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Nikon DSLR Cameras
D750
how your auto iso and flash works ?
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<blockquote data-quote="WayneF" data-source="post: 557069" data-attributes="member: 12496"><p>FWIW, Exif says ISO 1600 in the first one.</p><p></p><p></p><p></p><p>I assume Incandescent white balance, or Auto WB giving similar, so the blue background is window light, Daylight light, wrong for Incandescent WB. Mixing light sources is generally impossible, WB can only correct for one of them. Any try at a "compromise" WB will simply be wrong for both then.</p><p></p><p></p><p></p><p>FEC in camera and in flash body simply add to a total, so these two are the same thing, they add to the same total. And camera EC also adds to it, unless overridden in D750 menu E4.</p><p></p><p></p><p></p><p>The camera meter we see (indicating 0 EV now) is only reading the ambient exposure. It is not affected by flash. Flash has not fired yet, and flash has its own invisible metering system anyway. But flash will contribute to total exposure.</p><p></p><p>It does seem a bit bright, but you are fully exposing the ambient with ISO 1600 and 1/8 second and f/2.5. Any additional exposure from flash adds to add to be more than that existing full ambient exposure. -2 EV flash compensation will add and lift fully exposed ambient by 25%, which is 1/3 stop overexposure of the near foreground affected by flash (flash percentage calculator at <a href="http://www.scantips.com/lights/flashbasics4.html#percent" target="_blank">Flash pictures are Double Exposures- Outdoors</a> ).</p><p></p><p>Remember that you are affected by Nikons TTL BL automation. If the scene is brightly and fully illuminated (as here, with your ISO 1600 and 1/8 second and f/2.5), then it automatically provides less flash fill, trying to minimize overexposure by adding flash. Automation interferes with your own efforts, automation knows what it is trying to do, and it can sometimes tend to ignore you. </p><p></p><p> Saying, in this TTL BL case, I really doubt you will see any difference between -2 EV flash compensation, and 0 EV flash compensation. Automation has its own goals. I am agreeing with you, but you may not like my reasons.</p><p></p><p>The default TTL BL mode really expects to do its own automatic flash compensation. Your events will be much more controllable if you use manual flash mode, and then do what you see you need to do to get the results you want.</p><p>But automation will generally give automated results, the opposite of user control.</p><p></p><p>But if you set ISO 100 and 1/200 second and say f/5.6, the ambient would be dark, black even, and the flash would try harder. Your -2 EV would hold it back however, it would not be fully exposed by flash then. That should show a strong difference between -2 EV and 0 EV flash compensation.</p><p></p><p>Or you could set some exposure compromise, to handle ambient and flash individually as you wish them to be.</p><p></p><p>Or, switching to TTL mode (as opposed to default TTL BL mode) will be different, no system compensation automation trying for its own goals.</p><p></p><p>Your words suggest you expect TTL mode, but the Nikon flash metering default is TTL BL instead. Balanced flash, in its own way.</p><p></p><p>Spot metering will make that switch, TTL flash mode overrides TTL BL mode, but then you get Spot metering for the ambient, which introduces other issues, perhaps unexpected. Spot metering is not a point&shoot effort, instead we must understand how to use it. But if you can get the ambient exposure as you want it, then TTL mode will respond properly to flash compensation.</p><p></p><p>I like to use an older Nikon SB-800 flash, which has its own menu to force TTL or TTL BL mode. I think Nikon should provide that menu in the camera, but they don't. They only provide Spot metering, which is NOT for beginners, and unfortunately, also does Spot metering for the ambient (but the flash is Never Spot metering).</p><p></p><p>Spot metering generally works great with flash indoors, which causes no effect when we ignore the insignificant ambient. But if fully metering the ambient, then spot metering is spot metering, for ambient.</p><p></p><p>You and I have different goals. My goal is to suppress ambient in flash pictures, which makes it easy. Your goal is to fully support the ambient, much more complicated. But I think you would like manual flash mode to do that, so you can control it.</p></blockquote><p></p>
[QUOTE="WayneF, post: 557069, member: 12496"] FWIW, Exif says ISO 1600 in the first one. I assume Incandescent white balance, or Auto WB giving similar, so the blue background is window light, Daylight light, wrong for Incandescent WB. Mixing light sources is generally impossible, WB can only correct for one of them. Any try at a "compromise" WB will simply be wrong for both then. FEC in camera and in flash body simply add to a total, so these two are the same thing, they add to the same total. And camera EC also adds to it, unless overridden in D750 menu E4. The camera meter we see (indicating 0 EV now) is only reading the ambient exposure. It is not affected by flash. Flash has not fired yet, and flash has its own invisible metering system anyway. But flash will contribute to total exposure. It does seem a bit bright, but you are fully exposing the ambient with ISO 1600 and 1/8 second and f/2.5. Any additional exposure from flash adds to add to be more than that existing full ambient exposure. -2 EV flash compensation will add and lift fully exposed ambient by 25%, which is 1/3 stop overexposure of the near foreground affected by flash (flash percentage calculator at [URL="http://www.scantips.com/lights/flashbasics4.html#percent"]Flash pictures are Double Exposures- Outdoors[/URL] ). Remember that you are affected by Nikons TTL BL automation. If the scene is brightly and fully illuminated (as here, with your ISO 1600 and 1/8 second and f/2.5), then it automatically provides less flash fill, trying to minimize overexposure by adding flash. Automation interferes with your own efforts, automation knows what it is trying to do, and it can sometimes tend to ignore you. Saying, in this TTL BL case, I really doubt you will see any difference between -2 EV flash compensation, and 0 EV flash compensation. Automation has its own goals. I am agreeing with you, but you may not like my reasons. The default TTL BL mode really expects to do its own automatic flash compensation. Your events will be much more controllable if you use manual flash mode, and then do what you see you need to do to get the results you want. But automation will generally give automated results, the opposite of user control. But if you set ISO 100 and 1/200 second and say f/5.6, the ambient would be dark, black even, and the flash would try harder. Your -2 EV would hold it back however, it would not be fully exposed by flash then. That should show a strong difference between -2 EV and 0 EV flash compensation. Or you could set some exposure compromise, to handle ambient and flash individually as you wish them to be. Or, switching to TTL mode (as opposed to default TTL BL mode) will be different, no system compensation automation trying for its own goals. Your words suggest you expect TTL mode, but the Nikon flash metering default is TTL BL instead. Balanced flash, in its own way. Spot metering will make that switch, TTL flash mode overrides TTL BL mode, but then you get Spot metering for the ambient, which introduces other issues, perhaps unexpected. Spot metering is not a point&shoot effort, instead we must understand how to use it. But if you can get the ambient exposure as you want it, then TTL mode will respond properly to flash compensation. I like to use an older Nikon SB-800 flash, which has its own menu to force TTL or TTL BL mode. I think Nikon should provide that menu in the camera, but they don't. They only provide Spot metering, which is NOT for beginners, and unfortunately, also does Spot metering for the ambient (but the flash is Never Spot metering). Spot metering generally works great with flash indoors, which causes no effect when we ignore the insignificant ambient. But if fully metering the ambient, then spot metering is spot metering, for ambient. You and I have different goals. My goal is to suppress ambient in flash pictures, which makes it easy. Your goal is to fully support the ambient, much more complicated. But I think you would like manual flash mode to do that, so you can control it. [/QUOTE]
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D750
how your auto iso and flash works ?
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