pollysmithblackwell Loc: NY

It seems to me that an ISO of 6400 is much too high for an outdoor shot with good available light. If the ISO setting is Auto, I wonder why it set it so high. This probably caused all of the other settings to be out of whack, resulting in overexposure. I'd be curious to hear what the experts say about this scenario.

BebuLamar

The aperture was set at f/16 and the shutter speed was 1/1000 so under the brightest condition (the sunny 16) the ISO must be 1000. If the light isn't quite as bright as the sunny 16 like cloudy or overcast then ISO6400 isn't a surprised.

pollysmithblackwell Loc: NY

I will echo what CHG_CANON said about the high ISO. What I'm curious about is if the camera was set at AUTO ISO, why did it set it so high for the outdoor lighting conditions? It basically set you up for overexposure. I'd like to know so I can learn from your experience. :)

pollysmithblackwell Loc: NY

Okay. So the other settings were set first and the AUTO ISO followed? (Sorry - I didn't see my first post - didn't mean to post it twice.)

BebuLamar

yes the op used manual with auto ISO on so the aperture and shutter speed were set manually by the OP.

R.G. Loc: Scotland

Not an expert but I'll add this. The camera's metering (and therefore the metering mode) determines the level of exposure that the camera targets. In any of the auto modes (A,S, P and auto ISO) you control some of the settings but the camera uses whatever variable/s it's controlling to target the desired exposure level (as determined by the camera's metering).

In fully manual mode the targeted level of exposure is represented by the centre segment of the meter scale. In M+AutoISO you control the aperture and shutter speed so the camera uses the ISO to achieve the targeted level of exposure. That mode is referred to as Auto ISO but since you control two of the three exposure variables, your choices force the camera to use whatever ISO value is required to achieve the targeted level of exposure (as determined by the metering). So the ISO value is determined by both the user's choice of settings and also the camera's metering (which determines the targeted level of exposure).

In the posted example the metering mode resulted in the camera targeting too high a level of exposure. To be more precise, the targeted level of exposure was right for the subject (the bird) but not for the background. The user's choice of aperture and shutter speed forced the camera to use a high ISO value.

The title of the thread suggests that Auto ISO was the problem but it was actually the two factors just described that forced the camera to use such a high ISO value. And it was the metering mode that resulted in overexposure. Using fully manual with that metering mode would have given the same result.

CHG_CANON Loc: the Windy City

The 46MP resolution of the OP's D850 might render a SOOC JPEG that is too big to attach to UHH and not exceed the documented 20MB file size limit. But, we'd need to hear some details directly from the OP to judge if this suggestion is actionable or not.

profbowman Loc: Harrisonburg, VA, USA

I forgot that the OP has a camera producing 46 MP. However, my Sony produces 24 MP photos that are less than 6 MB out of the camera. So, I doubt that will be a limiting factor. If it is, saving the JPERGG aat 85% quality should reduce the image size sufficiently without destroying any EXIF data. --Richard

larryepage Loc: North Texas area

I have a 21 MP camera that can produce JPEGs all the way from 15 MB down to 1 MB or so straight from the camera. It all depends on what you choose in terms of resolution and compression, in addition to what you are actually taking pictures of.