8

I am new to photography (just 3 to 4 months of experience) and I am looking to buy a new lens (either 35mm or 50mm, but mostly 35mm because I have already decided Sigma 85mm f/1.4 DG HSM Art Lens for the creamy bokeh) for general street photography.

I like my images to be as sharp as possible. I went through many websites and youtube videos and many of them mention that Nikon 1.4g is superior to Nikon 1.8g. At the same time they also mention that Nikon 1.8g is sharper. Why do they say Nikon 1.4g better when Nikon 1.8g is sharper ?

  • 2
    No, you don't want your images to be as sharp as possible. You want your images to be good, which is a different thing entirely. – Agent_L Apr 19 at 9:41
  • 1.4 and 1.8 refer to the apertures of the lenses. There are a huge number of lenses with those apertures. It doesn't really change the question, but would be nice if you include the focal length. Are you referring to 35/1.4 and 35/1.8? 50/1.4 and 50/1.8? – xiota Apr 25 at 18:53
  • @xiota At the time of posting this question I was focusing more on 35mm. After going through several portraits of other photographers, I ditched my plan to buy 35mm and bought 50mm 1.4g because I liked the bokeh effect of 50mm more. Also because I received an opportunity to shoot portraits of a model and I think 50mm is good fit for the job – Prem Ramman Apr 29 at 16:04
  • @xiota I understood from the answers that pictures should have an artistic value and sharpness is just a part of it. And for the kind of art I envision for portraits I need 50mm but for landscape I might need 35mm. – Prem Ramman Apr 29 at 16:12
11

What did the reviewers say about why they chose one lens over the other? They have their own priorities and biases. You should evaluate the information they present and decide for yourself whether you agree with their conclusions.

Everyone tests lens sharpness because it's easy. Just photograph a resolution chart and read off the numbers. However, this method really tests lens-camera combinations.

  • Beyond a certain level of sharpness, most pixel peepers should be satisfied. For me, around 65 lp/mm is "good enough". A lens that is at least that sharp gives me plenty of detail to work with in real images that are not of resolution charts or brick walls.

  • The differences in sharpness among lenses that exceed sensor capabilities make no difference to final image quality.

There's more to lenses than sharpness.

How you prioritize these factors can result in a completely different lens being "better" for you than for me or anyone else.

  • aperture – Lenses with larger apertures are usually more expensive and can produce more background blur, but...

  • bokeh (quality of blur) – There's more to "bokeh" than simple blurriness.

  • chromatic aberration – Many well-regarded lenses have CA when used wide open, and wide open is the only way to get those perfectly round bokeh balls everyone is chasing after. As long as CA is not out of control and adds just a bit of color along some of the edges, it's part of the character of the lens. CA is typically reduced when the aperture is stopped down a bit. It can also be corrected by software during post processing.

  • color rendering

  • contrast

  • distortion – Usually only visible when photographing brick walls.

  • flare ghosts – Often used for artistic effect.

  • focal length – 35mm, 50mm, and 85mm have different fields of view. Composing subjects similarly within the frame requires standing at a different distance from the subject with each lens. On a crop-sensor camera, 28mm or 35mm would work well from a few paces away. With 50mm and 85mm, you'll have to stand further back, unless you're trying to capture people's nose hairs.

  • macro mode / close focusing

  • technology – autofocus, image stabilization, etc.

  • other factors – weight, size, price, water resistance, feel, etc. (as Davidmh notes)

  • veiling glare – I'm particularly concerned about veiling glare because it rapidly degrades images into uselessness.

    veiling glare

    However, a bit of veiling glare can add character.

    veiling glare


I have two 35-105/3.5 zoom lenses from the 1980s that are quite sharp. The sharpness results are maybe too good and I wonder if I read the chart wrong. Regardless, the modern lenses still look just a bit better, but not because of sharpness.

Imagine these are 1"x1" crops from 40"x27" images. About the same level of detail can be seen in the clock regardless of lens, but the newer lenses have better contrast.

  • Canon EF 24-105/4L @ 24/4; Nikon 24-70/2.8E @ 24/2.8; Nikon 24-120/4G @ 24/4

    Canon 24-105/4L @ 24/4 Nikon 24-70/2.8E @ 24/2.8 Nikon 24-120/4G @ 24/4

  • Pentax-A SMC 35-105/3.5 @ 35/3.5 and 35/4.5

    Pentax-A SMC 35-105/3.5 @ 35/3.5 Pentax-A SMC 35-105/3.5 @ 35/4.5

  • And do not forget non-optical parameters, like weight, size, price, water resistance, feel, etc. – Davidmh Apr 18 at 13:38
  • I wouldn't say chromatic aberration adds character to images unless you are deliberately going for a retro or disposable camera look. Fortunately however, automatic CA removal in Adobe Camera Raw is extremely good these days, so it's not normally a problem anymore – binaryfunt Apr 18 at 15:40
  • @binaryfunt The sample image is from a lens that is very sharp, when photographing resolution charts. There is a bit of color along some of the edges that doesn't detract from the image. Some very well-regarded lenses have the same feature. What makes the image unusable is the strong veiling glare. That said, a bit of veiling glare can also add character. – xiota Apr 19 at 0:20
  • 1
    @xiota I don't disagree with you about veiling glare. I just think chromatic aberration never adds character unless you're aiming for that "disposable camera" look, in which case anything goes for lens quality really – binaryfunt Apr 19 at 0:24
17

1) Sharpness is complicated.

Lens sharpness is just one aspect of the overall resolving power of a camera system. The appearance of crispness is separate from the rendition of detail. And a lens can be sharper in the center but not in the corners, or less sharp overall but consistent across the frame.

And that's not even getting into other factors that affect the system as a whole. Camera shake, subject movement, focus accuracy, diffraction — the list goes on. In fact, I'd go so far as to say that unless you are very meticulous with your technique, you won't ever notice a sharpness difference between these lenses, because any lens difference will be overwhelmed by the other things.

2) Sharpness is overrated.

It's fine if you like it, but recognize that sharpness is just one aspect of optical performance. All lens design is about compromise between various factors, and correction for one thing inevitably leads to compromise in another. See What image-quality characteristics make a lens good or bad? for a detailed look at this. Generally, though, when someone is saying that a lens is better than another even though the other is sharper, some of these other factors are probably at the forefront.

3) Don't forget that extra speed.

An f/1.4 lens can stop down to f/1.8. An f/1.8 lens can't open up to f/1.4.

4) But, finally, don't read too much into reviews — and don't get obsessed with "best".

There are basically three kinds of lens reviews on the Internet.

First, there are highly technical ones which measure the optical compromises and flaws using a workbench and special software and perhaps lasers. These are fun and can sometimes reveal useful information, but in general tend to emphasize small flaws and differences which rarely actually make a big difference to results.

Second, there are reviews by people who bought an expensive lens and need to tell everyone how great that lens is to help their internal justification. Since here we are comparing a $1700 lens to a $500 one — or a $200 one, if you are looking at the DX version — this may play more than a small part.

Third, there are subjective reviews from experienced photographers showing work they've made with a lens and talking about how it handles. These rarely mention technical details except in passing. These are the most useful in some ways, but you really have to read a lot to get a sense of whether you'll agree.

Overall, the best way to make this decision is to borrow or rent the lenses in question and try them each for a couple of weeks. (You need at least that time to really form a working relationship.) You'll probably find that you like the results you're getting with one better than the other — or if there is no clear winner, you can decide to go with the cheapest.

It's really easy to say "I clearly want the very best one!", but this is a trap. And, obsessing over technical reviews and measured sharpness play into that trap. What you want is a lens that fits your purpose — and your pocketbook.

  • As per 3rd point, does it mean at 1.8 both the lens will take 100% same image ? – Prem Ramman Apr 18 at 5:05
  • 7
    Brief resume of a conversation I had with the cinematographer on a high-budget TV show yesterday.. Him: "We use these old 1970s Fuji refurbs, £25 grand each, for primes" Me: What about those Arri 45-250 zooms you were using on [other movie]?" Him: "Too sharp, these give us a much better feel." – Tetsujin Apr 18 at 5:30
  • 2
    @PremRamman No two lenses will produce 100% the same image at the same settings. The amount of light that reaches the sensor is mainly influenced by the aperture and the shutter speed, yes, but how the light bounces inside the lens is completely dependent on the lens architecture. They will produce a very similar image, though, maybe even so similar that you won't notice the difference. – Ian Apr 18 at 6:51
  • +1 for Second, there are reviews by people who bought an expensive lens and need to tell everyone how great that lens is to help their internal justification.! – flolilo Apr 27 at 14:38
  • @PremRamman An F1.4 lens stopped down to F1.8 will have a polygonal aperture. An F1.8 lens wide open will have a circular aperture and defects associated with wide-open apertures. So the images could look very different. Stop both lenses down to F2.8 or smaller, and the images should look more similar. – xiota Apr 29 at 17:58
2

You want the lens for street photography. The AF-S DX NIKKOR 35mm f/1.8G is a great lens for street photography for a DX-format body like your D5600. It's very sharp. It's also very affordable. An f/1.4 lens would give you a little more flexibility in lower light but it would cost almost 10 times as much. The image quality would be comparable. Since you're new to photography, it's understandable that you want to make sure you're spending your money wisely on good equipment. But don't get hung up on tiny technical details. It's very unlikely that you would be unhappy with either the f/1.8 or the f/1.4. You might, however, be happier having more money in your pocket.

0

In reality, you don't want your images to be "sharper"

You want the primary subject of the image to be substantially sharper THAN THE BACKGROUND, and that's actually a totally different "thing".

In other words:

What you WANT is smooth, creamy, dreamy, bokeh.

Yes, the cheaper 1.8 lenses may be plenty sharp, but the bokeh may be poor. I have a the 50mm 1.8, and I literally never use it. While sharp the bokeh is USELESS. I suppose I could use it for a product shot since the BG gets cut out anyway, but YUK.

On the other hand I have a Nikkor 85mm 1.8 that has nice bokeh, though not as dreamy as the 85mm 1.4

When you pay a a ton of money for pro glass, what you are really paying for is how well the out-of-focus areas are rendered. My favorite lens is my Nikkor DC105. The DC stands for "Defocus Control" and allows you to adjust bokeh. It's a $1200 lens, and it's what is "normally" on my camera.

Look at an image you really like - you may find that the majority of the image is out of focus, with the subject in sharp focus. Such an image has more apparent depth.

Good Bokeh: Nikkor 80-200 f2.8

Daisy Good Bokeh

Nikkor DC 105mm f2.0

rose

Here's an example of bad bokeh I saw on DPReview (in a thread of bad bokeh images) — Yikes! EXIF indicates it's an Olympus 50-200 f2.8-3.5

Bird Bad Bokeh

As such, when choosing a lens pay more attention to how it renders the out of focus areas.

But also, with a 35mm and wider, pay close attention to barrel or pincushion distortion. Also, is your body a DX or FX? While DX only lenses are cheaper if you have a DX body, an FX lens will remain useful when you upgrade to an FX body.

  • Not trying to dispute it at all, but can't help not to notice that the last ('bad') photo is apparently much oversharpened in post, which tends to exacerbate bad bokeh. – Zeus May 2 at 2:35
  • Possibly, I didn't work on it, but I will say that the EXIF data does not indicate any post processing being used. – Myndex May 2 at 3:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.