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Shutter Speeds..

Started by jamieL, August 31, 2006, 14:24:29 PM

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jamieL

So Ive just gotten my lovely new Casio Exilm EX-Z120 (got it for Ã,£100 from Casio inc 512mb SD card!)

Anyway, I had a play with the shutter speeds earlier and tried it out with a speed of about 3 seconds I think. Problem was, the photo just came out nearly completely white. How do I make adjustments for this?

Im new to photography so just trying to learn the basics. Oh, and what does different ISO numbers mean? And which should I use in which situations?

Cheers!

brummie


jamieL

Cheers Brummie! That was great and very informative :) Problem with my camera is it only has two aperature values. 2.8 and 4.0 Ill just have to use the 2.8 for high shutter speeds and 4.0 for low :)

PuNk

ISO determines how light sensitive the the camera is, if its day time and you want a long exposure you want a low ISO (80 maybe?) that way it doesnt matter that the shutter is letting a lot of light in, because the sensor is less sensitive.

Night exposures however you probably want to let as much light in as possible.

ALSO: long exposures need a tripod, or something to put the cam on, theyre impossible in your hands.

also worth noting, high isos may result in noise in your picture, but a program called neatimage (shareware) is very good for removing that!

brummie

Quote from: jamieLCheers Brummie! That was great and very informative :) Problem with my camera is it only has two aperature values. 2.8 and 4.0 Ill just have to use the 2.8 for high shutter speeds and 4.0 for low :)

It is good. Explains quite alot in very little time :D

funkychicken9000

Does your casio do shutter priority?  Mine (Z750) has a mode where you choose the shutter speed, and it sorts the aperture and all the rest to make sure you still get out reasonably exposed photos.  Might be a mode called "S".

jamieL

Funky: Yeah, it has Shutter Priority, Aperature Priority, Manual, Easy Rec Mode (dont know what that is..) Best Shot, snapshot, Movie and voice recording.

M3ta7h3ad

Quote from: PuNkISO determines how light sensitive the the camera is, if its day time and you want a long exposure you want a low ISO (80 maybe?) that way it doesnt matter that the shutter is letting a lot of light in, because the sensor is less sensitive.

Night exposures however you probably want to let as much light in as possible.

ALSO: long exposures need a tripod, or something to put the cam on, theyre impossible in your hands.

also worth noting, high isos may result in noise in your picture, but a program called neatimage (shareware) is very good for removing that!

Ive managed 2 second exposures shake free, but it took like 15 shakey ones to get to that stage :D lol.

jamieL

Hmm.. So at first I thought the only aperatures I could do is 2.8 or 4.0... And Ive just found out that the more I zoom in with the 3x optical zoom, the higher the aperature goes up! :S

Russell

Thats right, although I aint sure why exactly, probably something to do with the distance from the lens to the sensor and stuff (am sure someone will come along soon and clear it all up)

But its why you see on lens specs a range of apetrure sizes, take my 18-55mm lens I got with my D50, it has a apeture range of f3.5-5.6.  Which means when the lense is at 18mm the apeture has a max size of 3.5 but when its at 55mm the max apeture is 5.6, it cant have a higher apeture than that value.

Going on a some specs of your camera your lens will do between f2.8-5.1.  So when your zoomed all the way out youll be able to have an apeture of 2.8 and all the way in youll be able to have an apeture of 5.1.

terry

Ive got the same camera and funny enough was playing with 1-3 second captures with the wind and the trees - see this picture:



What I did to reduce the the over exposure was to set ISO to 50, reduce the saturation and contrast to -2, set F to 4.0.  Oh and definitely use a tripod!

Serious

Quote from: jamieLCheers Brummie! That was great and very informative :) Problem with my camera is it only has two aperature values. 2.8 and 4.0 Ill just have to use the 2.8 for high shutter speeds and 4.0 for low :)

If thats the limit then some cameras can use neutral density filters that cut down the amount of light entering but without altering the colour balance so the end image looks the same but darker. These are often used by astronomers observing the sun with cameras.

For use without tripods take the focal length as the minimum shutter speed so a 500mm lens should get 1/500th of a second or use a tripod. For shorter lengths than 100mm I use 1/30th as a minimum to get a reasonable chance of shake free results.