Use of ISO?

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tigerimages

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How do you use the ISO on your camera?

Is there any other use for it other than to increase the shutter speed when the aperture is wide open in fading light?
 
I keep it on the minimum possible to get the best quality, but I'll freely change it to achieve the shutter/aperture settings I want.
I don't use the auto ISO.
 
I tend to keep the ISO as low as possible (usually 100 or occasionally 200) to reduce noise in the image. I'd only increase it to 400 & above to get a useable shutter speed or aperture in low light conditions.

The only other time I'd up the ISO would to to purposefully make a noisy / grainy image. However, whilst film grain can be attractive I find digital noise universally unattractive so with digital shooting I'd much rather add a grain effect in photoshop.

Well that's my take on it anyways :)
 
arclight said:
I keep it on the minimum possible to get the best quality, but I'll freely change it to achieve the shutter/aperture settings I want.
I don't use the auto ISO.
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You need to be aware that the minimum ISO isn't always the best quality, The "native" ISO should provide that. On your K20, it's 200.

Bob
 
OK, my field is football, or this applies to sports too where you have to freeze the action at high speed in low light. In the past I've looked up and thought that it's rather gloomy and automatically adjusted the ISO to suit but since I've been using a different lens that has given sometimes poor shutter speeds in average light I've been using it to increase the shutter speed regardless of the daylight available.
 
trapper501 said:
How do you know what the native ISO is for a camera? 40D here.
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It's based on tests and will be the ISO value where the signal-nosie ratio is the lowest. I used the term "native" but should have used "base native".
I'll dig out some values later.

Bob
 
Canon Bob said:
It's based on tests and will be the ISO value where the signal-nosie ratio is the lowest. I used the term "native" but should have used "base native".
I'll dig out some values later.

Bob
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I've had a google search based on your additional info, the values given seem to have a very large range so it depends who you believe.

One site said all Canon are native base ISO 100, but others offered 160 or 320.

(320 sounds rather high based on what you were saying this means)
 
DiddyDave said:
If you really want to add 'grain' I'd usually suggest doing that later in PP so you have more flexibility in the shot
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I really wouldn't. For one you're adding something that wasn't actually there. Just an effect. The grain won't be based on how the sensor processed the light. It'll just be some layer. You'll have loads of options to tweak the grain too. What is "right"? If you increase the ISO and let the camera do its thing then you will just accept the noise/grain in the shot as the right amount. I've never ever added grain. ISO does the job perfectly.

Oh and I use ISO to get girls.
 
Just a brief idea as to how the theory works....

The ISO is increased by increasing the amplifier gain. If a gain of 1 has .05 nosie on top then it's insignificant. As the gain is increased to 2 then it will likely still have .05 noise associated with it. A gain of 3 might see the noise increase to .075 and 4 will have 0.1, Things then start to climb and a gain of 5 will have 0.2, 6 having 0.3, 7 0.5 and so on. The best ISO to use will be the value where the noise is the lowest percentage of the total output (my figures were absolute and not %).

I've got a document somewhere that shows the s-n ratios in graphic format and it's easy to see where the "sweet spot" is.

Bob
 
Canon Bob said:
You need to be aware that the minimum ISO isn't always the best quality, The "native" ISO should provide that. On your K20, it's 200.

Bob
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Don't see that in the Pentax K20 Manual.
Default setting is AUTO and that ranges from 100 to 400 according to the lighting. Manual selection is necessary to go above 400.
Pentax K20 Manual does not say what ISO gives the best quality, but the Magic Lantern guide states it it 100. In practice I suspect the human eye would not detect any difference between 100 and 200.
 
Canon Bob said:
It's based on tests and will be the ISO value where the signal-nosie ratio is the lowest. I used the term "native" but should have used "base native".
I'll dig out some values later.

Bob
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I'd be most interested to read about that. Anything to eek out a little extra image quality.
 
Personally I would just shoot rather than get lost in numbers. I would happily use my 30D upto 1600 and my D700 up to 6400. They do a great job and I get the shot instead of walk around with a blackboard trying to do maths :)
 
Apologies for starting a discussion in a sharing section but it seems to have totally gone off track in the correct place where I originally asked.

How do you use ISO when you're shooting the sport of your choice?

I have always looked up at the sky and set it according to how gloomy it was but since I've been using my Sigma 300mm lens I've been trying to use it to get a higher shutter speed from the lens because sometimes using the old metod the shutter speed was really poor.

Have I finally sussed it out or are there other uses for ISO while trying to freeze fast paced action?
 
If shooting sports I try and work out what shutter speed I will need - depends on the sport though.

Then in Aperture or Shutter priority mode I see if am getting that shutter speed when composing on the action. Too quick I'll lower the ISO, not fast enough I'll up the ISO!
 
Gary Coyle said:
This is also the wrong forum i would suggest
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Why? It's where all the sports photographers post and I'm looking for an answer from a sports photographers perspective. I'm not looking for a replyh from someone who sticks his camera on ISO 100 and takes a photo of a rusty lock on an abandoned factory gates. Did you not read my reasoning on my first post?

And I'd set the ISO by looking at a gloomy sky at 2.50pm on a matchday and think hmm, ISO 800 should suffice. Since getting this Sigma lens and and struggling to get a decent shutter speed at times I've tried a different approach and am wondering how other sports shooters work.
 
Well I dont shoot much sports. But I always set my ISO depending on the subject I am shooting, and also the weather. :)
If it's something like Chess :lol: Then you would base your ISO more on the lighting available opposed to needing high shutter speeds.

But If i was shooting football/rugby. I would set my ISO for a rough shutter speed I would need aswell as the sky/light conditions also.
 
Threads merged as the new one was in the wrong forum, and as far as I can see your original question was answered, maybe a longer more explanatory first post in future may get you more specific replies.
 
tigerimages said:
Why? It's where all the sports photographers post and I'm looking for an answer from a sports photographers perspective. I'm not looking for a replyh from someone who sticks his camera on ISO 100 and takes a photo of a rusty lock on an abandoned factory gates. Did you not read my reasoning on my first post?

And I'd set the ISO by looking at a gloomy sky at 2.50pm on a matchday and think hmm, ISO 800 should suffice. Since getting this Sigma lens and and struggling to get a decent shutter speed at times I've tried a different approach and am wondering how other sports shooters work.
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But it can be applied to every single type of photography not just sport, if you require a certain shutter speed to do the job required (in your case freeze the action) then the answer will be the same wether youre shooting sport or another genre.

Apologies if i sounded harsh, i just thought you might get better responses in another forum.
 
Jimmy_Lemon said:
Threads merged as the new one was in the wrong forum, and as far as I can see your original question was answered, maybe a longer more explanatory first post in future may get you more specific replies.
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It wasn't answered at all. The second thread was aimed specifically at those folks who shoot sports and seeing as very few people who answered the original thread show up in the sports section I don't see how you can think it was answered. :cuckoo:

The original thread was turned on it's head away from the original topic.
 
It depends on what situation.

Sports, yes, exactly for that use. I just put the 40d straight on 3200 mode in dying light.

Anything else, either 100 or 200.

However I recently shot a roll of Delta 3200. Was beautiful.
The grain awesomely fat :D
 
tigerimages said:
It wasn't answered at all. The second thread was aimed specifically at those folks who shoot sports and seeing as very few people who answered the original thread show up in the sports section I don't see how you can think it was answered. :cuckoo:

The original thread was turned on it's head away from the original topic.
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Your original question(s) was

How do you use the ISO on your camera?

Is there any other use for it other than to increase the shutter speed when the aperture is wide open in fading light?
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Maybe you didn't get the answers you were after, but you should have just made it more clear in this thread what you were after. The sports section is in the photo sharing section of the forum, and is for photo sharing, not questions.

I would suggest changing the topic of this thread (click edit on the first post then click 'go advanced') to something along the lines of "How to best use ISO for sports photography" then further explain your question in the first post so people answer your specific question, not a VERY vague one that will receive a wide range of answers.
 
Jimmy_Lemon said:
Maybe you didn't get the answers you were after, but you should have just made it more clear in this thread what you were after. The sports section is in the photo sharing section of the forum, and is for photo sharing, not questions.
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Yes, I should've made it more clear but once I realised that the thread had gone totally off the course of what I was asking I put a new one in the more relevant forum hoping for a more specific answer from like-minded souls.

Food Poison, I haven't shot under the lights at all this year but when I did last year I shot solely on 3200 thinking that it was may be easier for the sensor to "hold" the action and not even thinking of trying 1600 to see how much it affected the shutter speed.
 
When you choose an exposure you have two creative controls at your disposal with which to give a particular appearance to your photo - Aperture to control depth of field and Shutter Speed to control motion (both of camera/lens and subject). The ISO is the thing you vary to get the correct exposure while meeting your creative goals. If changing ISO alone is not enough to get you a correct exposure, or the ISO you would need would be too noisey then you have to make some sacrifices either in choice of aperture, shutter speed or both.

Some people purposely use a high ISO to "creatively" generate noise in the image. Personally I have no desire to see noise, ever, so I stick with the lowest ISO that gives me an acceptable aperture and shutter speed setting. As a Canon user I avoid using intermediate ISOs on my xxD bodies as these are faked within the camera. On my 1D3 I will happily use any ISO from 100 to 3200. There is no point using any of the invented ISOs that are above or below the native range - i.e. the "L" or "H" settings - on any of my bodies.
 
Opposite to most of the replies, I use ISO50 on occasion to 'slow' the shutter down, an example of this is shooting waterfalls, I can often get a slow enough shutter speed to blur the water at f22 at ISO50, which perhaps I couldn't at ISO100.

My preference is to do it this way than add ND filters (or polarisers) to slow the shutter down.
 
i slap my D700 on auto iso upto 6400, and change the minimum shutter speed option to suit lens, conditions or subject.

the only time it comes off is when i use a tripod
 
tdodd said:
On my 1D3 I will happily use any ISO from 100 to 3200. There is no point using any of the invented ISOs that are above or below the native range - i.e. the "L" or "H" settings - on any of my bodies.
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Pretty much agree with the exception that I do use 6400, some venues need it :(
 
dod said:
Pretty much agree with the exception that I do use 6400, some venues need it :(
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I understand why you might do that but, if my understanding is correct, an exposure at 6400 ISO is actually an exposure at 3200 ISO at the sensor and the pixel values from that (under?)exposure are each doubled to "create" new values as though you had shot at 6400 ISO. The reason, I suspect, that L and H options are disabled by default, and that the manual recommends ISOs from 100-3200 is because the L and H ISOs aren't proper ISOs and should be used with caution (or not at all (unless you shoot JPEG)).

If you shoot to JPEG then that may well be worth doing, since nobody wants an underexposed or blurry JPEG. However, if you shoot to raw then there is nothing to be gained by simple numerical doubling of pixel values within the camera. You can do that just as easily in your raw processor. The downside of doing it in the camera before writing out the file is that you might send pixels into clipping that were actually captured perfectly well at the sensor.

Thus, for raw shooters, in the same way that you might sort out WB in post processing you might as well save "faking" your 6400 ISO exposure until then too and then you'll have the option whether to send pixels into clipping or salvage them. In effect, using 6400 ISO loses you 1 stop of dynamic range in the highlights.


......that's if my understanding is correct. :) (which I think it is).


In a similar way, 50 ISO images are actually captured by the camera sensor at 100 ISO and then the camera halves the resulting pixel values before saving the file. For a save to JPEG this may effectively perform a "highlight recovery" to some degree within the camera. Once again, for raw shooters, there seems to be no point. You actually end up with an overexposure of 1 stop, which might mean you clipped highlights that would not have been clipped if you'd had a "correct" exposure at 100 ISO.

My understanding of these things comes from raw file analysis work by a chap who goes by the name Panopeeper on some forums and GaborSch on others. Here's a thread with a discussion about "fake" ISOs and noise levels - http://photography-on-the.net/forum/showthread.php?t=625337. I tend to believe what Panopeeper says. So far I have not been let down.
 
tdodd said:
I understand why you might do that but, if my understanding is correct, an exposure at 6400 ISO is actually an exposure at 3200 ISO at the sensor and the pixel values from that (under?)exposure are each doubled to "create" new values as though you had shot at 6400 ISO. The reason, I suspect, that L and H options are disabled by default, and that the manual recommends ISOs from 100-3200 is because the L and H ISOs aren't proper ISOs and should be used with caution (or not at all (unless you shoot JPEG)).
Click to expand...

the d3 and d700 have hi settings after 6400 though
 
tdodd said:
If you shoot to JPEG then that may well be worth doing, since nobody wants an underexposed or blurry JPEG. However, if you shoot to raw then there is nothing to be gained by simple numerical doubling of pixel values within the camera. You can do that just as easily in your raw processor. The downside of doing it in the camera before writing out the file is that you might send pixels into clipping that were actually captured perfectly well at the sensor.

Thus, for raw shooters, in the same way that you might sort out WB in post processing you might as well save "faking" your 6400 ISO exposure until then too and then you'll have the option whether to send pixels into clipping or salvage them. In effect, using 6400 ISO loses you 1 stop of dynamic range in the highlights.


......that's if my understanding is correct. :) (which I think it is).
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The benefit, for RAW or JPEG, is a quicker shutter speed. Maybe I'm not understanding what your getting at :shrug:
 
dod said:
The benefit, for RAW or JPEG, is a quicker shutter speed. Maybe I'm not understanding what your getting at :shrug:
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What I'm getting at is that shooting at 6400 ISO for a higher shutter speed is no different to shooting at 3200 ISO and underexposing by 1 stop in order to get the same shutter speed that you would get by shooting at 6400 ISO. i.e. if you are using an autoexposure mode then shooting at 3200 ISO and -1 EC will be the same as shooting at 6400 ISO and 0 EC. The "real" raw capture will be the same either way. By setting 6400 ISO all that happens is the camera "fakes" the extra stop by doubling the captured values.

Either way, the sensor will gather an identical amount of light and the pixel values at the sensor will be the same. All that shooting at 6400 ISO accomplishes is that the camera then takes those values and doubles them within the camera before writing the raw file. This might force some pixels into clipping territory when actually the sensor pixels were not saturated at all. If you shoot at 3200 ISO the values are left just as they were captured. You then get to do the doubling (or some other degree of adjustment) in your raw processor and you get an extra stop of control over whether pixels get pushed into clipping or not.
 
i understand where your coming from now
 
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