ISO

[480sparky41 40]

Not really. You were describing software (apples), while unpopular was describing hardware (oranges).

Tomatoes, Apples, Oranges... they're all fruit.

 

[Solarflare]

Yes Nikon cameras have an Auto ISO setting.

You can set it on/off, you can set a maximum ISO, and you can set a minimal shutter speed.

I really love this automatic, except it would be really more comfortable if there was a direct dial instead of having to do menu surfing.

You love auto ISO? ISO is the one thing that I can never deal with having auto. I can shoot in shutter priority, aperture priority, but auto ISO drives me crazy. Your pictures get these wild jumps in feel that is really annoying and very difficult to fix in post.

So you rather have all your pictures equally noisy, instead of having each with the least amount of noise possible ?

To each their own, I guess. I'm used to having an automatic like this from my previous camera, a G11, and I love having an even more powerful automatic now on my D5100.

The main reason I could think of why anyone wouldnt want to have this automatic is that Canon DSLRs, as I heard, didnt had it in the past.

And as of right now I never "tell stories" with my pictures, so I dont really need them at the same quality of some sort.

I guess thats like the swirvel monitor. I keep hearing people complain about how superflous they are. I love them. I guess thats because I'm new to photography and thus I can see the advantage of them, while others did photography for decades and dont see why they need such stuff now.

 

[Solarflare]

Increasing the ISO makes the sensor more sensitive to light. ...........

Technically, incorrect.

Raising the ISO simply changes the algorithms used by the camera's processor on the data the sensor produces. The sensor will 'see' the exact same thing, whether the ISO is set to 50 or 512,000.

Given this, I've never understood why you can't change ISO in post if you shoot RAW? I mean I guess I understand that you can somewhat, but it almost seems to me like ISO should be 100% adjustable in post.

Yeah I wished I could find a good explanation for it somewhere.

From what I could gather from the Wikipedia article, apparently the ISO specifies how much the signal is amplified before presented to the A/D converter.

 

[fjrabon]

Technically, incorrect.

Raising the ISO simply changes the algorithms used by the camera's processor on the data the sensor produces. The sensor will 'see' the exact same thing, whether the ISO is set to 50 or 512,000.

Given this, I've never understood why you can't change ISO in post if you shoot RAW? I mean I guess I understand that you can somewhat, but it almost seems to me like ISO should be 100% adjustable in post.

Yeah I wished I could find a good explanation for it somewhere.

From what I could gather from the Wikipedia article, apparently the ISO specifies how much the signal is amplified before presented to the A/D converter.

I wasn't ever confused about it until I came here and a few people said it was digitally processed. Unpopular cleared it up by affirming that it is indeed a physical amplifier, not digital processing, which makes sense, because amplifiers don't work perfectly linearly. WHich makes sense that you can typically recover more in better quality cameras, since their ISO amplifiers are probably better quality, and thus better able to be 'corrected'.

 

[fjrabon]

So you rather have all your pictures equally noisy, instead of having each with the least amount of noise possible ?

To each their own, I guess. I'm used to having an automatic like this from my previous camera, a G11, and I love having an even more powerful automatic now on my D5100.

The main reason I could think of why anyone wouldnt want to have this automatic is that Canon DSLRs, as I heard, didnt had it in the past.

And as of right now I never "tell stories" with my pictures, so I dont really need them at the same quality of some sort.

I guess thats like the swirvel monitor. I keep hearing people complain about how superflous they are. I love them. I guess thats because I'm new to photography and thus I can see the advantage of them, while others did photography for decades and dont see why they need such stuff now.

Pros tend to complain about swivel screens because they are rough on their cameras, and those things are always going to be prone to breaking if you use your camera really hard, like pros do.

I just like to be control of ISO because it's such a rough adjustment. You're at ISO 100, and all the sudden your camera goes to ISO 200 and your 'sensitivity' is doubled out of nowhere. It's especially bothersome if you're shooting a series of pictures, as two similarly exposed photos with drastically different ISOs will look fairly different. Whereas with shutter speed, the adjustments are much more fine tuned, and subtle. While I try to shoot manual most of the time, Aperture priority isn't that big of a deal because letting your camera control shutter speed doesn't cause drastic changes in the look and feel of your pictures.

I look at my scene, get a feel for the lowest ISO I could shoot at, pick my aperture, and see if that gives me a shutter speed I'm okay with for a good exposure. If not I bump up my ISO. I definitely don't want my ISO jumping willy nilly all over the place. If it changes, I want to be the one that changed it.

 

[480sparky41 40]

I can't see what is so difficult to grasp here.

Some seem to think the sensor 'sees' the same thing, regardless of the shutter speed and aperture used. True, the sensor itself doesn't care (or even 'know') about the ISO setting, BUT: Only a certain combination of shutter speeds and apertures will produce a 'correct' exposure given the light from the subject. Anything else will result in black areas with no data or blown-out whites. Trying to recover from either one of those instances by somehow magically changing the ISO in post is futile...... the data simply is not there.

There's a reason you need so use high shutter speeds and/or small apertures in fully-lit mid-day scenes, & long shutter speeds and/or large apertures when shooting a candle-lit wedding. Brightly-lit scenes have an abundance of photons streaming into the lens, so they're numbers are limited by the short shutter time and smaller aperture. When shooting a dimly-lit subject, you need the opposite in order to make up for the LACK of photons.

If all the scenes capable of being photographed had the same EV, then yes, you could apply ISO in post. But at that point, it would not be necessary.

 

[fjrabon]

I can't see what is so difficult to grasp here.

Some seem to think the sensor 'sees' the same thing, regardless of the shutter speed and aperture used. True, the sensor itself doesn't care (or even 'know') about the ISO setting, BUT: Only a certain combination of shutter speeds and apertures will produce a 'correct' exposure given the light from the subject. Anything else will result in black areas with no data or blown-out whites. Trying to recover from either one of those instances by somehow magically changing the ISO in post is futile...... the data simply is not there.

There's a reason you need so use high shutter speeds and/or small apertures in fully-lit mid-day scenes, & long shutter speeds and/or large apertures when shooting a candle-lit wedding. Brightly-lit scenes have an abundance of photons streaming into the lens, so they're numbers are limited by the short shutter time and smaller aperture. When shooting a dimly-lit subject, you need the opposite in order to make up for the LACK of photons.

If all the scenes capable of being photographed had the same EV, then yes, you could apply ISO in post. But at that point, it would not be necessary.

So you're telling me that if you shot a scene that would be properly exposed at ISO1600, f/4 and 1/200 sec (about a typical concert shot) at ISO100, f/4 and 1/200 sec instead, then you could recover that in post? No, you can't, obviously, as anybody who has ever tried to do it can tell you, your picture would look awful compared to the photo shot with ISO 1600. It's not a "lack of photons" thing like you keep saying. That 16 stops of exposure difference is a result of the same 'photons' hitting the sensor, but different levels of amplification of that same signal.

The point we keep making is that the fact that ISO is the result of an imperfect physical amplifier, that's what means ISO 'mistakes' can't just be corrected in post. If the way you are presenting it was correct, you could just shoot your photos at a correct shutter speed and aperture, and the ISO would be completely irrelevant. It could be 50 or it could be 6400 or 12,800. Wouldn't matter, you could just adjust it in post, just like we can with white balance (which is digital processing, and thus can be perfectly fixed within the range of the sensor's limits).

If ISO were processing, you'd be able to recover like 16 stops with post processing. Instead we can recover like 2-4 without things getting really noisy.

Try this test. Take your camera, get a shot that's properly exposed at ISO1600, have it in manual in just change your ISO to ISO100. Then take a picture. Then in whatever PP program you use, adjust them to be exposed equally. Compare them. Obviously this isn't just a processing thing.

 

[480sparky41 40]

So you're telling me that if you shot a scene that would be properly exposed at ISO1600, f/4 and 1/200 sec (about a typical concert shot) at ISO100, f/4 and 1/200 sec instead, then you could recover that in post? No, you can't, obviously, as anybody who has ever tried to do it can tell you, your picture would look awful compared to the photo shot with ISO 1600

Did you read what I posted? I said the exact same thing.

. It's not a "lack of photons" thing like you keep saying.

Um, yes it is. A dimly lit scene has far fewer photons that can strike the sensor in order to create the image. That's why you need longer shutter speeds and larger apertures..... to allow more photons to enter the lens, strike the photosites and register so the image can be created without dataless shadows. In a sunlit scene, you need shorter shutter speeds and smaller apertures to CUT BACK on the excessive photos lest ye end up with blow-out highlights.

That 16 stops of exposure difference.....

ISO 100 to ISO 1600 is only 4 stops.

.......is a result of the same 'photons' hitting the sensor, but different levels of amplification of that same signal.

It won't the the 'same signal' if one scene requires ISO 100, f/4 at 1/200 and you use the same aperture for a scene that can be recorded 'correctly' at ISO1600

The point we keep making is that the fact that ISO is the result of an imperfect physical amplifier, that's what means ISO 'mistakes' can't just be corrected in post. If the way you are presenting it was correct, you could just shoot your photos at a correct shutter speed and aperture, and the ISO would be completely irrelevant. It could be 50 or it could be 6400 or 12,800. Wouldn't matter, you could just adjust it in post, just like we can with white balance (which is digital processing, and thus can be perfectly fixed within the range of the sensor's limits).

If ISO were processing, you'd be able to recover like 16 stops with post processing. Instead we can recover like 2-4 without things getting really noisy.

I swear, really, honest-to-God.... I'm agreeing with you here.. You cannot magically adjust ISO in post. I'm sure I've reiterated that several times now.

 

[fjrabon]

My point was that you keep talking like the only issue is too few photons hitting the sensor. That's not the only issue at all. If it were, what you agreed to that ISO can't be 'magically fixed in post', would not be the case.

If number of photons were the only issue, a photo shot at ISO6400 and ISO100 could be made to look the exact same in post, if they had the same aperture and shutter speed.

While you agreed that this couldn't be fixed, you kept saying that it was a 'not enough photons' issue. That doesn't make sense. In the example I gave the number of photons hitting the sensor, whatever it was, WAS THE EXACT SAME. Did you read the example you were replying to when I said it's not a number of photons thing? ISO doesn't change the number of photons hitting the sensor. It merely changes how much they are amplified. You can't amplify photons that aren't there.

and of course the same signal isn't recorded if the same shot is shot with the same settings, except ISO. Precisely because what is recorded is the amplified signal. Meaning that the issue is the amplification, not the number of photons hitting the sensor.

 

[480sparky41 40]

My point was that you keep talking like the only issue is too few photons hitting the sensor. ...

I will stop your quote right there and attempt to point out that THIS IS NOT TRUE. READ MY POSTS. (specifically, #s 19, 27, 36 and 38) In those posts, I also mention THE EXACT OPPOSITE OF THAT: >>>>TOO MANY PHOTONS CREATING OVER-EXPOSED/BLOWNOUT HIGHLIGHTS.

 

[brandolsx]

Alright I have been playing with the camera and the ISO more. I see that the higher the ISO the more "noise" or grain is shown in an indoor setting. What would be the reason for using a high ISO if you were looking for less grain and more clear photos. I understand there is an artistic effect with the grain but other than that is there a certain lighting to use a high ISO rather than a lower one? Also, I have seen that on my camera there are ISO settings called Hi 0.3, Hi 0.7, Hi 1, Hi 2 are these just higher settings for ISO or something completely different?

 

[480sparky41 40]

Sometimes you need the higher ISO in order to use a faster shutter speed and/or smaller aperture to obtain the results you desire.

The 'Hi" numbers are due to ISO standards not keeping up with current technology. ISO only officially goes to 10,000 so anything higher than that is not recognized by the ISO. So manufacturers cannot claim 12,500 or 16,000 ISO as they technically doesn't exist. But there's no standard for calling is something else, so they used Hi0.3, Hi0.7, etc.

 

[brandolsx]

Got it, Makes sense to me. I appreciate it!

 

[greybeard35 7]

Auto everything has its place like with everything else. When I hand the d7K to my wife I always just put it on Full Auto. She doesn't want to know or care about how to shoot it manually. ISO is the gain setting for the analog amplifier. The higher the ISO the more juice it sends to the sensor making it, well more sensitive but also noisier. Kind of like turning up the gain on a microphone. It becomes more sensitive and noisier at the same time. It is a trade off for sure.

 

[akophotog]

Just try different iso see which one is better sharpnes. Don't be afraid to use higher iso, some noise is good for your picture