Seems that most photographers choose the 50mm as their prime lens (at least from what I've read). I'm looking at getting a prime lens for my Nikon D3000 and the cost difference between the 35mm 1.8 and the 50mm 1.4 is quite significant. I know there must be some reason for the difference, and that the 1.4 will be able to get pictures in lower light and whatnot ~ it just seems that it is SUCH a large price difference for not much difference otherwise between the two lenses. So, this isn't a "weigh the pros and cons of the two lenses" so much as a "why do most photographers choose the 50mm 1.4"?

FWIW, I'm getting the lens to take pictures of my (fast moving) baby and toddler. I have the kit lens and a 55-200mm 4.0-5.6 zoom lens and have trouble getting good pictures without being outside.

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    FWIW 50mm (effective) as 'normal' is just a convention. I personally prefer 35mm and 85mm (effective) as they're more dramatic, of course dramatic != normal :) Look back through your photo collection and see what range in mm you like the photos of and pick a prime lens accordingly.
    – Shizam
    Nov 10, 2010 at 18:10
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    50mm isn't really "standard" on cropped sensor cameras like yours. It's just popular because those lenses are cheap and take good photos. This is partly because the camera makers perfected these lenses over many years, and partly because that focal length makes for a simple lens. But be careful, on your camera 50mm is quite zoomed in. As a test, set your kit lens to 55mm and walk around the house, getting a feel for whether you like that focal length. I went with a 35mm because it was more natural. At 50mm I found myself always trying to get further away from the subject.
    – rm999
    Nov 10, 2010 at 18:28
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    See also What is a normal lens?
    – mattdm
    Jan 19, 2012 at 15:13

8 Answers 8


Most standard because:

  • 50mm on a full frame is said to give a natural field of view.
  • 50mm is apparently an simple focal length to design

On a your crop sensor, it is 75e, while the 35mm is 52.5e. Thus, the 35mm lens will be closer to "normal"

Reasons why most photographers may choose the 50mm could be to use it for portraits on crop sensors. 75e is a great focal length for portraits, especially when combined with such a wide aperture. Other reasons may include: higher resolution, smoother bokeh, better color, better rendition, higher contrast and microcontrast, more flare resistance, less CA, less distortion, less vignetting, better build quality, faster AF, etc.

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    So would I actually be better going with the 35mm to get a more "normal" field, since I have a DX camera? Sep 3, 2010 at 3:31
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    Correct, and a 50mm lens if you want a bit of a telephoto for things like portraits.
    – eruditass
    Sep 3, 2010 at 11:17
  • Thanks! I've been trying to shoot at 50 for a few days to see if I like it...should I actually be shooting at 75 with my kit lens, or does the crop sensor on the kit lens adjust in the same way? Sep 3, 2010 at 13:32
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    @Sarah Yes, it affects the kit lens the same way; if you want to see roughly what a 50mm lens will look like, set the kit lens to 50mm. "Equivalent" focal lengths are just to give people a common frame of reference.
    – ex-ms
    Sep 3, 2010 at 20:47

Many photographers (especially those with full frame sensors or 35mm film cameras) opt for a 50mm prime lens because it is considered 'normal', i.e. not wide-angle or telephoto. Because these lenses are so popular, they are also produced on a relatively large scale, which also makes them cheaper than other lenses of the same speed.

With that said, there is probably a deeper underlying question to be answered:

Why is a 50mm lens considered 'normal'?

There are actually a few factors that contribute to this. If we look at a single human eye from a mathematical perspective (pun not initially intended), the focal length comes out to be around 17.2mm. [as a side note, its aperture is around f/2.1]. Our eye is, indeed, a wide angle lens.

Now, the eye's sensor size (the retina) is smaller than the 35mm film sensor that the '50mm normal' is based on. This will make the equivalent focal length of the eye longer, but not by enough to get it to 50mm, there is another factor at play...

The images that we take with our 50mm 'normal' lens are generally displayed on a screen, or printed (or developed) and displayed on a wall or in an album. Very rarely do we ever get so close to an image that it takes up our full Field Of View (if we did that, we would not consider the image we saw as 'normal' anymore). We generally hold a photo at a distance that makes it look 'normal' (optimally, at a distance equal its diagonal). Because the image only takes up a portion of our FOV when viewed this way, we are adding an additional crop factor, making the equivalent focal length even longer.

Only when we consider all these factors do we come up with a 'normal' focal length value of about 50mm. And remember, that value is only when the image is projected onto a 35mm sensor! for other camera types you need to multiply the magic 50 by your sensor's crop factor to get the 'normal' focal length for your camera.


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    I'd add that the analogy of our eyes as a lens is a bit misleading, because the images, as processed by our brain, are closer to a panoramic stitching than a single snapshot. Our eyes continuously scan a scene, and recompose it in a way that is not entirely perspective-based (interesting tidbit: Leonardo da Vinci understood this intuitively, and "cheated" with perspective in his paintings to get a more realistic looking scene than his peers. For instance, round objects in the foreground should be round, even if perspective say that they are really projected as an ellipse on the "sensor")
    – Bossykena
    Nov 11, 2010 at 19:03
  • That's an interesting answer. Do you remember the name of the article (I see it's been long ago, but still decided to try), that you referred to? The link is inactive now. Dec 10, 2013 at 8:30
  • This link? photosig.com/articles/585/article It works fine for me. The article is titled "The Human Eye - Our Prime lenses"
    – ltn100
    Dec 10, 2013 at 14:01

In addition to the answer above, both variants of the 50mm prime lenses (Canon & Nikon mounts) offer a huge bang for the buck.

Either lens (in the f/1.8 variety) can be had for under $100, or so.

I wish I still had the pictures (I do -- I just have no idea where,) but I did a direct comparison at 50mm between my Canon 24-70 f/2.8 L (~$1,200 is what I think I paid some time ago,) and my Canon 50mm f/1.8 prime (I bought this for $50 off of a for-sale board.)

If I recall correctly, the 50mm f/1.8 beat the 24-70 f/2.8L out at 50mm up to f/5.6.

So, with that said, if you like to shoot at 50mm (or 80mm on a 1.6x crop, etc.,) then it's a no brainer :)

Good luck!


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    Unfortunately, the Nikon 50mm f1.8 does not have an in-lens autofocus motor, so with the OP's D3000, it will not autofocus.
    – eruditass
    Sep 3, 2010 at 12:44
  • Ha, I was just going to say this :) Ya, the price difference I'm looking at is ~$190 (for the 35mm) or $440 (for the 50mm). AFAIK, the 50mm is a relatively new lens, so not really very easy to find used unfortunately. Sep 3, 2010 at 14:10
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    Nikon 50mm f1.8 is now available with in-lens autofocus motor
    – fubo
    Aug 12, 2015 at 7:23

I have a 50mm 1.8 (which unfortunately won't auto-focus for you) and the 35mm 1.8 DX. As mentioned above, the 50mm is really great for portraits - the crop factor with the 50mm gives lovely focus and crispness. I just recently bought the 35mm 1.8 DX lens from B&H and it too is quite good - great in lower light situations and fairly small (in size) so it doesn't add much weight to your camera. I paid about $190 for it, which is great considering how good these 'cheap' prime lenses actually are (as mentioned by Ian P above). For low-light close up photos i don't think you'll be disappointed with it.


It's actually just happenstance. The 35mm film still format was developed from an existing 35mm cine format, shot "sideways" to increase the image size, and the 2-inch cine lens was a cheap off-the-shelf lens at the time. Both decisions were cost-saving measures; 35mm film allowed the use of film ends, the unexposed bits at the end of, say, a 400-foot roll of film, and the 2-inch lens (a common, simple, easy-to-produce design) had the needed image circle while still being cheap enough. All of these decisions were made before a 35mm rangefinder camera was made, let alone a SLR.

50mm is actually rather long for a "normal lens". Consider that a 35mm frame is 24mm by 36mm. A square medium format camera has a frame that is 56mm by 56mm, and the "normal" lens for that format is 80mm; 150mm is considered "normal" for a 4x5 (inch) camera (think Speed Graphic).


I have the 35mm 1.8 and the 50mm 1.4 - and for people wanting thier 1st fixed prime I always point them at the 35mm 1.8 1st. Its cheap, light and will work on your D3000.

  • Agreed, for DX the 35/1.8 is the best "normal" lens!
    – gerikson
    Jan 12, 2011 at 18:29

The 50mm is "standard" because it's a cheap lens to produce, and in the era of slow films, having a fast max aperture for little money was a good thing for most photographers.

Many SLRs were sold with a 50/1.8 or 50/2 as a kit lens. When films became faster most consumers found a slower zoom lens to be more versatile.

I believe Oskar Barnack, the creator of the small-format camera (the Leica) chose 50mm as a standard lens because even if it was longer than the theoretical standard of 43mm it was easier to produce a good 50mm using the technology of the time.


This is popular because of few reasons
1. Bokeh , f1.8 , better than other lens(which are double its price) in low light.
2. Price of the lens to sharpness u get !
3. Good for portrait.
4. Light weight, I use as a walk around lens.
5. Fills life to you picture .

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