Why buy a 50mm f/1.8 prime if my 18-55mm kit lens already reaches 50mm?
Asked 10/15/2011
5 views
2 answers
0
I use a Nikon D3100 with the 18-55mm kit lens and I’m considering adding a 50mm f/1.8 prime. Since my zoom already covers 50mm, what practical advantages would the prime give me? I’m especially interested in portraits, low-light shooting, background blur, and overall sharpness. Also, are there any compatibility issues with the Nikon D3100 when choosing a 50mm f/1.8?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
14y ago
2 Answers
29
At 50mm on your 18-55, the max aperture is f/5.6. On the 50mm f/1.8, the max aperture is - obviously - f/1.8. It is perhaps not immediately obvious, but f/1.8 lets in 10-12 times more light than f/5.6. That is the difference between shooting at 1/10 second shutter speed (which is absolutely a no-go for moving subjects) and shooting at 1/100 (which is a usable shutter speed for moving subjects). Big difference indoors at night, for example. It lets you shoot without flash, or with the flash used as mere fill flash instead of it being the main light-source.
Note that Nikon has two variants of the 50/1.8, one with a built-in autofocus motor and an older one without. Do get the new one.
Originally by user3458. Source · Licensed CC BY-SA 4.0
user3458
14y ago
0
Generated from our catalog & community — verify before relying on it.
Yes—the focal length overlaps, but the big difference is aperture. At 50mm, your 18-55mm kit lens is only about f/5.6, while a 50mm prime opens to f/1.8. That lets in dramatically more light, which can mean much faster shutter speeds indoors and less need for flash.
A 50mm f/1.8 also gives:
- shallower depth of field for stronger background blur and subject isolation
- typically better sharpness, contrast, and fewer optical compromises than a kit zoom
- a fixed focal length, which can help you think more deliberately about composition
Tradeoffs:
- no zoom flexibility, so you may need to move your feet more
- you’ll likely switch lenses more often
- on a D3100, be careful which Nikon 50mm f/1.8 you buy: older versions without a built-in focus motor will not autofocus on that body. Choose the AF-S version if you want autofocus.
So while 50mm is already “covered,” the prime offers a very different shooting experience and image look, especially for portraits and low light.
Recommended products
UniqueBot
AI14y ago
Your Answer
Related Questions
Is a Nikon 35mm f/1.8 DX worth buying if I already have the 18-55mm kit lens?
Why buy a Nikon 35mm f/1.8 if my 18-55mm kit lens already covers 35mm?
35mm or 50mm f/1.8 for portraits on a Nikon D3100?
Which Nikon f/1.8 prime should I buy for a D3100: 35mm or 50mm?
Why does my Sigma 18-35mm f/1.8 look no better than my Nikon kit lens on a D3300?