Push vs. ISO

[Picsfor]

Blimey, thought the term "push" had long since disappeared into the ether of film.

I still do "push" my exposures because situations arise where i really needed a flash or a tripod and have neither.
Also, because i want a certain amount of noise/ grain in my shots, as i've said before.

But as i used to push in film days, it's something i've always done.
I think for me, noise/ grain is something i've learned to use to create an appearance.

The most i ever got to in film days was pushing a 3200asa 2 stops to 12800, but wow, some of those would never have been gained without it.

I'll leave you scientists to debate the fromulae and algorithms that prove your point. I just know that i use the camera, lens and some otheer bits of kit to create an image based on various settings applied!

 

[Meh]

I'll leave you scientists to debate the fromulae and algorithms that prove your point. I just know that i use the camera, lens and some otheer bits of kit to create an image based on various settings applied!

Fair enough +1

 

[awinphoto]

** On the digic5 press release I vaguely remember a key note at reduced noise... Canon claims in the above statement that the digic processes the image, hence controlling the noise... So it make perfect sense that the digic, if you take the statement above at face value, that the digic controls the noise better than the intel computer in this regards.

Awinphoto, yes absolutely the DIGIC processor "processes" or "develops" the image from the original read out values coming out the sensor. It also creates the RAW file which is more than just the pixel values and is a proprietary format. However, in terms of processing or developing an image, I believe that has more to do with producing the JPEG rather than creating the RAW file. Good point about "if we believe" as certainly anything we read from Canon has marketing spin (not that they're lying but could be exaggerating).

The DIGIC processor only sees the output from the A/D converter... in other words it's already digitally encoded and therefore no more noise will be added (processing artifacts possibly, but again that's more about producing the JPEG). DIGIC5 is getting quite powerful but in general an in camera processor is subject to constraints (speed, power) that the computer is not and because of this some noise reduction algorithms, etc. that are too slow for in camera use could be used in post processing allow additional tools but not less.

Other than the fact CR2 is proprietary and Canon might know things about the data in the file that a 3rd party application would not be able to access, I doubt the DIGIC processor can do anything that can't be done on a computer and even then Canon would build that functionality in to DPP.

For the most part, I get your question but to be honest, i'm not that geeky to pretend to have have that answer... I could pose a question to canon's cps reps next time we meet however i'm sure there's information there where they could tell me but then they would have to kill me. =) All i know is, in practice, in camera ISO boosting is cleaner than pushing in post production... I cant quite tell you why but it is what it is, for now.

 

[Meh]

All i know is, in practice, in camera ISO boosting is cleaner than pushing in post production... I cant quite tell you why but it is what it is, for now.

+1

Agreed, if the empirical testing shows it's cleaner then it is (although sometimes what we see leads to incorrect conclusions). Neuro's answer that up to a certain ISO setting the analog gain applied to the readout voltage before passing to the A/D converter make sense since that amplification is applied before noise is picked up from the ADC.

OP has been answered. In camera ISO results in less noisy images than underexposing and correcting in post. The caveat though is that might only be true up to a certain ISO setting.

 

[ejenner]

http://www.clarkvision.com/articles/digital.sensor.performance.summary/

This might be of interest if you want to start understanding sensors. Definitely worth a read IMO.

Also it shows why a 36MP FF sensor is either going to need major new technology (like doubling the capture of photos) or trade off IQ.