Canon 40D and ISO 3200

I'lll play. This was day 1 (or night 1) with the 40d...a little NR and it is soooo usable. f/2.8 and 3200 ISO. Shutter 1/250. I know, it's a little slow for soccer, but you gets what ya gets.

HOSTED PHOTO
please log in to view hosted photos in full size.

wayovrpar wrote in post #6314899
I'lll play. This was day 1 (or night 1) with the 40d...a little NR and it is soooo usable. f/2.8 and 3200 ISO. Shutter 1/250. I know, it's a little slow for soccer, but you gets what ya gets.

That is a PRETTY good shot...and that is what I am talking about.

Vascilli wrote in post #6314826
Good lord those ones are impossible.. good job for getting it. I love that place..

thanks! i've only been there twice, and i probably won't go back for awhile, but yes, i love it too!

hey pano, thanks for your replies. i have some more questions

to avoid confusion, i will refer to the highest iso setting on the 40D as iso "H," since from what i understand it is not truly iso3200, but iso1600 shot with -1EC and brought back up in camera right? you do not have any control of the post processing in camera, so it is like the camera threw that stop of highlights away for you, is what you're getting at?

is it true that you could just shoot iso1600 -1EC and bring it up yourself and have it equal the iso H shot, since you are doing what the camera is doing at ISO H?

i feel that what i just stated one line up is not true, since you said you are throwing away the top stop of highlights by shootiing iso H as opposed to iso1600 -1EC and bringing that up later. by bringing it up later, you have more control of when the highlights start to clip. is this your point? that with iso H you are forced to lose that stop at the top, while with iso1600 you can choose at what point to stop (for example bringing it up 2/3 a stop instead of the full stop)?

also, from what i understand now...by bringing the iso1600 -1EC shot up one stop in post processing, you are throwing away that upper stop of highlights yourself right? so there will be no difference between an iso H shot that is clipping and a iso1600 -1EC shot brought up 1 stop, because by bringing it up that stop, you will force it to clip, no?

also, is it true that the shadow noise will be the same between an iso H shot and a "iso1600 -EC brought back up one stop in pp" shot?

sorry, lots of questions. i tired to format it to make it easy to reply to. thanks in advance.

silvex wrote in post #6314857
Here you go both given same PP (one +2.85EV the other +0.85EV everything else the same)

Great. You just have demonstrated what I was preaching: use 800 with two stop underexposure instead of ISO 3200.

Was not it? You achieved the same with ISO 800, underexposed. (Btw, have you done this in raw?)

The point is, that if there had been something bright in the scenery, ISO 3200 would have clipped it, while ISO 800 could have capture it unclipped.

So...if I -1Ev IS03200 I would get 1/250 and -2Ev ISO3200...1/500!!!

NOOOO! The suggestion was all the time to meter for ISO 3200 and shoot with 1600 or 800 using that exposure, i.e. just like you did above. Why on earth would one underexpose with ISO 3200 if not forced to?

Panopeeper wrote in post #6315092
Why on earth would one underexpose with ISO 3200 if not forced to?

See above shot of two soccer girls...even at ISO3200 he di not get over 1/500 so he would need to -1Ev to get about 1/500 ...no choice. I would take a bit of noise vs. blurr.

oh, and what about the reverse? doesn't underexposing throw away shadow detail?
is there any difference in shadow noise/detail between a iso3200 shot and a iso1600 -1EC brought up later shot?

silvex wrote in post #6315123
See above shot of two soccer girls...even at ISO3200 he di not get over 1/500 so he would need to -1Ev to get about 1/500 ...no choice. I would take a bit of noise vs. blurr.

iso3200 and iso1600 with a -1EC will yield the same shutter speed. by going from iso3200 to iso1600, you are making the sensor half as sensitive to light, and also by putting in -1EC, you are telling the exposure sensor that its default exposure is for too long (2x too long to be exact). You halved the sensitivity, making the camera think it needed a shutter speed twice as long as that of iso3200, but by putting in -1EC, you told it that its shutter speed was 2x too long. therefore you "fooled" the camera, and it will give you the exact same exposure once brought back up in post processing.

Sfordphoto wrote in post #6315133
iso3200 and iso1600 with a -1EC will yield the same shutter speed.

He is already max out at ISO3200...he needs to get better shutter speed to freeze action.

Sfordphoto wrote in post #6315067
from what i understand it is not truly iso3200, but iso1600 shot with -1EC and brought back up in camera right?

Right. Look at following histograms of the unadultered raw data. These are fine histograms, i.e. very detailed, each color pixel column represents one single pixel level. (Only a 512 pixel level segment of the entire range is displayed at once.)

First the ISO 1600:

MIME changed to 'text/html' | Content warning: script

MIME changed to 'text/html' | Content warning: script

Creating the fake ISO (the multiplication) is usually not thought of as part of the post processing, because it affects the raw data as well, and it can not be influenced by setting, unlike contrast, saturation, WB, sharpness.

Exactly.

The issue is not only that I don't need to adjust the intensity by a full stop. Perhaps I do, because the shot was underexposed. However, I can do this selectively, for example in DPP by reducing the contrast and increasing the "exposure" or by curve adjustment. In ACR I can increase the "fill light", i.e. the very dark areas, without pushing out the highlights. Or I can increase everything with "exposure" but bring back the highlights with "recovery"; etc.

This technique is required with any ISO setting, if the dynamic range of the scenery was high and you exposed to the right: you need to save the shadows without destroying the highlights. That's the reason of working with raw data instead of JPEG.

silvex wrote in post #6315145
He is already max out at ISO3200...he needs to get better shutter speed to freeze action.

in which case he can do two things
1) keep camera at iso3200, dial in a -1EC, and bring it back up later, yielding a 1/500 shutter speed
2) put the camera at iso1600, dial in a -2EC, and bring it up two stops in PP, also yielding a 1/500 shutter speed

this would be like H2...equivalent of ISO6400.

Panopeeper wrote in post #6315158
Right. Look at following histograms of the unadultered raw data. These are fine histograms, i.e. very detailed, each color pixel column represents one single pixel level. (Only a 512 pixel level segment of the entire range is displayed at once.)

First the ISO 1600:



Now let's see the 3200 histogram:



Only every second pixel value is used (it is not so easy to show this on the greens). The pixel values of the 1600 have simply been multiplied by two. This results in "pushing out" the highest stop of the dynamic range, for the doubled values don't fit in the numerical range any more.



Creating the fake ISO (the multiplication) is usually not thought of as part of the post processing, because it affects the raw data as well, and it can not be influenced by setting, unlike contrast, saturation, WB, sharpness.



Exactly.



The issue is not only that I don't need to adjust the intensity by a full stop. Perhaps I do, because the shot was underexposed. However, I can do this selectively, for example in DPP by reducing the contrast and increasing the "exposure" or by curve adjustment. In ACR I can increase the "fill light", i.e. the very dark areas, without pushing out the highlights. Or I can increase everything with "exposure" but bring back the highlights with "recovery"; etc.

This technique is required with any ISO setting, if the dynamic range of the scenery was high and you exposed to the right: you need to save the shadows without destroying the highlights. That's the reason of working with raw data instead of JPEG.

thanks for the explanation pano. one question about how those graphs work...is it the same the histogram in ACR, displayed on the LCD, etc with highlights on the right? just making sure. also, what is the point of the dotted vertical yellow line? thanks

Sfordphoto wrote in post #6315130
oh, and what about the reverse? doesn't underexposing throw away shadow detail?
is there any difference in shadow noise/detail between a iso3200 shot and a iso1600 -1EC brought up later shot?

Keep in eye, that the metered exposure @ ISO 3200 is the same as ISO 1600 with -1 EV bias.; this means, that the sensor gets the same amount of photons. If that is few, then it ís few with any ISO. A higher ISO setting tries to make more out of the too low charge collected in the well (in the storage of the pixel on the sensor chip), but by doing so the noise becomes more visible. Note: the noise is present because of the low exposure, not because of the high ISO. The high ISO amplifies not only the useful image data but the noise as well.

i think one reason i am a bit confused by your two graphs is one says iso1600, f/5.6, 1/40, while the other is iso3200, f/2.8, and 1/15. it looks like these are two different pictures you are using to illustrate the point, which will also explain why it doesnt really look like the values are doubling. mind shooting the same subject, same aperture, just doing iso3200 and iso1600, -1EC in aperture priority mode? i think i'll see the doubling better that way.

Sfordphoto wrote in post #6315168
one question about how those graphs work...is it the same the histogram in ACR, displayed on the LCD, etc with highlights on the right? just making sure. also, what is the point of the dotted vertical yellow line? thanks

These histograms have nothing to do with what you see in DPP, ACR, etc. These reflect the non-demosaiced raw pixels; you never see this in the raw processors.

See the Histogram section of http://www.cryptobola.​com …ola/RawnalyzeGu​ideAll.htm

Now I go to bed (living in Pacific time).