Sensor dynamic range and EVs on stats query

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Squawk

Squawk

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I have a concept problem I’m sure is simple to understand and I’m hoping someone out there can show me the light. My first assumption are that the EV we see is the equivalent of stops, so in my mind 1 EV = 1stop. So when I look at my D500 I see EV ranges like -3 ± 20 EV quoted, so to me that’s 24 EVs I’ve got to play with, but that seems nothing to do with the sensor where I see 10.66 EVs for Photographic DR and 14 EVs for the Engineering DR at 100 iso (I understand the difference between the two) so it’s well short of the EVs quoted. So are the EVs I see quoted only useful in understanding the metering system? I can’t seem to figure out why I should think this is an important number when what I’d really like to know is what the DR of the sensor is at iso 100 and what the iso is at a sensor DR of 10 EVs (neither found on the stats).
 
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EV is short for the Exposure Value which results in a combination of shutterspeed plus aperture depending on the ISO used.
It’s the quantity/intensity of available light (luminance) translated by a lightmeter in all possible combinations of shutterspeed and aperture at a certain ISO.
Ie ISO100 F/2.8 ss 1/250 or ISO100 F/5.5 ss 1/125 are settings one can chose for the same EV.

So ONE EV number represents all possible combinations of shutterspeeds and apertures ,based on your chosen ISO value, you can think of to get correct exposure for your subject.
(Do you want to freeze it or not, do you want a large DOF or not aso)
 
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EV is short for the Exposure Value which results in a combination of possible shutterspeeds plus apertures depending on the ISO used.
It’s the quantity/intensity of available light (luminance) translated by a lightmeter in all possible combinations of shutterspeed and aperture at a certain ISO.
Ie ISO100 F/2.8 + ss 1/250 or ISO100 F/5.6 + ss 1/125 are settings one can choose for the same EV.
(If I remember correctly Nikon uses a F/1.4 lens and ISO100 for their stats.)

The EV range you’re quoting is the ability of the Lightmeter of the D500 to meter correctly NOT the PDR of its sensor. (Photographic dynamic range)

/edit
HERE you can find the PDR for the D500
 
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Thern said:
EV is short for the Exposure Value which results in a combination of possible shutterspeeds plus apertures depending on the ISO used.
It’s the quantity/intensity of available light (luminance) translated by a lightmeter in all possible combinations of shutterspeed and aperture at a certain ISO.
Ie ISO100 F/2.8 + ss 1/250 or ISO100 F/5.6 + ss 1/125 are settings one can choose for the same EV.
(If I remember correctly Nikon uses a F/1.4 lens and ISO100 for their stats.)

The EV range you’re quoting is the ability of the Lightmeter of the D500 to meter correctly NOT the PDR of its sensor. (Photographic dynamic range)

/edit
HERE you can find the PDR for the D500
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Thanks Roger. Just metering then. I think I’ll park that particular stat on one side. I had a D90 and a D800 a while ago they were quoted as 0 to 20 EV so the D500 is 20% better but in practical terms I don’t see the D500 struggling less in tricky dark / light situations. I’m sure it’s somehow useful info.

Still think it’s a pity sensor DR isn’t benchmarked and quoted on the official site. Seeing how DR/ISO changes would be a useful comparison but at least it’s available on 3rd party sites.
 
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Charlie Lasswell said:
If you want DR info you might check out https://www.photonstophotos.net/
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Thanks Charlie. That’s the site I use and the details are what I think should be shown on the manufactures web site. If someone is scratching their head over why someone will buy a D5 rather than a D850 with grip a lot of the answer is here. In fact it’s this site that has caused my problem as I totally understand why the data here is useful in understanding how I’d expect a camera to perform as the light changes. But Nikon don’t think this is a stat worth showing us and do think the EV metering range is something we should be thinking about. If I’m cynical I’d say they they’re just putting up stuff that looks impressive (to me 24EVs is really exciting) and it doesn’t matter that it’s not really something to worry about. But if it is something I should be excited about I’d like to know why, and I’m giving Nikon the benefit of the doubt and assuming the stat is important.
 
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Squawk said:
Thanks Ken. I think you just made my head explode. The table is as I’d understood but that chart took an embarrassingly long time before the light bulb came on. I think I’ll revisit when I’ve cleaned up the mess.
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Yes, it is a bit much to take in on first glance, but the main point I was hoping to convey is that EV1 or EV5 is an actual amount of light on these tables. So when somebody says that a camera can focus down to EV-3, this table will tell you what that light level looks like in camera settings.

--Ken
 
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Replytoken said:
Yes, it is a bit much to take in on first glance, but the main point I was hoping to convey is that EV1 or EV5 is an actual amount of light on these tables. So when somebody says that a camera can focus down to EV-3, this table will tell you what that light level looks like in camera settings.

--Ken
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The Exposure value represents all possible combinations of shutterspeeds and apertures for the measured luminance BASED on a given ISO.
Bright sunlight is EV15 at ISO100
(Do Google the Sunny 16 rule)
Same luminance but ISO set at 200 your meter meters EV16, ISO set at 400 it will be EV17, at 800 it’s EV18 aso.

So yes EV IS relative and!!
Just stating a camera is able to focus at -3 EV is WORTHLESS unless the ISO value is known!
 
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When Nikon quotes the EV ranges for metering and AF, it's simply telling you how bright / dark it can be and still have those system function properly. So, if you're trying to meter a scene that's out of range, the meter won't work - it'll just flash at you and the information it gives won't be reliable. If you're trying to focus outside of the specified EV range, then AF won't work properly (or at all). Think of EV as sort of the photographers version of lumens. So, Nikon isn't trying to state EV range for the sensor (EV range for the imaging sensor and EV range for the meter are wildly different things), just how bright / dark conditions need to be for those system to operate.

I actually talk about EV for 9 or 10 pages in my exposure book, but the above should cover it what's happening :)
 
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Steve said:
When Nikon quotes the EV ranges for metering and AF, it's simply telling you how bright / dark it can be and still have those system function properly. So, if you're trying to meter a scene that's out of range, the meter won't work - it'll just flash at you and the information it gives won't be reliable. If you're trying to focus outside of the specified EV range, then AF won't work properly (or at all). Think of EV as sort of the photographers version of lumens. So, Nikon isn't trying to state EV range for the sensor (EV range for the imaging sensor and EV range for the meter are wildly different things), just how bright / dark conditions need to be for those system to operate.

I actually talk about EV for 9 or 10 pages in my exposure book, but the above should cover it what's happening :)
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Kerrr-ching! Lights on at last. So I can still be best friends with my camera in a snow field or a rain forest. And the upper limit of 20 is a buffer because over that you’re probably suffering radiation burns, and the lower limit has to be looked at in terms of the iso performance of the sensor as while the camera may still talk to you it may be as grainy as a pebble beach. Thank you Steve, it was like applying a haze filter.
Your books are amazing but I’ve an owl sized brain and can get lost in the light.
 
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