Chris VenHaus
Offline
• •
Upload & Sell: Off
|
 p.5 #10 · Sony A7R4 incredible high ISO | |
alundeb wrote:
Having read all posts, but maybe not every post thoroughly, I think there is one piece of information missing. It is partially covered by output size normalization, but not completely.
The crops shown in the original post are from an area with very little fine detail. If we look at other parts, it becomes obvious that the acuity, in either the sensors or the processing, is not equal. The A7R4 samples are quite a bit sharper. That is even at native size, where the effect is normally the opposite everything else being equal. This must be taken into account when comparing these images, as there is always a balance between acuity and noise. Even in Jordan's post with normalized images in more detailed areas, I see more acuity in the A7r IV image. One must be careful here, as more noise may also give a false impression of acuity, but I don't think that is the cause of it here. If we process the images for equal detail and acuity, The A7r IV might look better.
My humble opinion is that the judges are still out regarding which camera is the best ISO 6400 - 12800 camera, the A7r III or A7r IV. In any case, there is very little difference in quantum efficiency per sensor area between any modern FF sensors, and what you lose by not using the 'optimal' camera, is not much.
Screenshot from DPR saved as PNG, no additional jpg degrading:
...Show more →
Totally agree here. I routinely shoot at 3200 and 6400 with my 5dsr (and D850) with excellent results for Astro-scapes. The 5DsR was supposed to be 'noisy', and terrible for astro, when it came out... with naysayers saying similar things about it vs what I'm hearing now about the A7r IV.
Taking 4 to 8 images at a reduced ISO (800 to 1600) and stacking with median filter can yield 2-3 stops of noise reduction... AND I have the benefit of large files for display/printing. For non-starry skies, there is usually little fine detail so noise reduction techniques can be used aggressively here... with little downside. Color noise easier to remove than chroma (without affecting detail much). For stars... stacking at 3200 or 6400 ISO, along with noise reduction techniques & masks can yield VERY impressive results... and that's with software NOW- without the benefit that will likely occur in future software and techniques. Simply put, I have images from many years ago that can be processed with newer software, with better results for noise than I could get back then. I bet these advancements continue to move forward with images I take today...
So... with high-rez sensors, you can easily get useful images with proper technique, and wind up with excellent resolution that EXCEEDS 'less noisy' camera with lower rez, and that would need to be up-rezzed to same print/display size as the higher-rez camera. All else being equal, the advantage goes to the higher rez sensor, IMO when noting field techniques to overcome the limitations of the sensor, i.e. multiple exposure stacks, or ISO exposure blends w/ lower ISO for blue hour.
Normalizing the DP Review test shots to same size, using low-light toggle, shows the A7R IV to be very similar to the best low light DSLR's and mirrorless on the market... and that was with using early version software to process. I have little doubt that when I take my A7r IV out for astro work, it will be at least as good as my D850, and even better than my 5DsR, which I was already happy with at high ISO for astroscapes/aurora.
PS- I only shoot landscapes & astroscapes. NO sports, action, wildlife, portraits etc... So the ISO noise I've seen thus far can be largely overcome with field and PP techniques for excellent end results.
Edited on Sep 16, 2019 at 10:06 AM · View previous versions
|
Archive 2019 · Sony A7R4 incredible high ISO
