[ ** updated: Dec 24, 2008 ]
One of the features of the new Nikon SB-900 speedlight is the thermal cut-out. This feature allows the speedlight to stop firing (ie, stop working), when there is danger of it over-heating from shooting too fast. The temperature guage can clearly be seen on the right-hand side of the SB-900 LCD display.
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I’ve shown in an earlier posting here what a speedlight can look like when it over-heats and starts cooking. Here is what my one SB-800 looks like:
I have to stress that this is through no fault of the equipment or the equipment manfucaturer’s design. *I* am using the speedlight outside of the recommendations. Purposely, as explained in the other posting.
With the SB-900 the Nikon engineers cleverly built in a thermal cut-out to stop someone from doing this by accident. It will let the speedlight cut out when a certain termperature is reached inside the unit. This is a good thing. It protects your speedlight from possible damage. Fortunately, the engineers also allows you to bypass this in case you do need to shoot faster than the speedlight is designed for. This is easily set via the menu on the speedlight. (One of the many plusses in favour of the SB-900 is the self-apparant menu.)
Some people don’t seem to be aware of this feature, which is strange considering they just spent $400+ on a top-of-the-range speedlight and didn’t bother to flip through the manual or figure out all the controls.
Others seem to think that this feature is a negative. They seem to think that this feature implies the SB-900 is prone to over-heating. Now, without doing destructive testing on my SB-900, I would say that I would be hugely surprised if the SB-900 is more prone to over-heating than any other speedlight, whether it be the SB-800 or any of the Canon speedlights. Having this feature does NOT make the SB-900 prone to this problem. It allows you to side-step the over-heating problem. In other words, it’s not a negative … it’s a positive, because the speedlight now warns you, and if need be, cuts out.
Therefore my take on the thermal cut-out feature of the SB-900 is that it is one of the advantages that the SB-900 has over other speedlights, and even more of an advantage that you can over-ride it. The best of both worlds.
Now, a few months of using the Nikon SB-900, I still think it is the god of all speedlights.
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** edited to add: Dec 24, 2008
With a bit more experience now of how the SB-900 thermal protection cuts in, I do believe Nikon over-engingeered this feature, because when the SB-900 goes into thermal protection, it also disables the camera’s PC terminal!
I photographed an event this past weekend, and when the on-camera SB-900 cut out, the PC terminal of the D3 was also disabled .. and this meant that none of my off-camera flashes worked. The off-camera flashguns would’ve saved me here, but in this instance the SB-900 over-rode the D3. There really is no reason for this to be designed this way, and is an unfortunate implementation of what really is a good option to have on the speedlight.
Similarly, if the batteries of the SB-900 become depleted, the camera’s PC terminal is once again disabled. And that’s just silly.
You have often eschewed the virtues of your Quantum -how does this compare ?
Comment by Adam — November 28, 2008 @ 7:59 pm
Comment by Neil — November 28, 2008 @ 8:03 pm
Seeing that you are happy with the SB900 and have put it through extensive real world testing …. what capabilities does it offer that the SB800 fell short on? (Besides the head rotation ability)
Comment by Butch M — November 28, 2008 @ 11:22 pm
Neil, I think Nikon have just released/are releasing a new firmware revision that resets the thermal cutout higher. The engineers might have been a little too protective.
http://nikonrumors.com/2008/11/05/nikon-sb-900-firmware-update-coming-soon.aspx
Firmware updates for speedlights? What’s next?
Comment by Dan F — November 29, 2008 @ 6:08 am
Thom Hogan has a very thorough review of the SB-900 and compares it to the SB-800. You can check out his review at http://www.bythom.com/sb900review.htm. I think that Neil and Thom both agree that this is a great flash. I just ordered one. Although I haven’t received it, to me the only drawback appears to be the size.
Comment by Jose Paulino — November 29, 2008 @ 10:22 am
The SB-900 firmware has already been released on Nov. 19. The official list does not talk about adjusting the thermal cutoff point.
I have the SB-900 and it is definitely bigger and heavier than the SB-800.
Comment by Stephen T — November 29, 2008 @ 5:17 pm
I too have the SB900. I have actually had the flash cut out on me during the cake cutting…..
I now over-ride it but I leave the audible tone on. I figure I can squeeze out a few more bursts when I absolutely need them and then swap out the flash during the “not so important” times.
brian
Comment by Brian — November 30, 2008 @ 3:37 pm
I have an SB900 and I can say that it might appear bigger then the SB800 but surprisingly it is actually lighter then the Sb800.
Regarding the thermal cutoff point you will notice a huge improvement if Alkaline batteries are used instead of NiMh.
Comment by Ovidiu Suteu — December 1, 2008 @ 11:54 am
Oh my goodness! This is a good thing indeed. My husband and I just about melted our SB-800 at a wedding this summer. I took the batteries (alkaline) out of mine and they were oozing and hot as biscuits. Not good. Of course the comp was about +2 to 3, so I should’ve been looking out for this. Thank goodness they cooled off and still worked! What a great feature for the 900!
Comment by Nina — December 16, 2008 @ 4:56 pm
Hi– I am wondering if you disable the temperature shut off feature does Nikon void your warranty?
Comment by Rose Latka — April 19, 2009 @ 8:35 am
Comment by Neil — April 20, 2009 @ 1:21 am
In response to Adam’s questions, though I am not an expert in lighting, I thought it might be helpful to post what I have learned about the Qflashes vs the SB-900. I recently purchased a T2D, an X3d-r (an upgraded X2) and I own all of the SB’s from 600 to 900. I have read through every review and forum discussion I can find online to learn the pro’s and con’s of the Qflashes vs Speedlights. Ultimately, there is more rumor and anecdote than clear fact. So, since I actually own both systems, I did some testing to try to figure out how the Qflashes really compare to an SB-900 which (aside from the heat cut out, which hasn’t been a problem for me) is a joy to use.
I was interested in:
a) the actual coverage of each (vs advertised), and
b) the actual power of each (vs advertised).
To do this, I compared the lighting pattern and intensity on an off-white wall about 10′ from the camera, with the flashes set on manual 1/64 and 1/8 power (i.e. both were compared at 1/64 and again at 1/8 power).
Quantum states that the standard reflector covers 70 degrees (in its wide position, something the 4 & 5 series no longer do). On a Nikon DX format camera (D300), that translates to a 23mm focal length. However, my test photo’s showed that to get a uniform lighting pattern, without any diffusion, the actual focal length was about 55mm, which is about a 25 degree coverage. Adding the opaque diffusion disks expanded the coverage to about a 45mm focal length (about 30 degrees). And, with the wide-angle (dome) diffuser (and no disks), the coverage was about 35mm (38 deg), though the drop off/vignetting was not too bad (maybe 1/2 stop) to about 24mm (54 deg).
By comparison, with the SB-900 set to its “even” coverage pattern, the lighting levels were extremely uniform across the frame, down to about 24mm (54 deg coverage) and very good, with very minor drop off (maybe 1/4 stop in the far corners) at 18mm.
Also, interestingly, the light output of the SB-900 regardless of light pattern, vs the T2 with the Wide Angle diffuser, and no disks, was about 1/2 stop higher. With out any diffusion, and with the light pattern of each matched as similarly as possible (SB zoomed to 28mm or 35mm with an 18mm actual focal length and using the CW pattern vs. reflector in Std position for the T2) the T2 was about 1/2 to 1/4 stop more powerful (depending on the zoom setting of the SB), with a round lighting pattern; the SB had a football (American) shape and the T2 a round pattern. All of the SB-900’s lighting patterns were more uniform in the center, and had larger centers, before there was any light drop off. With the CW & Std patterns, the drop off outside of the center, was fairly rapid, though was actually no worse than the T2; the drop off was just more abrupt.
I did not do the complete battery of tests with the X-series Qflash, but with the same settings, it was about 1 1/3 to 1.5 stops more powerful than the T (with X powered by the 400watt-second Qpaq configuration). I also did not run through all the tests with the Qflash’s reflector in it’s standard position (which is the 4 & 5 series only position), however a quick comparison between wide and std showed that the light drop off is much more abrupt with the reflector in standard position, similar to the SB-900’s Std & CW light pattern, though still less uniform across the center than the SB.
What I could not tell from these tests is whether the Qflash, when feathered could produce a wider, more even lighting pattern than an SB-900. That is the typical recommendation for key light position with a parabolic reflector. Based on some quick, flash-held-at-arms-length-and-feathered shots, I think the QFlashes “might” have an advantage there (i.e. be able to produce a wider, evenly lit area when feathered properly).
However, It seems clear to me that for on-camera fill, at least, the SB-900 is superior to the Qflashes: it is comparably powerful compared to the T (more powerful than the T with its WA diffuser), more uniform than the T or X, and is capable of lower levels then either. The X is more powerful, even with the WA diffuser, so the X seems a useful compliment to an SB when a lot of light is needed. Also, if overheating is a problem, the Quantums win on that count. Also, the Qflashes are a noticeably warmer light, so putting a 1/8 or 1/4 CTO or CTS on the speedlight and doing a custom WB probably makes sense if they are mixed (I haven’t tried this, but I plan to :).
Bob
Comment by Bob — June 18, 2009 @ 4:06 pm
Comment by Neil — June 22, 2009 @ 3:41 am
I don not understand this..could i be he only one on the planet with an SB 900 that does not overheat? I shot 5 weddings in the last month 2000 shots per job….shot 1400(with flash) with the sb900 and quantum turbo pack..never shut down….
my quantum’s die out before the flash does
Comment by Neil Calandra — October 31, 2009 @ 10:04 pm
Comment by Neil — October 31, 2009 @ 11:12 pm
I am not tech savvy with all the ins and outs of the digital nightmare! But what i do know is i shoot at ISO 320-400
have the flash on auto set to F4(sb900 as main light) bounced with a white card. And a Quantum Q flash as my second light also set to f4 (bare bulb with silver tube) …I adjust f stops if needed..And besides with the D700 you can really shoot the whole wedding(other than a dank reception hall) available light since noise is not an issue anymore
could it be that this flash is not meant to shoot all day at full power at a rapid pace?
I wish i had more of a technical grasp on this stuff…all i know is that works for me :)
Comment by Neil Calandra — November 1, 2009 @ 8:09 am
LOL open mouth insert foot! mine overheated on my last job…was getting heavy use. Back to my quantums !
Comment by Neil Calandra — November 29, 2009 @ 12:21 pm
great comments from everyone!
sb900
the thermal shutdown engages in specific situations….i did not do a scientific experiment, only experience
using low ASA, like 100ASA in TTL makes the SB900 flash ‘POP’ with more energy…the flash gets hot quick
using high ASA high 800/1000asa in TTL mode the flash doesnt work as hard…and subsequently you can get away with more flashes
also
if you face the flash head toward the subject (in TTL) the flash doesnt work as hard as it would if you bounce the flash around/like off the ceiling or back wall
the distance the light has to travel to create the exposure has an effect on the flash head.
lastly: the plastic fresnel lens on the sb900 gives a burning smell when the flash is used frequently. The manufacturer may have ‘forgotten’ to give a ‘breathing portal’ for the heat transmission of the flash heads.
Can someone ask Nikon if we need to drill holes into the Fresnel Lens of our SB900
s? Or should we ask Toyota to fix the problem?
Comment by John Ferris Robben — March 1, 2010 @ 12:41 am