Are there reasons to go for an f/1.4 over an f/1.8 lens as my first fast prime?

Question

I've been getting back into photography as a middle aged woman after not doing much of anything with it since high school and college. Back then I had a Pentax K1000 that I loved and took with me everywhere I went. Do digital has been new and overwhelming but also wonderful for me (the immediacy of Lightroom is wonderful).

I currently have only the kit lens, which is 18mm to 55 mm). I have decided to invest in a 35mm prime lens. My reasons are many but are likely important in terms of my question. I frequently find myself wanting to shoot in doors in low light situations (family and friends mostly but not entirely) or where I would like to create a shallower depth of field than what I can achieve with the kit lens. Also, sometimes I spend too much time worrying about focal length and I think it kind of jams me up. I'm looking to simplify. One thing I've decided to start doing is to just carry my camera with me everywhere to start looking at what I see daily in a different way and try to shoot something each day. I live in the suburbs and want to be as low key as possible.

I do not have a full-frame camera, which is why I am looking at the 35mm focal length and not 50mm. I just think it is a nice, versatile focal length. After doing some research it seems that my options are a fairly cheap Nikon f/1.8 that is made for DX cameras. Alternatively, the Sigma 35mm f/1.4 DG HSM Art is quite a bit more expensive but (a) would fit a full frame Nikon if I decide to upgrade at some point, which is certainly possible a few years from now and (b) has a wider max aperture. There is also a Nikon 35mm f/1.4 but it is very clearly out of my price range right now.

Certainly the price difference between the Nikon f/1.8 and the Sigma f/1.4 is not nothing for me, but if there are good reasons to pay extra for the Sigma I could do it. Any thoughts on how much of a difference the jump to the Sigma would be in terms of quality, versatility, etc. Or can anyone suggest other options?

Answer 1

I have not used the Sigma you refer to, but I have extensively used (and have owned for some time) the Nikon you refer to. I've shot it on both the D3200 and D7200. Usually the only lens I carry... and for a 3 week tour of Australia, it was pretty much the only lens that ever made it out of my backpack.

I do not have a full-frame camera, which is why I am looking at the 35mm focal length and not 50mm.

The DX "crop-factor" makes the 35mm DX behave roughly as a 50mm on 35 film.

(a) would fit a full frame Nikon if I decide to upgrade at some point, which is certainly possible a few years from now

The DX will fit a Nikon FX. Assuming it's anything less than 8 years old, the FX camera will automatically fall into "crop" mode and shoot using a reduced portion of the sensor. That is to say, it'll work - but behaving as if it were a DX body (with less than half the resolution of the full sensor). You'll get that "50mm-ish" equivalence.

The Sigma 35mm will behave as a 35mm on an FX body. You'll get full frame use, and it'll be significantly wider than it behaved on the DX.

(b) has a wider max aperture

Shooting at 1.4 is going to give you seriously shallow focus. You can see how shallow the 1.8 DX goes here: http://www.kenrockwell.com/nikon/35mm-f18.htm

I've found I rarely get down to f1.8, nearer 2.0 or 2.2 is vastly more common. Obviously it depends what you're trying to do...

[Upgrading to an FX] which is certainly possible a few years from now

The DX sensors are pretty awesome. They're getting better every day too. Getting up to an FX (and I have shot on one) is not only a huge leap in price but also a huge leap in weight... and ultimately (I believe) does not automatically add to the photos. The photographer makes the photos, not the camera.

DX bodies with the f1.8 35mm lens you're looking at are light, robust, and will do a lot. Even in the dark... even hand held. (There's no VR [vibration reduction] on that lens FYI.)

I've uploaded some personal photos shot on mine for your reference to flickr: https://flic.kr/s/aHskZb57Kg. Flickr pulls the EXIF data, so you should be able to see what settings I used. I've specifically included some "bad" examples where I feel the f1.8 depth of focus was too shallow.

I have hundreds of example shots - I've tried to pick a variety of situations. Leave me a comment if you want a specific example, and I'll happily have a hunt.

Hopefully someone else can comment on the Sigma!

Answer 2

If you really want to buy a full frame lens and now have a camera body capable of using older lenses without their own focusing motor, you should also consider the Nikkor AF-D 35mm f/2 as an option.

The three lenses you mention and the AF-D f/2 are all optically very good and you will have a hard time noticing any differences in image quality. I have never used the Sigma lens, but I've read that the mechanical quality is supposedly not so good.

The two f/1.4 lenses will give you a half or one stop larger aperture, which may allow you to take pictures where less light is available. You must however remember that you are running into such a shallow depth of field, that you easily may not be able to focus on your subject. No one here will be able to tell you if you use your camera enough in low-light situations, where a very narrow depth of field is acceptable, to justify the much higher price for any of the f/1.4 lenses.

Answer 3

Unless you absolutely need the extra stop of light for low-light shooting or you just really like the rendering of the Sigma I would personally go for the Nikon because it is smaller (by approx. 1/3 in both length and diameter), lighter (197 g vs. 660 g!), and I personally prefer its rendering. Both lens have great IQ, and 0.3m minimum focusing distance, so the only real difference on an APSC camera is the max. aperture.

I haven't owned either but used the Nikon on a friend's D7100 for a couple days and loved it. In practical terms the Nikon is small and light, has excellent IQ even at wide open aperture, though sometimes gives a bit of a "busy" bokeh, not that it's really noticeable.

The main advantage of the Sigma 1.4 on an APSC sensor is the 1 stop increased aperture. This can possibly be useful sometimes, for example when shooting indoors in rooms with small widows or at night, so that may be something to consider. Some people like the increased aperture for "Bokeh" shots or for blowing out the background in portrait shots, but the truth is that focus distance and focal length have a much bigger effect on how out of focus the background is in normal circumstances. Thus it probably makes more sense to just buy, for example, a dirt-cheap used 50mm f1.8 if you really find yourself lacking in this regard at a future time. Also, it probably makes no sense to buy it to "upgrade" to a FX camera unless you're sure you need a fast 35 mm lens in a couple of years, because your needs and available lenses will probably change before then.

Answer 4

Well, Nikon does make an FX ED 35/1.8 as well. :)

But part of the point of having a DX body is that you can get better lenses for less money. Unless your move to FX is imminent, the money you save now can be used on other things: a flash, a tripod, etc. that will also be useful on an FX body. The lens may not retain a lot on resale, but you probably could recoup at least half the cost of the lens when the time comes to switch to FX. See that as a rental fee for the number of years you'll have to use it. I tend to call the 18-55, and 35/1.8 or 50/1.8 and a 70-something telephoto zoom the 'training wheels triple' most dSLR newcomers get as a first basic set of lenses with which to get enough experience to know the specific lenses they need to match their personal style/subjects/budgets.

While a 35mm f/1.4 lens is undoubtedly going to give you more maximum aperture to work with, FX sensor coverage, and higher-grade glass, a larger max. aperture also means a lot of other things: a bigger, heavier, and more expensive lens, possibly more softness wide open, a smaller/tougher-to-hit target for autofocus wide open, more possibility of chromatic aberration and vignetting wide open. You may be using your f/1.4 lens stopped down to f/2 anyway if you want to get "best performance" out of it.

That's not to say it may not be worth it. But while the lens may cost four times as much, it's only going to be 2/3 stop more on the maximum aperture than an f/1.8 version, which may perform similarly to the f/1.4 from f/2 downwards.

You may want to consider renting the f/1.4 you're looking at before buying it, or consider purchasing it used. Consider, too, that if you're seeing "better" images coming from an f/1.4 vs. the f/1.8 35mm lenses around, that someone who's willing to buy a full frame body and pay more for the more expensive lens may also have more experience, skill, talent, and time to put into photography than the rank beginner who can only afford the lower-end lens. :)

Low light can only be conquered so far by maximum aperture (believe me, I know. I adapted an old Olympus OM 50mm f/1.2 to slap on my 5DMkII to try it). A flash or tripod will actually extend your low light capability--even with the slow kit lens--quite a bit farther than f/1.4. Also, while maximum aperture is a factor in achieving background blur, it's not the only factor, just the most easily controlled one. Subject distance, background-to-subject separation, sensor format, and focal length are also factors that contribute, and even f/1.2 on full frame can't always completely blur the background at given subject distances.

Answer 5

Reasons to go for an f/1.4 lens:

• the ability to shoot at f/1.4 and f/1.6 for shallower DOF and low light conditions
• it's usually has better image quality at f/1.8 and f/2 than an f/1.8 lens. The advantage usually disappears by f/2.8-5.6, depending on the lenses.
• it usually has nicer out-of-focus rendition (bokeh)
• it often has better build quality and durability

Reasons to go for an f/1.8 lens:

• it's usually much cheaper
• it's usually physically smaller and lighter
• it often has less geometrical distortion
• depending on a particular lens, it could be less susceptible to flare and ghosting
• it could have smaller filter diameter

As I assume you already know, a 35mm lens will act as a 50mm lens on your crop-sensor camera. The one thing you should also consider is the fact, that the 1.5x crop factor equally applies to the effective DOF that you get in the images. It means that in terms of rendering depth of field a 35mm f/1.4 lens shot wide open will look like 50mm f/2.1 and f/1.8 will look like f/2.7. Needless to say, a shallower DOF gives you better subject isolation.

There are many good 35mm f/1.4 and f/1.8 lenses to choose from. Aside from Nikon and Sigma you should also consider Tamron as many of their lenses are really great, particularly 35mm f/1.8 full frame lens.

Another consideration is an FX vs DX lens. If you could upgrade to full frame in not so distant future, it could prove useful to buy an FX lens in the first place. On the other hand, a 35mm lens on a full frame camera actually acts like, well, a 35mm lens, so to achieve the same field of view as you had on a DX camera you will have to buy a dedicated 50mm lens.

All in all, it usually boils down to how much money you have available and to which lens you like more in terms of how it renders the image. The truth is, you pretty much gent go wrong with any of these lenses as neither of them is bad.