ISO chart

I remember seeing a breakdown of ISO progressions based on which ISOs produced the least amount of noise. It was not linear, ISO 160 might be cleaner than ISO 100. I did bookmark the discussion and then managed to loose the bookmark. Does anyone else have that at hand?

I think that this is the link your looking for:
http://www.fredmiranda​.com/forum/topic/68294​5/0

Actually the chart is buried within that first link.
http://forums.canonpho​togroup.com/showthread​.php?p=5225
Do remember though that though ISO 160 has less noise than ISO 100 or 200, it doesn't come for free.

gjl711 wrote in post #7463839
Do remember though that though ISO 160 has less noise than ISO 100 or 200, it doesn't come for free.

Please explain....... If 160 has less noise than 100, what are you giving up by using 160?

msowsun wrote in post #7464369
Please explain....... If 160 has less noise than 100, what are you giving up by using 160?

ISO 160 is a pic taken at ISO 200 and pulled back a stop. The camera is not actually capable of taking a true ISO 160 pic. Therefor you loose a little in the highlight detail. It's basically shooting to the right. A slightly overexposed image pulled back has less noise than a perfectly exposed image. But the cost is a bit of dynamic range.

AHHHHH..... I see

Basically, if you want to take good photos, ignore ISO noise issues. Use the ISO you need and forget about it. The more you worry about ISO noise, processing, etc, the less you focus on what is needed, i.e. taking the photo.

gjl711 wrote in post #7464405
ISO 160 is a pic taken at ISO 200 and pulled back a stop. The camera is not actually capable of taking a true ISO 160 pic. Therefor you loose a little in the highlight detail. It's basically shooting to the right. A slightly overexposed image pulled back has less noise than a perfectly exposed image. But the cost is a bit of dynamic range.

I had read about this before, that the in-between ISO settings were digitally simulated with a loss of DR. If I want to maximize the signal:noise ratio by exposing to the right, I can do that manually. Or if I want to underexpose to get a bit more shutter speed, I can do that manually too.

That's why I set up my 1D Mk III to use only the full-stop ISO settings. I won't use the extra ones and having to click through them would just take longer.

Thanks every one, this is why I spend time here. Now does this hold true for all canons? I have the 50D.

The link provided by gjl711 was the one I one I had been looking for, good job. Thanks again.

I had read somewhere that the Canon 1D series actually do provide hardware 1/3 stop ISO adjustments, but I do not have a source.

basroil wrote in post #7464839
Basically, if you want to take good photos, ignore ISO noise issues. Use the ISO you need and forget about it. The more you worry about ISO noise, processing, etc, the less you focus on what is needed, i.e. taking the photo.

This is good advice, i should use it more often than I do

thatkatmat wrote in post #7465005
This is good advice, i should use it more often than I do

I agree but still feel the knowledge is useful. I prefer to experiment when I have time and then use what I learn intuitively.

gjl711 wrote in post #7464988
I had read somewhere that the Canon 1D series actually do provide hardware 1/3 stop ISO adjustments, but I do not have a source.

Here is one scholarly work that makes that statement:

Noise, Dynamic Range and Bit Depth in Digital SLRs by Emil Martinec © 2008
http://theory.uchicago​.edu …0d/tests/noise/​index.html
"Higher end Canon models implement ISO gain via a two-stage amplification system; one amplifier for the "main" ISO's 100-200-400-800-1600 etc, and a second-stage amplification to implement the "intermediate" ISO's 125-250-500-1000 etc. and 160-320-640-1250 etc.....Lower end Canon models do not perform analog amplification for the intermediate ISO's, rather the intermediate ISO's are implemented by a multiplication of the raw data in software after quantization, and there is only a single stage amplification in hardware; strictly speaking, they do not have intermediate ISO amplification."

gjl711 wrote in post #7464405
ISO 160 is a pic taken at ISO 200 and pulled back a stop. The camera is not actually capable of taking a true ISO 160 pic. Therefor you loose a little in the highlight detail. It's basically shooting to the right. A slightly overexposed image pulled back has less noise than a perfectly exposed image. But the cost is a bit of dynamic range.

Just to avoid any confusion, the image is not pulled back "a stop", its pulled back 1/3 of a stop.