# Half black photo with Flash in Auto mode Nikon D3100



## Kimskams (Aug 13, 2015)

Dear gurus

I am suddenly having this problem with my nikon d3100. I took photos last night n those were ok but tonight its taking photos with half top dim( almost black ). Problem occurs only on flash n fotos are fine when taken without flash. Im using auto mode. I found a similar thread on this forum of 2011 but no solution was posted so i thought to ask here myself. Thanks 

PS: i hv tried formatting memory card n restetting shoot options.


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## Vtec44 (Aug 13, 2015)

Your shutter speed may have been too high for the flash sync speed.  You can either lower the shutter speed or turn on Auto FP in your camera.


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## 480sparky (Aug 13, 2015)

The TOP of the image is black?

1. That rules out the shadow of a hood.
2. Shutter speed too high?  Hmmmm. Too high a shutter speed usually turns the bottom of the image black and the second curtain is already on it's way down by the time the first curtain is fully open and triggers the flash.

Maybe you've got the camera's flash settings set to rear curtain synch *and* your shutter is too fast.


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## astroNikon (Aug 13, 2015)

Vtec44 said:


> Your shutter speed may have been too high for the flash sync speed.  You can either lower the shutter speed or turn on Auto FP in your camera.


I don't think the d3100 has AutoFP?
thus the OP should try lowering the shutter speed.


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## Derrel (Aug 13, 2015)

D3100 does not offer FP Synch mode...so...I dunno, the shutter speed is likely exceeding the X-synch's maximum speed setting. The phrase "in auto mode" is interesting...if the flash was properly dedicated to the camera, "auto" mode on the camera would set the synch speed or slower, but if "auto" mode means "AUTO-flash" setting _on the flash unit_ and it's not a properly dedicated unit, the flash would not communicate with the camera and it would be possible to get too fast a shutter speed, and to get the black bar.

As astroNikon and 480sparky and Vtec44 all have suggested--try *lowering the shutter speed*. Try ISO 250, Manual metering mode, lens set to f/5.6, flash on AUTO mode, the "wide f/stop setting" if there are two or three color-coded AUTO mode setting values to choose from, shutter speed set to 1/125 second...blast off a few frames, see what gives.

When troubleshooting things like this, it helps a LOT if you can include the model and brand of the flash, so people can do a quick lookup on-line; today there are like a zillion different made in China flash units; some have TTL mode, some offer TTL mode and also AUTO-flash mode; some are manual flash only, like the lowest priced units.


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## 480sparky (Aug 13, 2015)

Another possibility is.......... start cringing now......... a bad shutter.


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## robbins.photo (Aug 13, 2015)

480sparky said:


> Another possibility is.......... start cringing now......... a bad shutter.



True, but if it were a bad shutter or possibly the mirror not releasing properly it would show up on all photos, not just the ones taken with a flash, so that should be easy enough to check and hopefully rule out.


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## Vtec44 (Aug 13, 2015)

I'm just waiting for this to turn into a 5 page discussion about world peace.


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## Derrel (Aug 13, 2015)

Vtec44 said:
			
		

> I'm just waiting for this to turn into a 5 page discussion about world peace.



How about a discussion about Metta World Peace instead?

Metta World Peace - Wikipedia the free encyclopedia


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## WayneF (Aug 13, 2015)

Kimskams said:


> I am suddenly having this problem with my nikon d3100. I took photos last night n those were ok but tonight its taking photos with half top dim( almost black ). Problem occurs only on flash n fotos are fine when taken without flash. Im using auto mode. I found a similar thread on this forum of 2011 but no solution was posted so i thought to ask here myself. Thanks



A common problem with black banding with flash  is when the shutter is too fast for camera sync. The D3100 cannot sync flash faster than a 1/200 shutter speed.  *What was the shutter speed?* (it is reported in the images Exif information).

Still, there are two problems with thinking this here:
The camera Auto mode will not allow this problem, if it recognizes the flash is present.
So which flash? Off camera flash?  Triggered how?  How could it have fooled Auto mode?  (was the shutter speed actually faster than 1/200 second?).
If it was a TTL flash on the hot shoe,this problem should not have been possible, so something else happened, and we need more detailed information about what actually happened?
And two,  you said at night, so a shutter faster than 1/200 seems very unlikely anyway, not from Auto mode.



480sparky said:


> The TOP of the image is black?
> 2. Shutter speed too high?  Hmmmm. Too high a shutter speed usually turns the bottom of the image black and the second curtain is already on it's way down by the time the first curtain is fully open and triggers the flash.



Top and bottom are arbitrary, in different cameras. For example, the D300 and D800 shutters run in opposite direction in regard to top or bottom banding.  And of course images are inverted, so we see the opposite of either (D300 top, D800 bottom).


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## wfooshee (Aug 13, 2015)

The camera wouldn't necessarily be aware of a 3rd-party flash unit, but still trigger it through the main center pin, the one that's existed since hotshoes were invented.

Auto mode setting a shutter speed higher than 1/200 in a situation that needs flash sounds a bit goofy, too, unless ISO is simply way too high.... Unless the user is trying to fill flash in a daylight situation, in which case a generic flash is not going to give good results without careful planning and settings, which definitely won't involve auto mode.


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## KmH (Aug 14, 2015)

WayneF said:


> For example, the D300 and D800 shutters run in opposite direction in regard to top or bottom banding.


Huh? You lost me with that statement.
A D800 shutter runs from bottom to top for an exposure? Because a D300 shutter moves from the top to the bottom to make an exposure.
Does Nikon say that somewhere? I've looked at quite a few web/sites pages (including Nikon) and can't find anything about that.
Sounds interesting. Weird, but interesting.
How about some links?

Gravity aids shutter curtain opening when the camera is held in the landscape/horizontal orientation if the shutter curtains start at the top of the shutter mechanism and move towards the bottom of the camera.
In vertical orientation the shutter curtains move side to side and the direction would depend on if the shutter button was at the top or bottom.

Nikon specs for the D300 and D800 say the same thing about the shutter:


> Electronically-controlled vertical-travel focal-plane shutter



At any rate the OP used a D3100, and a D3100 shutter moves from top to bottom to make an exposure.

If the top half of the photo made with a D3100 is dim or black, that means the bottom of the image sensor was partially covered by the front shutter curtain.
That is what would be seen with the camera set to rear curtain flash firing sync with the shutter speed set to faster than 1/200.
1/200 is the x-sync speed because it is the fastest shutter speed that allows both shutter curtains to be open 
At a sync speed faster than 1/200 the 2 shutter curtains form a variable size slit. The faster the shutter the narrower the slit.
At 1/250 the slit is way wider than if the shutter speed is set to 1/4000.


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## WayneF (Aug 14, 2015)

KmH said:


> WayneF said:
> 
> 
> > For example, the D300 and D800 shutters run in opposite direction in regard to top or bottom banding.
> ...



OK, try here:   Maximum Shutter Sync Speed for Flash




> Gravity aids shutter curtain opening when the camera is held in the landscape/horizontal orientation if the shutter curtains start at the top of the shutter mechanism and move towards the bottom of the camera.



Gravity is a trivial concern.. the shutter is very thin, and is driven by a motor.


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## 480sparky (Aug 14, 2015)

If gravity 'assists' the shutter curtains,  do I need to adjust the speed when shooting in portrait orientation?  How about when the camera is upside-down? How much exposure difference is there?


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## Vtec44 (Aug 14, 2015)

I have nothing to add but just want to get this to page 2.


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## wfooshee (Aug 14, 2015)

I have never heard of adjusting the speed to accomadate orientation. I would venture a guess that any deviation in shutter speed from landscape vs portrait is significantly less than the 1/3 stop adjustment available to us.

As for which half of the image is black, that CAN be changed by synching rear curtain vs. the standard front curtain. If the flash is triggered with the normal front curtain sync, it goes off when the front curtain is fully open. With top-to-bottom shutter travel that will show the bottom of the image dark, as the second curtain has already covered the top of the sensor, and the inverted image puts the dark area at the bottom. With rear curtain sync, the flash triggers the instant the rear curtain is ready to start. With too high a speed that means the front curtain has not fully opened, so in this case the rear sync is actually _earlier_ than the front sync. The top of the image will be dark.

It is possible that the shutter blades are hanging or not traveling freely which would mess up the timing. That may not even affect exposure too much if the blades are traveling slower than expected but evenly slow. The gap between them will be the right timing, just the blades aren't clear of the frame when they're supposed to be. If one blade travels differently than the other, than exposure gets adjusted from the intended exposure. If one blade sticks and continues, you'll have a lighter band at that point of the frame. I had that with a Canon AE-1 that would occasionally show a slightly lighter band about 2/3 the way across the frame. That was a horizontal cloth shutter, and the rear curtain was sticking just a bit, and where it stuck got more exposure.

I still haven't seen what flash is being used. If it's a Nikon flash, or a 3rd party designed for Nikon, it should limit the maximum shutter automatically just by being attached and powered on. A cheaper 3rd-party flash may not have the smarts to do that, and you can set whatever shutter speed you want. If it's a proper flash that the camera should communicate with and you get shutter interference with the flash, then the shutter is probably not working right, most likely slow blade travel.


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## The_Traveler (Aug 14, 2015)

I was doing a search for 'whirled pees" and this thread came up.


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## WayneF (Aug 14, 2015)

wfooshee said:


> As for which half of the image is black, that CAN be changed by synching rear curtain vs. the standard front curtain. If the flash is triggered with the normal front curtain sync, it goes off when the front curtain is fully open. With top-to-bottom shutter travel that will show the bottom of the image dark, as the second curtain has already covered the top of the sensor, and the inverted image puts the dark area at the bottom. With rear curtain sync, the flash triggers the instant the rear curtain is ready to start. With too high a speed that means the front curtain has not fully opened, so in this case the rear sync is actually _earlier_ than the front sync. The top of the image will be dark.




Your thought out logic sounds good, but if you actually go try it,  the camera does NOT work that way.  At least the Nikon D300 and D800 cameras do Not change the banding with either Rear or Front curtain sync.  The banding is identical either way (different from each other, but the same with respect to Rear/Front Curtain sync).   Just actually try it.

I've often wondered about how Rear Curtain sync can handle the timing.  The full duration of a speedlight at maximum power level is normally pretty near the maximum sync speed.  It can be a slight issue for front curtain sync cutting off the trailing tail of fading flash at maximum sync speed.  Holding shutter back to maybe 1/160 second is often seen better for seeing all of the speedlight maximum power level.  Not a big difference, not saying very significant, but the numbers are pretty close.

So how would rear curtain do this?   It cannot wait to trigger until the rear curtain is ready to close, since then there won't be any time left for a long flash duration.   So surely it has to trigger early by some nominal time to allow a nominal flash duration?  Maybe it even backs off about by Maximum sync speed to allow most of a maximum power flash before it closes?  Which would mean that maximum sync shutter would not be Rear curtain at all?    This would not matter for a very slow shutter (as is often the point of Rear), and Rear Sync is pointless anyway at a fast shutter, when it doesn't matter what it does.  So that is my made-up theory (also totally lacking evidence).


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## wfooshee (Aug 14, 2015)

WayneF said:


> Your thought out logic sounds good, but if you actually go try it,  the camera does NOT work that way.  At least the Nikon D300 and D800 cameras do Not change the banding with either Rear or Front curtain sync.  The banding is identical either way (different from each other, but the same with respect to Rear/Front Curtain sync).   Just actually try it.



So I dig out my old Canon 300TL (which goes with my T90 film camera) and set my shutter to 1/500. Sure enough the black band is at the bottom of the image on both modes. I think I know why....

Just guessing, but maybe the rear sync isn't actually tied to the curtain itself, but still to the front curtain, plus a delay for the shutter duration. A fast enough shutter means too small a duration to affect the timing.



WayneF said:


> I've often wondered about how Rear Curtain sync can handle the timing.  The full duration of a speedlight at maximum power level is normally pretty near the maximum sync speed.



According to my SB-600's manual, the duration at max power is 1/900 second, less than a third of the sync speed shutter duration (1/250 on my camera.) 1/64 power is only 1/25000 second. Studio lights are different in how their flash tubes work, and for some their duration is shortest on highest power, and actually gets longer with reduced power, resulting in the possibility of closing the shutter during the lighting if you aren't careful.



WayneF said:


> This would not matter for a very slow shutter (as is often the point of Rear), and Rear Sync is pointless anyway at a fast shutter, when it doesn't matter what it does.  So that is my made-up theory (also totally lacking evidence).



I agree that rear sync is useless unless you're talking long shutter durations, but as long as we're doing thought experiments  I'll point out that my hypothesis in my earlier post was that his shutter was malfunctioning by "dragging" the blades. The gap between curtains may be timed correctly (giving a correct shutter speed) but if the blades are moving too slowly, timing of events such as flash sync get screwed up. It may be that the shutter is indeed set to 1/200, and forced to that setting by the flash, but slow-moving blades are resulting in the curtain not being "out of the way" in time when the flash goes off.


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## WayneF (Aug 14, 2015)

wfooshee said:


> So I dig out my old Canon 300TL (which goes with my T90 film camera) and set my shutter to 1/500. Sure enough the black band is at the bottom of the image on both modes. I think I know why....
> 
> Just guessing, but maybe the rear sync isn't actually tied to the curtain itself, but still to the front curtain, plus a delay for the shutter duration. A fast enough shutter means too small a duration to affect the timing.



It never seems worded that way, but it seems a good guess. The second curtain is just a timed delay from the first curtain, so I suppose they can easily add 5 seconds shutter duration to it.  Otherwise, they need a way to trigger the flash awhile before the rear curtain moves, which seems unnecessarily complex.




> According to my SB-600's manual, the duration at max power is 1/900 second, less than a third of the sync speed shutter duration (1/250 on my camera.) 1/64 power is only 1/25000 second. Studio lights are different in how their flash tubes work, and for some their duration is shortest on highest power, and actually gets longer with reduced power, resulting in the possibility of closing the shutter during the lighting if you aren't careful.



Actually, speedlight maximum power level is the same concept as monolights.  But the monolights simply reduce the voltage to set lower power (which is slower, less energetic), where the speedlight always sets full voltage, but truncates the duration with IGBT for lower power levels (which is of course faster).  The monolights become more red, and the speedlights become less red (chops off the cooler tail).

The ISO standard for flash duration is the standard t.5 spec, which is the time between the half power points (which is a standard thing for engineers measuring difficult things that trail off with no definite end point).  This is true of speedlight maximum power too.   Then the universal rule of thumb is that  the t.1 time (the 90% power above the 10% power points) is three times t.5, which would be more useful for photographers.   So the t.5 1/900 second is actually 1/300 second t.1 duration.   And of course, 10% is not zero, so there is still some more too.

Top end Nikon camera models specify flash sync at 1/250 second, but they offer 1/320 second sync and can do it.  They clearly do 1/320 second fine, but Nikon adds a footnote saying "the range might be a bit less" at 1/320.  That is just Nikon speak, and my guess is they imply at maximum power, due to chopping off a long flash duration.  Not a factor at lower power (for speedlights), and the later manuals seem to be dropping that now (but they still spec 1/250 and offer 1/320).

t.5 is why the speedlight 1/2 power duration is usually near the full power duration...  Because full power is measured to the half power points, and 1/2 power cuts off the flash tube at the half power point.  Some like the SB-600 are a bit further from being equal, 1/900 and 1/1600 second.  This also depends on rise time, and that lower power flashes are faster than higher power flashes.  But the SB-800 is 1/1050 full  and 1/1100 half.



> I agree that rear sync is useless unless you're talking long shutter durations, but as long as we're doing thought experiments  I'll point out that my hypothesis in my earlier post was that his shutter was malfunctioning by "dragging" the blades. The gap between curtains may be timed correctly (giving a correct shutter speed) but if the blades are moving too slowly, timing of events such as flash sync get screwed up. It may be that the shutter is indeed set to 1/200, and forced to that setting by the flash, but slow-moving blades are resulting in the curtain not being "out of the way" in time when the flash goes off.



The focal plane shutter is not blades, but is two very thin roll-up titanium curtains, both driven by the same motor. That is the beauty, shutter accuracy is controlled by a simple quartz delay starting the second curtain.

I think we need to hear from the OP first,  to at least hear the actual shutter speed, and maybe the flash type and situation (off camera?) before we scare him telling him the shutter is bad.  He said "problem only occurs with flash".  Any thing is possible, but that probability seems pretty low at this point,


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## The_Traveler (Aug 15, 2015)

What a great and useful thread.


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## wfooshee (Aug 15, 2015)

WayneF said:


> The focal plane shutter is not blades, but is two very thin roll-up titanium curtains, both driven by the same motor.



Roll-up???? Where's a roll-up titanium shutter? The old cloth focal-plane shutters rolled on spools, but the modern shutters are blades. Four blades for each "curtain."

Naked shutter blades found with a Google search

Titanium _can't_ roll onto a spool. Making the curtain out of blades makes it stowable in the space above and below the image sensor.



WayneF said:


> I think we need to hear from the OP first,  to at least hear the actual shutter speed, and maybe the flash type and situation (off camera?) before we scare him telling him the shutter is bad.  He said "problem only occurs with flash".  Any thing is possible, but that probability seems pretty low at this point,



My busted-shutter theory is speculation, but from having seen it before, a mechanical issue like dragging curtains can throw off the timing. It would be nice for the OP to come back and answer some of the questions.


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## WayneF (Aug 15, 2015)

wfooshee said:


> Roll-up???? Where's a roll-up titanium shutter? The old cloth focal-plane shutters rolled on spools, but the modern shutters are blades. Four blades for each "curtain."
> 
> Naked shutter blades found with a Google search
> 
> Titanium _can't_ roll onto a spool. Making the curtain out of blades makes it stowable in the space above and below the image sensor.




OK,  my blunder then.   Here is more detail:

Nikon s Honeycomb-pattern Titanium Shutter - Index Page

I was going too fast, sorry.   Thin metal can roll up, and cloth curtains always did, so I didn't pause to question it.      But yes, the rule is, question everything.


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## KmH (Aug 15, 2015)

WayneF said:


> KmH said:
> 
> 
> > WayneF said:
> ...


No thanks.
I prefer an independent source of your information.

As far as the titanium shutter info in the article you linked to:


> the famous Titanium shutter was finally replaced with an aluminum alloy version for the FM2n in 1989.



So Nikon abandoned the titanium shutter some 20+ years ago?


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## WayneF (Aug 15, 2015)

KmH said:


> No thanks.
> I prefer an independent source of your information.



Suit yourself.  Yeah, for all you know, I might have screwed up and mounted one camera upside down on the tripod.   Then maybe gravity messed it up.   LOL



> As far as the titanium shutter info in the article you linked to:
> 
> 
> > the famous Titanium shutter was finally replaced with an aluminum alloy version for the FM2n in 1989.
> ...



Says it did in the FM2n, which is actually quite well known.

It was only YOU that extended it to all Nikon.


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## Avishekh Gautam1 (Oct 1, 2017)

WayneF said:


> wfooshee said:
> 
> 
> > So I dig out my old Canon 300TL (which goes with my T90 film camera) and set my shutter to 1/500. Sure enough the black band is at the bottom of the image on both modes. I think I know why....
> ...


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## Avishekh Gautam1 (Oct 1, 2017)

I too have the similar problem but with Nikon d5500. That is, while taking photos on automode, and with flash on the photos have dark band on the upper third of every photos. I would like to mention only when the flash is turned on and the problem persists irrespective of whichever mode I use auto mode or program mode with flash on. With no flash everything is fine. The shutter speed is 1/60-1/200 usually in automode when i have observed the band, never outside that range.


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## WayneF (Oct 22, 2017)

Avishekh Gautam1 said:


> I too have the similar problem but with Nikon d5500. That is, while taking photos on automode, and with flash on the photos have dark band on the upper third of every photos. I would like to mention only when the flash is turned on and the problem persists irrespective of whichever mode I use auto mode or program mode with flash on. With no flash everything is fine. The shutter speed is 1/60-1/200 usually in automode when i have observed the band, never outside that range.




I cannot explain that.  If the shutter speed is not faster than 1/200 second, then that should never happen.  The camera will not even allow the shutter speed to go faster with a hot shoe flash it recognizes (can communicate with).  So you say that part seems to be working, but somehow the sync timing is incorrect.  Seems impossible, at least I've never seen it, and I cannot imagine any option that could cause it. I would be convinced that it is a defective malfunction, and you should contact Nikon about repair before warranty expires.

FWIW, what is the flash mode set on the flash?


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