ISO speeds..

[laguano]

When using the Manual setting on the G7, i noticed it gets pretty noisy/grainy at 800, is that bad for that rating? it is pretty noticable on the screen. Is it due to the sensor size? thanks in advanced.

 

[DwainDibley]

I'm still learning myself, but from what I understand so far is that the higher the ISO setting, the more sensitive to light your camera's setting is. The trade-off is that it introduces more digital noise, i.e. graininess into the picture.

That graininess is normal, the amount varies from camera to camera. My Digital Rebel is pretty good on noise levels, even on 1600 ISO but it is still noticeable and not as good as lower values.

I think the general opinion is to use as lower ISO as possible where you can, and use the flash or longer exposures (if you have a tripod) rather than iincrease the ISO.

Hope that helps a bit! :thumbup:

 

[fmw]

It is because of the sensor size. However, I would recommend using the lowest ISO rating possible always. I even use a tripod before raising mine above minimum.

 

[laguano]

thanks for the replies, it is mostly because i have no other option but to take pictures in low-light conditions. so i use ISO of 200, but sometimes, i have tricky subjects that need a faster exposure, which requires a higher ISO to get the lighting right, i would use flash. but i think i would buy a hotshoe, any other hotshoes that work besides the speedlite series?

 

[Garbz]

All cameras start getting grainy around there. I try to shoot as little as possible over 320.

 

[ksmattfish]

Sensor size has a lot to do with it, but if you are underexposing at all that will influence it too. From what I've seen Canon cameras have some of the least noise at higher ISOs. If anything their problem is color noise, which is easily fixed by applying a bit of color noise reduction. The noise in my 20D's ISO 1600 shots (properly exposed) is still cleaner than the grain I got with 35mm Fuji NPH 400 film.

I've read that the 1/3 stop ISO ratings between the standard ISO scale (100, 200, 400, etc...) in Canon cameras are software adjustments rather than hardware adjustments, and often produce more noise than sticking with the standard ISO settings. The charts I've seen say ISO 320 is noisier than ISO 400. I haven't done any testing myself, as the old scale works just fine for me.

If I'm shooting hand held I'll take a little extra noise over camera shake blur any day.