Aperture or ISO

D

Duke_Haphazard

Suspended / Banned
Messages
42
Name
James
Edit My Images
No
I'm having trouble deciding on both these two factors, and too be honest I don't 100% percent understand the implications of both.

Can anyone give me more advice on the two and how they work together. For instance, is it better to have your aperture set to let lots of light in, yet having a long shutter time, and low ISO, or is it better to have it the other way around and have a problem with noise/grain on the picture from the high ISO?

Any info about the two will be appreciated.
 
For me it all comes down to how you want your DOF to be..if you want to shoot at a certain f-stop to achieve a certain DOF .. youll have to raise the iso. depends on the situation really. personally ill always try to shoot at a lower f-stop if i can get the results i want, as everytime you up the iso, you introduce more noise..
 
Aperture controls the background blur.

ISO controls the noise (grain).

That is the most simple way to put it. So they aren't really connected.

Yes, if you have a wider aperture you won't need such a high ISO to keep the shutter fast enough, but that's it really.

If you have the aperture set to 3.5 the focal point is going to be quite small, so that might not work for the situation yonu are in. You might want quite a lot in focus. So, you change the aperture to 8.0 and the shutter speed will decrease - then you need to bump up the ISO.

OK, they are connected :P
 
For me the best settings I would recommend for a beginner would be;

Aperture Priority
ISO AUTO to ISO800

That way you can choose how much you want in focus and don't worry about anything else. It's a step away from auto - you get a nice bit of control.
 
:plusone:

this is a good question as i also get mixed up with them both... and what to do more of & less of.. and when to do it.. so i will be keeping a close eye on this thread..

thanks.
 
Last edited:
BarryG said:
Aperture controls the background blur.

ISO controls the noise (grain).

That is the most simple way to put it. So they aren't really connected.

Yes, if you have a wider aperture you won't need such a high ISO to keep the shutter fast enough, but that's it really.

If you have the aperture set to 3.5 the focal point is going to be quite small, so that might not work for the situation yonu are in. You might want quite a lot in focus. So, you change the aperture to 8.0 and the shutter speed will decrease - then you need to bump up the ISO.

OK, they are connected :P
Click to expand...

Aaa! aperture controls how much light enters your camera at any one time, the background blurnis irrelevant if the subject you are focusing on is a long way away. By ( the focal point is going to be quite small) you mean shallow depth of field. It all depends on the situation and the subject you are shooting. Get ur self a bunch of dslr magazines, you'll learn alot from the and figuring out what works for what.
 
lucky_13 said:
Aaa! aperture controls how much light enters your camera at any one time, the background blurnis irrelevant if the subject you are focusing on is a long way away. By ( the focal point is going to be quite small) you mean shallow depth of field. It all depends on the situation and the subject you are shooting. Get ur self a bunch of dslr magazines, you'll learn alot from the and figuring out what works for what.
Click to expand...

Terminology mix up that's all.

My advice is sound for a n00b.
 
Aperture, shutter speed and ISO are the 3 aspects that control exposure. If you adjust one then you must adjust at least one of the others in order to keep the exposure at an acceptable level.

In addition to exposure, each of them control a different aspect of the finished image.

Aperture controls DoF.

Shutter speed controls wether the image is "frozen" or not.

ISO controls how much noise the image contains.

There are other ways of controlling exposure. Filters help but that is a whole topic!

This is a starter for you, there is a lot more to learn but I hope this helps.

Andy
 
This is a daft analogy adapted from someone else's idea... Hope it helps :)

A good exposure is a fixed amount of light being recorded....so imagine a normal sized bucket of paint equals a good exposure.

Three things affect how much light (paint) reach the sensor to effectively empty a whole bucket. (full exposure)

The shutter is how quickly the paint is poured.

The aperture is the size of a funnel being used.

And the ISO increases the paints concentration.

ISO can effectively push the concentration up to say making half a tin of paint equal a full bucket just like a full exposure.

Shutter speed could be quickly throwing the whole bucket, or pouring it slowly.

Aperture could be a huge funnel wide open so the paint falls straight through. or very slim, which takes much longer...and splashes far less (..making a wide DoF for instance)

hmm .. close anyway. :thumbs:
 
Last edited:
I nearly always plan a photo from the aperture first. I'll decide on the subject and what I want to achieve from it. Once decided I'll set the aperture to get the required DOF, secondly decide on the shutter speed I want (eg. whether to blur say a waterfall or freeze the motion altogether) and then adjust the ISO to achieve the exposure I want (whether under, over or exactly on).
Once you get used to it then it will become easier to visualize the outcome you want and make the settings to achieve it. Whether other people use the same method I have no idea, but that method seems to work for me. Of course, that method isn't always the same, depending on what I'm shooting or if I'm in AV or TV which cuts out some of the steps to get the same result.
 
Thanks for the info guys. I'll have a look at some of the guides that have been linked. I'm not a big fan of shooting in auto, I prefer manual. Which is why I'm asking :D
 
Duke_Haphazard said:
Thanks for the info guys. I'll have a look at some of the guides that have been linked. I'm not a big fan of shooting in auto, I prefer manual. Which is why I'm asking :D
Click to expand...

You should read some of my previous rants about wanting to shoot manual for all the wrong reasons.:bang:
ISO is dependant on the amount of light you have, this helps those of us that remember film, ISO 200 or lower in good light, 400 and higher in the winter and indoors (most of this photography wasn't even possible with film).

Then honestly, shoot Aperture priority when you want to control DoF, and shutter priority when you need to control subject movement, obviously when the shot's not possible, tweak the ISO to suit.

Then work out when the camera meter is getting the exposure wrong and work out the best way round it, Manual or Exposure lock, or Exp Comp or spot metering. :)
 
Phil V said:
You should read some of my previous rants about wanting to shoot manual for all the wrong reasons.:bang:
ISO is dependant on the amount of light you have, this helps those of us that remember film, ISO 200 or lower in good light, 400 and higher in the winter and indoors (most of this photography wasn't even possible with film).

Then honestly, shoot Aperture priority when you want to control DoF, and shutter priority when you need to control subject movement, obviously when the shot's not possible, tweak the ISO to suit.

Then work out when the camera meter is getting the exposure wrong and work out the best way round it, Manual or Exposure lock, or Exp Comp or spot metering. :)
Click to expand...

What he said.
 
You must log in or register to reply here.
Back
Top