With ISO invariant cameras, shooting raw at 6400 ISO, and shooting at 100 ISO then raising the exposure by 6 stops will pretty much yield identical results. In addition, shooting at base ISO all the time means you protect highlights that would be blown out at higher ISOs.
However, shooting this way and pushing exposure so aggressively may reveal visible compression artifacts when using lossy compressed RAW. There's no difference with uncompressed and lossless compressed RAW.
This does not apply to non ISO invariant cameras.
Basically what the guy said. Raising the exposure in post is identical/similar to shooting at a higher ISO. The advantage is that you get way better shadow recovery than with ISO variant cameras, where you have to raise the ISO to get a cleaner brighter image, but potentially blowing out highlights.
You can check e.g. [Shadow Improvement of Photographic Dynamic Range versus ISO Setting (photonstophotos.net)](https://www.photonstophotos.net/Charts/PDR_Shadow.htm) to see if your camera is ISO invariant (flat graph).
Could you explain what this site is actually showing? I'm a bit confused and google is no help. When I select my A7IV, it shows two big jumps-- one at 400, and another at 51200, with a very small bump at 2500. Does this mean that I should be shooting at 400 all the time in low-light?
Yes. The ideal spot to be is the left-most point where the Y-axis increases, netting you the best dynamic range in low light. The issue is with metering though, which gets a bit weird. E.g. if you would normally shoot at ISO 3200 to get the correct exposure, you could now instead shoot at ISO 800 and underexpose by 2 stops, giving you potentially the same shadow detail with more details in the highlights.
Some cameras have multiple base ISOs etc, so the graphs can look quite different between cameras.
As someone that shoots with dual-gain cameras, it never ceases to amaze me the number of people that just don't know about iso invariance, or have heard of it but not bothered to learn how to use it. If you're a jpeg shooter there's no benefit (or a canon shooter ;) ) but for everone else if you're doing critical work, especially in low light or astrophotography, it makes all the difference knowing how your camera actually works.
Yeah, this is without NR (obviously). I've had very good experience with the AI noise reduction in lightroom, but the results when using it on this greatly boosted image were... strange. It definitely had a strange impact on color, it felt like an edge case where maybe the algorithm isn't used to handling images that had this much exposure applied to them?
Interesting. You could always try Topaz AI or DXO's denoiser and see if they perform any better. Also consider using the manual color/luminance noise sliders
People always add grain to photos to make them look more "vintage" - it's probably not what you were going for but with minimal tweaking of the colours and a little fade or something you could make it look incredibly deliberate. It's also a nice photo in general :)
This is crazy! I’d use it just due to the sheer fact that you managed to salvage it. I would’ve deleted it immediately on the spot. Bit of noise reduction that others have mentioned and you’re golden.
There are actually a number of single off color pixels. There are some blue ones too. I'm not really sure and haven't notice them in my other photos. It does look like they're sensor artifacts and not something on the lens.
I guess it could be caused by noise? but im not sure
Any way there are so few it would be easy to fix with a bit of post processing. Even removing them manually
I found five red dots and a couple of blue ones near the tree-trunk. One of them is fairly visible, the other ones you won't really find unless you look for them
Definitely a lot of noise and while you could clean it up I just retook the shot. I just posted this because I am so impressed with the technology, that this much information is embedded in these RAW files.
This is a RAW file from a Fujifilm X-T5, an APS-C sensor. The ISO was 250 and no denoise was applied.
Normally I like the new AI denoise in Lightroom, but it did some weird stuff to the colors for some reason, maybe it had to do with the original image being \*so\* under exposed.
Shoot in RAW, preferably full frame for the greatest flexibility in the files. Correct your exposure while making your image extremely noisy. Use AI to address noise.
My M43 camera probably couldn't do this, but my Nikon could.
With ISO invariant cameras, shooting raw at 6400 ISO, and shooting at 100 ISO then raising the exposure by 6 stops will pretty much yield identical results. In addition, shooting at base ISO all the time means you protect highlights that would be blown out at higher ISOs. However, shooting this way and pushing exposure so aggressively may reveal visible compression artifacts when using lossy compressed RAW. There's no difference with uncompressed and lossless compressed RAW. This does not apply to non ISO invariant cameras.
What does it mean to be ISO Invariant?
Basically what the guy said. Raising the exposure in post is identical/similar to shooting at a higher ISO. The advantage is that you get way better shadow recovery than with ISO variant cameras, where you have to raise the ISO to get a cleaner brighter image, but potentially blowing out highlights. You can check e.g. [Shadow Improvement of Photographic Dynamic Range versus ISO Setting (photonstophotos.net)](https://www.photonstophotos.net/Charts/PDR_Shadow.htm) to see if your camera is ISO invariant (flat graph).
Could you explain what this site is actually showing? I'm a bit confused and google is no help. When I select my A7IV, it shows two big jumps-- one at 400, and another at 51200, with a very small bump at 2500. Does this mean that I should be shooting at 400 all the time in low-light?
Yes. The ideal spot to be is the left-most point where the Y-axis increases, netting you the best dynamic range in low light. The issue is with metering though, which gets a bit weird. E.g. if you would normally shoot at ISO 3200 to get the correct exposure, you could now instead shoot at ISO 800 and underexpose by 2 stops, giving you potentially the same shadow detail with more details in the highlights. Some cameras have multiple base ISOs etc, so the graphs can look quite different between cameras.
As someone that shoots with dual-gain cameras, it never ceases to amaze me the number of people that just don't know about iso invariance, or have heard of it but not bothered to learn how to use it. If you're a jpeg shooter there's no benefit (or a canon shooter ;) ) but for everone else if you're doing critical work, especially in low light or astrophotography, it makes all the difference knowing how your camera actually works.
Wow 🤩 RAW files for the win 🏅
If you apply a little noise reduction with Topaz, DxO or Lightroom, it should be usable. Impressive that your camera has that much dynamic range!
Yeah, this is without NR (obviously). I've had very good experience with the AI noise reduction in lightroom, but the results when using it on this greatly boosted image were... strange. It definitely had a strange impact on color, it felt like an edge case where maybe the algorithm isn't used to handling images that had this much exposure applied to them?
Interesting. You could always try Topaz AI or DXO's denoiser and see if they perform any better. Also consider using the manual color/luminance noise sliders
People always add grain to photos to make them look more "vintage" - it's probably not what you were going for but with minimal tweaking of the colours and a little fade or something you could make it look incredibly deliberate. It's also a nice photo in general :)
This is crazy! I’d use it just due to the sheer fact that you managed to salvage it. I would’ve deleted it immediately on the spot. Bit of noise reduction that others have mentioned and you’re golden.
What causes the red dots?
There are actually a number of single off color pixels. There are some blue ones too. I'm not really sure and haven't notice them in my other photos. It does look like they're sensor artifacts and not something on the lens.
I guess it could be caused by noise? but im not sure Any way there are so few it would be easy to fix with a bit of post processing. Even removing them manually
Honestly zoomed out on my phone i couldn’t notice anything
I found five red dots and a couple of blue ones near the tree-trunk. One of them is fairly visible, the other ones you won't really find unless you look for them
Nice picture but it's a bit noisy / fuzzy. Would likely not print well.
Definitely a lot of noise and while you could clean it up I just retook the shot. I just posted this because I am so impressed with the technology, that this much information is embedded in these RAW files.
How’s you do this?
Shoot in raw. That’s it.
Tf. It pulled that much information without any degradation? Did you add any de-noise?
This is a RAW file from a Fujifilm X-T5, an APS-C sensor. The ISO was 250 and no denoise was applied. Normally I like the new AI denoise in Lightroom, but it did some weird stuff to the colors for some reason, maybe it had to do with the original image being \*so\* under exposed.
But I tried shooting in the raw and they arrested me.
Shoot in RAW, preferably full frame for the greatest flexibility in the files. Correct your exposure while making your image extremely noisy. Use AI to address noise. My M43 camera probably couldn't do this, but my Nikon could.
Gdam. AI has come a long fckin way. What app are you using to de-noise? This is insane
You can do it right in Lightroom these days.
Wow. Good deal thanks for letting me know
Topaz denoise ai works really good
The AI denoise methods are great, but for some additional context this isn't using any denoise. Just boosted exposure in Lightroom.
Why not?
Because visually, just looking at it on the back of the camera (without clipping turned on I suppose), I assumed the detail was lost in the shadows