Thursday, September 13, 2012

The Nikon D600's Tragic Flaw

David Hobby (THE Strobist) posted about the Nikon D600's tragic flaw: its 1/200 sync speed. If you're new to flash photography, you may be wondering why there was a groan from lighting enthusiasts when they found out about this.

What is sync speed?
Sync speed is the highest shutter speed that will allow your camera to use a flash without HSS (discussed below). Imagine your shutter is like a canvas in front of a window. When you press the shutter, the window (which represents the shutter curtain) moves across the canvas for the exposure. Above a certain speed, that window can't get any faster. Instead, to get a higher effective shutter speed, the window becomes narrower -- narrower than the canvas -- while sliding across at the same maximum speed. The narrowing of that window poses a problem for flash photography because the entire flash burst happens in an instant. Since the canvas is never fully exposed (because the window becomes narrower than the canvas), the flash burst is partially blocked. The blocked portion of the canvas receives none of the flash.
The maximum speed the shutter can travel without narrowing that window is the sync speed. If you somehow force the camera to exceed the sync speed while using flash, the shutter curtain will block a portion of the image and that portion of the image won't be lit by the flash. Oftentimes, this makes the image unusable. For this reason, when you're using a flash, the camera either will stop you from using a higher shutter speed, or will allow you to exceed the shutter speed but with HSS activated, which has disadvantages of its own (see below).
Overpowering Ambient
The reason sync speed is critical for flash photography is it can control the ratio of ambient light to the flash. Remember that the flash burst is nearly instantaneous. If you reduce the shutter speed, the amount of ambient exposure will decrease. However, the exposure from the flash is not affected as long as the shutter speed is slower than the duration of the flash, and you don't exceed the sync speed.
So it goes like this: let's say you're shooting in day time (let's say your exposure is ISO 100, 1/125, f/8). The light isn't flattering so you decide to use a flash with an umbrella. You take a shot. If you didn't change your exposure then the flash's additional light would cause the shot to be overexposed. But you knew that so you underexposed the ambient light by 1 stop, let's say. ISO 100, 1/125, f/11. At ISO 100 and f/11 your tiny speedlight in an umbrella doesn't have enough power to illuminate the subject so she's underexposed. You could double your flashpower by adding another speedlight. Or instead, you could use ISO 100, 1/250, f/8. Your ambient is the same but at ISO 100 and f/8, your speedlight has twice the exposure than ISO 100 and f/11. In other words, the sync speed allowed you to decrease the amount of ambient light without affecting the flash, thus increasing the flash power relative to the ambient light.
Freezing Action
The other reason sync speed is important is because a higher sync speed allows you to shoot at high shutter speeds, which is useful when you're freezing action.
Nikon D600
The D600's sync speed is only 1/200, compared to high-end Nikons with a sync speed of 1/250. Everyone kind of knew that the D600 was a lower-end model compared to the D4 and D800 so there had to be some sort of compromised spec. So, I expected a shorter shutter life like 150,000 instead of 200,000. Maybe it wouldn't have a magnesium alloy body (fortunately, it does). I did not expect Nikon to screw us with the sync speed. That is a serious handicap, like not having an ISO button or WB button. (Nor did I expect a shutter speed max of 1/4000.) I guess Nikon wants to make absolutely sure no professional will opt for the D600 instead of the pricier D800 or D4.
What about ISO?
One cool feature of the D600 is the low 100 base ISO. DSLRs of the previous generation usually had a base ISO of 200. One question is whether the D600's 100 ISO can compensate for the sync speed for overpowering the ambient. The answer is no. When you lower the ISO you indeed decrease the ambient. Awesome! But you're also decreasing the flash exposure. Argh. So in terms of ratio of ambient to flash, you haven't changed anything. Indeed, this is also why having a high base ISO of 200 is not an issue with respect to overpowering ambient. (Yes your ambient is twice as strong, but so is your flash.) Don't get me wrong - I'm glad the D600 has a low ISO because it means I can shoot at an aperture one stop wider (for shallow depth of field) than I could with ISO 200.
What about HSS?
Middle and high-end Nikons have a high speed sync (HSS or Auto FP in Nikonese). Remember that narrow sliding window? What HSS does is to rapidly pulse the flash while the window is moving across the canvas like a continuous source of light, thus illuminating the entire canvas. No more shutter curtain showing up in the shot. The problem with HSS is that it decreases your flash power by more than two stops. You read that right. Your flash has less than 1/4 the power it has when it is not in HSS. So HSS doesn't help at all when you're trying to overpower the ambient. (It does help for freezing the action or for using a wider aperture for shallow DOF.)
Although the 1/200 sync of the D600 is disappointing, there are a couple of mitigating factors.
Non-HSS 1/250
First, the D600 CAN sync at 1/250 without using HSS. The catch is the flash range will be reduced (i.e. the flash exposure will be decreased). The decrease is not as big as when you switch to 1/250 with HSS. However, it is a decrease nonetheless. I've had a D300 which had a similar feature (1/250 sync with non-HSS 1/320) and the decrease was noticeable but didn't seem like much. I will try to run tests to quantify the difference. David H. guesses the difference is 1/3 of a stop, which if true means there is effectively no power advantage to the 1/250 sync (again, there's still a benefit from freezing the action or using a wider aperture).
Dynamic Range
I expect the D600 to have a very good highlight dynamic range of newer cameras like the D7000 (5 stops of highlight range), D800 (5 stops of highlight range) or D4 (over 5 stops of highlight range), significantly better than the highlight range of the D700 (3.4 stops) or D3 (3.9 stops). If I can block the ambient light on the subject then I believe I can achieve a similar effect as having a higher sync speed by bringing down the exposure of the background during postprocessing. It's more work but hey, it's better than nothing.
Darn you Nikon but I'm sticking with my D600 preorder. If you're on the fence, I suggest you preorder it now and ask questions later. You can always cancel your preorder or scalp it on ebay.


  1. Mic, I really think D3 you had a while ago is a better value than D600, if you can tolerate the weight of D3. D600 doesn't seem that much better than D7000 with almost doubled price, except it is full-frame.

    I agree with you that Nikon is trying to make sure no pro photog will be using D600.

    1. Thanks for the suggestion Xiaoli. I think the D3 and D700 are still good cameras, and if the D600 had a super serious problem, like it did not have autofocus fine-tuning (micro AF adjust) I might have bought a used D3 or D700 instead.

      However, between the D3 and D600, I am guessing the D600 will have better image quality (high ISO and dynamic range). I also like the new features of the D600 such as the video capabilities, smart auto ISO, and remote live view (with the WU-1b). We shall see whether it is indeed as good as I am hoping... :)

      Best regards,

  2. I don't see it as a flaw, David whines about it as if he lost two stops of light, however that 1/4000 max shutter speed would be a more serious flaw for fast lens shooters.

  3. You all keep saying no pro will use it and that is crazy! Only sports photographers are effected in any way with the limitations of this camera! Portrait and commercial uses don't shoot at over 1/200 lol and what sports tog uses a flash? lol

    1. Hi. You know, I really can't blame Nikon for trying to dissuade professional photographers from getting the D600 because it is a very capable camera even for professional needs. As for whether pros will use it or not, I don't know - I'm not a pro. I'm just saying the 1/200 sync and 1/4000 shutter were likely intended to discourage pros from using this.

      I think you're combining two things - you're saying sports pros won't mind the sync speed limitation, and you're saying portrait and commercial won't mind the 1/4000 shutter speed, therefore no one will mind the limits. I see it the reverse way: sports pros won't mind the sync but they will mind the 1/4000 shutter. Portrait and commercial won't mind the 1/4000 shutter but they will mind the 1/200 sync.

      As an aside, I don't know whether portrait and commercial guys in general shoot over 1/200. I do know that shooters who know anything about lighting (including portrait, commercial and event) do want as high a sync speed as possible.

      If it turns out that pros do adopt the D600 in droves, hey that's great. I have no problem whatsoever with that. I agree the D600 is an awesome camera. I've never been more excited about the D600 than any other camera I've had!

      Best regards,

  4. After 12 years shooting weddings with heavy Canon 1 and 5 series, then most recently Nikon D3s, I've been crying out for something smaller and lighter but capable of very high quality images and low light performance.
    The D800 would have been the ideal choice was it not for those huge 36mp files with no reduced raw option. I did try it but with 70mb files, I soon ran out of memory and decided that the D800 just wasn't for me.
    For me the D600 was a breath of fresh air and I had one on pre-order with a view to use the D600 as my back-up to my D3s.
    I've shot over 30 weddings with the D600 now and I have to say that it's an incredible camera.
    Compared to everything I've used previously this little camera is the clear winner.
    It just seems to work regardless of the environment or conditions. The images are quite simply stunning with incredible detial. The ISO is incredible, the dynamic range is amazing and the metering is very accurate.
    The AF was the biggest issue for me at first as I was used to the D3s system, but I soon adapted to the new system and now almost every shot is in focus.
    I was so impressed with the D600 that I just sold the D3s and invested in a second D600.
    I was a little worried about the size as I didn't want to give people the impression that I was an amateur with an entry-level camera, but gripped the D600 still looks like a pretty serious camera. It actually isn't too much smaller than the D800, but it's a lot lighter which has made my life so much nicer during a 12 hour wedding!
    I will most likely invest in the D800 in the near future, but until that time comes the D600 is exactly what I need and I have no regrets selling the D3s.

    1. Thanks so much for giving us a working pro's perspective of how the D600 performs on an assignment (or 30 :) )! It's awesome to know that the D600 has performed ably, and is even more than a match for the legendary D3S. Thanks again!

      Best regards,

  5. Mic,
    I'm trying to understand the two Auto FP settings for the D600, as well as when the internal flash is used in commander mode. Please confirm if I understand correctly. Looking at the e1 custom flash sync setting on the D600 manual, page 234, the two choices are 1/200s and 1/250s. I understand that this means Auto FP is engaged when the shutter speed goes ABOVE the chosen setting. Further, shooting at 1/250th with the 1/250s custom function setting uses a flash firing method in between standard and Auto FP that yields a bit more flash power than Auto FP, but not as much as standard. It then becomes Auto FP above 1/250th. Conversely, the 1/200s custom setting goes into Auto FP mode at 1/250th. Which begs the question, why does Nikon offer two settings if the user gets more flash power at 1/250th with the 1/250s custom setting? Does this special 1/250th case only apply to the built-in flash, or does it affect net power output for all compatible flashes such as the SB-910? When the built-in flash is used as a commander, can it fire the SB-910 as a remote (wireless) flash at shutter speeds above 1/250th?

    On a related note, I have observed that Auto ISO doesn't select as high an ISO when the SB-910 is attached. If I turn off or detach the SB-910 the difference in chosen Auto ISO can be very big (6400 with SB-910 off vs. 400 with it on.) I find I have to specifically select a higher ISO if my goal is to combine flash with low ambient light while using faster shutter speeds and/or smaller aperatures.

    Thanks in advance for any comments and suggestions you might have.

    1. Hi Ken. Sorry it took me a while to respond. My wife is sick and I had to take care of the kids, so I got tied up. Anyway...
      1. Yes, 1/250 Auto FP means above 1/250 the D600 uses HSS and 1/200 Auto FP means above 1/200 the D600 uses HSS. In the former case, you're correct, the D600 uses a non-HSS sync method that yields more flash output than HSS but less than normal sync.
      2. I can understand why someone would use 1/200 (no Auto FP) for e1 but I haven't thought of a logical reason why anyone would use 1/200 Auto FP instead of 1/250 Auto FP. Perhaps if you use some sort of exotic flash unit that can't work at non-HSS 1/250 then maybe that's one reason? I'm just speculating...
      3. The 1/250 non-HSS sync works with any flash, not just Nikon flashes.
      4. If the popup commander is contributing to the exposure then the highest sync speed it can shoot is 1/250 assuming option e1 is set to 1/250 Auto FP. If the popup is not contributing to the exposure (set to "--") then it can command the slaves at any sync speed, even 1/4000.

      About the Auto ISO, here's what I think is going on: when there is no flash, then the Auto ISO will select the highest ISO you allow in order to get sufficient exposure (all ambient). When you attach and turn on the flash, then the exposure is carried mostly by the flash, so the D600 need doesn't go out of its way to stretch the Auto ISO to get enough ambient in. Can you try manual exposure mode and expose for the ambient? I think if you do that then the D600 Auto ISO will go as high as you allow it in order to achieve the exposure you set, even if the flash is turned on.

      Best regards,

    2. Mic,
      You don't need to apologize for what amounted to a very brief delay. Family always comes first! I hope your wife is feeling good again.

      Thanks for clearing this up. As you suggested, I tried Manual with Auto ISO using the SB-910. When I chose 100th at F8, Auto ISO gave 2500 without the flash. With the flash, it changes to ISO 400. From this experiment I found that proper ambient exposure while using flash may require setting a specific ISO.

      From your reply, I have now learned the use of "--" with the pop-up flash to command the SB-910. I had been setting it at "iTTL" and EV-3 to minimize it's exposure contribution, but now I see that I can basically just turn it off as far as light output is concerned. Thanks for that tip!


      I also got the SC-29 off-camera cord. I'm not sure how useful it will be since I can use the pop-up flash to fire the SB-910, whether the pop-up is set to add fill flash or not. In low light, I guess having the IR autofocus assist lamp on the camera hot-shoe will come in handy when the SB-910 is firing into an umbrella or softbox. However, the SC-29 tethers the camera to the flash, which has to be nearby, adding the risk of pulling the flash & light stand over. Due to the way the coiled cord is attached to the ends, the flash is best used on the left side of the camera from the shooters perspective, else the cable is bent back 180 degrees at the strain reliefs. I wish they had a 3-piece system with a 5m straight cable attached with removable plugs secured to the shoe on each end. Long ago, I had something like this when I shot with an Olympus OM-2. I found the SC-29 instruction sheet to be nearly useless, having poor & confusing translations. Mic, do you think I am overlooking other uses for the SC-29, or did I buy something that I really don't need? (I can always return it.)

      Thanks again.

    3. Hi Ken. About the SC-29, I find it useful in several ways:
      - It's useful for 100% reliable shooting in conditions that are difficult for optical triggering e.g. bright outdoors.
      - Even when the popup commander is disabled, it will still contribute a bit to the exposure. An infrared panel such as an SG-3IR is one solution, but the SC-29 (or any other TTL cable) is also another issue.
      - As you pointed out the AF assist is handy but you can get a lower cost TTL cable for most of the benefits to save a bit if you don't feel that you need the TTL cable that often.

      I rarely use the SC-29 for a studio-style setup shot because as you said I don't want to trip over the cable (although ironically I used a TTL cable last night for precisely that). In the real world I most often use the SC-29 with my Lastolite Brolly Grip handheld umbrella. Now that I have the Aokatec AK-TTL I have considered using that instead but in my opinion the TTL cable is easier to remove and mount as needed, compared to the AK-TTL.

      Best regards,

    4. correction, in bullet point 2, I meant solution not issue.

    5. Thanks for the comments on the SC-29. Yeah, outdoors it is probably necessary for reliable triggering if the SB-910 is to either side of the camera.

      Imaging EXPO is here in Atlanta next month. I plan to attend the product exhibits over a 2-3 day period.

      I will try to get familiar with various tripods, lighting equipment and other accessories, as well as get some hands-on with cameras, lenses, etc. I am particularly curious about the Sony A99.

      Anyway, the Brolly shoot thru grip looks useful. I already have a 30" white transluscent umbrella from over 30 years ago when I was first into photography. That looks like a good way to hold the flash so it points to the center. Do you have any trouble with the umbrella shaft not staying in place as some comments indicate at Amazon/B&H? What flash settings do you tend to use (Standard or Even illumination, focal length, etc.) for best effect with the shoot thru?

    6. Hi Ken. Re the Brolly Grip, I like it. It is a lot of effort to use but it's hard to beat the quality of light you get in circumstances where there are few alternatives. Here is a detailed review:

      Re the umbrella shaft, it's held only by friction. I used to wrap tape around my umbrella shaft to increase the friction. However, now that I have the trifold umbrella it works just fine with the brolly grip without any hacks. Trifold review:

      Flash settings - I use TTL and I normally zoom the flash just because if I don't, much of the light gets eaten up. I find that the light quality is not that different whether I completely fill the umbrella or not. On the other hand when I do use the wide angle panel or other means to fill the umbrella, there is a huge difference in flash output. Therefore I usually zoom the flash.

      Have fun at the expo Ken!

      Best regards,

  6. Your point about the 250 sync losing about a third of a stop does not make sense. If the shutter cuts off any light you would have a section of the frame in darkness (shutter curtain shadow). It could reduce the ambient light, but would have no effect on the flash portion of the exposure. Only the aperture affects the flash exposure. On a canon with a speedlite on the camera if you set the camera on 1/1000, then camera automatically sets the shutter speed to 1/250th so that the photo can be taken correctly unless you enable HSS. I would also think that Nikons have this saftey feature.

    HSS actually slows down the exposure compared to standard flash, so whereas a standard flash exposure duration at normal sync speed might be 1/10,000th of a second. If you turn on HSS it will increase the flash duration such that there are no shutter curtain shadows on the frame. So perhaps you set your camera at 1/500th HSS and now the flash duration needs to give light throughout that shutter exposure of 1/500th (as the shutter curtain slit passed over the from) which of course is much much slower than 1/10,000th of a second. For capturing action all flash at normal sync speed would provide your fastest exposure and an f stop that underexposes ambient light would prevent the ambient light from creating a blur in the image.

    1. Hi Peter. The only part where I mentioned about losing 1/3 of a stop is about the non-hss 1/250 mode so i will assume that's what you're referring to. The d600 like other higher-end nikons can exceed its natural sync speed without using hss but there is an unspecified reduction in flash power. What David H was guessing was that even though you can use 1/250 without using hss he was speculating a 1/3 stop loss therefore no net gain in ability to overpower sunlight. Actually i found it is worse - about 1 stop loss. So the ideal shutter speed for overpowering ambient is still the 1/200 sync speed although 1/250 non-hss is better than 1/250 with hss. Try it out.

      Anyway i've had the d600 for a year now and the 1/200 sync hasnt made a difference for me.

      Best regards,

  7. Mic, thanks for sharing your thoughts and experiences using speedlights with the Nikon D600. I've had a D600 for about six weeks and recently used it to shoot a portrait for a special project. I like using ambient light and augmenting with a natural looking fill flash and set up my subject next to a wall of windows with nice, diffuse natural sunlight filling the hallway. Shooting the D600 in manual mode at ISO 100, f/2.8, 1/500, I used the pop-up flash in commander mode to trigger a nearby SB700. I selected Auto FP 1/250 and used the D600 menu to force the SB700 to under expose by 0.7 stop. The resulting image turned out great. I've been using Auto FP with my D90 for years but this was my first opportunity to take advantage of this feature with the D600. I'm just going to leave the flash sync mode at this setting since the Auto FP doesn't kick in unless I'm using an exposure faster than 1/250. Thought I've only had this body a few weeks, I've used it for nighttime street photography, time lapse sequences, shooting HD video, sports and now portraiture. Honestly, I think the D600 would make a great all-around second body for just about any pro photog, or even a primary body for someone who needs a lightweight body with outstanding IQ.

    Again, thanks for sharing your thoughts and experiences.


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