[PuxaVida]

[quote name='Walter Schulz' timestamp='1299073099' post='6439']

Test it and post results. I tried ...

Again: You can't trick the laws of physic.



Ciao, Walter

[/quote]





I don't want to mess with the related holy law of physics, because simply I don't know it <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/blink.gif' class='bbc_emoticon' alt=':blink:' />... I thought you can introduce Mr. Law-of-Physics to me <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/tongue.gif' class='bbc_emoticon' alt='' />... Really, I don't understand the interdependencies between pushing up exposure in RAW converter and law of physics (especially when it comes to the noise in the image). How can we compare the results of signal amplification (ISO gain) with a RAW converter functionality?



Serkan

[Guest]

Any results yet?



Ciao, Walter

[allanmb]

Ok, so I did a quick test with my 7D and 85mm f/1.8. I exposed a shot correctly in fairly dim light at ISO 6400, f/1.8, 1/160. I then took another shot at ISO 1600 and pushed it 2 stops in post. Below you will find a 100% crop of each and below that you will see a link to the full size image.



I think its pretty clear to see in the crop that the noise on the pushed image is considerably more. Also the full size image shows that there is less dynamic range: you will notice that the blacks clip early around the tyres.



So to conclude, it looks like its best to use the higher ISO and let the A/D converter do the work rather than use a lower ISO and push in post.







ISO 6400



[url="http://farm6.static.flickr.com/5094/5497871122_92f40b7fd8_o.jpg"]ISO 6400 Full Size[/url]





ISO 1600 + 2 stops



[url="http://farm6.static.flickr.com/5300/5497876688_c38ee74755_o.jpg"]ISO 1600 Full Size[/url]

[PuxaVida]

I got similar results on D700:



ISO 800, 1/640 @ f/5.6 vs.

ISO 200, 1/640 @ f/5.6 (pushed-up +2 in ACR).



The pushed up image has more saturation, contrast and noise, and less dynamic range. But I think increasing exposure in ACR does not only change brightness but also manipulate other settings. The result was beyond my expectations.



Serkan

[Guest]

[quote name='PuxaVida' timestamp='1299327878' post='6524']But I think increasing exposure in ACR does not only change brightness but also manipulate other settings.[/quote]

You're right about this one if you're using the standard profiles in ACR. Feel free to repeat the test using untwisted camera profiles.

[quote name='PuxaVida' timestamp='1299327878' post='6524'] The result was beyond my expectations.[/quote]

I, however, expected the test wouldn't meet your expectations. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' /> And I suppose I'm not the only one.



Been there, done that.



Ciao, Walter

[PuxaVida]

[quote name='Walter Schulz' timestamp='1299329483' post='6525']

You're right about this one if you're using the standard profiles in ACR. Feel free to repeat the test using untwisted camera profiles.

[/quote]



How can I do it in ACR?

I, however, expected the test wouldn't meet your expectations. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' /> And I suppose I'm not the only one.



Been there, done that.

Walter, I thought that you were saying "it makes no difference" (because of the holy laws of physics you still owe to explain me <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/tongue.gif' class='bbc_emoticon' alt='' />)... But it makes difference. The IQ in pushed up image is far too different than the ISO boosted one. So if you can help me with the issue above, I will check it again...



Tia,



Serkan

[Guest]

[quote name='PuxaVida' timestamp='1299330425' post='6527']How can I do it in ACR?[/quote]



[url="http://lmgtfy.com/?q=untwisted+camera+raw+profiles+"]Google is your friend![/url]



We can discuss the IQ degration issue later.



Ciao, Walter

[allanmb]

[quote name='PuxaVida' timestamp='1299327878' post='6524']

I got similar results on D700:



ISO 800, 1/640 @ f/5.6 vs.

ISO 200, 1/640 @ f/5.6 (pushed-up +2 in ACR).



The pushed up image has more saturation, contrast and noise, and less dynamic range. But I think increasing exposure in ACR does not only change brightness but also manipulate other settings. The result was beyond my expectations.



Serkan

[/quote]



I dont understand, what were your expectations? Do you think its better to push the image in ACR?

[Guest]

OT: Sorry, hit key. Can't delete post.

[PuxaVida]

[quote name='allanmb' timestamp='1299355349' post='6539']

I dont understand, what were your expectations? Do you think its better to push the image in ACR?

[/quote]



No, not at all... I mean the ISO gained image was noticeably better than the pushed up image.



Serkan