DX

Discussion in 'Nikon' started by tiaan_seynberg, Sep 16, 2011.

  1. Good day, will I be correct when saying that DX will not fit on a fullframe camera, so when the lens does say DX it will be a prime lens
     
  2. DX and FX refers to the size of the image circle produced by the lens, the mounting is the same (known as the F-mount)
    There are zooms on FX and DX formats.
     
  3. ShunCheung

    ShunCheung Administrator

    This is an image sample where I used a DX lens (the new 40mm/f2.8 DX AF-S Micro) on the full FX frame on a D700. Notice the corner vignetting.
    I am sure others will help you with the definition for DX and "prime."

    [​IMG]
     
  4. thanks, that help me alot Shun :)
    Then it is safe to buy the 16-85mm
     
  5. I would test before buying.
     
  6. Just to be clear: a "DX" lens only produces a good quality image over the size of a crop-sensor DSLR (i.e. any Nikon DSLR except the D700, D3, D3s or D3x, which are "FX" or full-frame, having a sensor the size of a 35mm film frame). You can physically attach a DX lens to any of these "FX" cameras, and the FX cameras offer a mode in which they use only the pixels which correspond to a crop sensor by throwing away pixels at the edges - but this means you get a lower resolution image. If you use the full area of the FX frame, as Shun did, the edges will be dark (possibly black, depending on the lens and focal length) and soft. It is generally not a good idea to buy a DX lens, like the 16-85, for use on an FX camera for this reason. If you have a crop-sensor camera, these dark and soft areas are outside the edges of the sensor, so DX lenses work perfectly on these cameras.

    Canon's equivalent to DX lenses - EF-S lenses - will not physically attach to a full-frame Canon camera. Nikon gave you the opportunity to use them in an emergency, but it's not generally advisable.

    As for "prime", a prime lens is the opposite of a zoom lens - i.e. a prime lens only has one focal length. It's unrelated to FX and DX coverage. I hope that helps.
     
  7. it does Andrew, thanks
    so basically I have no idea what to buy :)
    I thought the D300 was also fullframe,
    So I think then to upgrade rather to the D7000 with the 16-85mm lens, I know the D7000 is not a fullframe camera
    and later get the Nikon 70-200mm
     
  8. Glad to help, Tiaan. The D300 is a crop-sensor camera, like the D7000 (but without as many pixels in its sensor). Perhaps you could let us know what you've got (presumably a D300?) and what you're trying to achieve, and we can weigh in with some suggestions?
     
  9. I have the Nikon D60 body
    lense : 18-55mm nikon, 55-200mm nikon and the 150-500mm sigma
    I want to be able to have a good lens and not be pro for if something pops up, I can do studio work or weddings, I do wildlife but just for fun.
     
  10. So I think then to upgrade rather to the D7000 with the 16-85mm lens, I know the D7000 is not a fullframe camera and later get the Nikon 70-200mm
    Great plan, that'll work well for you.
     
  11. Thank you, Tiaan. Firstly, the D60 has a crop sensor, and the 18-55 and 55-200 are both DX lenses; the 150-500 Sigma covers full frame as well. It might help to know which 18-55 lens you own - there were three versions (one with VR) - I believe the VR version was first provided as a kit lens for the D60, so I'm assuming that's the one you've got. Oh, and a disclaimer: I've no direct experience with any of these DX zooms, I'm only advising based on reviews.

    A quick look on photozone.de suggests that the 16-85 is a bit sharper (especially in the corners, wide open) than the 18-55 lenses. It is obviously slightly wider, and would save you switching between your 18-55 and 55-200 if you wanted to access the 55-85mm range. Having said that, it's a relatively small and incremental advance over what you've got.

    For studio work and weddings, I would suggest that the sharpness in the corners of the frame are unlikely to be as much of a problem as the limited maximum aperture of the lenses you own - and the 16-85 won't help with that. Having a wider aperture available will help you shoot in lower light (VR only helps when you're moving, not when the subject is) by letting you use a faster shutter speed at the same ISO settings, and gives you creative control over the depth of field to make your subject stand out from the background. These may or may not matter much for studio work depending on your style, but do matter for weddings, where ugly things in the background and poor lighting tend to be common.

    As such, I'd suggest either an f/2.8 zoom - Tamron and Sigma both offer f/2.8 zooms in the ~17-50mm range, although wide open corner performance is a bit iffy on some of them and the cheaper Sigma isn't f/2.8 at the long end of the focal range - or a fast prime such the Nikkor 50mm f/1.8 AF-S, Sigma 50mm f/1.4, the Tamron 60mm f/2 or a Tamron 90mm f/2.8. These will blur the background reasonably well, and the Tamron prime lenses are macro lenses, which means you can get close-up shots of detail at weddings as well. You might also consider the Samyang 85mm f/1.4, if you're prepared to focus it manually; or - if you're planning to switch to a DSLR that has a focus motor (it won't autofocus on the D60) - the 85mm f/1.8 Nikkor is also quite good, and both these 85mm lenses will lose the background more than anything else suggested. Obviously the problem with the primes is that you're stuck at one focal length, so you need to decide whether you can live without the flexibility of a zoom and plan your shots. The general consensus is that, on a DX camera, 60mm is about right for conventional full-length/upper body portraits (50mm is perhaps a little wide), and 85-90mm is about right for head-and-shoulders images - but that's a very loose rule. Any of these options, except possibly a Sigma 17-50 f/2.8 OS, are cheaper than the 16-85.

    For wildlife, you're probably best off sticking with your 150-500 (although I have trouble with the 500mm end of mine); a 70-200mm f/2.8 would just about be a useful wedding length and on the short end of useful for wildlife, but it's very expensive. Otherwise, the 18-55 and 55-200 are a pretty good combination - I wouldn't worry about getting a "slightly better" version lens that covers the same range unless you're absolutely sure you don't need more aperture and extra flexibility.

    I hope that helps, or at least that it gives you something to think about - if only so we can offer more clarification.
     
  12. Just to add: the D7000 is obviously a substantial step up from the D60 (although so is a D5100; the D7000 is in a different league when it comes to handling, though). The sensor on the D7000/D5100 is good enough that it shows up the limitations of the 16-85 more than your current camera will. If you want larger prints and you're happy with the depth of field you currently get, a D7000 or D5100 will serve you well - I just wouldn't expect the 16-85 to be as vast an improvement as the camera is.
     
  13. Shun - your example looks like an upgrade for the Holga folks.
    Mark
     
  14. Shun's example shows that the new 40mm DX almost covers FX. Sometimes the corner vignetting is much more extreme. Here is an example using my 18-70 DX lens on a FX body. Some lenses like the 12-24 DX look similar at their widest focal length but by around 18mm the 12-24 DX covers FX although the corners are still soft.
    00ZL5i-398871584.jpg
     
  15. Tiaan,
    Andrew's answer gives a lot to chew on, I'd just want to add one question you should ask yourself: in which way is my D60, or my lenses, holding me back?
    Upgrading the body sure gives a nice step up in many ways, but if that only adds options you do not need or use, it is wasted money. Getting a better lens can be great, but the 18-55 at f/8~f/11 is not at all a bad lens. Since you can spend money only once, better to put it where it counts the most.
    As for DX being prime - a prime is a fixed focal lens (no zoom); there are some DX primes (4 at the moment), and a lot of FX primes. FX lenses can be used on DX cameras no issue, the reverse, well Walt's example is clear enough :)
     
  16. Andrew thanks for the advice, sorry I get only back to the forum now, so basically keep the lenses I have and get a Nikon 50mm and maybe a 10-20mm Sigma
     
  17. Hi Tiaan. Only you can say where your current collection is limiting you. :) A fast 50mm prime would give you more ability to blur the background of portraits and work in low light than your current zooms, so I think that's not a bad idea. If you don't want to spend too much, the Nikkor 50mm f/1.8 AF-S appears to be very good - the AF-D is not very good at f/1.8 and won't autofocus on your camera, so it's worth paying the premium for the AF-S version. If you want to spend more, the f/1.4 Sigma is probably better-regarded than the Nikkor AF-S equivalent, although each have their merits.

    A 10-20mm (or something with a similar range) will provide some functionality that your current lenses don't, but I'd be sure that you want it. I find ultra-wide lenses to be useful for landscapes, architecture and giving an overview of large crowds - they're not flattering for portraits and hard to use for wildlife (except some flora). It didn't sound like you wanted one, from the interests you've stated so far, but maybe I misunderstood - how often do you find yourself at the wide end of your current widest zoom? I would suggest trying a 10-20mm in a shop before buying, since something that wide is a bit of an acquired taste. Good luck.
     

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