Am I thinking along the right lines? ISO/Aperture

[Iris]

Hi,

Can you settle a discussion for me? It's not a complicated one but I am just starting out so I'd like to know if i was thinking along the right lines or if I'm way out:

I was having a chat with a friend yesterday about his holiday, so I asked if he'd got any good shots and he said he'd set his aperture narrow so his shots were pretty grainy which hadn't been obvious on the camera screen at the time. Now, to me this would suggest he'd set his aperture too narrow and has left the ISO on Automatic and it's been too high. He says it's because he hand-held the camera. To me, if his aperture was set too narrow for the circumstances resulting in his shutter speed being too slow his shots would be blurry not grainy. Am I right or way off the mark?

He has the same camera as I do, the Canon 500D and when using Aperture mode I keep a check on shutter speed and ISO too, if the shutter speed drops below 1/60 and the ISO goes up above 400 or 800 (depending on conditions) then I change the f stop down gradually until I get a better combination (1/60 seems to be the slowest speed I can hand hold at and not get blurry shots)

Any feedback or opinions would be hugely appreciated, it's taking me a long time to get my head around the technical details

 

[aeronic]

grainy = high iso
blurry = hand held and too slow shutter

In simple terms.

 

[Iris]

grainy = high iso
blurry = hand held and too slow shutter

In simple terms.

Yeah I thought so, he still argued I was wrong. I know it sounds daft, but because I'm new to all this I feel like everyone else knows more than I do and didn't feel suitably qualified to put him right

Thanks

 

[SpikeK6]

As above.

Also think along the lines of your shutter speed needs to be the same or higher as the focal length.
If you are shooting at 100mm then your shutter speed needs to be 1/100 or above so set the apperture and ISO to suit.

All three are relevent to each other.

I always shoot raw so i can make the most of PP and also shoot manual most of the time so this allows me to get everything right in camera first.

Best thing to do to get used to your camera and what does what is to go out and mark down the settings and adjust either way and see what results oyu get then go from there.

spike

 

[Iris]

As above.

Also think along the lines of your shutter speed needs to be the same or higher as the focal length.
If you are shooting at 100mm then your shutter speed needs to be 1/100 or above so set the apperture and ISO to suit.

All three are relevent to each other.

I always shoot raw so i can make the most of PP and also shoot manual most of the time so this allows me to get everything right in camera first.

Best thing to do to get used to your camera and what does what is to go out and mark down the settings and adjust either way and see what results oyu get then go from there.

spike

That makes sense - I was using the 1/60 with my 50mm lens. I have a computer full of rubbish photos where I just wanted to see what happened if I adjusted something

 

[HoppyUK]

Hi,

Can you settle a discussion for me? It's not a complicated one but I am just starting out so I'd like to know if i was thinking along the right lines or if I'm way out:

I was having a chat with a friend yesterday about his holiday, so I asked if he'd got any good shots and he said he'd set his aperture narrow so his shots were pretty grainy which hadn't been obvious on the camera screen at the time. Now, to me this would suggest he'd set his aperture too narrow and has left the ISO on Automatic and it's been too high. He says it's because he hand-held the camera. To me, if his aperture was set too narrow for the circumstances resulting in his shutter speed being too slow his shots would be blurry not grainy. Am I right or way off the mark?

He has the same camera as I do, the Canon 500D and when using Aperture mode I keep a check on shutter speed and ISO too, if the shutter speed drops below 1/60 and the ISO goes up above 400 or 800 (depending on conditions) then I change the f stop down gradually until I get a better combination (1/60 seems to be the slowest speed I can hand hold at and not get blurry shots)

Any feedback or opinions would be hugely appreciated, it's taking me a long time to get my head around the technical details

Without seeing the pictures is hard to say, but your theory is sound. Either way, grain (noise) and a high f/number are unrelated. Noise is created at high ISO, but also under-exposure promotes it a lot, which is another possible side effect of choosing a too high f/number.

Your shutter speed of 1/60sec max with a 50mm lens is in line with the hand-holding rule, which is actually effective focal length and shutter speed, ie actual focal length x crop factor, so on your Canon 50 x 1.6 = 1/80sec, but a lot depends on individual circumstances.

 

[alexmonkeychops]

Perhaps you should set the ISO manual so it doesn't auto adjust (assuming it is on auto iso)

Then you can experiement with different aperture without ISO going up too high to make the shots grainy.

 

[kicsrepins]

This thread has also helped me, thanks guys