Sep 132012
 

Finally a fast 50! The new Nikon 18-5 f/1.8 Lens for the “1” System. 

Nikon announced (so far) ONE lens for the Nikon 1 system. You know, the “camera I expected to hate”. I am expecting a V2 announcement after they released the J1.2 (J2) but who knows..let’s see how it goes. All I know is that the new 18.5 1.8 lens will finally bring a fast 50mm equivalent to the 1 series and I for one am excited to see how this lens renders on the 1 series camera. Though I would expect a V2  to be announced simply due to the fact that Sony came out swinging recently with the RX100 and while the sensor is the same size its performance easily exceeds the Nikon 1′ sensor. So something like a V2 with better sensor performance would be sweet. Add on this 18.5 lens and you have the fast 50 experience on the little 1 series. So far all I have seen from this is the lens and no samples. It’s cheap but most generic 50 1.8 lenses are. You can pre-order from Amazon for $186

 

You can pre-order the Nikon 18.5 f/1.8 Lens HERE for $186!

  80 Responses to “Finally a fast 50! The new Nikon 18-5 f/1.8 Lens for the “1” System.”

  1. Hard to understand why they didn’t bring this out a year ago. It’s not like moderately fast normal lenses are difficult to design, or expensive to build.

    I kind of like my V1, but I don’t love it. This lens will help, but I’m struggling with whether to sell the camera now and just hope that Nikon really has a V2 up their sleeve. I’m not hopeful; usually there are leaks or hints of some kind, but I haven’t seen even one, except for wishful thinking in the fora.

    • You’re right.
      These lenses are easy to design with CAD. It should have been out last year. And a 35mm equiv. f1.8!

      • And an 85 or 100 equiv. f1.8. And then I’m done. (Not a big wide-angle fan)

      • I agree that a 35 equivalent should have been introduced either instead of or along the 50 plus a 20 and an 85 or thereabouts and you have a really useful package…
        Too bad the public cant influence the cam manufacturers as to what we would like to have vs what they think we should have…

    • Anyway, the 18.5mm f/1.8 rocks! And that’s what it’s about man. Super small and lightweight and reasonably good build quality. And you can confidently use this baby wide open too. Seriously, what more do you need? Coupled with the 10mm f/2.8 and the upcoming 32mm f/1.2 you’ve got a nice set of primes that cover many situations. Hey, that Nikon 1 stuff is so small, you can throw a couple of zoom lenses in your bag too and you won’t even notice that it’s there. It’s like a Hobbit camera. Downsize baby, downsize!

  2. If Nikon can deliver RX100 quality in the V2, combined with snappy auto focus and a range of inexpensive, fast primes, they’ll have a sweet little system. The 1 System has different strengths than most of the mirrorless competition, and that’s fine, but Nikon has got to keep pushing things forward.

  3. Sweet! I pre-ordered too! Now a fast 35mm and 85mm and we’re set! And maybe a V2 with even better sensor. The V1 still runs circles around most DSLRs. How many Mirrorless or DSLRs can shoot off 40 RAW images in a few seconds and not even blink? Very, very few! Nikon 1 rocks!

    • You can’t just choose one metric and then declare “runs circles around most DSLRs.” You might as well call the Toyota minivan “better than most other cars” because it has more cupholders. Yeah, if you’re a golf instructor and are always shooting in bright light, then the V1 might be good. But for most other people, I have no use for “shooting off 40 RAW images in a few seconds and not even blinking.” I take very deliberate photos. Surgical here, not pray and spray.

      • LOL “Pray and spray”…I love it!

      • You dont have to shoot 40 images at one time in seqeunce, but if you look at the contact sheets of the few great film photographers you”l find that they too at tines shooting like 15 frames on one particular subject witht he same composition one after another. That is also “spraying and praying as well” The old days when your thumb was your FPS, you could miss the shot in between the cocking of the shutter. Now today with all the fast FPS it would be silly to gorgo it if it in the end you get that picture. Some very famous photog said” it’s always luck” . It is beter to get the photo no matter how you do it rather than not getting the picture. Folks today use words like “chimping”. As if chimping or not dfoing made one a btter photgrapher…it doesn’t.During the film era, they had “chimping” too. It was called ” looking at your contact sheet after you develope it”. They also had FPS and spray and pray, just on a slowly rate, it’s no different than today. What matter is not what you do to get the photo, what matter is the photo.

        • LOL! I can imagine how fun it is to review your photos at the end of the day. 10-20 photos of every scene. What a nightmarish way of practicing photography but to each his own.

          • He didn’t say 20 images of every single scene – but it is nice to be able to do so for the highly dynamic scenes which you can’t really time or predict.

            Still, this is another reason why the V1 is a great option: you can take a picture using the Smart Photo Selector mode, which takes 30 pictures for you can then picks the best one, thus taking over all the above steps and providing the result immediately, not later hunched over the computer tinkering with a contrast slider for hours while your spouse is alone in bed. Of course you can still second-guess the system if you want, so no loss there

          • That’s what the DELETE button is for on the camera or the computer. Back in the day the old timers had it too, it was called ” looking at the contact prints and NOT developing bad shots.” Shooting a hundred shots and getting one decent shot is better than pretending to be some hot shot and missing the shot intierely. If you look at the contact prints of even Magnum photographers you’ll see at time in a scene they stay there witht he same composition and fire muliple shots, sometimes even near the entire roll of the film to try and get the right timing of shot…and that was before auto FPS cameras. To have a tool and not use it because of some silly. If someone can get three good shots out of a thousand , it’s better than one, is it not? Just because someone takes their time and shoots one picture once a day even, it doesnt garantee that the one pic is any good. It’s like the folks who cry about “chimping” made up words in order to make some foks feel better about themselves. “Chimping” or lookign at the photo a second after words doesn’t do anything for or against a photo once it’s already taken. They had “chimping” back in the film days too, it was called ” looking at your negative or contact print after developing.” LOL. Does it matter if someone look at the pics he took 2 seconds after or a month after? LOL

      • agjios, you’re making fun of the shooting technique, but actually, because of its fast cycle rate and the nice long zoom, the V1 is surprisingly good for sports and events like airshows.

        Sometimes “spray and pray” is a useful and respectable technique.

  4. Yes, Nikon has a poor strategy with this system 1..
    But, for me who own one…
    The most important is that this lens is a reality now.

  5. Yes, can’t wait to see some more images from this lens and how the IQ and bokeh compare to that of the RX100!

    I have, and love, both cameras.

    But while the RX100 has been hogging most of the spotlight, it may now have reason to feel a little bit of… lens envy.

    Where the N1 will be able to capture a 50mm FoV at f1.8, the biggest aperture the RX100 can offer at that focal length is f3.5.

    I know 35mm may be one of the most popular focal lengths, but personally I’m more of a 50mm shooter.

    Come on Nikon, lets see some (more) images (there are a few here: http://imaging.nikon.com/lineup/acil/lenses/1_nikkor_185mm_f18/sample.htm).

    I’ll have a big helping of DoF, with an order of sharpness on the side. And can I get that to go please, I’m in a bit of a hurry? :)

  6. Relax man, he’s just having a laugh. Why be so serious?

  7. I pre-ordered mine, now I just have to sit and wait. Well not really, I’ll take pictures and wait. As for a V2, I don’t think it’ll be coming too soon. Of course it’s just my opinion but if there was a V2 with a better sensor coming out soon then why would they have released the J2 with the “old” (but actually still current) sensor? It would have just made sense to hold back and release both with the new sensor simultaneously. I’m sure a V2 will be announced, but not for at least 6 months. Anyway, I’m not too concerned with it. The V1 is still as fun as ever for me and the new faster lens will keep it fresh for me.

  8. I agree with all the above comments. I have not purchased a V1 simply because I think Nikon were hanging about waiting to see how it sold and I wasn’t confident they would bring out some fast primes. What they should have done, as previously mentioned, is bring out the fast primes to start with. People may have bought into the system in much greater numbers. What’s happened now, while Nikon were hanging around naval gazing other camera makers have upped their game bringing out exiting new models for us to choose.

    I do like the look and feel of the V1 and the built in viewfinder really does sell it to me. I have tried to use cameras without a viewfinder and I just cannot get on with them, I much prefer a viewfinder, and if optical so much the better. This is one of the reasons the Fuji X100 is so well thought of.

    If I thought Nikon were committed to this system then I would not hesitate to buy it but if they bring out a “2” version then the price of the “1” will drop like a stone leaving me with yet another expensive camera worth £100.

    • Those of us who did buy it now have a $1000 camera that’s selling at retail for $450 after less than a year on the market. And even before there’s a follow-on model.

      As far as I know, that’s never happened before.

      It’s hard not to feel a little unhappy about that.

      • Yup, a harsh reality. Luckily I bought my J1 with 10mm f/2.8 about two weeks ago. Even new, it’s now a bargain! Got the little grip too. A fine cheap system camera.

    • The questioning of Nikon’s “commitment” to the 1 Series always surprises me. This isn’t Mamiya, releasing a completely new and totally incompatible family of lenses for each and every camera model they ever introduced. Nikon has had, for 50 years, exactly one mount: F. Now, historically, they have introduced a new mount, and they continue to boast how they “designed it from the ground up” and have been working on it for years. But as if that weren’t enough, they named the new family the *1* Series! Could it be any more symbolic or clear? The “1” Series is Nikon’s future, and they’ll introduce dozens of lenses for it over the next 50 years and eventually sell another 70 million of those, too. If you like it, get one, if not, cool, but let’s not pretend the best new camera introduced since digital is going to up and go away in a year. If nothing else, admitting they were wrong by retiring the family would be committing brand suicide for Nikon; they’ll never do it.

  9. No VR though. But maybe I can cope with it…;)

  10. I would hesitate calling this a fast lens, since you’ve kinda gotta take sensor size into account. An f2.8 lens on a P&S and an f2.8 lens on a medium format camera are two very different lens behaviors. This f1.8 for Nikon 1 is only equivalent to an f4.9 lens on a 35mm sensor, which isn’t exactly speedy.

    • SO much mis information out there on this topic. This is still an f/1.8 lens! It has the light gathering ability of an 1.8 lens NOT a 4.9 lens. Meaning you can get more done in low light with it. Light Gathering = 1.8. Depth of Field – 4.9 – so it is indeed a “fast” lens. Just not a fat shallow DOF lens.

      • Yes, but you’re not taking sensor size into account when it comes to the amount of light being gathered. F1.8 meters the same, but more light is obviously being collected by a larger sensor.

        So, you can raise the ISO of the larger sensor, because it has a cleaner signal.

        In other words, assuming identical sensor technology, shooting an f1.8 lens on an 13.2mm x 8.8mm sensor at ISO 200 would be like shooting an f4.9 lens on a 24mm x 36mm sensor at ISO 1400-ish, both in terms of DOF and image quality.

        That’s the only point I’m trying to make.

        • GH, +1.

        • Using that logic, a truck going 100 km/h is faster than a car going 100 km/h.

          How fast a lens is has nothing to do with how big a sensor it’s attached to. DOF is a different concept.

          • 1) That’s simply a flawed analogy :)
            2) see my message below.

          • Would you consider an f2.8 lens on 6×6 film to be considered fast? What about on Nikon 1?

          • ”Using that logic, a truck going 100 km/h is faster than a car going 100 km/h.”
            Exactly, a truck going 100km/h will be able to deliver a lot more cargo in a given time than a car going 100km/h. Why do you think the shipping industry uses such huge container ships if they could transport the same amount of goods using an equal number of tiny speed boats.

            ”How fast a lens is has nothing to do with how big a sensor it’s attached to. DOF is a different concept.”
            You are right. A lens with a 1cm aperture will be equally fast regardless what sensor size it is used on, when it is made to focus on a longer distance on a larger sensor the sensor will receive the light at a lower density though and the lens will be tagged with a different focal length and F-number than the smaller format lens.

        • Steve Huff,

          The light gathering capacity of 18.5 mm f/1.8 on a small Nikon 1 sensor is exactly the same as that of 50 mm f/4.9 lens on a full-frame sensor. Just compare the entrance pupil diameters of these lenses 18.5 mm / 1.8 = 10.2 mm for the first lens, and 50 / 4.9 = 10.2 mm for the second. In other words the area from which the lens collects light is exactly the same for these two lenses. The image projected by the 18.5mm Nikon 1 lens is obviously smaller and therefore brighter, but each pixel of a 10 megapixel CX sensor will receive exactly the same amount of light as each corresponding pixel of a bigger full-frame 10 megapixel sensor behind a 50 f/4.9 lens. That means that the resulting noise in images taken with 18.5 f/1.8 + CX and 50 f/4.9 + FX at the same shutter speed to a very good degree will be the same. In other words ISO 200 of a 2.7x crop camera is about as noisy as ISO 200 * 2.7 * 2.7 ~= 1400 of a full-frame camera, just like GH mentioned above (as long as you are comparing sensors of the same generation, as they typically have very similar efficiencies).

          To sum it up:
          135 format equivalent focal length = (actual focal length) * (crop factor)
          135 format equivalent F-number = (actual F-number) * (crop factor)
          135 format equivalent ISO = (actual ISO) * (crop factor)^2

          Makes comparing different lens/sensor formats so much easier :-P.

          • I think what most people do not realize is that the noise is already present in the light that creates the image. Sensors simply capture that noise, amplifying midtones noise to approximately the same degree irrespective of pixel size or the manufacturer. DxOMark webpage has a good intro article on that, called “Essential characteristics of noise” if you are curious to learn more.

          • Bingo! Great explanation. Thanks.

          • You’re thinking backwards…

            Your whole argument centers around the size of the sensor. That has nothing to do with how fast the lens is.

            If I had an 18.5mm f/1.8 lens that was the size of a swimming pool, attaching it to a V1 wouldn’t give me any more light than the little Nikon lens.

            I would have to attach it to a bigger sensor to get more light, but it’s still the same lens. It’s not the lens’ fault that you attached it to a puny FF sensor, rather than a proper swimming-pool sized sensor.

            Were I a lens, I would take offence to your whole line of reasoning.

            Judge not a lens by the size of the sensor it is attached to. Judge it by its true nature — its focal length, aperture, and resolving power. :-)

            • ”Judge not a lens by the size of the sensor it is attached to. Judge it by its true nature — its focal length, aperture, and resolving power. ”

              A 18.5mm F1.8 full frame lens would be quite a different beast than this little Nikon 1 lens. You cannot simply use this Nikon lens on a full frame sensor and expect it to be a full frame 18.5mm F1.8 lens, in fact you would have to increase the distance to the sensor far enough to make it’s image circle cover the whole sensor which would end up giving you a 50mm F4.9 macro lens.

              • “You cannot simply use this Nikon lens on a full frame sensor and expect it to be a full frame 18.5mm F1.8 lens,”

                I’m sure you could get it to fit with the appropriate adapter — but you’d have some pretty serious vignetting. :-)

              • About the same amount of vignetting as a full frame 50mm F1.8 used on a 97x65mm sensor. The simple fact is that a full frame lens with the same F number as a Nikon 1 lens captures over 7 times more light.

          • dmojavensis, you sound like you’re a professional or long-time hobbyist, to have such thorough and clear thoughts on the subject. Which makes it all the worse to be so totally wrong about your conclusion, since the authority and certitude with which you present your case are going to lead many amateurs to believe an incorrect dogma, much like the “growing earth” hypothesis harms people by misleading them about pate tectonics.

            The question is not how much light enters the lens pupil, but how much *reaches the sensor* at the focal plane. Luminosity decreases with the inverse square of distance travelled. Thus, if the 18.5mm is 1x, then to travel 50mm is 2.7x greater, so the luminosity is halved 2.7 times over. In your equation and argument, you state that “the area from which the lens collects light is exactly the same for these two lenses”, and thus the same light reaches both sensors (once focused by their respective lenses). This false premise is the problem, and the reality is that the 1/(Sqrt(2)^(2.7))x of light reaching any given point on the sensor is *less* in the 4.9 by 61% – not the “same light” at all.

            Think about it: why is there no photography resource documenting the mathematics you describe? Because it’s not real.

            In fact, it’s worse than that; it’s contradictory: either
            a) the focal plane must be located at the tip of the lens, in which case the equation is self-contradictory because focal length would be 0, or
            b) the light is effectively traveling totally perpendicular to the focal plane all along the focal distance, which it doesn’t, because of the particle/wave dual nature of energy propagation in electromagnetic fields – light. The very fabric of the universe disagrees with what you are saying.

            f/1.8 is the same in all cameras, as far as light per unit area of the sensor. That’s why the metric exists in the first place – to measure the amount of light reaching the sensor to produce a constant exposure regardless of the overall size of the film.

            The math is the same re: noise.

            So no, the Nikon 1 is not doomed to have to have hyper f/<1 18.5mm lenses in order to produce comparable exposures to an f/1.8 50mm. It already does that with an f/1.8. Just go shoot the 4 images in question and compare. Thank you.

            • Hi SG, no offence but what you have just written is mostly incorrect :). I will explain why tomorrow (sorry, it’s my time to sleep now :)).

              But for now, if you are curious you can peruse “Image sensor format” Wikipedia article, particularly paying attention to the sections 1, 2, and 3.

              • dmojavensis, no offense taken, we are all students at times. Everything I said is correct (notwithstanding any amazing physics you might describe); instead, what it seems – having read all your comments in this thread – is that you are attempting to “hijack” f-number for a concept it’s not directly intended to.

                The article you mention, which I have read many times and now re-read, never discusses luminosity at the focal plane (which f-numbers relate across different size systems), instead comparing things like depth of field.

                Contrast this with the *actual* wikipedia article on f-number, which states explicitly and succinctly the following, without the clever physics I proffer in my explanation:

                “A 100 mm focal length lens with an aperture setting of f/4 will have a pupil diameter of 25 mm. A 200 mm focal length lens with a setting of f/4 will have a pupil diameter of 50 mm. The 200 mm lens’s f/4 opening is larger than that of the 100 mm lens but, given the same light transmission efficiency, both will produce the same illuminance in the focal plane when imaging an object of a given luminance.”

                What you seem to be hijacking f-number for is indeed fair game – there is no explicit measure of DoF given on lenses (for good reason) and photographers, especially the professionals, have real need to be able to determine it in their work.

                However, ultimately, when discussing “f-number” one is discussing luminance at the focal plane as a function of focal length / aperture. When you wish to discuss Dof et al, it is your burden to say something like “the equivalent ‘f-number for DoF’ for this lens is f-number * crop factor”

                You even admit below your poor adaptation of the term: when Anders H says “I [...] can confirm that the amount of light that reaches the sensor at any given aperture is exactly the same no matter the sensor size”, you respond “in terms of brightness only”.

                Yes, in terms of brightness only. That’s what f-numbers measure! Hello there!

              • I’ll be brief (with a “proper” reply later):

                You haven’t read the article carefully, have you? :)

                Quote from the section on “shot noise” : “If the exposure is constrained by the need to achieve some required depth of field (with the same shutter speed) then the exposures will also be in relation to the square root of the sensor area, producing the interesting result that if depth of field is a constraint, image shot noise is not dependent on sensor area.”

                The talk of “hijacking” F-numbers is irrelevant simply because we already “hijacked” the 135 format focal length equivalent as a proxy for the angle of view. Or is that unorthodox too? :)

                We wouldn’t need to use none of the “equivalent” variables if we just used millimeters for aperture, degrees for the angle of view, and the total exposure over sensor area (in say lux second * m^2) for “ISO”.

              • “If the exposure is constrained by the need to achieve some required depth of field…” – there you have it.

                The exposure is *not* constrained in this manner. The only constraint is the luminosity per area, which f-number describes.

                …unless you explicitly state that you are comparing DoF, which the people who “know” what they’re talking about (such as I presume yourself) never do. What we end up with then is hordes of people who don’t understand the geometry involved spouting off rehashed versions of what they read such as “this 18.5mm is really only a f/4.9″, giving the impression it produces incredibly dark photos, which it of course absolutely does not do.

                Just read the DPReview article on this same lens to see what I’m talking about. Literally dozens of people going on about this being an f/4.9 lens, which it isn’t. It says it, correctly, right on the barrel of the lens: 1:1.8.

                Just saying something like “this f/1.8 lens is equivalent to a f/4.9 in full-frame” is incorrect, as you have not refuted the very clear statements already given above (from wikipedia, to start). If you had said “this f/1.8 lens is equivalent to a f/4.9 in full-frame in terms of its depth of field” then you would have a leg to stand on.

                Please, you’re doing more harm than good. f/1.8 is f/1.8 on all cameras (though t-stop may be different, given major transmission differences in the lenses). DoF varies with sensor size also, but DoF is NOT f-number.

              • Jesus! How hard is it to understand one sentence?! :)) Anyway, I’ll quote it one last time, this time with comments.

                1) ““If the exposure is constrained by the need to achieve some required depth of field” — in our Nikon 1 example that would be achieved using 18.5 mm lens at f/1.8 on Nikon 1 and by using 50 mm at f/4.9 on FX sensor (I hope you don’t question this fact).

                2) “(with the same shutter speed)” — this fixes the total exposure: the overall “amount” of light that will reach each respective sensor.

                3) “then … image shot noise is not dependent on sensor area” — exactly the point many people are trying to make.

                Notice, nobody mentions that “ISO” will be the same for every sensor size in this case (if that is confusing to you). In our example if say Nikon 1 was set to “ISO” 100, then the FX camera will be at “ISO” 729 (=100*2.7*2.7). What matters is that at these “ISO” settings shot noise (~=noise in midtones) in the final images will be very similar, i.e. not dependent on sensor size.

                Do you get it now? )))

              • Again: “If the exposure is constrained by the need to achieve some required depth of field” – it is not.

                We are discussing f-number, which describes how “fast” a lens is, ie how “fast” a traditional shutter could open/close to allow the same amount of light to reach the focal plane. When talking about equivalencies of f-number between lenses, to create the same exposure, the equivalency is 1:1. f-number is f-number is f-number.

                Talking about DoF equivalencies? You must say that each and every time you try to say “equivalent f-number for this lens” etc.

                Not clarifying confuses people, many, many of whom say things – because they’ve read arguments like yours – like “this f/1.8 lens is really an f/4.9″ – it is not. This is an f/1.8 lens. It exposes the same amount of light as an f/1.8 in any other camera in a given time period.

              • 1) The exposure IS fully constrained by the F-number and shutter speed. What is there to argue? :))

                2) The Wiki article answers your question precisely. I’m not sure why you can’t see this.

                What is says (again, using our 18.5 f/1.8 lens as an example), that at its “fastest” f/1.8 aperture this lens will give you exactly the same : a) shutter speed, b) depth of field, c) field of view, and d) (to a very good approximation) midtones image noise (at say base ISO100) as 50mm f/4.9 lens on a full-frame camera set to ISO 729=100*2.7*2.7.

                And of course, if you set that full-frame camera to ISO 100, the lens to f/1.8 you will still get the same shutter speed, though much lower image noise and shallower DoF.

                How is this not a useful comparison?!

              • I don’t usually use all caps, and this isn’t for shouting, just to draw attention to emphasis:

                “If the exposure is constrained by the NEED TO ACHIEVE SOME REQUIRED DEPTH OF FIELD”

                “Exposure” is NOT thus constrained.

                We are talking about just equivalent exposure between lenses, not equivalent exposure + equivalent DoF.

                The latter case is interesting, and photographers want to know it. It is as you describe, f-number*crop etc.

                The former case, however – the case of just equivalent exposure NOT constrained by the need for a constant, equivalent DoF – is just f-number.

                As the wikipedia article on f-numbers states, to produce the same exposure, two lenses need only have the same f-number: “The amount of light transmitted from each object in the lens’s field of view to each unit of area of the film (or sensor) decreases with the square of the f-number” – this, correctly, says nothing about the overall size of the lens or the focal plane – it is irrelevant. f-number is dimensionless – it applies equally to all lenses regardless of their actual physical size.

                Talking about exposure? Talk about equivalent f-numbers (which is easy because it’s the same number across all lenses for a given exposure).
                Talking about DoF? Do not talk about equivalent f-numbers using the formula. Instead, talk about “equivalent f-numbers for a given DoF” using the formula.

              • “What is says (again, using our 18.5 f/1.8 lens as an example), that at its “fastest” f/1.8 aperture this lens will give you exactly the same : a) shutter speed, b) depth of field, c) field of view, and d) (to a very good approximation) midtones image noise (at say base ISO100) as 50mm f/4.9 lens on a full-frame camera set to ISO 729=100*2.7*2.7.”

                Changing ISO is not relevant, except that it directly illustrates what you are not understanding. We are talking about light reaching the focal plane, not how increasing the sensitivity of a sensor receiving less light can produce the same level of exposure as a regularly sensitive sensor receiving more light. The question is, how much light *reaches* both sensors.

                If two lenses are set at the same f-stop, then their sensors are receiving the same light per unit area.

                Let me ask you a hypothetical to clarify. You have 2 cameras, with the same shutter speed and the same iso. One has an 18.5 f/1.8, and the other has a 50mm f/1.8; which one gets more light per unit area of the sensor?

                NEITHER – they both get the same amount of light. This is the purpose of f-number. That’s the whole point.

                “A 100 mm focal length lens with an aperture setting of f/4 will have a pupil diameter of 25 mm. A 200 mm focal length lens with a setting of f/4 will have a pupil diameter of 50 mm. The 200 mm lens’s f/4 opening is larger than that of the 100 mm lens but, given the same light transmission efficiency, both will produce the same illuminance in the focal plane when imaging an object of a given luminance.”

                If you had a 2mm f/1.8, like an iPhone, such a photo would (and does everyday!) also look equally bright, and if you had a 5000mm f/1.8 it would also look the same.

                Very simple concept once one grasps the inverse square law. DoF is neither here nor there.

              • Okay, this conversation has looped now: you keep repeating yourself without apparently reading my replies (they have answered your questions already).

                I will summarize one last time — no comments in this thread afterwards.

                1) Nobody argues that two lenses with different focal length but same F-number create an image with the same brightness. That’s a well known fact. :))

                2) A 18.5mm f/1.8 lens on CX format at any given ISO at any given shutter speed *AND* 50mm f/4.9 lens on an FX format at 2.7*2.7 times higher ISO and the same shutter speed will produce exactly the same images in terms of shot noise (~=image midtone noise) *and*, by coincidence, angle of view, depth of field, and diffraction effects. Basically most of the things that make a photograph. Therefore it is a convenient way to compare camera systems with different sensor size.

                In other words if you buy a Nikon 1 + 18.5 f/1.8 thinking that you are going to get the same low noise performance as Nikon D800 + 50 f/1.8 you are fooling yourself. Say you get an ISO100 and you need 1/50 sec at f/1.8 thinking “a guy with 50mm f/4.9 lens on a full frame is at disadvantage now. He will need to use ISO729 so get the image at 1/50 sec”. The reality is that that guy will get exactly same image noise at ISO729 as you at ISO100 — FX has 3-stop noise advantage over CX (for the reasons described above). And if the guy with D800 wants less noise, he will simply use 50 f/1.8 at the same 1/50 sec and ISO100 and get 3 stops less noise than you can in principle get with your small camera.

                That’s all :). If you have any other questions — peruse the posts above, the Wikipedia article, and maybe materials on image noise on DxOMark website.

                Good luck.

              • It’s been interesting watching you two go at it.

                I think you’re basically both right — but SG takes issue with dmojavensis fast and loose language.

                SG is just talking about the lens.

                dmojavensis is talking about the lens and sensor size, in combination.

                This is the clearest (and most useful) statement in the thread so far — and not fast an loose at all…

                “2) A 18.5mm f/1.8 lens on CX format at any given ISO at any given shutter speed *AND* 50mm f/4.9 lens on an FX format at 2.7*2.7 times higher ISO and the same shutter speed will produce exactly the same images in terms of shot noise (~=image midtone noise) *and*, by coincidence, angle of view, depth of field, and diffraction effects. Basically most of the things that make a photograph. Therefore it is a convenient way to compare camera systems with different sensor size.”

                Thanks for writing it, but maybe you should both go shoot some photos, instead. :-)

              • Edgar, that last statement was precisely my point! I’m glad that I finally found the right words to convey my point :).

    • An f1.8 lens on the V1 is the same “speed” as an f1.8 lens for medium format. The difference is in apparent depth-of-field.

      It’s getting old being lectured by online “experts” who don’t quite get the concept.

      • Sorry, but I understand the concept. Maybe rather than insulting me, you should read my explanation above. People sure are sensitive in here. I wasn’t attacking any one.

        • Scott, completely agree with GH. This person is trying to help you to better understand how cameras work. And, instead of learning, you are just wasting the opportunity. And if you disagree (wrongfully in this case :)), just explain what specifically is incorrect.

    • I made a test with the FT1 adapter on my J1 with a D type Nikon lens and can confirm that the amount of light that reaches the sensor at any given aperture is exactly the same no matter the sensor size – tried on FF and the J1.

      As another reader said an f/1.8 is and f1.8 is an f/1.8 :-)

    • I’m sure that there will be a lot of folks who buy this lens thinking the f/1.8 will mean they can get great subject isolation and bokeh. Needless to say, the photos will still look like all the rest of the generic iphone-like “everything in focus from 1foot to infinitiy.”

      • It’s not the same as 50 mm f/1.8 on a full frame, but not *that* bad ;). You still get noticeable DoF control with 50mm at f/4.9-ish on a full-frame. Certainly more than you get from a smartphone :).

  11. http://www.nikon.it/it_IT/product/1-nikkor-lenses/1-nikkor-18-5mm-f-1-8
    http://www.sigmaphoto.com/shop/30mm-f28-ex-dn

    Sigma 30 ex dn over nex (60.6 x 38.6 mm)
    Nikon 18,5 f1,8 over nikon 1 (56 x 36mm)

    Sigma: 45mm f4,2
    Nikon: 50mm f4,9

    Same price. Come on… there’s no advantage to chose nikon 1 over nex system.

  12. SG’s explanation is unassailable. As to GH and dmojavensis vs Scott, what we have here is a tempest in a teapot, and I think you should all forget the offense (real or imagined) and go forward.

  13. I did a really quick comparison (‘Crazy Comparison??’) here of the DoF from a 1″ type sensor (Sony RX-100) vs. the equiv. on a full frame (D700) sensor. Sorry the FoV was a little off…

    http://www.flickr.com/photos/mars_observer/7989081834/

    • What do you think? Is this a valid test??

      • Hey Shawn! Thanks for posting this. There is so much confusion on how to compare camera systems of different formats. Even Steve Huff, with all due respect to his otherwise excellent website, is confused :((.

        Could you please shoot this scene with the same or similar FoV using these “equivalent” settings :

        Sony RX100, 10.4 mm, f/1.8, ISO400
        Nikon D700, 28 mm, f/5, ISO3200
        same shutter speed (whichever you need for proper exposure).

        We should see that the FoV, and DoF are essentially the same, and Nikon loses in terms of noise by about 0.5EV (when viewed at the same size) because of its older sensor design (had it been Nikon D800 the noise would have been about equal).

    • I don’t think anyone is trying to say that the DoF on a f/1.8 lens built for the CX sensor will be the same as a f/1.8 on a lens built for a bigger sensor. I agree with SG, Steve, and others that the DoF will be different (as you have proven in your pictures) but that the aperture is still a true f/1.8. Maybe you inadvertently proved both of these arguments with your shots anyway. The RX100 obtained pretty much the same exposure as the D700 with a lower ISO (80 compared to 250). Shutter speeds were listed as the same, the only other variable was the RX100 using f/1.8 and the D700 using f/5.0. For the D700 to get the same fill of light the ISO had to be bumped up to 250. If you have the time and inclination, I’d be really curious to see the difference if you re-did these shots with the only difference being the f/5.0 and f/1.8. If shutter speed and ISO are set to the same settings and the D700 shot comes out less exposed then the only variable affecting the test is the aperture. This would tell us that the DoF is true to the above mentioned calculation but that the light gathering ability (the main argument going on here) is independent and is true to the f/1.8 indicated. In any case, thanks for taking these shots and posting them!

  14. Here is a photo from my nex5 & zuiko 50/1.8
    http://s1270.photobucket.com/albums/jj605/digitaldawg/nex5/?action=view&current=77db3e34.jpg
    Poor photo.

    I could really have done with Olympic stadium more recognizable
    whilst having the light gathering of a 1.8

    J1 50/1.8 would been just right.

    (there are lots of times FF, APSC 1.8 is just too shallow).

    • I’m just starting to do some (handheld) night and low-light photography, but generally I’ve found a good methodology to be:
      1. bump up the ISO to the highest setting that you feel is acceptable (re: noise)
      2. stop down the aperture to the point it will give you the DoF you need

      If that doesn’t work, you may need to look at getting a camera that will give you better performance at higher ISOs, or choose the subjects differently – ones that can be shot with a more shallow DoF.

      Of course you could use a tripod if there’s no motion (though personally, I don’t want to carry a large tripod).

      But what I like about the NEX for night is the Anti-Motion Blur feature and, as well, because it’s so light-weight, you can use/carry a smaller ‘Gorilla-pod’.

      • Anti-Motion Blur feature yes i will have to try it
        as at iso1600 1/30th f1.8 i wasnt steady enough handheld
        (iso3200 i only do for b&w)

  15. Why wouldn’t you just stop down the 50/1.8 on nex5 if the depth of field seemed to shallow at f/1.8?

    • Because nex5 was already iso1600 (1/30th f1.8)
      i didnt want to use 3200

      if i had stopped down to f2.8 the horse would have been blacked out at iso 1600

      • Don’t forget that you would get about 2-stop worse noise performance on that Nikon 1 camera. So noise- and DoF-wise a photo at f/1.8 on Nikon 1 would be about the same as a photo taken at f/3.2 on NEX camera as the same shutter speed.

  16. Ran out of time this weekend for more test shots, but maybe next weekend! :)

Don't just sit there! Join in and leave a comment!

© 2009-2014 STEVE HUFF PHOTOS All Rights Reserved
21