Auto ISO

merv

merv

Messages
1,118
Name
Mervyn
Edit My Images
Yes
Hope I can explain this OK.
When on auto ISO for planes etc I set the camera to Shutter Priority. I understand what happens then is as light is needed the lens opens up first to its maximum aperture THEN if still more light is needed the ISO is bumped up. Correct?
NOW
I was reading today that it is better to set the camera to Manual mode so that you can select shutter speed and aperture separately eg if you want depth of field. If I select a higher aperture value, say f8 for depth of field on an f2.8 lens, will the ISO start to be bumped up sooner ie as soon as f8 is reached?
Hope this is clear
merv:bang:
 
merv said:
Hope I can explain this OK.
When on auto ISO for planes etc I set the camera to Shutter Priority. I understand what happens then is as light is needed the lens opens up first to its maximum aperture THEN if still more light is needed the ISO is bumped up. Correct?
NOW
I was reading today that it is better to set the camera to Manual mode so that you can select shutter speed and aperture separately eg if you want depth of field. If I select a higher aperture value, say f8 for depth of field on an f2.8 lens, will the ISO start to be bumped up sooner ie as soon as f8 is reached?
Hope this is clear
merv:bang:
Click to expand...

I think you have it right. You're certainly right for 'S' mode.

In manual, you simply dial in the sutter speed and aperture and they're then fixed at those values no matter what, (F/8 is not reached as such). The camera then uses iso to get what it meters as a correct exposure. You can use exposure compensation to adjust this as well. If the camera runs out of iso, it either under exposes or over exposes. The aperture and shutter speed never change.

Examples:

Manual mode with auto iso. Lets assume the scene/light doesn't change.

You select F/4 and 1/250, the camera might choose iso 400.

If you now dial in F/4 and 1/125, the camera will now choose iso 200

If you now dial in F/5.6 and 1/125 the camera will bump iso back up to 400.

If you now dial in F/5.6 and 1/125 and also -1 ev, the camera will select iso 200.

You get the picture. :)
 
Last edited:
I shoot Manual Mode with auto-ISO 90% of the time. It's great for action but I shoot most things with it now and works as Graham has explained so well above.

Another thing in this mode is to consider using spot metering (thinking of planes against skies here).

The easyISO mode on the D800 (also on D7000 & D4?) is a killer too.
 
That's brilliantly explained Graham - you should be a teacher. I think I was in tune with most of that but hadn't thought of using the exposure compensation facility.
If I use shutter priority only the aperture will open up to f2.8 on the lenses I use. Even on a plane it is possible to get part of it in focus and due to the low depth of field the wing tip can be out of focus. Fine if thats what you want. I'm really pleased to understand this now
Thanks Graham
merv:bang:
 
gad-westy said:
In manual, you simply dial in the sutter speed and aperture and they're then fixed at those values no matter what, (F/8 is not reached as such). The camera then uses iso to get what it meters as a correct exposure. You can use exposure compensation to adjust this as well.
Click to expand...

You cant use exposure compensation on some cameras when in manual mode (because it defeats the object of being in manual) I think they forgot auto iso means the camera is selecting the exposure .... I know my canon bodies dont allow it..
 
I set the maximum to 12800 on my D3s and never notice any adverse noise
merv
 
gramps said:
Do you guys using auto iso set a maximum? I've been using a max of 1250 but it's a random figure.
Click to expand...

With a D3s Gramps, you can ramp up the max ISO quite a bit from there. The D3s is very forgiving at stupidly high ISOs.

And even if there is a bit of noise, I'd rather have an in-focus shot with some noise than a blurred shot without.
 
chromatin64 said:
And even if there is a bit of noise, I'd rather have an in-focus shot with some noise than a blurred shot without.
Click to expand...

Thanks, I was trying shutter mode with auto iso yesterday and was quite pleased with the results until I got inside a church when it all went pear-shaped ... will be interesting to try again and see the results with a higher iso.
 
KIPAX said:
You cant use exposure compensation on some cameras when in manual mode (because it defeats the object of being in manual) I think they forgot auto iso means the camera is selecting the exposure .... I know my canon bodies dont allow it..
Click to expand...

The op is using a D3s, and I really disagree that it defeats the point in being in manual. It adds a new exposure mode, you can still use full manual or you can have what might be described as shutter and aperture priority mode. It's pretty damn useful at times.
 
merv said:
That's brilliantly explained Graham - you should be a teacher. I think I was in tune with most of that but hadn't thought of using the exposure compensation facility.
If I use shutter priority only the aperture will open up to f2.8 on the lenses I use. Even on a plane it is possible to get part of it in focus and due to the low depth of field the wing tip can be out of focus. Fine if thats what you want. I'm really pleased to understand this now
Thanks Graham
merv:bang:
Click to expand...

No problemo. I discovered this by 'feature' by accident and now think it's brilliant. Not for 100% of the time maybe as sometimes you still want to lock exposure but I have a quick menu item set up to turn auto iso on off rapidly so it's there when I need it.
 
chphotos said:
I set the maximum to 6400 on my D700.
Click to expand...

Ditto. Would be a stop higher on a D3s. The D700 copes nicely at 6400 but it's still possible to produce horribly noisy images without careful exposure. I watch the histogram like a hawk once iso gets at this sort of level.
 
gad-westy said:
The op is using a D3s,
Click to expand...

I know.. but the advice was given in general to everyone so I was pointing out it wouldnt work for everyone..

gad-westy said:
and I really disagree that it defeats the point in being in manual.
Click to expand...

How? Manual means you control the exposure.. auto iso means the camera cotrols the exposure.. how can you disagree facts?


gad-westy said:
It adds a new exposure mode, you can still use full manual or you can have what might be described as shutter and aperture priority mode. It's pretty damn useful at times.
Click to expand...

I didnt say it wasnt useful did i ? and i use it myself so wasnt exactly knocking it was I? I know exactly what it does thasnk you...., but it still defeats the whole concept of manual exposure if the camera takes over the exposure..
 
KIPAX said:
You cant use exposure compensation on some cameras when in manual mode (because it defeats the object of being in manual) I think they forgot auto iso means the camera is selecting the exposure .... I know my canon bodies dont allow it..
Click to expand...

You can with Nikon Tony, it is useful for birds in flight when you want to quickly add a +EV.
 
Martyn... said:
You can with Nikon Tony, it is useful for birds in flight when you want to quickly add a +EV.
Click to expand...

I know and I know its useful :)

I have to reproduce it on a canon.. put into Tv (shutter priority) mode... set maximim aperture to 2.8 in the cfn meu system.. ..then set my shutter speed.. so thats set.. the aperture cant go over 2.8 so there both solid like manual.. then auto iso and exposure comp works because i am in tv mode :)


i have to do all that to get the same thing you get manual+auto iso on nikon.. so i do know its useful and i do use the same..

either way its still not manual though :)
 
KIPAX said:
I know.. but the advice was given in general to everyone so I was pointing out it wouldnt work for everyone..



How? Manual means you control the exposure.. auto iso means the camera cotrols the exposure.. how can you disagree facts?




I didnt say it wasnt useful did i ? and i use it myself so wasnt exactly knocking it was I? I know exactly what it does thasnk you...., but it still defeats the whole concept of manual exposure if the camera takes over the exposure..
Click to expand...

Wow, not sure what I said to upset you so much. I don't want to get into a argument over semantics, I was merely trying to answer the OP.

As far as I'm concerned there is an 'M' mode on a Nikon camera. It either allows you full manual control of exposure or you can let the camera juggle iso to give auto exposure. Whether you want to call that manual mode or something else is up to. I really don't care.
 
Sorry can we just be clear.. I ahvent knocked manual+auto iso... i havent said its not usful either.... use it myself!!!

I said its NOT manual because the camera takes over the exposure.. thus your not in aperture priotity.. your not in shutter priority.. your not in manual.. your in ISO priority..its a semi auto mode and it gives the camera control over exposure..


thank you :)
 
Last edited:
KIPAX said:
Sorry can we just be clear.. I ahvent knocked manual+auto iso... i havent said its not usful either.... I sue it myself!!!

I said its NOT manual because the camera takes over the exposure.. thus your not in aperture priotity.. your not in shutter priority.. your not in manual.. your in ISO priority..its a semi auto mode and it gives the camera control over exposure..


thank you :)
Click to expand...

It's the exact opposite of iso priority in that iso is the only thing that isn't prioritised. And as I say, you might not call it manual but I access this mode by selecting manual on my camera.
 
Last edited:
gad-westy said:
It's the exact opposite of iso priority in that iso is the only thing that isn't prioritised.
Click to expand...


oops I meant one thing and wrote the other.... ironic really :)


gad-westy said:
And as I say, you might not call it manual but I access this mode by selecting manual on my camera.
Click to expand...

Now your putting words into my mouth.. I said it defeats the point of manual.... its a fact.. if you are letting the camera choose iso then you are not in manual...just because the pretty little dial on your camera says your in manual dont be fooled.. your not..


seriosuly.. dont believe everything your camera tells you :)


ooer i like that line.. gonna use it again.
 
Morning Tony...............:wave:
 
KIPAX said:
oops I meant one thing and wrote the other.... ironic really :)




Now your putting words into my mouth.. I said it defeats the point of manual.... its a fact.. if you are letting the camera choose iso then you are not in manual...just because the pretty little dial on your camera says your in manual dont be fooled.. your not..


seriosuly.. dont believe everything your camera tells you :)


ooer i like that line.. gonna use it again.
Click to expand...

Tony,

I really don't understand the point you're trying to make. Nobody, myself included has suggested that this option gives you full manual exposure. I've never said it and never thought it. In fact I went to great lengths to explain exactly how it worked in direct response to the OP's exact question and given his reply it sounds like it was helpful. I was very careful to not leave anything open to interpretation. The only reason I refer to it as manual is because that is the program that has to be selected on the camera to operate it in this manner. I could have tried to make up some some sort of other terminology for it but that would be totally confusing to anybody reading this, particularly the OP because ultimately they're going to have to select manual mode to do this.

The issue here seems to be that there is a difference between what would generically be called manual exposure and what this mode is actually doing. I can't help that I'm afraid, it is what it is.

As a side note, I found it pretty insulting when I have taken quite a bit of time to answer a query in the clearest manner possible and somebody comes along with little one liners pulling it apart in the most pedantic manner possible. You might think I'm 'wrong' but I'm pretty confident that everything I've said on this thread is correct and I'll stand by it.

And I think that is my last post on this thread.:)
 
Last edited:
gad-westy said:
As a side note, I found it pretty insulting when I have taken quite a bit of time to answer
Click to expand...

OMG what colour blouse are you wearing this morning?

I was trying to add to the information.. you wrongly took the hump and it went downhill from there..sadly..


gad-westy said:
And I think that is my last post on this thread.:)
Click to expand...

Heard that one before :)
 
or on a 5D2 where it thinks auto ISO in manual or with flash equals to 400. :bang:

i really miss auto-ISO in manual mode, it is the main advantage of shooting digital. such a stupid firmware design decision. :cuckoo::thumbsdown:
 
Last edited:
Need a new mode to sort this one out. AS mode (Aperture AND Shutter priority)
You control the Aperture and Shutter and fix that and the camera changes the ISO to keep the best exposure at the set Aperture and Shutter values.
 
ernesto said:
Need a new mode to sort this one out. AS mode (Aperture AND Shutter priority)
You control the Aperture and Shutter and fix that and the camera changes the ISO to keep the best exposure at the set Aperture and Shutter values.
Click to expand...

Good idea. Since there are two things we're controlling - shutter and aperture - we can call it "Multi Mode", or "M-Mode" for short.

Oh, hang on...
 
Gentlemen if I had known this thread would have caused such controversy with SOME of you, I wouldn't have asked the question in the first place. This meant to be an enjoyable pastime, not the third world war!
Thanks Graham for your initial civil response to my question
merv:'(
 
simonblue said:
For some reason i always set the iso myself,maybe a kickback to the days of film :)
Click to expand...

There are the odd occasions when its a godsend.. I usually forget the options there.. but now and then its saved the day.. people moving between quite bright and dark areas...quickly in and out of dark shadows.. like a big stand at a sports stadium taking up half the pitch with itss shadow.. auto iso comes in real handy
 
KIPAX said:
There are the odd occasions when its a godsend.. I usually forget the options there.. but now and then its saved the day.. people moving between quite bright and dark areas...quickly in and out of dark shadows.. like a big stand at a sports stadium taking up half the pitch with itss shadow.. auto iso comes in real handy
Click to expand...
And shooting under floodlights where the light coverage drops off by a couple of stops in the corners, better to have a "noisy" shot than no shot.
 
basically if your shooting and you require a certain aperture and shutter speed as in sports.. you ahve some leeway with shutter and can change that... but if the change in lighting is extreme and you want a certain aperture and the shutter speed would go outside your range then auto ISO is the one to use... again fast moving sports and auto iso probably better than changing it yourself..
 
Will give it a go,their have been times when i have hit the iso button quickly,as the shutter speed drop,and i still want to use the same apeture :)
 
Now I notice that when I use auto iso the metadata of my images always seems to display the max, i.e. if I have auto iso set to say 1250 max then every photo I take will show the iso as 1250 in the metadata.
Does this mean that the camera is shooting at iso 1250 or is it that it just that it defaults the metadata to the maximum iso?
Or have I got another setting wrong somewhere?
 
You must log in or register to reply here.
Back
Top