Things for New FX Users to Think About

The transition from DX to FX isn't always seamless

Congratulations! You’re moving from DX to FX.

Condolences! You’re moving from DX to FX.


Nikon's mostly FX 2012 through 2014 and their aggressive pricing on the D610 meant that a lot of you reading this site opted for your first FX camera. Here are some of the things new FX users need to deal with:

  • Realign your lens set. What that realignment is depends upon how you were shooting with DX. For example, a lot of DX shooters were using lenses like the 24-120mm as their primary lens on their DX camera. While that lens will still work on your FX camera, you now have a 1.5x change in angle of view. Whereas before you had a 36-180mm equivalent, now you have an actual 24-120mm: the lens shoots wider and not as telephoto as you remember. Unfortunately, there's no good option here, as Nikon doesn't make 35-xxmm FX lenses any more. My recommendation: learn how to use wide angle effectively and keep your 24-120mm (this is not about wider angle of view, it's about moving your position closer to the subject).

    Others needing lens realignment are those who have all or mostly DX lenses. First thing to try: some DX lenses mostly (or fully) cover the FX frame, so you might not be as bad off as you thought. So you have some experimenting to do: turn off the Auto DX option and set FX Image Area and try out your old DX lenses. See what you can use them for. Don't forget the 5:4 option if your new camera supports it. The 35mm f/1.8 DX works very nicely at 5:4 on FX bodies, for example. Once you've figured out what is still salvageable in your DX lens set, then and only then consider what FX options you should get to fill the gaps. I'm a big fan of the 28mm, 50mm, and 85mm f/1.8 lenses for new-to-FX users. These are all very good optics at reasonable prices.

    I wrote last year about lenses for the D800, but let me reiterate about the zoom options that cover the mid-range: the 24-70mm f/2.8 is the best choice. The 24-120mm f/4 is relatively close and just fine, too. The 24-85mm VR would be my next choice, but on a D800/D800E/D810 you're starting to have less lens than the camera wants, especially at the long end where you're riding close to diffraction impacts even wide open. Ditto the 28-300mm: it's a decent lens all things considered, but it's the weakest of this bunch and the f/5.6 maximum aperture at the top end of its range on a D8xx starts to push you towards diffraction impacts.

    D600, D610, and D750 users probably will be fine with any of those four zooms, though I'd still rate them in the same order: 24-70mm, 24-120mm, 24-85mm, 28-300mm.

    Which brings me to another point: the 16-35mm, 24-120mm, and 70-200mm f/4 lenses aren't a bad set for the new-to-FX crowd. All three are very good lenses. Sure, they're not f/2.8, but they're also not as big or as expensive as the f/2.8 lenses. Do you really need f/2.8? After all, you probably got a low light boost just from moving from an older DX to new FX body.

  • Get used to the smaller focus area. Technically, the physical area covered by the FX bodies is the same size as on the DX bodies. Only the DX bodies have smaller sensors, so their focus area is a larger proportion of the frame.

    Unfortunately, this means that focusing on the rule of thirds intersections is no longer possible on FX, where it was just barely achievable on DX. The usual new-to-FX reaction to the perceived smaller area is to put the center AF sensor on the subject, focus, and reframe. But reframing changes the geometry and your focus plane will move (typically it will swing in back of your subject).

    The D6xx's AF pattern is slightly smaller than the D750, D8xx models, and D4/D4s, which makes the D600 and D610 users the ones that have the most frequent negative response to the change from DX to FX. Of course, those are exactly the group that is doing most of the DX to FX switching right now, too.

    If you focus and reframe, you have to understand the geometry involved and adjust. You can adjust in a number of ways: (1) manually adjust--practice enough and you can get very good at tweaking focus this way, especially if you're always using the same AF-S lens; (2) use DOF to cover you--select an aperture a stop smaller than you were going to use (but be aware of focus shift, as some lenses will shift focus when stopped down); or (3) use Live View--if your subject is static enough, Live View lets you put focus where you want it.

    Unfortunately, the viewfinder screens used these days are optimized for brightness, not for rendering detail, thus manually focusing isn't as easy as it was in Ye Olde Film Days (which came before Modern Film SLR Days). This bothers enough people that they go to third party focus screen vendors for help. I'm not sure they get as much help as they expect, though.

    D800, D800E, and D810 owners have the trickiest problem. When you pixel peep at D8xx images, even a small miss in focus easily shows up in your pixels at non-diffracted apertures. This leads some D8xx owners to think that their camera focuses worse than the other Nikon DSLRs. No, it doesn't. It resolves better. What I typically see is that people moving to the D800, D800E, or D810 are finding out for the first time just how precisely they've been focusing and handling the camera. The old 6mp and 12mp cameras just didn't reveal that, but 36mp certainly should.

    Finally, note that field curvature comes into play with FX where it didn't show up nearly as much in DX (we weren't always using the full image circle of the lens). This too has implications on focus-and-reframe, so it's important to know whether the lens you're using has significant field curvature or not (typical of fast primes, not so much with zooms). The more you're reframing and the more field curvature there is, the bigger the problem you'll have.

    The bottom line on focus is that you have to pay more attention to getting the details right (pardon the pun), and may have to learn some new habits or develop new techniques. Practice helps. Lots of practice helps more.

  • Be prepared for pixel proliferation. The smallest FX body is now 16mp. The typical DX user moving up to FX was at 12mp, and some were at 6mp or 8mp. File sizes just got larger for a lot of you. That means you need higher capacity cards, it takes longer to transfer the same number of photos to your computer, and you need more file storage on your computer.

    You could shoot JPEG Medium or JPEG Small to alleviate those problems, but then I'd have to wonder why you were a candidate for an FX body in the first place. I've met people who are using D800's as point and shoots for small web photos, but that's overkill, in my opinion.

    There are things you can consider to reduce the file size problem. If you used to shoot RAW(NEF)+JPEG, shoot just RAW(NEF) and extract the embedded JPEG in the raw file only when you really need the JPEG. Consider 12-bit instead of 14-bit raw recording for raw, and consider Size Priority instead of Optimal Quality for JPEG Quality. I wouldn't generally recommend the most aggressive compressed NEF, which compromises highlight detail, but I'd certainly pick Lossless Compressed over Uncompressed.

    It may be time to upgrade your computer, too. Editing 36mp D8xx raw files on a state-of-the-art processor with plenty of RAM is a much different experience than doing so on a five year old computer with the RAM minimum for the OS. But even the 16mp of the D4 can tax older systems. An i5 processor and 8GB RAM are now probably a baseline for serious photographers, and most of us long-time FX users have better than that.

    Storage requirements tend to grow linearly on pixel count differences, all else equal. If you needed 100GB a year with your 6mp camera, a 12mp camera probably generated 200GB a year, a 24mp camera will likely generate 400GB a year, and a 36mp camera will produce over a half terabyte. Serious users want three sets of storage: working images, backed up images, and archived (preferably off site) images. Make sure you're upping your main and backup drive sizes accordingly.

Those are just a few things to get you thinking about your transition from DX to FX. Master those three things and you'll be well on your way to enjoying your new gear. I'll have more about some of these items later in the year.

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