Are there any "rules" for using ISO?

Started Apr 3, 2013 | Discussions
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Are there any "rules" for using ISO?
Apr 3, 2013

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.  Using aperture-priority produces slower shutter speeds, and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
baloo_buc
Veteran MemberPosts: 6,766Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

There is certainly a rule:

Increase the ISO when other means of adjustment (shutter speed and aperture) could not be used anymore.

In most cases you can set the aperture as wide as possible and the shutter speed as high as needed and then increase the ISO speed.

If you use Nikon you have a powerful tool in ISO Auto. You either use A mode and set the aperture while setting the shutter speed via the ISO Auto (the soft way) or use the M mode and set both the aperture and shutter speed and let ISO Auto to manage the exposure (the hard way).

In the A mode if the max ISO is reached then the shutter speed is modified downwards.

In the M mode if the max ISO is reached then underexposure occurs and when the minimum ISO is reached overexposure occurs.

Let's say you have as light ISO200, f/5.6 and 1/320 s. The ISO Auto is set at shutter speed of 1/640 s and max ISO Speed at ISO3200. Your current ISO is ISO200, which is the minimum ISO setting also for ISO Auto.

In A mode you set f/8. Then the camera will use ISO Auto and set the shutter speed at 1/640 s and the ISO Speed at ISO800.

In M mode if you set f/8 and 1/500 s then the ISO Auto will set ISO640.

If the light is ISO200, f/5.6 and 1/20 s there is another situation:

A mode f/8 (set by you), 1/160 s (set by ISO Auto) and ISO 3200 (set by ISO Auto).

M mode f/8 (set by you), 1/500 s (set by you) and ISO 3200 (set by ISO Auto). In this case underexposure occurs (1,7 EV).

 baloo_buc's gear list:baloo_buc's gear list
Olympus XZ-1 Nikon D90 Nikon D5100 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Tokina AT-X Pro 12-24mm f/4 DX II +9 more
Reply   Reply with quote   Complain
Hugowolf
Forum ProPosts: 11,308
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.  Using aperture-priority produces slower shutter speeds, and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

There are no rules as such. You just want the lowest ISO that will give you the shutter speed and aperture you need.

If your shots are not exposed correctly using a semi-automatic mode like shutter or aperture priority, it has nothing to do with ISO, it is an exposure problem. What exposure mode are you using: spot, partial, matrix/evalutive, average?

Does your camera not have an auto ISO mode?

Brian A

Reply   Reply with quote   Complain
Limburger
Senior MemberPosts: 4,037Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.  Using aperture-priority produces slower shutter speeds, and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

Susan

-- hide signature --

GreenMountainGirl

Not clear to me what you're saying but anyways...

DOF is affected by aperture in your case and nothing else. Maybe you mean switching from Av to Tv didn't affect DOF.

How did you raise ISO in Av mode?

Maybe try full auto (forget EC) and raise the ISO to a level you get your shutter speed and aperture you need.

As well have a read on metering I think that far more interesting than EC.

Short: get out of automated modes.

-- hide signature --

Cheers Mike

 Limburger's gear list:Limburger's gear list
Fujifilm FinePix X100
Reply   Reply with quote   Complain
Virginia Bill
Contributing MemberPosts: 764Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.  Using aperture-priority produces slower shutter speeds, and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

Susan

-- hide signature --

GreenMountainGirl

What's missing here is information about your metering mode. Shutter, aperture, and ISO are fundamentally and reciprocally linked; if you change one you will either change the amount of light hitting your sensor (in manual mode) or your camera will change another setting to maintain what it regards as accurate exposure (in any automatic metering mode).

For animals with a telephoto, I'd use spot metering on the animal; any other mode might react to foliage, sky, or ground enough to require adjustments in postprocessing.

You need to understand what the meter is trying to tell you. It's calibrated to produce a standard grey tone from the light your subject is reflecting into your lens. If your viewfinder contains very bright material (snow, sky, white sand are the classic examples) the meter will underexpose. If your viewfinder contains a lot of dark material (a tree line in low light for example), the meter will overexpose. Most metering modes use various averaging or weighting algorithms (usually called matrix metering) to produce pleasing results. You can also choose a mode favoring the central area of the viewfinder so that something like 60% of the reading comes from the central area. Spot metering takes its reading only from the very center of the viewfinder.

For deer at 300mm I'd use manual mode, high shutter (1/500 or faster), and spot metering. If changing aperture didn't produce enough light, I'd raise ISO.

 Virginia Bill's gear list:Virginia Bill's gear list
Leica Digilux 2 Panasonic Lumix DMC-LX5 Leica M8 Pentax K-5 Pentax smc DA 21mm F3.2 AL Limited +8 more
Reply   Reply with quote   Complain
Barrie Davis
Forum ProPosts: 21,460
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.

How low is the light? What shutter speeds and apertures are you getting presently, and at what ISOs?  Refer to you EXIF files, and then you can tell us. Better still, post some pictures complete with EXIF details.

Using aperture-priority produces slower shutter speeds,

No...

The shutter speed will depend on the aperture YOU prioritise, so you are in charge. If the shutter is too slow to still movement, then the aperture YOU SELECTED is too small for the available light at the ISO you are using, requiring the camera to set a long shutter speed...

Remember, swapping about between different modes (A and S etc.) DOES NOT alter which shutter speed and aperture combinations are needed for correct exposure. All that changes is which one (shutter or aperture) that YOU must select. What's more, in performing the task, you are still obliged to make a sensible selection, AND to meter accurately after doing so...

... or you will still end up with duds.

The idea of the semi-automatic exposure modes is that you only have to monitor ONE exposure factor, the shutter or the aperture, instead of BOTH. It saves some of the work of Manual Mode, but not ALL of it.

and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

Conventional advice for best image quality is to use the lowest ISO value that yields usable shutter speed and aperture combinations in the strength of light prevailing.

However, in DIM LIGHT it may not be possible at low ISO at all, but likely needs quite HIGH ISO, especially if...

1) ... you are using a long lens, say 300mm, and need to freeze camera shake (you are)....

2) ... if your lens does not have a particularly wide aperture at long f-lengths (most do not)...

3) ... and your subject is moving... (which it is)

As may be seen when all three are combined with dim light, you have the perfect storm of worst possible shooting conditions .

The only recourse is to wind UP the ISO to a MUCH higher setting.

Q: How far up?
A: The minimum amount that yields USABLE shutter speeds and apertures...

....  but it will still be quite a lot, that's for sure.

Make a start at 1600, and go up from there.
Combine with the widest aperture your lens has got.
Check the resultant shutter speed to see that it is one you can (a) hand-hold (b) will freeze the subject.

-- hide signature --

Regards,
Baz
=
"Ahh... But the thing is, these guys were no ORDINARY time travellers!"

Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to baloo_buc, Apr 3, 2013

baloo_buc wrote:

There is certainly a rule:

Increase the ISO when other means of adjustment (shutter speed and aperture) could not be used anymore.

In most cases you can set the aperture as wide as possible and the shutter speed as high as needed and then increase the ISO speed.

This is what I do, but still tend to get some underexposures.  The photos are taken in early evening when the light is falling away.  For instance, took some photos at f/5.6, 1/250sec,  ISO 320 which turned out OK.  But when I raised to f/16 and 1/500sec, ISO 800 the picture was underexposed.  I think I was using shutter priority, but not sure.  Another underexposed photo was taken at f/5.3, 1/250sec, ISO 640, also probably shutter priority.

If you use Nikon you have a powerful tool in ISO Auto. You either use A mode and set the aperture while setting the shutter speed via the ISO Auto (the soft way) or use the M mode and set both the aperture and shutter speed and let ISO Auto to manage the exposure (the hard way).

My camera is a Nikon D7000 (sorry, forgot to mention that), but I have never tried the Auto ISO.  My reasoning is that I want to learn how to use the camera's functions, not let the camera do everything.  When I first started using my camera, I set it on manual all the time.

Thank you Victor for your help.

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
Leonard Migliore
Forum ProPosts: 10,117Gear list
Like?
I have a couple
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

I have been experimenting with low-light images of moving subjects (mostly deer) and getting mixed results.  Using aperture-priority produces slower shutter speeds, and raising ISO does not seem to work.  Using shutter-priority works better, but still often have to make exposure adjustments in LR4.  Most of these photos are at/close to 300mm, so have not noticed any significant effect on DOF, just need to get a better idea of ISO (and exposure compensation) because there often isn't much time for "test photos"!

My first rule:

A sharp noisy picture is better than a blurred clean picture.

My second rule:

Go to ISO 800 whenever there's a chance of blur. My personal choice of ISO 800 is because my D300 is not bad up to there; other photographers and cameras will have differing limits. "Chance of blur" depends on the situation. If I'm using 300mm handheld, I want my shutter speed 1/500 or faster. If I'm using a tripod, I'll probably want 1/250 for most critters unless they're quite torpid.

My third rule:

See the first rule. If ISO 800 doesn't work, raise it until the shutter speed is fast enough. Deal with the noise in Lightroom.

I don't remember what camera you have, but it's probably much better for high ISO than a D300. You just have to decide what your tolerance is for noise. And "making exposure adjustments" in Lightroom is the same as changing ISO. So if you're limiting the ISO to 1600, and then have to bump the image 2 stops in LR, you've actually taken the picture at ISO 6400.

-- hide signature --

Leonard Migliore

 Leonard Migliore's gear list:Leonard Migliore's gear list
Canon PowerShot G12 Nikon D300 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF-S DX Nikkor 10-24mm f/3-5-4.5G ED +9 more
Reply   Reply with quote   Complain
Leonard Migliore
Forum ProPosts: 10,117Gear list
Like?
Crank that ISO
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

baloo_buc wrote:

There is certainly a rule:

Increase the ISO when other means of adjustment (shutter speed and aperture) could not be used anymore.

In most cases you can set the aperture as wide as possible and the shutter speed as high as needed and then increase the ISO speed.

This is what I do, but still tend to get some underexposures.  The photos are taken in early evening when the light is falling away.  For instance, took some photos at f/5.6, 1/250sec,  ISO 320 which turned out OK.  But when I raised to f/16 and 1/500sec, ISO 800 the picture was underexposed.  I think I was using shutter priority, but not sure.  Another underexposed photo was taken at f/5.3, 1/250sec, ISO 640, also probably shutter priority.

If you use Nikon you have a powerful tool in ISO Auto. You either use A mode and set the aperture while setting the shutter speed via the ISO Auto (the soft way) or use the M mode and set both the aperture and shutter speed and let ISO Auto to manage the exposure (the hard way).

My camera is a Nikon D7000 (sorry, forgot to mention that), but I have never tried the Auto ISO.  My reasoning is that I want to learn how to use the camera's functions, not let the camera do everything.  When I first started using my camera, I set it on manual all the time.

A D7000 has excellent high ISO capability. It's going to be real good up to ISO 1600 and will give you useful exposures up to 6400 or so. Lightroom 4 does a very good job on noise.

As others have noted, the metering mode is not important; the exposure is.

-- hide signature --

Leonard Migliore

 Leonard Migliore's gear list:Leonard Migliore's gear list
Canon PowerShot G12 Nikon D300 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Nikon AF-S DX Nikkor 35mm f/1.8G Nikon AF-S DX Nikkor 10-24mm f/3-5-4.5G ED +9 more
Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to Hugowolf, Apr 3, 2013

Hugowolf wrote:

There are no rules as such. You just want the lowest ISO that will give you the shutter speed and aperture you need.

If your shots are not exposed correctly using a semi-automatic mode like shutter or aperture priority, it has nothing to do with ISO, it is an exposure problem. What exposure mode are you using: spot, partial, matrix/evalutive, average?

I have the setting at matrix/evaluative.

Does your camera not have an auto ISO mode?

Yes, my Nikon D7000 (sorry, forgot to mention that) does have auto ISO, but I have never tried it.   Sounds like it might be a good idea to give it a try...  My reason initially for not using it was because I wanted to learn to use the camera functions, not let the camera do everything for me.  Forgot all about it!

Thanks Brian!

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
nelsonal
Senior MemberPosts: 2,456Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

baloo_buc wrote:

There is certainly a rule:

Increase the ISO when other means of adjustment (shutter speed and aperture) could not be used anymore.

In most cases you can set the aperture as wide as possible and the shutter speed as high as needed and then increase the ISO speed.

This is what I do, but still tend to get some underexposures.  The photos are taken in early evening when the light is falling away.  For instance, took some photos at f/5.6, 1/250sec,  ISO 320 which turned out OK.  But when I raised to f/16 and 1/500sec, ISO 800 the picture was underexposed.

Just so you know, going from f/5.6 to f/16 is reducing the aperture/exposure by 3 stops, the shutter speed adjustment was a 4th stop reduction, and your ISO increased brightness by a stop and a third so you're second photo was 2 and 2/3s less bright than the first.  Leaving the aperture at f/5.6 with the other two settings (1/500th and ISO 800 would have resulted in a second picture that was similarly bright as the first).

If the second exposure was selected on manual, you'll want to add stops somewhere to compensate for stops you're removing, if it's on an auto-metered setting (my guess would be spot) it would appear to have metered on something considerably lighter colored (like a sunlight reflection or patch of pure white hair in the light).

Reply   Reply with quote   Complain
baloo_buc
Veteran MemberPosts: 6,766Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

baloo_buc wrote:

There is certainly a rule:

Increase the ISO when other means of adjustment (shutter speed and aperture) could not be used anymore.

In most cases you can set the aperture as wide as possible and the shutter speed as high as needed and then increase the ISO speed.

This is what I do, but still tend to get some underexposures.  The photos are taken in early evening when the light is falling away.  For instance, took some photos at f/5.6, 1/250sec,  ISO 320 which turned out OK.  But when I raised to f/16 and 1/500sec, ISO 800 the picture was underexposed.  I think I was using shutter priority, but not sure.  Another underexposed photo was taken at f/5.3, 1/250sec, ISO 640, also probably shutter priority.

If the light was the same f/16, 1/500 s would have required ISO 5000 not ISO 800 to be properly exposed.

If you use Nikon you have a powerful tool in ISO Auto. You either use A mode and set the aperture while setting the shutter speed via the ISO Auto (the soft way) or use the M mode and set both the aperture and shutter speed and let ISO Auto to manage the exposure (the hard way).

My camera is a Nikon D7000 (sorry, forgot to mention that), but I have never tried the Auto ISO.  My reasoning is that I want to learn how to use the camera's functions, not let the camera do everything.  When I first started using my camera, I set it on manual all the time.

You have a powerful tool you paid for and not using it. I reckon you don't understand the aperture and shutter speed. The aperture f/5.6 will let you 8 times more light (i.e. 3 stops) than f/16. In order to compensate for such loss of light you should either reduce shutter speed 3 stops (to 1/30 s) or increase ISO speed 3 stops (to ISO 2500) or any combination of these two that gives you 3 stops.

Thank you Victor for your help.

Susan

-- hide signature --

GreenMountainGirl

 baloo_buc's gear list:baloo_buc's gear list
Olympus XZ-1 Nikon D90 Nikon D5100 Nikon AF-S DX Nikkor 16-85mm f/3.5-5.6G ED VR Tokina AT-X Pro 12-24mm f/4 DX II +9 more
Reply   Reply with quote   Complain
mike703
Veteran MemberPosts: 5,918
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 3, 2013

GreenMountainGirl wrote:

This is what I do, but still tend to get some underexposures.  The photos are taken in early evening when the light is falling away.  For instance, took some photos at f/5.6, 1/250sec,  ISO 320 which turned out OK.  But when I raised to f/16 and 1/500sec, ISO 800 the picture was underexposed.  I think I was using shutter priority, but not sure.  Another underexposed photo was taken at f/5.3, 1/250sec, ISO 640, also probably shutter priority.

This is a bit weird.  If f/5.6 and 1/250 sec at ISO 320 was OK, how did you end up with f/16 and 1/500 sec and ISO 800, which is about 3 stops less exposure?  If course that pic is massively underexposed... but the camera wouldn't have let you do that unless you were in manual mode and ignoring the frantic warning somewhere that the picture would be underexposed.  f/16 is a rather ridiculous aperture to be using in low light (it's a tiny hole that doesn't let much light in and would only normally used in very bright light) and does suggest that you are slightly confused...

If balancing shutter speed, ISO and aperture worries you, don't use manual mode (yet).  Use one of the auto modes - the camera is very good at calculating the correct exposure so let the camera do its thing.  Probably the simplest and most widely used auto mode is aperture priority (Av).  Select this and, as you are shooting in fading light, set your lens to its widest aperture (smallest f-number... so f/4 is a much bigger hole than f/16 and lets in a lot more light).  See what shutter speed you get.  WIth a 300mm lens hand-held ideally you want 1/500 second or quicker, so raise the ISO until you get 1/500 sec.  Now you're good to go.

Don't worry if you have to raise the ISO to 800, 1600, 3200... as others have said your camera's sensor is very good and even at ISO3200 you can get clean looking pics using the noise reduction in your processing software.  ISO6400 is usable if necessary - noise can be cleaned up (there are some amazing noise-reduction programs out there), but blur due to a too-slow shutter speed ruins the shot.

If your camera has an auto-ISO mode, an easy way to get the same effect is to set widest aperture on the lens (smallest f-number); 1/500 sec shutter speed; and let the ISO do what it wants.  If it really is too dim and the ISO is trying to go off scale (above 6400) you'll have to bring the shutter speed down to maybe 1/250 sec but only do that as a last resort.

Good luck

Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: I have a couple
In reply to Leonard Migliore, Apr 3, 2013

Leonard Migliore wrote:

My first rule:

A sharp noisy picture is better than a blurred clean picture.

My second rule:

Go to ISO 800 whenever there's a chance of blur. My personal choice of ISO 800 is because my D300 is not bad up to there; other photographers and cameras will have differing limits. "Chance of blur" depends on the situation. If I'm using 300mm handheld, I want my shutter speed 1/500 or faster. If I'm using a tripod, I'll probably want 1/250 for most critters unless they're quite torpid.

I try to get sharp pictures, but it doesn't always work.  That is why I have been trying shutter-priority.  Especially when I try to hand-hold - so use my tripod whenever possible.  But it is limiting when photographing the deer because they keep moving around, which is often rapidly.  Used 1/250 for my last shoot, at 5.6 and ISO 640, and the photos were underexposed.  They could be fixed in LR4, but want to be able to do it "right"!  Guess I should try to raise the ISO...

My third rule:

See the first rule. If ISO 800 doesn't work, raise it until the shutter speed is fast enough. Deal with the noise in Lightroom.

I don't remember what camera you have, but it's probably much better for high ISO than a D300. You just have to decide what your tolerance is for noise. And "making exposure adjustments" in Lightroom is the same as changing ISO. So if you're limiting the ISO to 1600, and then have to bump the image 2 stops in LR, you've actually taken the picture at ISO 6400.

Sorry, I didn't mention it - Nikon D7000 - so it's well-rated for high ISO.  Probably I just a little afraid of going too high!  OP suggested going to auto-ISO, but not sure it ought to be necessary, plus using it wouldn't necessarily help me to learn!

Thanks Leonard!

Susan

-- hide signature --

Leonard Migliore

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to nelsonal, Apr 3, 2013

nelsonal wrote:

Just so you know, going from f/5.6 to f/16 is reducing the aperture/exposure by 3 stops, the shutter speed adjustment was a 4th stop reduction, and your ISO increased brightness by a stop and a third so you're second photo was 2 and 2/3s less bright than the first.  Leaving the aperture at f/5.6 with the other two settings (1/500th and ISO 800 would have resulted in a second picture that was similarly bright as the first).

Nelsonal, I think you just precipitated an epiphany!  I do know about stops and halving/doubling light, but for some reason never thought about ISO the same way.  THANK YOU!!!  That fills in my mental blanks about the "Triangle".   This makes it easier to figure out what to do.

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to baloo_buc, Apr 4, 2013

baloo_buc wrote:

You have a powerful tool you paid for and not using it. I reckon you don't understand the aperture and shutter speed.

Victor, I think you are right.  In theory I understand about aperture and shutter speed, but for practical use it isn't really ingrained in my thinking.  I have a chart with the f-stop, shutter speed, and ISO values on it, including an illustration of each of the lens apertures, which I think I will have to concentrate on making use of it.

You aren't the only one who has pointed this out!  And I do appreciate all the "wake-up" calls.

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to mike703, Apr 4, 2013

mike703 wrote:

This is a bit weird.  ...  f/16 is a rather ridiculous aperture to be using in low light (it's a tiny hole that doesn't let much light in and would only normally used in very bright light) and does suggest that you are slightly confused...

It is a bit weird...  I am realizing that I have not been applying the basics of aperture, etc.  Trying to think too much about DOF, ISO and not about the relationship between f-stop and shutter speed first.

Probably the simplest and most widely used auto mode is aperture priority (Av).  Select this and, as you are shooting in fading light, set your lens to its widest aperture (smallest f-number... so f/4 is a much bigger hole than f/16 and lets in a lot more light).  See what shutter speed you get.  WIth a 300mm lens hand-held ideally you want 1/500 second or quicker, so raise the ISO until you get 1/500 sec.  Now you're good to go.

I was using Av most of the time until I wasn't getting fast enough shutter speeds, so switched to shutter-priority.  That is when I began having trouble with exposure, and made some wrong turns in the process!

Don't worry if you have to raise the ISO

800 is the highest I have raised the ISO, but then I messed up the picture by using f/16!  Guess it is time to try the higher ISO settings, and watch the low light warnings...

Thanks Mike.  Now that I asked the question and got so many answers saying the same kinds of things, I feel kind of dumb.  But everyone has been kind, and helped me to "see the light"!

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
CSPoole
Regular MemberPosts: 366Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 4, 2013

From Wilba's FAQ Rebel Forum:

Might Help.

Thanks,CSPoole

 CSPoole's gear list:CSPoole's gear list
Canon PowerShot SX50 HS Canon EOS 550D Canon EOS 600D Canon EF 50mm f/1.8 II Canon EF 85mm f/1.8 USM +4 more
Reply   Reply with quote   Complain
nelsonal
Senior MemberPosts: 2,456Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to GreenMountainGirl, Apr 4, 2013

It's fine if you want to use manual mode to learn exposure, but either use the meter or chimping as a way to check your estimate.  At the bottom middle of your viewfinder is a meter that should show +____0____- With vertical bars under these signs, if you see these bars, it means your camera will record a very dark (bars toward the -) or very bright (bars toward the +) image.  Sometimes that may be what you want (if the subject and background are very dark or light---think of a child in a light color out playing in snow) but most of the time you'll want that meter fairly close to the middle (blue sky, green grass, etc are all pretty close to 0 on the meter).   This is especially true if you use matrix/evaluative metering (as it's rare that a whole scene will be that bright or dark).

Reply   Reply with quote   Complain
GreenMountainGirl
Contributing MemberPosts: 665Gear list
Like?
Re: Are there any "rules" for using ISO?
In reply to Virginia Bill, Apr 4, 2013

Virginia Bill wrote:

For animals with a telephoto, I'd use spot metering on the animal; any other mode might react to foliage, sky, or ground enough to require adjustments in postprocessing.

I never thought about changing the metering mode.  Thank you for suggesting it - I will have to try that.

For deer at 300mm I'd use manual mode, high shutter (1/500 or faster), and spot metering. If changing aperture didn't produce enough light, I'd raise ISO.

Manual mode doesn't always work for me when there isn't a lot of time to focus because I don't see the sharpness well enough.  But using Aperture-priority or Shutter-priority with AF ought to work OK if I get the other parameters right!

Thank you for your suggestions.  You explain it very clearly, easy to understand.

All the Best,

Susan

-- hide signature --

GreenMountainGirl

 GreenMountainGirl's gear list:GreenMountainGirl's gear list
Nikon D7000 Nikon AF-S DX Nikkor 18-105mm f/3.5-5.6G ED VR Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 55-300mm f/4.5-5.6G ED VR Sigma 150mm F2.8 EX DG Macro HSM +2 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads