I am a fairly incompetent photographer with very shaky hands. I would like to produce sharp images, but am not too bothered about artistic impression. Last year, I was given advice about operating at high ISO and this greatly improved my satisfaction. I set the camera at 1600 ISO and worked in Programme mode. I didn't detect any deterioration from "noise" (or it was far less apparent than the previous blurring from shaking hands!).
I have just come back from the Pantanal where the weather was mainly dull and overcast (2.5 days of sun in 13). I upped the sensitivity to 3200 on the duller days and, again, noticed no "noise" deterioration. Notwithstanding, although some pictures were, by my standards, acceptably sharp, they were by no means all satisfactory. I am wondering about the accuracy of the autofocus in dull light and am beginning to think that shakiness may not be my only problem.
I am using a Nikon D3200 camera with a 70-300 lens. At full zoom, the 35mm equivalent focal length is 450mm and maximum aperture size is f 5.6. The quickest shutter speed is one 4000th of a second. I have set the camera to Programme mode and I produce JPEG Fine shots.
At 3200 ISO and 450 mm (35 mm eqiv), shutter speeds ranged from 1/1000 sec to 1/4000 sec and aperture from f 5.6 to f 13. This all seemed quite logical. However, I couldn't understand how the camera was making its decisions when ISO was 1600. Usually, the pictures were taken at f 5.6 with speeds ranging from 1/250 to 1/2000. Why, therefore, were there occasional apparent anomalies? For example, the camera chose to take one picture at 1/200 sec at f 7.1 and another at the same shutter speed at f 14. As it happened these pictures were quite good so shakiness is clearly not always a problem for me at 1/200. However, I would have expected the auto programme selection to have chosen f 5.6 and a faster speed in these two cases - as it appeared to do in the majority. Can anyone explain this?
Is it possible to take a picture before the autofocus has fully adjusted? Could I be inadvertently taking a picture before the camera is ready? Alternatively and particularly in dimmer light can autofocus prove inaccurate and lead to pictures that are not sharp? If so, if I persevere with high ISO settings, might it be better to work in aperture priority mode to gain greater depth of field in the hope of overcoming inaccurate focussing?
I would appreciate any advice from the experts here.