AUTO ISO: Issue to set lowest ISO setting (Z8)

[CameraLex]

I noticed that the Z8 is noisier than my old D500 at ISO 400.
When I looked up how the noise performance of the Z8 is against the D500 (see attached chart which confirms high level of noise at low ISO) I came aware of the dual gain sensor behavior.
Looking at the chart I am now convinced I do not want to shoot with ISO lower than 500 on my Z8.
Because I shoot Manual auto ISO I want auto ISO to start at ISO 500 and go up.
I can setup the Maximum AUTO ISO but I can't figure a way out to set the base to ISO 500.
Any idea's?

Thanx in advance
Lex

-I've searched the forum group but came up ampty handed...-

 

[Cameron T]

Read noise is only part of the story.

Photographic Dynamic Range versus ISO Setting

You still get more Dr at base iso.

I recommend you also stop pixel peeping, because higher density sensors will look noisier at 100% regardless of iso performance. Following ettr can also improve your images and noise in the shadows.

As far as I'm aware, there doesn't seem to be a way to set a higher base iso in auto iso mode, and my z9 doesn't allow me to do it.

 

[JAJohnson]

Because I shoot Manual auto ISO I want auto ISO to start at ISO 500 and go up.
I can setup the Maximum AUTO ISO but I can't figure a way out to set the base to ISO 500.
Any idea's?

I think the setting you’re looking for is in the ISO sensitivity settings menu. Set ISO sensitivity to the base value you desire, 500 in your case.

Hope that helps!

 

[Cameron T]

I think the setting you’re looking for is in the ISO sensitivity settings menu. Set ISO sensitivity to the base value you desire, 500 in your case.

Hope that helps!

That option is the iso when you're not in auto iso. It's not a minimum, or at least I was able to still go below on my z9, so it isn't a hard minimum

 

[JAJohnson]

That option is the iso when you're not in auto iso. It's not a minimum, or at least I was able to still go below on my z9, so it isn't a hard minimum

It’s also the base setting for Auto ISO. I don’t think it’s a hard minimum, though.

 

[CameraLex]

Read noise is only part of the story.

Photographic Dynamic Range versus ISO Setting

You still get more Dr at base iso.

I recommend you also stop pixel peeping, because higher density sensors will look noisier at 100% regardless of iso performance. Following ettr can also improve your images and noise in the shadows.

As far as I'm aware, there doesn't seem to be a way to set a higher base iso in auto iso mode, and my z9 doesn't allow me to do it.

The sensor of the Z8 has the same density photosites as the D500, so that is not the issue here.
And yes I pixelpeep because I shoot birds at great distances and so I releay heavily on cropping. That's where you see difference between the D500 and the Z8 which I find peculiar especialy because the Z8 is so much newer.

 

[Cameron T]

If you're shooting and exposing well, the read noise difference doesn't matter nearly as much as you think it does. If you're cropping that hard, better field craft and a longer lens will matter more than any bit of tech in the camera.

 

[John Navitsky]

a little trick to setting base iso is to flip to non auto iso, set the iso, the flip back. what you set it to will now be your base iso.

that said, you almost assuredly DO NOT want to set your base iso to 500.

yes, there's a bit of a weird hiccup on that chart due to the dual gain, but in real world, just ignore it.

there is much to love about the z9 shooting at iso 64, i go there whenever circumstances allow. i use manual + auto iso a lot, and i leave my base iso at 64. set it and forget it.

i suggest that if you're seeing issues there are other variables at play, this isn't a hardware problem imo. i shot the d500 for many years and am very fond of it, but from a hardware perspective, there's pretty much no way in which the d500 is better than the z8/z9.

iso 64, baby!

https://flic.kr/p/2pe9MSv

 

[Nimi]

I noticed that the Z8 is noisier than my old D500 at ISO 400.
When I looked up how the noise performance of the Z8 is against the D500 (see attached chart which confirms high level of noise at low ISO) I came aware of the dual gain sensor behavior.
Looking at the chart I am now convinced I do not want to shoot with ISO lower than 500 on my Z8.
Because I shoot Manual auto ISO I want auto ISO to start at ISO 500 and go up.
I can setup the Maximum AUTO ISO but I can't figure a way out to set the base to ISO 500.
Any idea's?

Thanx in advance
Lex

-I've searched the forum group but came up ampty handed...-

First, no argument that lower ISO will give you the highest dynamic range. But...

You can't compare two cameras as you did, since the chart doesn't adjust for gain or sensor size. There is a fine-print note on that tab, just below the chart. The slope is interesting, but the comparison is invalid.

The DR chart can be used though, and as noted by Cameron T, the larger sensor is better along the ISO curve.

Finally, noise in modern sensors like the Z8 is purely electronic, nothing to do with pixel size. You can get excellent noise performance (although not the dynamic range) out of a very dense CMOS sensor.

 

[bleirer]

Along the same lines as above, the notes in the chart the op posted say there is no adjustment for image size, while the photographic dynamic range chart is normalized as if one was viewing equal size images with equal pixel dimensions. That could be why the op says the d500 does better for noise. What may be happening is you are used to zooming in a certain amount in lightroom or whatever, and when you zoom in equally, for example to 100%, the z9 looks noisier, but when you look at them to compare the z9 image at the same size, same pixel dimensions, same viewing distance they look different. This is something that is reported a lot here as folks get high megapixel full frame cameras from lower megapixel crop cameras. The only true apples to apples comparison is at same size same viewing distance same pixels.

 

[CameraLex]

If you're shooting and exposing well, the read noise difference doesn't matter nearly as much as you think it does. If you're cropping that hard, better field craft and a longer lens will matter more than any bit of tech in the camera.

500pf with 1.4TC is all I can do. So if the tech can help me, it would be realy helpfull. But as I said, the noise is worse on my z8 at ISO 400 so why take pictures at that value?

 

[Steve]

I tend to agree with the comments about. I wouldn't worry about trying to shoot the camera at ISO 500 all the time.

To answer your original question no, you can't. When the camera uses auto ISO in manual mode, it will go as low as it likes no matter what the base iso is set to. And honestly, that's a good thing. After all, if you locked it in at ISO 500 and ended up in conditions that demanded a lower ISO (like 100), you may end up in a situation where you were overexposing a bunch of images before realizing it.

 

[John Navitsky]

500pf with 1.4TC is all I can do. So if the tech can help me, it would be realy helpfull. But as I said, the noise is worse on my z8 at ISO 400 so why take pictures at that value?

perhaps some examples with settings

 

[CameraLex]

I tend to agree with the comments about. I wouldn't worry about trying to shoot the camera at ISO 500 all the time.

To answer your original question no, you can't. When the camera uses auto ISO in manual mode, it will go as low as it likes no matter what the base iso is set to. And honestly, that's a good thing. After all, if you locked it in at ISO 500 and ended up in conditions that demanded a lower ISO (like 100), you may end up in a situation where you were overexposing a bunch of images before realizing it.

Hi Steve, thanx for answering my question. At least I know I can't set the base iso in AUTO ISO at 500.
And I understand that if the conditions are met that demand lower ISO I get overexposure but that isn't different than my Max AUTO ISO the other way around. And when shooting wildlife it is more common to have not enough light for fast shutterspeeds. But keeping my eye on the exposure meter

I still don't get why a bigger sensor (FF) with the same photosite density (photosites per inch) can not be compared to a smaller sensor (APS-C). The photosites of the D500 sensor are approximately the same and when I crop to a smaller size than APS-C than the cropped images are comparable as well.
So in other words... Put the Z8 in DX mode (is in camera cropping) and compare to the D500. I think to see more noise on my Z8 pictures at ISO 400 than on my D500 files though I cannot compare the two scientifically because I sold my D500 to pay for the Z8.

 

[Steve]

Hi Steve, thanx for answering my question. At least I know I can't set the base iso in AUTO ISO at 500.
And I understand that if the conditions are met that demand lower ISO I get overexposure but that isn't different than my Max AUTO ISO the other way around. And when shooting wildlife it is more common to have not enough light for fast shutterspeeds. But keeping my eye on the exposure meter

I still don't get why a bigger sensor (FF) with the same photosite density (photosites per inch) can not be compared to a smaller sensor (APS-C). The photosites of the D500 sensor are approximately the same and when I crop to a smaller size than APS-C than the cropped images are comparable as well.
So in other words... Put the Z8 in DX mode (is in camera cropping) and compare to the D500. I think to see more noise on my Z8 pictures at ISO 400 than on my D500 files though I cannot compare the two scientifically because I sold my D500 to pay for the Z8.

Happy to help

On the higher end of the ISO range, while you can limit it, it's not a big problem if you underexpose. You can use the exposure slider in a RAW processor to essentially do the same thing the camera does and end up with the same result as if the camera had just shot at a proper ISO (with most modern, ISO invariant cameras). So, if the proper ISO was 6400 and you maxed out at 3200, you could take that 1 stop underexposure, add a stop in Lightroom, and end up with the same result as an ISO 6400 shot from the camera.

I can't say for sure on the D500 vs Z8 in DX crop - I think they should be about the same. However, without one in each hand to test the same target at the same time, it's tough to tell

 

[CameraLex]

Along the same lines as above, the notes in the chart the op posted say there is no adjustment for image size, while the photographic dynamic range chart is normalized as if one was viewing equal size images with equal pixel dimensions. That could be why the op says the d500 does better for noise. What may be happening is you are used to zooming in a certain amount in lightroom or whatever, and when you zoom in equally, for example to 100%, the z9 looks noisier, but when you look at them to compare the z9 image at the same size, same pixel dimensions, same viewing distance they look different. This is something that is reported a lot here as folks get high megapixel full frame cameras from lower megapixel crop cameras. The only true apples to apples comparison is at same size same viewing distance same pixels.

I do not agree or do not understand.
The photosites of the Z8 and the D500 are approx the same size so in my opinion comparable.
If I put the Z8 in DX mode I get a picture that is about 19,4 MP while the D500 creates files with approx 20,9 MP and view is also the same so that is comparable in my opinion

 

[John Navitsky]

when comparing the d500 to z8 in fx mode, first downsize the z8 image to 20mp

 

[bleirer]

When you are looking at things like noise, sharpness, even dof, it is assumed one wants to view the image at the same size. So frame filling shots from two cameras would be normalized to judge how the cameras compare. A 45 megapixel full frame image can be downsampled to a 20 megapixel image, and part of the downsampling is noise reduction because the algorithm is drawing on information from surrounding pixels to downsample, so the result is less noise. You are not asking about printing but that is a good comparison. Imagine printing equal size prints from each camera, the full frame higher megapixel camera is going to have an advantage. Yes the pixel density and the exposure per unit area is similar, but the total light from the larger sensor area is greater.

Just try it using your software, equalize the two and view them side by side, see if you see the difference.

 

[John Woodworth]

I do not agree or do not understand.
The photosites of the Z8 and the D500 are approx the same size so in my opinion comparable.
If I put the Z8 in DX mode I get a picture that is about 19,4 MP while the D500 creates files with approx 20,9 MP and view is also the same so that is comparable in my opinion

Is it possible that your inherent assumption that the”view is also the same” is giving rise to a divergence in the discussion?

How did you frame the subject in the comparison?

If the subject filled the frame in both sensors, the larger FX sensor in the Z8 has collected way more total light from the subject than the DX sensor of the D500. In an equalized comparison, the larger FX frame would be shrunk down to match the smaller DX sensor by combining pixels. (As an aside, if you were shooting a perfectly gray card, the exposure on each pixel for both FX and DX would be the same, but there are almost twice as many FX pixels and hence twice the amount of light collected.)

The fundamental assumption underlying this result is that noise in modern cameras is due to the statistics of photon counting. Today’s cameras are mainly counting individual photos (in most shooting scenarios)! The other main limitation is quantization in the ADC’s used to digitize the charge collected…If it’s a 12-bit digitizer, the best that can be done is less than 12 stops.

If you didn’t move the camera, just switched FX to DX, then I think you are right.

I hope this helps.

 

[CameraLex]

when comparing the d500 to z8 in fx mode, first downsize the z8 image to 20mp

No, than the view would not be the same. I crop or shoot the Z8 in DX mode to get the same view, same size and same amount of pixels (approx)

 

[CameraLex]

When you are looking at things like noise, sharpness, even dof, it is assumed one wants to view the image at the same size. So frame filling shots from two cameras would be normalized to judge how the cameras compare. A 45 megapixel full frame image can be downsampled to a 20 megapixel image, and part of the downsampling is noise reduction because the algorithm is drawing on information from surrounding pixels to downsample, so the result is less noise. You are not asking about printing but that is a good comparison. Imagine printing equal size prints from each camera, the full frame higher megapixel camera is going to have an advantage. Yes the pixel density and the exposure per unit area is similar, but the total light from the larger sensor area is greater.

Just try it using your software, equalize the two and view them side by side, see if you see the difference.

I use the same lens on both D500 and Z8 in DX mode. This delivers a picture with the same view, same DOF, same amount of pixels (approx)!

 

[John Navitsky]

No, than the view would not be the same. I crop or shoot the Z8 in DX mode to get the same view, same size and same amount of pixels (approx)

ok, that’s why we’re all confused. that’s a bit of an unusual approach

 

[CameraLex]

ok, that’s why we’re all confused. that’s a bit of an unusual approach

What is so unusual?
I first had a D500 and shot birds with the 500PF and now I do exactly the same with the Z8.
In FX I get a wider view due to the FF sensor so I would crop more to get the same end result. If I shoot in DX the pictures are directly comparable.
And that is what I do. I compare the pictures with the same view, same lens, same ISO etc. and than I think the Z8 has more noise at ISO 400 and I thought the chart from potonstophotos (see post before) does verify this.

 

[Nimi]

What is so unusual?
I first had a D500 and shot birds with the 500PF and now I do exactly the same with the Z8.
In FX I get a wider view due to the FF sensor so I would crop more to get the same end result. If I shoot in DX the pictures are directly comparable.
And that is what I do. I compare the pictures with the same view, same lens, same ISO etc. and than I think the Z8 has more noise at ISO 400 and I thought the chart from potonstophotos (see post before) does verify this.

You might be seeing it, but the chart is meaningless. Look at the notes below the chart; sensors cannot be compared due to size and gain. Which is essentially what everyone on the thread tries (and failing) to explain to you. The dynamic range chart is relevant and related and shows a direct comparison between the sensors.

 

[CameraLex]

You might be seeing it, but the chart is meaningless. Look at the notes below the chart; sensors cannot be compared due to size and gain. Which is essentially what everyone on the thread tries (and failing) to explain to you. The dynamic range chart is relevant and related and shows a direct comparison between the sensors.

I indeed do not comprehend what the size of the sensor has to do with it because I only use the DX/APS-C part of it. Which is in theory and practice only the middle section of the FF sensor.
On the other hand... Looking at the dynamic range of the D500 and Z8 in DX mode shows that the D500 has more dynamic range...???
But why does the Z8 in FX mode has more dynamic range than in DX mode? Is the dynamic range calculated over all photosites? If so than I only should compare the dynamic range of the Z8 in DX mode with the D500. Otherwise it would be logical to shoot in FX mode and crop to DX mode in postprocessing while in my perspective the end results would be the same. You crop off the photosites out of the APS-C frame in camera or in PP.
I clearly miss some basic understanding here.