lens review: Nikon 50mm f/1.4G vs Nikon 50mm f/1.8G
The 50mm lens in general is an interesting optic. Not necessarily for what it does, but how it seems to have fallen out and back in favor over the years. For example, in the 1970’s pretty much all 35mm film cameras shipped with a 50mm lens. Zooms weren’t something that just came with the camera as a kit lens. It was the 50mm lens that was the “kit lens”. So the first thing the serious amateur would do, is dump the 50mm lens and get a zoom lens to get some variety in their photographs.
Then over the years, more compact and slower aperture zooms became the norm. Even more so during the digital era.
Now, as more of the newer photographers are realizing that a 50mm lens is an inexpensive way of getting super-shallow depth-of-field, the 50mm lens is seeing something of a resurgence in popularity. That super-shallow DoF is a look that your f5.6 kit zoom lenses just can’t give you.
With that, a 50mm lens deserves a place in your camera bag. It takes up little space, and is (usually) inexpensive. (Well, until you step up to something like the Canon 50mm f1.2L … but that’s another story.)
Nikon released the Nikon 50mm f/1.8G (Amazon) as an update to the popular Nikon 50mm f1.8D (Amazon), and as a more affordable option than the Nikon 50mm f/1.4G (Amazon) … so let’s look at how it performs.
A quick summary, comparing the Nikon 50mm f/1.8G to the Nikon 50mm f/1.4G
- sharpness wide open at f1.8 is very close the f1.4G optic. Stopped down to f5.6 both lenses are razor sharp. As you’d expect from a lens with a fairly simple optical design like a 50mm lens. (Until you get to the Canon 50mm f1.2L which shifts focus as you stop down. But, that’s another story.)
- the bokeh of both lenses look the same to my eye
- focusing of the f1.8G is noticeably faster than the f/1.4G which is kind of a slouch. This might be due to the longer focusing “throw” of the f/1,4G optic. But the f1.4G just seemed slow and has received sharp criticism for that. The newer f1.8G is a huge improvement.
- the f1.8G is more than $200 cheaper than the f1.4G
- the f1.4G has a 2/3rd stop faster maximum aperture than the f1.8G
(As an aside – I have tried three copies of the Sigma 50mm f1.4 lens at various times .. of which two exhibited back-focusing straight out of the box. That’s less endearing.)
1/500 @ f1.8 @ 200 ISO
This is typical of the look one can achieve with a 50mm lens, and using shallow depth-of-field.
In this case, the background is melting away not only because of the shallow depth of field, but also because of the way I shot against bright light, and allowed the background to over-expose. Just for interest sake, the background here above Jessica is an art display of pieces of linen blowing in the wind. (It was also seen here in this review of the Canon 8-15mm f/4L fisheye zoom lens.)
observations on the optical sharpness of the Nikon 50mm f/1.8G
With fast primes, I do think we don’t often use the lens for how sharp they are to the very edges. We photograph 3-dimensional subjects. Not flat scenes. (Besides, if you wanted sharp images from edge-to-edge for a scene that is “flat”, you’d just use an appropriately smaller aperture.)
Fast primes tend to show distinct vignetting when used wide open. But this isn’t a negative in my opinion. It can in fact lend a specific “look” to the images. (The Canon 85mm f1.2L is great for this … lending a noticeable vignette when used wide open with the 5D body.) So the usual way of testing lenses would tell you about their optical quality .. but it would most likely not have much bearing on how the lenses are used – bringing attention to your subject via the shallow depth of field.
With these two images (click through to larger versions), you can see the difference in depth of field between f1.8 and f5.6 … but this shallow depth-of-field comes at a (slight) expenses of optical sharpness when used wide open.
Here are 100% crops (unsharpened) of her right eye of those two photos. The image at the left is for an f1.8 aperture, and the second image is for the lens used at f5.6 aperture.
The lens shows that typical slight haze (even though it looks sharp-ish) that you get with these lenses. So for me, this lens is sharp wide open, in that I would happily use it at wide apertures if I needed the shallow depth of field. If you want super-sharp though, then stop down. Those are your options.
bokeh: Nikon 50mm f/1.8G compared to a few other Nikon 50mm lenses
Before we look at the bokeh of this lens, keep in mind that shallow depth of field is not the same thing as bokeh. Bokeh is the evaluation of how pleasing the out-of-focus areas (usually) in the background appears. Also, we’re going to look at a single scene here. To really get an idea of the bokeh of a lens, we’d have to use it in a variety of situations at different focus distances and different apertures.
But this single example will already give us a good idea of whether the lens has pleasant bokeh or not.
Using a tripod, I took a series of photographs of Jessica at a specific distance. The crop images are from the top-right-hand corner.
The 50mm f/1.8G and f/1.4G show pretty much the same bokeh when used at f1.8 Note the way the out of focus areas are oval and have a soft edge to them. The f/1.4G lens appears to have slightly more round shaped out of focus highlights than the f/1.8G …. but this is such a small difference, that it wouldn’t factor in buying the one lens rather than the other.
Stopped down a little bit to f2.8 it still looks quite similar.
Comparing the newer f/1.8G lens to the f/1.8D we see that the bokeh of the G lens is more pleasing than the D optic. The out of focus highlights of the D lens has a harder edge to it, and would make the background less smooth than for the G optic. So this means to me that the f/1.8G lens has better bokeh than the f/1.8D
Stopped down to f2.8 it would appear the same and we even see that the D lens starts to exhibit a kind of hexagonal edge to the circles. (Both lenses have 7 blades to the diaphragm though.)
Just as a comparison to how the bokeh would look when it is less pleasing, here is how the older manual focus Nikon 50mm AIS lens appears at f2.8 …. the hexagonal shapes are quite distinct.
In summary … the bokeh of the Nikon 50mm f/1.8G is an improvement over the f/1.8D
The f/1.4G improved in a similar way over the older f1.4D lens in terms of its bokeh. Notice here how intrusive the bokeh of the Nikon 50mm f/1.4D can be when used wide open.