D300 flash problems when using Auto ISO

<p>I use a Nikon D300. With Auto ISO set at min ISO of 200, max ISO 3200, min shutter of 1/500 and Aperture priority, the camera works perfectly.<br>

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If I use flash (either pop-up or a SB 800) the ISO reverts to the minimum ISO set as above and will not vary under differing lighting conditions. The ISO will not change under slow synch flash mode.<br>

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I have updated the Firmware to 1.11 a and b.<br>

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Is this normal for a D300 or do I have a hardware problem.</p>

<p>According to my notes, that is normal behavior for the D300 and earlier bodies. It was changed in the D300S and later; the ISO can vary but will be calculated during the pre-flash so whatever is displayed in the viewfinder may not be accurate. As a result, I never use auto ISO when using flash, even as just fill. I was burned too many times by this inconsistency using D300 and D300S bodies interchangeably. A fixed ISO is a better way to go anyway with flash so it is one of the principal differences along with minimum shutter speed in my stored "Flash" memory bank.</p>

<p>Agree with Curt. On both my Nikon and mirrorless cameras, I disable auto ISO when using flash because of inconsistent results.</p>

<p>The D300 has an annoying way of doing auto ISO. The auto ISO setting overrides everything, even the manually-set ISO. That will lead to very bright images if you try and use studio lights - the camera will set the ISO to what it thinks you need b/c it has no way of knowing about the studio lighting. On more modern cameras the auto-ISO function is a setting along with the manual ISO settings.</p>

<p>Curt, Hosteen and Patrick,<br>

Thanks for the response, guys. My principal interest is bird photography, which often can benefit from fill flash. Fluffing around with manual ISO settings to achieve a balance between shutter speed and overall exposure (as I have been doing) is not always productive - the bird usually disappears! <br>

I feel Curt has confirmed my suspicions. As an example, the D7100 with Auto ISO and fill flash (with a SB 800) works perfectly in the field, with some clever exposure adjustments for background and subject.<br>

Looks like it might be time for an upgrade.</p>

<p>Minimum ISO is normal for a D300 if a flash is recognized, but there are three generations of Nikon iTTL Auto ISO and flash, so it is hard to explain.</p>

<p>"Auto ISO with flash" variations:</p>

<p>1. <a href="http://nikonites.com/products/dslr-3/d300-110/" target="_blank">D300</a> and all older iTTL models dated up through D300.<br /> 2. newer cameras, in between 1 and 3, starting with D300S.<br /> 3. and most recent very few models, about <a href="http://nikonites.com/products/dslr-3/d800-227/" target="_blank">D800</a> on.</p>

<p>Type 1. Never boosts Auto ISO if flash was recognized present, being used. Auto ISO stayed at Minimum with flash. Except for Commander, it might boost ISO <strong>ONLY IF</strong> the TTL flash power was otherwise insufficient. This works best, IMO, how flash ought to be (i.e., Auto ISO off).</p>

<p>Type 2. Always boosted Auto ISO fully according to the ambient metering, regardless if flash is used or not, so flash indoors was always highest ISO. This makes flash be fill flash, and incandescent light is orange. Bad plan. Turn Auto ISO off.</p>

<p>Type 3. Nikon thankfully reconsidered this - Newest models (with flash indoors) only boost Auto ISO by two stops (like ISO 100 to ISO 400) for external flash, but <strong>still always fully boosts ISO for internal flash, like Type 2</strong>. ISO 400 is normally enough for bounce.</p>

<p>Nikon does not specify this Auto ISO behavior with flash, but Exif of a simple test picture with indoor TTL flash will show the Auto ISO it obviously used, so you can recognize which type camera you have.</p>

<p>Type 2 - Using Auto ISO to boost the ambient with flash makes the orange incandescent light become visible, adds ISO noise, and converts the TTL BL flash system to be fill flash instead of main flash. Bad plan.</p>

<p>If an older flash with an actual TTL mode vs TTL BL mode menu, actual TTL mode will overexpose it if the ambient is fully metered (the sum of fully metered ambient and fully metered TTL is greater than the ambient meters, requiring compensation, which is normal). TTL BL mode (default if no TTL/TTL BL menu) generally not bad about overexpose.</p>

<p>The internal flash is tiny, and at any distance more than a few feet, might need additional ISO. Shouldn't need maximum ISO. Type 2 and 3 do the ISO thing.</p>

<p>It seems stupid to use Auto ISO with a manual flash. A manual flash cannot react to Auto ISO. So if the camera recognizes a manual flash is present, then it will lock Auto ISO at the Minimum value, in any model, 1, 2, or 3.<br /> <br /> Try flash without Auto ISO. Maybe use up to ISO 400 for the little internal flash if needed. ISO 400 is normally enough for bounce too.</p>

<p>Your D300 is working fine, this is normal for the camera. The problem with the later bodies is that the auto ISO boosts the iso level which can lead to some inconsistent results. People either like that or they don't. I prefer the D300 version myself, but that's me. </p>

<p>I've found that its better to leave my D7200 in manual ISO when I use flash. </p>

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