, 35mm or even an 85mm. Get to know how you shoot first, then buy with a purpose. My 2 cents.
The 50mm f/1.8 lens is a decent lens from an optical perspective. It has good sharpness, and honestly can't be beat for its price. It should be noted, however, that it has a very cheap, fully plastic body. I also have the 18-55mm kit lens that came with my 450D, which has an all plastic body. During a recent trek through the Colorado Rockies, however, I somehow managed to crack the mount. I can't say exactly how it happened, as I never dropped it or anything. Its just an example of how fragile a plastic body really is, and how short a life the lens may have if you do indeed purchase one.
I would say the 50mm f/1.4 is also a good lens, with a much better body build, and just as good if not better sharpness than the f/1.8. Might be worth the extra cost to have a more durable lens.
Same here, I've the 50mm f/1.4, and as my fastest lens I couldn't live without it for concerts and low-light photography. It is much sturdier than the 50mm f/1.8 and is worth the upgrade, in my opinion. At this price though, the f/1.8 is almost disposable. Note that the 50mm f/1.4 can get jammed if you press hard on its sides. I don't think you can accidentally do it while operating it the recommended way, but it has happened to me and two other friends when we left the lens detached at the bottom of a Lowepro camera bag, and the camera + another lens on top of it was pressing hard. Symptoms include not being able to focus anymore, but Canon will fix that problem for free (you still need to ship it).
Yes, it's utterly worth it to have a fast prime in the bag, but... No, it's not worth it to get the EF 50mm f/1.8 II for four reasons, all of them relatively new lens releases as of the time of this writing (2015):
This is an updated version of the 50mm f/1.8 II. The price (~US$125) and optics are mostly identical. But the addition of the STM focus motor, a much-better designed manual focus ring, and having a metal mount plate and barrel, rather than being all-plastic construction makes this much better value for the money, if you're purchasing new. The 50mm f1.8 II's plastic mount plate in particular did lead to well-known problems such as the lens getting stuck on the camera. And it's cheaper than a used 50mm f/1.8 MkI.
50mm is great as a portrait length on an APS-C camera, mimicking the field of view of an 85mm lens on full frame. It is, however, a little long/narrow in FoV for more general purpose shooting, such as landscape, street, or social shooting. The 24mm f/2.8 STM, while slower, more expensive, and possibly less useful for available light shooting than a 50/1.8, mimics the field of view of a 35mm lens on full frame--a focal length that's just slightly wider than normal (similar to cellphone camera lenses), and can be suitable for portraits, landscapes, street, and shoots close enough to do near macros. There's a reason a lot of the large-sensor compacts with fixed lenses have a 35/2 equivalent. In addition, this lens is a "pancake" lens--super compact, very tiny. You can think of it more like a body cap you can shoot with. It's discreet and very easy to pack and take with you when you need to travel light. The EF 40mm f/2.8 STM is the full-frame version of this lens, but again, will be longer than "normal" on a crop body.
But, I hear you say--I could buy a used EF 50mm f/1.8 II for a lot less cash. And you could. But if you really need to go supercheap and don't mind all-plastic iffy-construction and possible conditions issues of a used lens, then there's the super-thrifty fifty Yongnuo clone, the YN 50mm f/1.8. Amazon is currently listing it for US$60 (with Prime).
A bit more expensive than their 50/1.8II clone (~$110), this lens, however, is a clone of the discontinued Canon EF 35mm f/2 (which has since been replaced by the $600 EF 35mm f/2 IS USM). And it's "normal on a crop"; that is the field of view mimics that of a 50mm lens on a full frame camera, and can pretty much be used the way a 50mm prime was used for decades on film. And f/2 is only a third of a stop slower than f/1.8.