D7100 with SB900 randomly underpowered flash output
I'm new here (as of today), so forgive me if this subject has been discussed and I didn't see the existing thread. I'm experiencing randomly occurring low flash output when using an SB900 speedlight on my D7100 body. About 20-25% of my flash exposures are under-lit with no seeming explanation. I'll attempt not to be too wordy, but I'd like to provide all the pertinent info and testing results I've done. I can use the SB900 in question on my D300S body all day long and have no flash output problems. Conversely, I can use an older SB800 speedlight on the D7100 body and again have no problems. I borrowed a friend's SB900 for testing purposes and found that I experienced the same intermittent low flash output. All of these results came from "real world" shooting situations, so in order to provide a much more controlled testing environment I placed the D7100 on a tripod with the SB900 mounted on the camera's hot shoe and aimed it towards a mid-key toned studio backdrop about 10 feet away. ISO 800, Program mode, direct flash with no modification or change in flash head position, 18-105 VR lens. No exposure compensation, no flash compensation. About as basic a set-up as possible. I stood there and released the shutter for 18 exposures with no changes at all to the scene, ambient lighting, camera or flash settings. Exposures were made 4 to 8 seconds apart and at no time did the ready light on the flash turn off or even flicker, so I wasn't shooting so fast or calling on the flash to dump so much power that it wasn't at full capacity between exposures. Of those 18 shots, 5 of them exhibited low flash output randomly throughout the sequence. Exposure of ambient light sources (a small strip of light coming through a window in the scene) remained constant; only the flash power was decreased. In fact, I can visually see the diminished output as I am shooting before I even check the image on the monitor. When I contacted Nikon service and support about the problem back in July, they had me send in both the speedlight and camera. As is often the case with technical service departments, they initially wanted to question/blame my knowledge and techniques but after 20+ years of shooting Nikon I am convinced that user error was/is not to blame here. No problems were found with the camera and the speedlight was refurbished with numerous replacement parts. Upon the equipment being returned to me, the problem still exists. So I contacted Nikon again two weeks ago and they had me submit more sample images which clearly demonstrated the problem, and I documented all the information I've provided here (and then some). Today I was informed that they could not duplicate the problem in their service department and I was just stunned. They plan to return both items with no further service provided. Fortunately I was persistent enough to be put in touch with a customer service supervisor who seemed genuinely interested and said he would try to snag my equipment before it was shipped and try to duplicate the problem himself. He called me back within an hour, telling me he had indeed recreated my controlled shooting scenario and found the same problem by using their own in-house equipment (mine may have already been shipped unrepaired). He also said he found the same problem when he used an SB900 on a D300 body, but I reminded him that the combination that gave me no problem was with a D300S. His next step is to report his findings to a senior service technician and wait for some explanation. So... whew! All that being said, has anyone else experienced this phenomenon using a D7100 and SB900 in combination? I can't imagine that I've left out any details, but I'll gladly clarify or provide any other useful info that I can, and I'll be very appreciative of your feedback and replies.
#1. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 0quenton8 Nikonian since 11th Apr 2010Fri 13-Dec-13 07:39 PM
Any chance your flash was in "TTL-BL" mode instead of "TTL"?
I find this with my SB600 from time to time. If I look at a result and it looks dark and I don't see any OTHER problem that might cause it, I will look at my flash mode.
Not sure how it gets switched but it seems to.
#4. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 1Fri 13-Dec-13 08:39 PM
According the the metadata, the speedlight was indeed in TTL-BL mode, but again I have to point out that I was shooting under a totally controlled situation where absolutely nothing changed with regards to camera or flash settings, the scene, ambient light, position. EVERYTHING was identical. So even in TTL-BL mode, every image should have been identically exposed. Five of the eighteen shots randomly displayed low flash output, by probably around two stops (just judging visually).
>Any chance your flash was in "TTL-BL" mode instead
>I find this with my SB600 from time to time. If I look at a
>result and it looks dark and I don't see any OTHER problem
>that might cause it, I will look at my flash mode.
>Not sure how it gets switched but it seems to.
#2. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 0
Hi Dan, welcome to Nikonians.
It must be frustrating to not have the techs see it but that is often the case since a unit sometimes needs a few of the variables to be present that does not go in the box.
For example the metering is commonly tweaked between model changes so it is not unusual to see slightly different behavior of the metering between models.
I would seek to isolate more factors that might contribute to the problem.
What lighting was ambient, florescent, perhaps?
Does this happen in all metering modes?
Does it occur more with some color targets than others?
Does it occur in TTL BL mode or outdoors in sun?
To limit variables, I would do the tests in manual exposure mode to make sure the exposure is not left up to an automatic or semiautomatic mode like P, A or S.
Are you using a target that fills beyond the focal point in the VF?
Does it occur more in AF than MF?
Try an experiment with controlling as many variables as possible:
Tripod mount, indoors and turn off the lights to darken the room and not be illuminated by any AC powered lights, manual focus.
Cover the VF before taking the shots, MF, and run a cycle of spot, CW and Matrix and at slow, mid and faster shutter speed. and a moderately low fixed ISO, say 200.
These tests would be primarily to see if under the least automatic settings whether the problem is reproducible. If it does not occur, start adding more setting ambiguity by adding less controlled variables such as turning on room lights, adding one element at a time until the problem occurs often enough not to be random errors.
That is where I would start. The first wild guess is related to ambient lighting and shutter speed versus AC mains frequency. If is never happens at 1/10th of a second, you can safely cross off artificial light intensity cycling with the mains.
Good luck and report back your experiments when you get the camera back
St Petersburg Russia
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#3. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 2Fri 13-Dec-13 08:32 PM | edited Fri 13-Dec-13 08:38 PM by briantilley
Hi Stan, and thanks for the input. This is not a problem of metering/exposure between camera models so much as it is between exposures by the D7100 of the EXACT same scene over a period of a couple of minutes. Setting aside the "real life" shooting situations and variables, I had set up a completely controlled environment where NOTHING changed relative to the camera, the speedlight, or the scene between exposures. Even though I was in Program mode, the metadata from each file shows that the same shutter speed and aperture were used for every image. When I was shooting the tripod-mounted images, the ambient light in my studio was moderate and unchanging as was my position relative to the viewfinder (so I was blocking no more nor less of the light entering it). I touched absolutely nothing except the shutter release, and five of the eighteen exposures I made clearly exhibited low flash output by what visually appears to be about two stops. So regardless of my initial settings, it would stand to reason that every image in the sequence should be identically exposed. Sadly, that is not the case. At least I've apparently generated some interest on the part of the Nikon customer service supervisor who was able to duplicate the problem even though the service department could allegedly could not do so, and he was as puzzled as I am.
#5. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 3km6xz Nikonian since 22nd Jan 2009Fri 13-Dec-13 09:14 PM
By "nothing changed" do you mean you tried with no ambient light from electric sources?
As you know, the flash metering it totally independent of the camera metering calculations so using an auto mode that is metering for its own middle grey exposure in the camera can introduce variables that confuse the tests.
What was the ambient light source and what did it measure?
St Petersburg Russia
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#6. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 5Fri 13-Dec-13 10:08 PM
Stan, there was no ambient light from electric sources. The ambient light in the room was low to moderate and came from diffused light coming from windows in the room. I did not measure the ambient light level, but it remained unchanged throughout the minute or so during which I made the eighteen exposures and it was less than what would be required for a proper exposure without flash. By "nothing changed", I mean the ambient light, camera position, tripod position, scene, camera and flash settings were all constant. I touched nothing except the shutter release. Therefore it would seem to me that ALL things being equal, every exposure should have been given the same amount of flash output. That is not the case. Images one and two were correct, three and four were underflashed, the next four were correct, then another underflash... and so on. There is no rhyme or reason as to what is causing the speedlight to have visibly (as in I can see it when I'm shooting) randomly diminished output. And yes, I am aware that camera metering and flash metering are different. The bottom line is that if NO variables change between all the exposures, then they should all be correctly lit. Do you not agree? Please don't think I'm being argumentative, just trying to be very clear with as much info as possible. Thanks again for the input.
>By "nothing changed" do you mean you tried with no
>ambient light from electric sources?
>As you know, the flash metering it totally independent of the
>camera metering calculations so using an auto mode that is
>metering for its own middle grey exposure in the camera can
>introduce variables that confuse the tests.
>What was the ambient light source and what did it measure?
>St Petersburg Russia
#7. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 0
Hi. I had this same repeatable problem on my new D7100 and took a series of identical photos using my SB-900 on my D3200, D700 thence D7100. Took the evidence to Nikon service centre who were able to repeat the problem. They were instructed by Nikon Australia to replace the hotshoe. When I asked them not to repair the item as I would take it back to the retailer for a refund (as I didn't think it was hardware but a firmware problem) Nikon Australia suddenly pulled out a firmware update from Singapore, stated on the repair form as 'Latest firmware installed not yet available to public'. The issue has now been remediated. If you can't get anyone to acknowledge the problem, the authorised Nikon service centre who fixed this for me are Digicam email: email@example.com.
#8. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 7MEMcD Nikonian since 24th Dec 2007Thu 10-Apr-14 02:18 PM
Welcome to Nikonians!
What version of Firmware did they install in your camera?
You can check by going into the Setup Menu (Wrench icon) and scrolling down to Firmware version.
#9. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 8quenton8 Nikonian since 11th Apr 2010Thu 10-Apr-14 10:42 PM
I have seen some random dark shots using my D7100 with my SB600.
I have been using a D90 for a few years and have not seen this.
The number is small (as a percentage) and has not been much of a problem because I usually take multiple shots of a situation -- but there is no question in my mind that about maybe 1 in 30 or 40 shots comes out dark for no reason.
I would be happy to see a published solution!
#10. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 9Howker Registered since 21st Jul 2010Sun 13-Apr-14 02:42 AM
I wish I could figure out what might be causing this problem. My setup is exactly the same - D7100/SB900
What is galling is Nikon's attitude to customer service. No wonder the D600 did such damage to their reputation. Will they never learn!
We Nikonians are so loyal they treat us like mushrooms!
I will watch this posting in the hope a solution is found.
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#11. "RE: D7100 with SB900 randomly underpowered flash output" | In response to Reply # 0
I have had this type of problem on two other cameras and in both cases it was a bad flash module circuit board that needed to be replaced. Once on a D1x and once on a D200. As with your experience the flash problem was intermittent and I initially thought it was a bad battery.
A single bad battery can cause similar symptoms and a standard battery tester will show the battery as good and at 100%. I bought a pulse load battery tester and it quickly showed that one of the Nimh batteries was only at 40% capacity when 100% charged. It could move the voltmeter but it inhibited the charging of the capacitors in the flash and with maximum draw under this load the voltage level also dropped and with Nimh batteries the voltage is marginal even with good batteries for operating the electronics of the flash.
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