Originally posted by xmeda Fast aperture lenses are mainly about shallow depth o field. Low-light is rather secondary effect.
Flash is about light CONTROL even on sunny day. Using either as low-light only option how to gather some light is just emergency with usualy weak image output. And you can add IBIS too...
Basically, I'd agree... though there are, as always, exceptions. I've seen some great artistic photography in low-light situations with the flash as the primary light source.
Originally posted by xmeda ISO above 1600 is rapidly loosing details and dynamic range, while noise increases quickly. No matter if we are talking about K1, K3 or 645Z.
I agree with this, too. Cameras like the K-1 / K-1II and KP are pushing the boundaries quite a bit, but still... above ISO 1600, things do start going down hill quite quickly.
Originally posted by xmeda Yes ISO6400 images can be usable if you only need some pic for facebook/instagram/web presentation.. but not for serious work. DNR processors are better and better, but everything has its limits. Even best algorithm cannot create data out of nothing. That is painting then, not photography
Here, though - with respect - I disagree. Well-exposed ISO 6400 images processed with some degree of skill can be way, way better than you describe. I'd push my K-3 as high as ISO 20,000 for a small-ish social media shot... But skillfull (which doesn't have to mean time consuming) use of noise reduction techniques - colour, especially - in post-processing can yield excellent images at ISO 6400 and even higher, depending on the subject, size of reproduction and intended viewing distance.
Careful (by which I mean, "not heavy handed") noise reduction isn't painting at all - it's just a valid means of improving an image, like contrast, clarity, exposure and tone curve adjustments. As we all know, software like Lightroom does a certain amount of noise reduction and other image processing by default, even if you zero all the sliders. If using noise reduction means our images are painting rather than photography, everything processed through Lightroom (and most other raw processors, as well as *every* in-camera JPEG engine) is a painting, not a photograph. So, this is still very much photography.
Sure, I wouldn't want to shoot a landscape or product shot at that kind of sensitivity - anything with a lot of fine detail that needs to be reproduced, in fact. But there's no reason not to use high ISO settings for street, documentary, sports, that kind of thing. We tend to forget how many great shots were taken in the film era with higher sensitivity films yielding rather grainy output.
The shot below was for an article I wrote some time ago. It was taken with a 12MP Pentax Q (the earliest version, with its tiny 1/2.3" sensor) at ISO 3200 and processed in Lightroom 6. Part of the processing involved colour and luminance noise reduction plus sharpening, carefully balanced to retain and bring out detail while keeping noise to an acceptable level. OK... the size of reproduction here is small, and there is still some noise visible, but it's a perfectly usable photograph from an older, small sensor camera at a silly ISO level. In fact, this photo looks good viewed at screen-filling size on my 17" laptop or 23" external monitors. The ageing K-3 is capable of considerably better results at ISO 6400 and higher, as you'd expect. As for the KP, K-1 and K-1II... well...
Last edited by BigMackCam; 10-08-2018 at 01:48 PM.