Racmanaz Loc: Sunny Tucson!

Ysarex Loc: St. Louis

Yikes! Lots of misinformation there. Yikes again! I started writing here while the video was running -- more misinformation! No, using the exposure slider in LR is not the exact same thing as raising the ISO on the camera.

No, Fuji cameras don't have two separate analog amplifiers, the sensor has two different read channels.

He really gets noise wrong.

This guy has done some OK videos -- this isn't one of them.

Racmanaz Loc: Sunny Tucson!

There is no misinformation in his explanation, he is just over simplifying the info to help us understand the conceot.as he mentioned. Seriously, stop with your nitpicking every little detail, you are making yourself look arrogant and a know-it-all, you aren't.

Ysarex Loc: St. Louis

He does say he's oversimplifying, but he gets too much wrong. The video does misinform.

* You can not apply ISO either by setting the dial on the camera or in post production using the exposure slider. The exposure slider in post software does not change ISO.
* The signal from the sensor does not pick up photon noise as it travels toward the ADC.
* Fuji cameras do not have two separate analog amplifiers.
* He said, "...ISO is nothing more than amplification of the signal." You can argue that's an oversimplification but it's a very common oversimplification that has a lot of people misinformed and confused; looks like including him. We should avoid that oversimplification because we know it misinforms people.
* There is not another amplifier behind the ADC.
* [This is at 13 minutes] He says, "...camera's that are ISO invariant have very little noise usually around this step and this step in the process." And he points at his chart to the area of signal movement from the analog amplifier to the ADC and from the ADC to the amplifier that doesn't exist. That may be the case but that's unrelated to why the camera may be ISO invariant. The read noise that matters to ISO invariance is the noise present before ISO amplification not after.
* He needs to stop talking about changing ISO in post production. You can't do that.
* He recommends avoiding the two top ISO values 25600 and 51200 because the signal is digitally amplified. That seems to only be true of ISO 51200 -- at least according to the site he references Photons to Photos.

If I wanted to nitpick every little detail that list would be twice as long. He should better understand what he's talking about before publishing these things -- he does misinform.

Racmanaz Loc: Sunny Tucson!

Your arrogance is unbecoming and tiresome, I will take his word over yours any day. You just think you are a know-it-all when in fact, you know very little. I see how you are always at odds with this video poster and the members who made comments on my other post of the same presenter. Get off your high horse and stop being so friggin anal.

Ysarex Loc: St. Louis

Feel free to prove anything I said is incorrect given you're so well acquainted with what I know.

Here's an announcement for Aptina's patent on dual capacitance sensors: http://image-sensors-world.blogspot.com/2010/09/aptina-enters-dslr-world-with-16mp-aps.html and here's an article by Thom Hogan talking about the same and noting Sony's acquisition of that patent and the appearance of that sensor technology in Fuji cameras: https://www.sansmirror.com/newsviews/2016-newsview/jan-mar-2016-newsviews-2/dual-gain-becoming-the-norm.html
So it's on the sensor itself and of course as such there are not two separate analog amplifiers in Fuji cameras. There's proof what I said is correct. Now you go ahead and prove that something else I said is wrong. I'll check back in the morning.

Racmanaz Loc: Sunny Tucson!

11-12 year old outdated links.

Racmanaz Loc: Sunny Tucson!

Like I said, I will believe his word over yours. It's of no use arguing any point with you because you have this faulty idea that you know better than anyone else. I have watched how you respond to others, you are an arrogant know-it-all.

selmslie Loc: Fernandina Beach, FL, USA

That's a distinction without a difference. Either term explains the dogleg in that camera's DR vs. ISO plot.

The transition may occur at ISO 640 for some models but not all of them. Not all Fuji cameras have a similar dogleg and not all cameras with doglegs have only one.



Does this mean that the X-Pro3 has a triple gain amplifier? There is a transition between ISO 250 and 320 and anther one between ISO 800 and 1000.

His information is generally correct in that you should avoid the high and low extended ISO ranges (the open circles) since there the camera is not actually using the gain in the A/D converter to produce the expected change in JPEG SOOC brightness.

Noise is subjective and you need to pixel peep to see the difference.

He is correct about the relationship between changing the ISO in the camera and using the Exposure slider in ACR or Capture One - the effect on the brightness of the final image is the same. That's because the linearity of ISO vs exposure is constant by design in all cameras, even in the extended ranges.

Maybe you should try and present something comprehensive on you own rather than spend all of you time nitpicking the work of others.

Some of his presentations may not use the best metaphors to illustrate his ideas (the ice tray, for example) at least he is doing a better job than you are.

selmslie Loc: Fernandina Beach, FL, USA

No, it just means that the ADC conversion uses different algorithms depending on ISO.
Would this have made it clearer to the viewer? Probably not unless they understand software.

Ysarex Loc: St. Louis

Term? This isn't about terms it's about facts. The dogleg in the chart he shows is not explained by the incorrect fact that the camera has two separate analog amplifiers. It does not.

His information that the ISO 25600 value is one of those (the open circles) ISO values is incorrect.

He is incorrect to say they are exactly the same thing. He also says the exposure slider in the software adds exposure. Would you back that up? Does the exposure slider in LR/C1 add exposure? Since ISO is according to him the "exact same thing" would you also agree that ISO adds exposure?

selmslie Loc: Fernandina Beach, FL, USA

You and I and lots of others know it’s not the same thing.

But it’s called the “Exposure” slider in you computer’s software so, even if it doesn’t change the ISO or exposure originally used by the camera, it does the same thing. It changes the brightness of the image.

Maybe you should take on Adobe and all of the others and see if you can get them to change the name of the slider. Good luck with that.

Belaboring your point here only shows us the limit of your comprehension and your pettiness.

Ysarex Loc: St. Louis

In previous threads you've made the same point that the exposure slider in software doesn't change exposure. Because they both lighten the image doesn't mean they both do the same thing. They both do one same thing among other things that are not at all the same.

The brakes in your car stop your car.
Hitting a tree stops your car.
Using the brakes or hitting a tree both do the same thing.

He said in the video [6 minutes in] that raising the exposure slider in software adds exposure and is the exact same thing as raising the ISO. Do you really want to argue that's correct?

selmslie Loc: Fernandina Beach, FL, USA

That one same thing was the object of the demonstration.

If you want a more "accurate" demonstration, write it yourself. I'll bet you can't.

Your argumentative nit picking is still petty and asinine.

TriX Loc: Raleigh, NC

I agree that’s incorrect and it’s not “nitpicking” or a trivial matter. Changing the exposure in post multiplies the digital array by a constant, while changing the ISO in the camera either changes the amplifier gain or multiplies the digital array by a constant or both. It depends on the camera and on the particular ISO where the transition occurs, and the effect of those two methods of changing the ISO is not the same.

Why is this important? Because believing they are the same leads some to wrongly assume that everything should be shot at base ISO and corrected in post, which is, in my opinion, a mistake, leading to more noise and other detrimental changes. “ISO invariance” in many cases is a solution looking for a problem. If you accidentally or are forced to underexpose, then it can save an otherwise unusable image, but it’s not a reason to always shoot at base ISO and correct later, and equating the two methods can further that idea, which has been espoused repeatedly on UHH in the past.