High ISO Questions

[smoke665]

Yes, they have noise and yes, there is less dynamic range ... but as a tool to document the event they are quite useable and reflect, to a much greater degree, the tone of the event

Is this Luminance noise, Chrominance noise, or both???

Even the Sony A7s, arguably the king of current high ISO,

Might want to research that. I think even the A7ii is only 25.6k. I haven't had the opportunity to see some images from the D500 at the 50k range, but some of the samples I've seen from the Pentax KP at the 51.2k mark are pretty darn good. Maybe not something that you'd want to blow up to a wall size poster, but still not bad.

 

[Gary A.]

Mainly luminance, very little color noise.

 

[smoke665]

The ISO increase they require is designed to force an underexposure of the sensor and then the ISO brightening boost is withheld from the raw file which then receives special tone curve processing to produce the JPEG. Paradoxically this technique reduces DR and that includes DR in the raw file. The raw file is effected by the withholding of the ISO post processing

Agree with this to a point. It's my understanding (at least for Pentax) that the s curve expansion instructions are saved in the metadata file of the raw image. Until you choose to develop the image with those instruction nothing happens to the raw file. I can't find anything to refute your comment that at that point the raw file would be changed forever, but I was under the assumption that it wasn't.

I agree as a whole, the process works by forcing an overexposure in the shadows, and an underexposure in the highlights, but again, I was under the assumption it was a post process and the image data should still be in the raw file, so how would this create a loss dynamic range?

 

[Destin]

Yes, they have noise and yes, there is less dynamic range ... but as a tool to document the event they are quite useable and reflect, to a much greater degree, the tone of the event

Is this Luminance noise, Chrominance noise, or both???

Even the Sony A7s, arguably the king of current high ISO,

Might want to research that. I think even the A7ii is only 25.6k. I haven't had the opportunity to see some images from the D500 at the 50k range, but some of the samples I've seen from the Pentax KP at the 51.2k mark are pretty darn good. Maybe not something that you'd want to blow up to a wall size poster, but still not bad.

@smoke665 watch this video.



Granted it's a YouTube video. But he offers the raw file to view if you wanna download it, and it looks pretty damn good considering we're talking ISO 51,000!

It wasn't long ago I was shooting a pair of Nikon D80s, and 3200 looked FAR worse than what 51,200 does on the D500.

 

[smoke665]

Mainly luminance, very little color noise.

Interesting, I could live with that. So many of my earlier attempts to utilize higher ISO had both.

 

[smoke665]

But he offers the raw file to view if you wanna download it, and it looks pretty damn good considering we're talking ISO 51,000!

This pretty much follows along with what I've seen in the Pentax release. 51.2 in both seems to be pretty much the threshold. Granted there is some visible noise but not objectionable and as @Gary A. pointed out earlier in some case could actually enhance the mood of the photo.

 

[jsecordphoto]

Yes, they have noise and yes, there is less dynamic range ... but as a tool to document the event they are quite useable and reflect, to a much greater degree, the tone of the event

Is this Luminance noise, Chrominance noise, or both???

Even the Sony A7s, arguably the king of current high ISO,

Might want to research that. I think even the A7ii is only 25.6k. I haven't had the opportunity to see some images from the D500 at the 50k range, but some of the samples I've seen from the Pentax KP at the 51.2k mark are pretty darn good. Maybe not something that you'd want to blow up to a wall size poster, but still not bad.

When I say king of high ISO, I don't it has the highest ISO values, I mean it performs the best at high ISO and in low light.

 

[MSnowy]

This is the only 51,200 iso picture I have taken with d500. Straight out of the camera

 

[Destin]

I'll be shooting a hockey game in a dimly lit rink Tuesday. Will try some real life 51,200 shots and post them up here.

 

[Designer]

GETCHUR DR. PEPPER HERE!



ICY DR. PEPPER!



ICE COLD DR. PEPPER!

 

[Ysarex]

Off to the grocery store and I took the X-T2 along (same sensor as D500).

The highest ISO setting on the T2 is 25K here's that shot:

And here's the full-res file for pixel-peeping popcorn eaters: ISO25K.jpg

Same photo with one stop underexposure. So I just left the ISO at 25K and stopped the lens down +1 to get an equivalent ISO 51K exposure:

And again the full-res file: ISO51K.jpg

Low DR weather unfortunately but look under the truck and you can see the pretty rapid fall off.

Joe

 

[Ysarex]

The ISO increase they require is designed to force an underexposure of the sensor and then the ISO brightening boost is withheld from the raw file which then receives special tone curve processing to produce the JPEG. Paradoxically this technique reduces DR and that includes DR in the raw file. The raw file is effected by the withholding of the ISO post processing

Agree with this to a point. It's my understanding (at least for Pentax) that the s curve expansion instructions are saved in the metadata file of the raw image. Until you choose to develop the image with those instruction nothing happens to the raw file.

Nothing ever happens to a raw file -- you can't alter them.

I can't find anything to refute your comment that at that point the raw file would be changed forever, but I was under the assumption that it wasn't.

The effect of the D-range function on the raw file occurs in the camera when the photo is taken. My use of the term "ISO post processing" is probably the problem here. I'm referring to the post processing applied to the sensor signal by the camera. In digital cameras raising ISO
1) biases the metering system and
2) post processes the sensor signal.
ISO doesn't alter the sensor's response to exposure it alters how the sensor data is processed. Pentax's D-range highlight function forces an ISO increase to at least 200. You can't use it at base ISO 100. Without the D-range function engaged, raising the ISO from 100 to 200 would do both items 1) and 2) above. With the D-range function active item 2) is withheld. At ISO values above 200 1 stop of ISO brightening is withheld. The raw file is therefore effected.

I agree as a whole, the process works by forcing an overexposure in the shadows, and an underexposure in the highlights, but again, I was under the assumption it was a post process and the image data should still be in the raw file, so how would this create a loss dynamic range?

The raw file is effected by the D-range function's forced underexposure. Maximum DR = a full sensor capacity exposure at base ISO. Any reduction in that full capacity exposure = reduction in DR. So the raw file is effected by having it's DR capacity hamstrung as it were.

Joe

 

[smoke665]

This is the only 51,200 iso picture I have taken with d500. Straight out of the camera

Wow, that's insanely clean for 51.2. Did/have you attempted any cleanup post??? Are the lower ISOs progressively cleaner? I had to take the my K3ii out for a test run, two shots 51.2 straight out except for the crop, with a 300 mm Sigma. Seems to be more color noise in mine, though that might be partly lens and focal length related. I did notice that the inside shot closer to the subject seemed cleaner.

IMGP2833.jpg by William Raber, on Flickr

IMGP2843.jpg by William Raber, on Flickr

 

[smoke665]

Low DR weather unfortunately but look under the truck and you can see the pretty rapid fall off.

Probably more noticeable on your original, but as internet images on my end I'm not seeing much difference between the two. I guess it comes down to knowing all of your camera's features and abilities, and then using the best settings for the job at hand. To me having the High ISO capability is just another tool in the box.

 

[astroNikon]

I bought the D500 to go alongside my D750.

Before I bought it I took sample shots at various ISOs on a D5500, D7200, D610, D750, D810 for comparison. I had on my Flickr shots of all those cameras compared at various ISOs, but have since deleted them.

With the D500 Hi-1 would be the max, "I gotta absolutely get the shot" but isn't recommended.

In test shooting the D500 against the D750 in bad lighting / low lighting indoor soccer I've found the D500 just could not keep up with the D750, using the same lens. Sports is very demanding as you *have* to have a minimum shutter speed so it's up to the ISO to compensate the exposure along with the sensors light gathering ability.

Nikon also has excellent software to handle the image processing. I've always been curious how much of the image is software versus if it came from the sensor right to a file. And as mentioned the higher the ISO the less DR you can obtain.