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Category: New Questions

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Photography Question 
Jaime Brandel
BetterPhoto Member

member since: 6/5/2004
 

Fixed Vs. Zoom Lenses


I am going to buy a wide-angle lens in the very near future (I have a Canon 20D). What is the advantage of buying a fixed lens when you have so many more composition options when shooting with a zoom? I shoot mainly people...what focal length should I be looking for so I can shoot groups without any weird distortion? Any advice would be hugely appreciated! :)

4/25/2006 8:33:30 PM

 
Brock E. Litton

member since: 5/6/2005
  Back in the day... I'm not sure just what day ...but prime lenses were inherently sharper than zooms. But, alas, with the help of computers, today's zooms are very comparable as far as sharpness and colour go. If you're looking for wide-angle, the Canon 10-20 is amazing. It retails for around 799.99. A friend of mine purchased a Sigma 10-20 for less than half the price, and he really likes it. Good luck.

4/28/2006 7:35:42 AM

 
Bob Fately

member since: 4/11/2001
  Jaime, while Brock is correct that many of today's zoom lenses (at least the better ones) are optically as good as primes, there are two differences of note:
Primes can be much faster - a 50MM f1.4 offers a 3-stop advantage over a 17-70 f4 lens. This doesn't mean that you must use the widest aperture, but in terms of limiting depth of field so your subject "pops" against a blurred background, faster is better. Of course, faster lenses also afford the ability to take available light shots when it's just plain darker.
Primes are generally lighter in weight - something to possibly consider if you plan to carry your camera around all the time. Of course, the weight advantage goes away if you consider an 85MM f1.4 lens, but that's another story.
As for what focal length - well, that's got a lot to do with your shooting style. Certainly a zoom gives you more flexiblity, though of course with a prime you can walk towards or away from the subject. The weird distortion you mention is no doubt perspective distortion - this happens with very wide-angle lenses when they are used too close to the subject.
Say you want to take a head-and-shoulders shot of me. With a 50MM lens (a short telephoto for your camera), you could stand about 6-8 feet away from me and fill the frame, and my facial features would look "normal" (well, forgetting about my third eye and all).
Now switch to a super-wide angle lens - like a 14MM or less. In order to fill the frame with my head and shoulders, you'd need to stand much closer - a couple of feet or less from my nose. So here's what happens - because the distance from the camera to my nose is 2 feet (say) and from the camera to my ear is 2 feet 6 inches, the perspective makes my nose look outlandishly large. The ratio of those distances is basically 1:1.25. With the 50MM lens, the ratio (6 feet to 6'6") is about 1:1:08 - which we generally see as normal. If you took the same shot a third time, this one with a 600MM lens from 60 feet away, then my face would look somewhat "flattened", because the ratio of camera-to-nose to camera-to-ear would be tiny (1.008 or so).
The point is, this perspective distortion has only to do with how close you are to the subject. If you like street scenes, or to capture entire outfits rather than just the face, then a wider-angle lens could suit you fine.

4/28/2006 2:14:00 PM

 
Jaime Brandel
BetterPhoto Member

member since: 6/5/2004
  Thank you both so much for your time in answering my question. Lenses are becoming more and more confusing. I am currently assisting a professional at weddings and hope to shoot my own eventually. My favourite types of shoots are babies and children, and also families. Basically, I want to become skilled at it all, and I need the right lenses to do the job. I know I will need to buy a 70-200 but I also want a wide angle that will help me with vast scenic shots as well as group portraits. Brock, perhaps the 10-20 is what I should look into, as I know that on a digital SLR wide angle isn't as wide. Bob, thank you for the info on distance from the subject. I wasn't aware that distortion only really happens when you are close to the subject!

5/2/2006 8:19:41 PM

 
Dale 

member since: 7/1/2000
  Jaime,

Even with todays advances in technology, prime Canon L-series lenses still have a small edge over even the L-series zoom lenses. You will find that the prime Canon L-series lenses offer better correction and overall higher resolution and sharpness. Although, in order to extract every ounce of resolution and contrast from these prime Canon L-series lenses, your technique and approach must be top drawer. This usually means shooting at a low ISO such as 100, camera body tripod mounted with a high quality tripod such as a Gitzo 1228, and using a cable release. Even the slightest amount of shake or vibration of the camera body or lens will shave off bits of sharpness and resolution that these high quality lenses are capable of. Realistically, if you will be doing most of your shooting hand held, then a set of zoom lenses such as the Canon EF 16-35 f/2.8L USM, the Canon EF 24-70 f/2.8L USM, and the 70-200 f/2.8L IS USM lenses will enable you to handle just about anything that comes through the door. You do get what you pay for, and the Canon L-series lenses represent the finest lenses for Canon bodies. If you want to really get involved with shooting weddings, you will need a few of the fixed focal prime lenses in your bag such as the EF 24mm f/1.4L USM, the EF 35mm f/1.4L USM, or the new version EF 85mm f/1.2L USM lens. Often times, many weddings will be limited to available light shooting only, and many times even f/2.8 will be too slow for these situations. Furthermore, the faster 1.4 lenses tend to focus more accurately in dim light situations than compared to the slower lenses.

Dale

5/3/2006 10:38:52 PM

 
Jaime Brandel
BetterPhoto Member

member since: 6/5/2004
  Great information Dale...thank you so much! You confirmed a few focal lengths that I was looking at. But as far as the wide angle is concerned, wouldn't it be better to go as wide as possible? Like the 10-20 that Brock had mentioned? I recently used a 17-35 in a small church wedding, and the shot I got of the entire church (inside) from the back did not look like a wide angle shot...the pro I am working with told me it was because I am using a digital camera.

5/3/2006 10:52:12 PM

 
Dale 

member since: 7/1/2000
  Jaime,

The Canon 20d that you are using has a 1.6x crop factor, so this is why a wide angle lens perspective may not appear as wide. If you were using a Canon 5D or a 1DS Mark 2, the perspective would be according to the true focal length since these bodies feature a full frame CCD sensor. The widest zoom that Canon currently has available is the EF-S 10-22mm f/3.5-4.5 USM lens. This lens has a bit of distortion at 10mm, and if you shot a group of people, you will notice that people standing towards the end of the image are not very sharp. This lens is one of the newer Canon lenses that have been optimized for use with a digital ccd sensor, but I feel that the speed of this lens is a little slow unless you're using flash. Keep in mind that even the best lenses don't have exemplary performance from edge to edge at the largest aperture. If you have to shoot at the 10mm focal length at the maximum aperture of f/3.5, you may find that there is too much distortion for your tastes, especially if you have to make print an enlargement beyond 8"x10".

Dale

5/3/2006 11:31:51 PM

 
Amanda Murray

member since: 10/24/2005
  Thanks for being so thorough with your responses! I am learning so much by reading other better photo member's questions! I am always thrilled when people take the time to step back from a question and explain some of the theory and vocabulary, as well as offer answers.

5/8/2006 8:47:50 AM

 

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