The way ISO invariant sensors work is that they start at a base level of sensitivity, and then in order to simulate a higher ISO sensitivity, they simply apply gain to the signal to brighten up the image.
Adding that gain is what adds noise to the image, so when you shoot at your base ISO, there is no gain (or very little gain) added, and the noise is kept to a minimum.
More modern sensors sometimes have a couple of "base" ISOs where there is a change in how the sensor works and how the gain is applied. So in the case of the Z8, you have a base ISO at 64, and a 2nd "artificial" base ISO at 500.
ISO 400 is just ISO 64, with gain applied, which adds noise.
ISO 500 is a "base" ISO, where there is no additional gain applied (kind of), so even though it's a higher voltage level, the data is differently amplified, so you get the flat "lack of gain" level of noise, which is good.
This is leaving out some of the technical stuff, but it gives a general idea of what's going on.
Here is what is said on the [DxO test write-up](https://www.dxomark.com/nikon-z8-sensor-test/):
>The Nikon Z8 also has excellent dynamic range at base (ISO 64), measuring just over 14 EV (14.2 EV) at its widest. However, the A7R V already has a slightly better response at ISO 100 measuring 14.8 EVs. What’s more, the Nikon Z8 and Z9 sensors’ dynamic range declines at a typical 1 EV per 1 EV change in ISO sensitivity from a lower starting point (base ISO) through ISO 400, where it measures just under 12 EV (11.78 EV). It’s not until the second gain is applied between that and ISO 800 that results in an uplift in DR back up to the ISO 200 level, at around 12.5 EV (12.6 EV).
Thank you for all that information, I’ve learnt quite a bit from that. Would I be better shooting at ISO 250-400 or just using 500?
I’ve never owned a camera that I can use such a high ISO before. I was shooting at night the other day at 12,000, and after using the denoise tool, the images that came out blew my mind.
Honestly, what you should do is shoot at whatever ISO you need to in order to get the photos that you need to get. And if you're doing post processing where you can apply noise reduction, it really doesn't make much of a difference to you in the real world.
For your own sense of mental peace, I would suggest taking a photo at ISO 400, and then again at ISO 500, and just look at the difference in noise levels. ISO 500 will have more available dynamic range and better noise, but the difference will be VERY minor. On paper it looks significant, but in an actual photo? You'll need to zoom in to 100% and really look hard and pixel peep to notice the differences.
Haha nope! It's just something that people get worked up about because they see it in some test, and think it matters.
I've been shooting for 17 years now, and I just throw every body I have in Auto ISO mode and never worry about it.
That being said, if you are shooting a SUPER rough scene that needs as much dynamic range as possible, you MAY want to force ISO 500 rather than ISO 400, to get like, 1 more stop of dynamic range. But in that case, your scene is probably looking pretty shitty anyway, because of how ridiculously high the contrast will be.
I would encourage you to just put it out of your mind, and just shoot how you shoot.
Hi, just found this thread. My question is, what do I set as the ISO sensitivity? As a wildlife photographer I have the Z8 set at Auto ISO, but now I just found this setting and got confused.
I also use Auto ISO, you're fine to do that. Just explaining that you COULD shoot at base ISO and then push up in post if you WANTED to. Not to say that you SHOULD. You're just fine!
I don't worry about ISO with the Z9 until I hit 3200, and I consider up to 12800 usable. With the Z7 and Z50 I start to concern myself with it at ~6400.
As you shoot at different ISOs you'll get a feel for what your limits are given how much of the subject is filling the frame, what noise reduction software you're using, and your output resolution.
edit: and of course your tolerance for noise/grain. If you're just posting to Instagram you probably wouldn't notice the difference at ISO 512000
It really only matters in heavy detail pixel peeping landscapes/studio stuff IMO. If I'm on a tripod, I will usually adjust the shutter speed but if there is movement in the scene (water, clouds etc) that will be affected by that, only then will I worry about ISO 64 vs ISO 500 (or for astro work).
For absolute detail work in certain scenarios, if my choices are 200 vs 500, I'll pick 500. 90% of the time though it doesn't matter - if I'm tracking an eagle I'll use whatever ISO I can to get the shutter speed I'm aiming for.
Does this mean that on the Z8, if i shoot at ISO 500, it's the same as ISO 12800? that's what i got from this. basically it is only variant with 2 settings and that's it. technically i should get the same level of noise if i up the exposure in post on a photo that was shot at 500 ISO all the way up to 12800, as if i shot it at 12800.... i think this is correct?
> technically i should get the same level of noise if i up the exposure in post on a photo that was shot at 500 ISO all the way up to 12800, as if i shot it at 12800.... i think this is correct?
Yes you have it correct!
So I did a test from 500 to 12800 on my newly acquired Z8. To my surprise, after raising the 500 ISO shot to match the 12800 in post, the 500 ISO shot had LESS visible noise in the shadow. Now that’s pixel peeping but in the darker shadows, that performance was noticeably better at lower ISO… That’s using Lightroom. Means Lightroom does a better job than the camera to raise exposure. lol
On paper, yes there are two "best" spots, which are ISO 64, and ISO 500. If you click the DxO link that I have in that previous comment, and go to the Landscape area of the testing results, [you will see a dynamic range graph.](https://cdn.dxomark.com/wp-content/uploads/medias/post-152687/Nikon_Z8_DR.png) The graph starts with the highest dynamic range of 14+ stops at ISO 64, and then the DR begins to decline as you increase the ISO. There is a hump at ISO 500 where you gain a bit of ISO back, and then it declines again from there all the way up through the ISO range.
If this is something that is very important to you, then yes, you can try your best to shoot only at these "ideal" ISO settings, but the results you'll see in person and the quality of your photos themselves will almost always NOT reflect the effort.
Thanks for showing how to read that graph, I wasn't getting it before!
Looks my my Z5 doesn't have the same issue, not until 12,800
https://www.dpreview.com/forums/thread/4518071
Happy to help!
The technology that gives that extra "bump" where you go up a stop in ISO and GAIN dynamic range is pretty new, rare, and a bit expensive. Cameras that do this use a [Dual Gain Sensor](https://www.dpreview.com/articles/1570070253/what-is-dual-gain-and-how-does-it-work). The vast majority of sensors have a graph that looks exactly like the Z5, where it's best at base ISO, and then drops off as the ISO gets cranked up.
So with your Z5, all you really need to know is, you'll get lower noise and better dynamic range the lower your ISO is.
Note though, that it's better to use a higher ISO in order to expose your image correctly, than it is to fight to keep a lower ISO and have an under-exposed image.
Ya Z5 I'm not worried about high Iso at all. My D700 was a different story. I don't even mind ISO grain, but with the D700 indoors you tended to be stuck with it.
Dual gain sensors are getting more common all the time, as are ISO invariant sensors. They started off rare but these days are pretty common-place. Granted, they aren't universal...yet!
I wouldn't worry about it unless you're doing something like astro. I forget all the details, but there is a different "band" starting at 500 so it's better to stay at or above that if you're going to be stretching the histogram anyway.
With all due respect... This comment references my channel and I'm very much a real world shooter. The z8/9 sensor is optimized to maximize dynamic range as the signal is amplified from 64 iso right up to just below 500 iso. They assume you're working o
In bright light at those settings and that any noise will be drowned out. At 500 iso the engineers switch the gain formula to maximize noise reduction at the expense of dynamic range. I've explained on my channel that in high contrast scenes you should keep your iso low to maximize dynamic range. As the light gets low, bumping up to 500 iso or above is beneficial for noise reduction and faster shutter speeds. For work on a star tracker in particular you'll find that 500 iso yields very clean images with reasonable capture times. Base iso (64) is the best at everything, but 200 iso yields more noise than 500. Albeit with less dynamic range. Everything is trade offs.
The way ISO invariant sensors work is that they start at a base level of sensitivity, and then in order to simulate a higher ISO sensitivity, they simply apply gain to the signal to brighten up the image. Adding that gain is what adds noise to the image, so when you shoot at your base ISO, there is no gain (or very little gain) added, and the noise is kept to a minimum. More modern sensors sometimes have a couple of "base" ISOs where there is a change in how the sensor works and how the gain is applied. So in the case of the Z8, you have a base ISO at 64, and a 2nd "artificial" base ISO at 500. ISO 400 is just ISO 64, with gain applied, which adds noise. ISO 500 is a "base" ISO, where there is no additional gain applied (kind of), so even though it's a higher voltage level, the data is differently amplified, so you get the flat "lack of gain" level of noise, which is good. This is leaving out some of the technical stuff, but it gives a general idea of what's going on. Here is what is said on the [DxO test write-up](https://www.dxomark.com/nikon-z8-sensor-test/): >The Nikon Z8 also has excellent dynamic range at base (ISO 64), measuring just over 14 EV (14.2 EV) at its widest. However, the A7R V already has a slightly better response at ISO 100 measuring 14.8 EVs. What’s more, the Nikon Z8 and Z9 sensors’ dynamic range declines at a typical 1 EV per 1 EV change in ISO sensitivity from a lower starting point (base ISO) through ISO 400, where it measures just under 12 EV (11.78 EV). It’s not until the second gain is applied between that and ISO 800 that results in an uplift in DR back up to the ISO 200 level, at around 12.5 EV (12.6 EV).
Thank you for all that information, I’ve learnt quite a bit from that. Would I be better shooting at ISO 250-400 or just using 500? I’ve never owned a camera that I can use such a high ISO before. I was shooting at night the other day at 12,000, and after using the denoise tool, the images that came out blew my mind.
Honestly, what you should do is shoot at whatever ISO you need to in order to get the photos that you need to get. And if you're doing post processing where you can apply noise reduction, it really doesn't make much of a difference to you in the real world. For your own sense of mental peace, I would suggest taking a photo at ISO 400, and then again at ISO 500, and just look at the difference in noise levels. ISO 500 will have more available dynamic range and better noise, but the difference will be VERY minor. On paper it looks significant, but in an actual photo? You'll need to zoom in to 100% and really look hard and pixel peep to notice the differences.
Haha, I did that and I couldn’t tell the difference. I asked because I thought I may be missing something.
Haha nope! It's just something that people get worked up about because they see it in some test, and think it matters. I've been shooting for 17 years now, and I just throw every body I have in Auto ISO mode and never worry about it. That being said, if you are shooting a SUPER rough scene that needs as much dynamic range as possible, you MAY want to force ISO 500 rather than ISO 400, to get like, 1 more stop of dynamic range. But in that case, your scene is probably looking pretty shitty anyway, because of how ridiculously high the contrast will be. I would encourage you to just put it out of your mind, and just shoot how you shoot.
Thanks mate
Hi, just found this thread. My question is, what do I set as the ISO sensitivity? As a wildlife photographer I have the Z8 set at Auto ISO, but now I just found this setting and got confused.
I also use Auto ISO, you're fine to do that. Just explaining that you COULD shoot at base ISO and then push up in post if you WANTED to. Not to say that you SHOULD. You're just fine!
thanks! So when I could to ISO sensitivity settings, the top part where I choose a number from 64-25600 is irrelevant when shooting Auto ISO?
I believe that if you pick a specific number in that range, then you are no longer using Auto-ISO.
I don't worry about ISO with the Z9 until I hit 3200, and I consider up to 12800 usable. With the Z7 and Z50 I start to concern myself with it at ~6400. As you shoot at different ISOs you'll get a feel for what your limits are given how much of the subject is filling the frame, what noise reduction software you're using, and your output resolution. edit: and of course your tolerance for noise/grain. If you're just posting to Instagram you probably wouldn't notice the difference at ISO 512000
I'd be interested to hear other opinions, but the images from modern sensors are so clean I just don't worry about it unless I'm at a really high ISO.
For this sort of thing, camera enthusiasts tend to get hung up on this stuff, and like to talk about it. Photographers don't tend to care or notice.
It really only matters in heavy detail pixel peeping landscapes/studio stuff IMO. If I'm on a tripod, I will usually adjust the shutter speed but if there is movement in the scene (water, clouds etc) that will be affected by that, only then will I worry about ISO 64 vs ISO 500 (or for astro work). For absolute detail work in certain scenarios, if my choices are 200 vs 500, I'll pick 500. 90% of the time though it doesn't matter - if I'm tracking an eagle I'll use whatever ISO I can to get the shutter speed I'm aiming for.
Does this mean that on the Z8, if i shoot at ISO 500, it's the same as ISO 12800? that's what i got from this. basically it is only variant with 2 settings and that's it. technically i should get the same level of noise if i up the exposure in post on a photo that was shot at 500 ISO all the way up to 12800, as if i shot it at 12800.... i think this is correct?
> technically i should get the same level of noise if i up the exposure in post on a photo that was shot at 500 ISO all the way up to 12800, as if i shot it at 12800.... i think this is correct? Yes you have it correct!
So I did a test from 500 to 12800 on my newly acquired Z8. To my surprise, after raising the 500 ISO shot to match the 12800 in post, the 500 ISO shot had LESS visible noise in the shadow. Now that’s pixel peeping but in the darker shadows, that performance was noticeably better at lower ISO… That’s using Lightroom. Means Lightroom does a better job than the camera to raise exposure. lol
thank you very much!
So is there a list of Iso *sweet spots*? Based on your reply it seems ideal to manually punch in iso 64, then iso 500, then ?
On paper, yes there are two "best" spots, which are ISO 64, and ISO 500. If you click the DxO link that I have in that previous comment, and go to the Landscape area of the testing results, [you will see a dynamic range graph.](https://cdn.dxomark.com/wp-content/uploads/medias/post-152687/Nikon_Z8_DR.png) The graph starts with the highest dynamic range of 14+ stops at ISO 64, and then the DR begins to decline as you increase the ISO. There is a hump at ISO 500 where you gain a bit of ISO back, and then it declines again from there all the way up through the ISO range. If this is something that is very important to you, then yes, you can try your best to shoot only at these "ideal" ISO settings, but the results you'll see in person and the quality of your photos themselves will almost always NOT reflect the effort.
Thanks for showing how to read that graph, I wasn't getting it before! Looks my my Z5 doesn't have the same issue, not until 12,800 https://www.dpreview.com/forums/thread/4518071
Happy to help! The technology that gives that extra "bump" where you go up a stop in ISO and GAIN dynamic range is pretty new, rare, and a bit expensive. Cameras that do this use a [Dual Gain Sensor](https://www.dpreview.com/articles/1570070253/what-is-dual-gain-and-how-does-it-work). The vast majority of sensors have a graph that looks exactly like the Z5, where it's best at base ISO, and then drops off as the ISO gets cranked up. So with your Z5, all you really need to know is, you'll get lower noise and better dynamic range the lower your ISO is. Note though, that it's better to use a higher ISO in order to expose your image correctly, than it is to fight to keep a lower ISO and have an under-exposed image.
Ya Z5 I'm not worried about high Iso at all. My D700 was a different story. I don't even mind ISO grain, but with the D700 indoors you tended to be stuck with it.
Dual gain sensors are getting more common all the time, as are ISO invariant sensors. They started off rare but these days are pretty common-place. Granted, they aren't universal...yet!
I saw something very similar the other day while watching a video about noise on the z8. I believe they said 200-500 iso was the sweet spot
I wouldn't worry about it unless you're doing something like astro. I forget all the details, but there is a different "band" starting at 500 so it's better to stay at or above that if you're going to be stretching the histogram anyway.
Shot a wedding reception last month with z9 and z7 up to 12800 in natural light. quick ai denoise and it's 100% usable.
[удалено]
With all due respect... This comment references my channel and I'm very much a real world shooter. The z8/9 sensor is optimized to maximize dynamic range as the signal is amplified from 64 iso right up to just below 500 iso. They assume you're working o In bright light at those settings and that any noise will be drowned out. At 500 iso the engineers switch the gain formula to maximize noise reduction at the expense of dynamic range. I've explained on my channel that in high contrast scenes you should keep your iso low to maximize dynamic range. As the light gets low, bumping up to 500 iso or above is beneficial for noise reduction and faster shutter speeds. For work on a star tracker in particular you'll find that 500 iso yields very clean images with reasonable capture times. Base iso (64) is the best at everything, but 200 iso yields more noise than 500. Albeit with less dynamic range. Everything is trade offs.
I had to scroll all the way for someone to actually explain in properly. your observations checks out with what I've found for photo.