Originally posted by Ikarus For equivalent AOV, DOF and exposure, the focal length and f/stop scale with the crop factor and the ISO with the crop factor squared (since the total light is the same, but the sensor area is 1.5^2 larger for FF, so the light intensity drops by the same amount). So yes, ISO scales
up for FF, not down, so if you move to FF, you better get used to using higher ISO settings. Mind you, higher ISO does not imply more noise when changing the format. See for instance
here for more details.
Yes. Thank you. You caught me in a rather senile moment.. I originally was thinking 3000 on crop would behave like 12000 on FF. But somehow I turned myself around to thinking and articulating something completely beyond that.
Originally posted by Ikarus It does suffer for sure, but what are the options with the given parameters? You can't open the aperture any wider than 2.8 with this lens, and you can't possibly drop the shutter speed without making things worse. In fact, I wouldn't be surprised if the shot were better with double the ISO for the sake of a faster shutter speed.
In this case? You just grin and bear it by taking the shot.
But the other options are either using a flash, using 1-2 stop smaller ISO and hoping you can pull up from shadows later, or not bothering to take the photo at all (which is a realistic option). But I take a more strict approach that if the outcome is garbage, it generally needs not be photographed. I'm looking for a relatively narrow range of IQ quality and if I'm not getting that, then the shots are at best snapshots to document the event occurred or at worst test shots to show why not to use high ISO.
Unless, of course you have some sentimental need for it... but as already mentioned, that is different.
That's not snobbish either because, even as a hobbyist, my name is going on my output. And I'm not putting my name on shots I'm very dissatisfied with, even if the photographic 'world' considers those shots meager for other reasons (like my poor photographic skill). On those high ISO shots, I would be very dissatisfied with them due to the performance of the camera alone. Add me to the equation and it's probably even worse.
On crop ISO 80-100 are my ideal, 200 is fine, 400 is OK, 800 is bad, 1600 is upper limit. Anything over that falls off the ISO cliff and is unusable for anything beyond the above mentioned uses. Printing seems to mask some of the noise to a given point but it doesn't the loss of detail. I don't find film grain attractive. Some do and that's ok. Yet, so far, every single shot I've seen on these forums trying to prove the noise is fine has further proven (to me) my thoughts on this. It's an impasse. A difference of opinion.
FF is better but not by much. I've see that 81275 D5 image (actually he offers the RAW for download) and it is horribly noisey. Even looking at 1:4. Still, it is the best >64k ISO shot I've seen and a feat for digital cameras for sure. But not practical for daily use either imo. The noise is somewhat fine but is peppered throughout and there is an obvious loss of detail on the facial features. That type of noise might actually print better than the blotchiness we have.. but on screen its atrocious. Gradients in the bg aren't close to smooth either and actually do blotch quite visibly. If anything, that example more likely means a couple of stops down are within the realm of usable (for me) and that is pretty big for digital cameradom. But that camera is also 6k alone.
Again, if you don't see a problem with higher ISO values, then use them. This is a personal matter. But I'm not convinced at all.. and that is fine.. It is OK to have my PoV just as it is OK for you to have yours.