What are the differences between the EF 50mm f/1.4 use and EF-S 18-55mm IS

[FREDMCFADDEN]

My daughter has asked for my old camera and I have given it to her. It is the Rebel EOS T1i. She wants some new lens's but before I invest I would like to know a few things. The 2 lens's we currently have are the EF-S 18-55 IS and the EF-S 55-250 mm F/4-5.6 IS. What are the differences between the EF 50mm f/1.4 use and EF-S 18-55mm IS? She wants me to buy the EF 50mm f/1.4. 

Thanks in advance.

[ScottyP]

The EF 50mm f/1.4 is a fixed length lens, and the 18-55 is a zoom lens that can shoot at any of the lengths between 18 and 55. 

The reason someone would want to get a fixed 50 when they already have 50 covered in an 18-55 lens?

Much brighter lens.  The f/1.4 lens is 3 stops faster than the zoom lens. That means it lets 8 TIMES MORE LIGHT into the camera in the same amount of time. That means when you are shooting indoors and lighting is not bright like outdoor sunlight, you can use a shutter speed that is 8 times faster than what you could get using the kit zoom lens. That is hugely important. If you had the zoom lens you might have so slow a shutter that your subjects are blurred from motion, or you might have to raise the ISO setting higher to compensate, and that gives ugly grainy images. 

Shallower depth of field. With a wide aperture lens like the f/1.4 lens, you can isolate your subject from the foreground and background. This is one big difference between an ordinary snapshot and a nice photo. You can get rid of distracting things in the shot by making them out of focus. 

Sharper and lighter.  In trying to make a zoom lens take acceptable images at every length between 18 and 55 the designers have to make compromises. It is not going to be a stellar sharp image quality at any length because it has to be decent at all lengths.  The fixed length lens, however, can be designed to be sharp at that one length. It is also usually a lighter lens, though those kit zooms are pretty light too, really. 

You may also consider getting the new 50mm f/1.8 STM lens. It is a great upgrade to the previous "nifty fifty" "plastic fantastic" 50mm f/1.8. The old version was slow and noisy to focus.  It had just 5 aperture blades and they were straight so the out of focus highlights would appear like little pentagons. The new STM is fast and quiet at focusing, has more aperture blades and they are curved so the highlights are nice and round. It also has some lens coatings that cut down on flare and give a more saturated image.  The price is just $125.00.  

I love fixed length "prime" lenses. My everyday walk around lens for 2 years has been a 35mm fixed prime and it makes my photography look and work better. 

[Waddizzle]

ScottyP gave a very explantion of the differrences.  You will able to use the faster shutter speeds in low light conditions, or perhaps more importantly lower ISO settings.  Lower ISO settings will reduce the chances of having grainy photos.

"Canon 6D, EF 70-200mm L f/2.8 IS mk2; EF 24-105 f/4 L; EF-S 17-55mm f/2.8 IS; EF 85mm f/1.8; Sigma 35mm f/1.4 "Art"; EF 1.4x extender mk. 3; 3x Phottix Mitros+ speedlites"

Excuse me Mr. Fer Tographer, but how are you able to use that EF-S lens on a 6D?  ???  The extender?

[ScottyP]

That list used to include a T3i body. I sold the camera on Craigslist but there were no takers on the lens. I am needing to sell it too. Perfect condition. Only used for 1 year then put away when I got the full frame camera.  Evidently the photo-taking population of Pittsburgh which understands why a 17-55 f/2.8 is better than a kit 18-55 is smaller than the population that buys camera bodies. 

[ebiggs1]

If she were my daughter, I would have her get ahold of Scott and buy the EF-S 17-55mm f/2.8 IS USM Lens from him.  As a general use lens it will be far better than any prime 50mm.  Primes are pretty limited in their use.  As a general rule you zoom with either the lens or your feet.   One or the other.

[RobertTheFat]

---

@ebiggs1 wrote:

If she were my daughter, I would have her get ahold of Scott and buy the EF-S 17-55mm f/2.8 IS USM Lens from him.  As a general use lens it will be far better than any prime 50mm.  Primes are pretty limited in their use.  As a general rule you zoom with either the lens or your feet.   One or the other.

---

That lens is one that you should probably test first, before buying it for a Rebel. I've bought two of them: one for myself (with my first 7D) and later one for my wife. Mine had a serious backfocus problem and required 9 points of AFMA. Hers was OK, which is lucky, since her T2i doesn't have AFMA. I think my experience was a reminder that despite the nice IQ of the 17-55, it isn't an "L" lens.

[ebiggs1]

Bob from Boston,

"Mine had a serious backfocus problem"

On my "Top 10" things to worry about today, that would be number 10.

[RobertTheFat]

---

@ebiggs1 wrote:

Bob from Boston,

"Mine had a serious backfocus problem"

On my "Top 10" things to worry about today, that would be number 10.

---

You wouldn't be so dismissive if you'd been in my shoes. The 7D and the lens had arrived a day or two before a critical photo shoot, an award ceremony at MIT. I almost always use two cameras at events, and at the time I had a 50D and a Rebel XTi. I was very keen to replace the Rebel with the 7D; so even though I hadn't had time to run tests, I decided to wing it. But afterwards when I looked at the pictures taken with the 7D, they were too blurry to use. Fortunately my 50D, with an original Sigma 50-150 f/2.8, worked well enough to bail me out. I guess it was a lesson learned, because since then I've never been stupid enough to take a camera or lens on an important shoot witout testing it first.

[ebiggs1]

Bon from Boston,

"...  since then I've never been stupid enough to take a camera or lens on an important shoot witout testing it first."

Yes, yes experience is the best teacher.  Lesson learned, never, I mean never, take untested gear to an important shoot. Cardinal rule number 1.  Glad that is over for me!

On the other hand nine out of ten (or maybe 90 out of 100) of the ef-s 17-55mm f2.8's will not show that behavior.

[ScottyP]

My lens had/has zero problems and focused dead-on.