Doing dumb things

[Overread]

worst I find is ISO and how it won't change when you change modes - I really can't understand why it remains fixed over all the modes - its not like aperture or shutter speed remain fixed so why ISO?

 

[table1349]

worst I find is ISO and how it won't change when you change modes - I really can't understand why it remains fixed over all the modes - its not like aperture or shutter speed remain fixed so why ISO?

It's that fixed ISO that dictates the changes in the aperture and or shutter speed in the different modes. There has to be one constant for the other things to relate to.

 

[Overread]

huh? now you lost me there - aperture and shutter speed (as far as I know) are fixed values with aperture being a fixed diameter of the aperture blades and shutter speed being - well the speed of the shutter.
I can't see how having a different ISO would affect the settings in different shooting modes. Of course you will get a different result with a different ISO, but you have already changed modes to get different settings (quicker) so the end result is already changed

 

[table1349]

huh? now you lost me there - aperture and shutter speed (as far as I know) are fixed values with aperture being a fixed diameter of the aperture blades and shutter speed being - well the speed of the shutter.
I can't see how having a different ISO would affect the settings in different shooting modes. Of course you will get a different result with a different ISO, but you have already changed modes to get different settings (quicker) so the end result is already changed

We may be thinking on different plains here. When you say change modes I only think of Manual, Aperture Value and Time Value or shutter speed. I have never used anything else. So when you change modes, the ISO remains at what it is set. Any changes to either aperture or shutter changes can make changes to the other but not the ISO. It is the constant that the two are always relating to. You have to manually change the ISO separate from the mode.

If you are talking about things like portrait mode, landscape mode, sport mode, etc. then I have no idea as I have never used them. I do believe that at least with Canon if you change to the full Auto mode it will change all three values. At least from what I have heard.

 

[Dubious Drewski]

my camera works with out batteries, but such is life.

What?! But what about the meter? How do you see your histogram? How do you view each picture after taking it if you don't have batteries?!

 

[saycheese76]

I have a wood burning camera.

 

[Overread]

hmm I think an example might clear the air - and yes by modes I was refering to same ones that you were (though in my case shutter priority, aperture priority and full manual).

Lets say I am shooting a landscape shot with a medium telephoto or a zoom lens like a 70-200mm at the 70mm end. So its early morning and I am shooting in manual mode from a tripod and my settings are something like:

f16, ISO 100, shutter speed something slow for the low light.

However I set up shutter speed to something like
f2.8, shutter speed 1/100 and would like to set ISO to 800.

This is so if something flies into my view that I can capture with a shot I have a decent chance of getting the grabshot. However because ISO is fixed and I am shooting the landscape I have to not only shift the mode wheel, but also change the ISO from 100 to 800 to get a shot that is not totally black - it takes longer and might cost me the shot.

So far I still find it hard to understand your explination and myself the only reason I can think of for ISO to be fixed is that its a hang on from the film days when you could not change you film ISO - thus when cameras went digital a fixed ISO across the modes would have been easier for people to adapt to as it would have been more familiar. Now that things have moved on its somehow stayed in the works as a fixed setting. That is at least the only way I have come to understand it -- though I might be missing something important out

 

[table1349]

hmm I think an example might clear the air - and yes by modes I was refering to same ones that you were (though in my case shutter priority, aperture priority and full manual).

Lets say I am shooting a landscape shot with a medium telephoto or a zoom lens like a 70-200mm at the 70mm end. So its early morning and I am shooting in manual mode from a tripod and my settings are something like:

f16, ISO 100, shutter speed something slow for the low light.

However I set up shutter speed to something like
f2.8, shutter speed 1/100 and would like to set ISO to 800.

This is so if something flies into my view that I can capture with a shot I have a decent chance of getting the grabshot. However because ISO is fixed and I am shooting the landscape I have to not only shift the mode wheel, but also change the ISO from 100 to 800 to get a shot that is not totally black - it takes longer and might cost me the shot.

So far I still find it hard to understand your explination and myself the only reason I can think of for ISO to be fixed is that its a hang on from the film days when you could not change you film ISO - thus when cameras went digital a fixed ISO across the modes would have been easier for people to adapt to as it would have been more familiar. Now that things have moved on its somehow stayed in the works as a fixed setting. That is at least the only way I have come to understand it -- though I might be missing something important out

Ok, but by using your example my question would be, how is the camera to know what ISO to pick? It doesn't see the fly in. It doesn't recognize what it is you are trying to do. It's doesn't know a landscape from a flying bird to a wedding portrait and it doesn't know all of a sudden that you would like that bird that just flew into the viewfinder to be properly exposed. It is metering off of what you have told it to and that is all. The photographer does understand the differences and the photographer must make the choice of what settings to use to adjust for the changes.

In manual you pick all three settings and the meter gives you a good idea if you are right.

In AV you pick the ISO and the aperture and the shutter speed is adjusted by the camera based on the metering,

In TV you pick the ISO and the shutter speed and the aperture is adjusted by the camera based on the metering.

Full auto mode is the only mode that does what you want, but then the camera is still making a guess at the settings based on the metering mode choosen and the overall area being viewed by the camera.

Perhaps what you are looking for is a mode where you would set the aperture and shutter speed and the camera would then choose the ISO based on the metering.

I see no other way that it could work as the camera has to have direction from the photographer.