[Got myself a Lumia 735 a few months ago and loved it – coming from WP7, the jump to WP8.1 was fantastic. Except the downgraded performance of Xbox Music (from Zune), IE11 (crashed on sites where WP7 IE was rock solid) and the flaky Skype integration. Hoping Windows 10M would fix this, I installed the insider preview and so far, i\’m impressed. Upgrading unofficially (and voiding my warranty) got me thinking of ways to push the phone further… Considering the 735 has the same cpu, RAM, screen and sensor size as the 830, shouldn\’t it have the same DNG output capabilities? Windows 10 Mobile seems to be a one-build-suits-all deal, so the code must be there, and disabled on a phone-by-phone basis. I went digging. Derausgewanderte helped me out, and we got it partially working with registry editors. All good so far. I then found keys for manually changing min and max ISO, potentially getting even crisper images. I set the minimum value at "10", and started snapping. And got stuck. The images shot with 10 compared to follow up images at 100 and 400; are of course significantly different, and look sharp and detailed when compared to each other. But to me, the quality of the 10 ISO shots seem familiar to what i used to achieve with 100ISO shots on WP8. 100 ISO shots now look like what used to be 400 ISO, and the 400 shots feel like they have the sensitivity of ISO 800 (for example). How is ISO actually calculated on smartphones? Is there any correlation between the numbers and true sensitivity, or is it all just relative to the limits of the devices sensor? By setting the minimum value to 10, have i shifted the scale to the left, making "10" the new "100" and "100" the new "400"? Have I actually done anything to lower the noise? Scoured the web, and can\’t really find much info. Can anyone shed some light? 🙂
Do you have sample photos? Take a photo both with the normal un-modded settings and with the modded settings with varying ISO values but with the same shutter speed and the same lighting conditions. For example, a photo of a page of a newspaper with varying sizes of text (this can be reproduced without copyright infringement, unlike books), taken at the same distance each time using a tripod (or with very steady hands). This way we can accurately compare the performance at different ISO values between the modded and un-modded phone settings. But I did read a bit further from your posted links… it seems that the ISO values are simply being shifted, since (based on the NPU page you posted) bringing down the minISO also brings down the maxISO value allowable in the camera settings (even if the adjuster allows more).