how much does light affect ISO?

[themadness]

i took some indoor shots last night and they were very dark and grainy. i contacted canon to get some info to be sure it wasnt a mechanical issue with my camera(ps sx 120). he said ISO should be low to prevent grain (200 or less) which i understand. i feel like the room was bright enough, so why were my shots so dark and grainy?

btw i was in manual. i am trying to learn........

[mrdale]

If you would post a photo with EXIF info we can probably ascertain the problem.

[RichardTaylor]

Don't believe your eyes when it comes to light levels. Believe your camera's exposure meter (up to a point) and especially the histogram.

Without seeing your photographs. I believe they were dark and grainy because they were under exposed.

How did the histogram look?

Could you please post an example with exif info.

[themadness]

i already junked the pics b/c i hated them....plus they were nudes. my camera doesnt have a histogram. i was using 4 sources of light, all standard incandescent light bulbs. i tried using flash and that gave me crap glares. adjusting the other controls didnt change anything in the shots much either, so now i think i may be retarded (photographically challenged)......

[RichardTaylor]

Reshoot a "safe" subject in similar conditions and post the pics along with exif info.

Check the histogram in an editing program.

Do not be afraid to bump your ISO up if need be.

[themadness]

these were the settings i had........ i remember them pretty well and they are still stored in my cam from what i shot last night.

ISO----200
f2.8
0"4

the lights were standard bulbs from lamps in the room with no shades so the light was bright and harsh(rookie!). there were 3 lamps triangulated abut 15 feet apart with the subject in the middle. i also used the over head light, so the room was plenty light. i also tried the pop up flash and external add on flash the mounts to the tripod socket. it was VERY ghetto lighting.

i know this is vague as humanly possible..........

[dakwegmo]

Are you using standard room lamps? If so, refer back to Richard's comments about not believing your eyes. Check your camera's meter and it will give you a good indication of whether the shot was properly exposed. In a high contrast scene if you properly expose for the highlights, you can still pick up noise/grain in the shadow areas.

[themadness]

yes they were standard room lamps. the noise was pretty consistent through out the pics, even in the highlight areas. i tried correcting it in photoshop but was unsuccessful, i guess due to the severity of the pixelation. i was getting better quality photos from my 7mp kodak bridge camera!

[dcclark]

Originally Posted by themadness

yes they were standard room lamps. the noise was pretty consistent through out the pics, even in the highlight areas. i tried correcting it in photoshop but was unsuccessful, i guess due to the severity of the pixelation. i was getting better quality photos from my 7mp kodak bridge camera!

Standard room lamps are DIM. Human eyes, on the other hand, are AMAZING for their ability to function so well in dim light. Your camera, sadly, is not that amazing (and no camera is good enough to be amazing in ultra-dim light).

In other words, even 4 incandescent lamps will not light a room well enough to get a good exposure. Your camera had to increase the ISO to try and keep your shutter speed reasonable, and the result was BOTH a slow shutter speed, and lots of grain from the high ISO.

It takes a lot of experience to recognize what "dim" and "bright" light really is. You have to know your equipment, and experience lots of lighting situations.

[themadness]

the camera was a budget decision, i am satisfied w/ quality of the images outdoors. it also has pretty decent quality indoors in auto mode. manually and priority modes are a bit lacking tho. my next step may be to go to a nikon bridge cam. my needs just dont justify a high dslr, but i do have expectations that i want met. my knowledge of manual settings is very limited. how talented do you have to be to pull of soem the incredible images i see on this forum? am i expecting too much?