Blurring / Shaking + ISO's

[ratcliffe]

I'm not sure if this is the right bit of the forum, but here goes nothing!

I use an old Canon Ixus v2 to learn some of the basics, and I am basically a "holiday snapper" sort of cameraman at the moment. I am having a problem in that my camera always gives me the "shake" icon when I try and take a photo without the flash on underwater.
If I turn the flash on, it doesn't seem to be a problem.

Is there a setting to help with this ?


In addition, when I was on holiday I tried playing with the ISO settings. I changed it from Automatic to ISO 400 to see what would happen, as I was trying to get some closeup shots. All that happenned was that the photos became much more grainy, rather than better which is was I was expecting
I cannot do Macro for close up as the camera cannot do this, so any advice for settings would be a big help.

I can post some examples if it would help...

[Cussy]

Derek,
The camera is defaulting to a slow shutter speed, hence the shake symbol, then when you turn the flash on it is selecting (probably) 1/60th second, which wont cause shake.

The images wont look that different at the higher ISO as the camera is then also changing the aperture/shutter speed ratio. On my old compact i would always shoot on aperture priority as the camera seemed to rather change the A than shutter speed. So your shots are different, just that you might not see the difference.

Cameras are optimised for bright sunny days, so underwater they go all thick and stupid on you, even my D80 at times. This is why I shoot totally on manual nowadays.

What I would say for close-up is low ISO and higher shutter speed, let the flash do the work for you (if it can). Higher ISO for wide-angle as you are more reliant on natural light.
HTH,
Rob

[ratcliffe]

Ah thanks Rob, that makes a lot more sense than anything that the manual could tell me

Low ISO - is that the lower the number, or is it the other way around ? (I haven't got my camera or book to hand to check that)

Thanks for the help.

[Cussy]

Originally Posted by ratcliffe

Low ISO - is that the lower the number, or is it the other way around ? (I haven't got my camera or book to hand to check that)

I meant low number, so ISO100 (you then get less noise)

How you can think about it is the camera has three variables; shutter speed, aperture and ISO (sensitivity - some call it ASA, but it's the same). So if you have a perfect exposure and adjust one, you have to adjust either or both of the others. If you think of the usual speeds (1/30, 1/60 etc) as you change up by 1 stop, you have to adjust one of the others down by 1 stop [this was a lot easier with film as each option was a stop, now in the digital world we have all sorts of divisions between each setting).
HTH,
Rob

[ratcliffe]

Thanks again, I will have a play with the settings at home, and then try it out the next time I dive.

[Seatreker]

The ISO is the "speed" of the film that you are using, in other words the "Film" or "Sensor" is given a "sensitivity" rating........... the lower the number, say....ISO 100.....is not very sensitive and needs Either more time OR a larger aperture (lens opening) = lower "F" stop.
So when you have low light conditions.............you would need either, or a combination of.........
High ISO speed.........
Wide open aperture = low "F" stop number
Slow shutter speed................

High ISO = usually means more noise (digital) more grain with film.
Wide open aperture = usually less depth of field but that depends on the camera to subject distance............
Slow shutter speed = subject liable to show signs of movement...........tripod required in some circumstances...............
Everything in life is a trade off, what you gain here you will loose there.......

I hope that is of some use to you.

Try this link, i have found it useful in the past.....................
Dave.