Lab Report - ISO Accuracy
The actual sensitivity of each indicated ISO is measured using the same shots as are used to measure ISO noise levels, we simply compare the exposure for each shot to the metered light level (using a calibrated Sekonic L-358), middle gray matched. We estimate the accuracy of these results to be +/- 1/6 EV (the margin of error given in the ISO specifications). Note that these tests are based on the sRGB JPEG output of the cameras, in accordance with ISO 12232:2006, the standard used by camera manufacturers. In our tests we found that measured ISOs from the Nikon 1 V3 are approximately 1/3 EV undersensitive compared to the marked ISOs. This means that ISO 200 indicated = ISO 160 measured.
Noise and Noise Reduction (JPEG)
By Rishi Sanyal
ISO range noise comparison
Below is our standard JPEG noise comparison, comparing the Nikon 1 V3 against similar competitors. By default, the camera leaves NR on; you can turn it off by setting 'High ISO Noise Reduction' to 'Off'.
We noted, however, that even with 'High ISO Noise Reduction' set to 'Off', the EXIF data reported that a NR setting of 'Minimal' was used from ISO 200 upward. Given that the higher ISO shots look cleaner than those from a comparable camera with NR set to 'Off' (e.g. Sony RX100 III), we think Nikon is applying noise reduction to JPEGs even when this setting is set to 'Off'. This comes as no surprise, as most manufacturers apply some level of noise reduction to JPEGs.
Given the rather high levels of underlying noise at higher ISOs prior to noise reduction, even at its 'Off' setting NR tends to smudge low contrast detail readily. Turning High ISO NR 'On' manages to smudge the detail even more. In fact, detail retention suffers significantly at higher ISOs compared to similar cameras of its class. Both the Sony RX100 II and its own predecessor, the V1, perform better in this regard, though it's worth keeping in mind that the V1 is a lower resolution camera and, therefore, will naturally have a pixel-level noise advantage.
ACR Raw noise (ACR 8.6 noise reduction set to zero)
Given that it was virtually impossible to turn off all noise reduction in JPEG, the Raw results below give a better idea of the capabilities of the sensor itself. It's clear that the V3 is a rather noisy camera, showing more noise at high ISOs than its competition. Furthermore, at lower ISOs, you'll be limited by how much you can raise shadows due to the extra noise present at very low signals - something we talk about over in our JPEG Tone Curve/Dynamic Range page.