High ISO

[Aneela]

Guys,

Hope your well and looking forward to the jubliee weekend, ive just recently started to explore the world of photography and its just not a click of button is it.

I was just wondering if anyone can help me.

I have just recently bought a canon mkii 5d and ive messing around with ISO etc and it seems that at an ISO of 1600 above i start to get some noise and as i move up i get more and more.

Just wondering if there is an optimum level to shoot at using the correct aperture and shutter, is there a rule of thumb.

I just want to increase the sharpness, which is the depth of field, which i understand is aperture controlled and reduce the noise.

Just wondering if any of you guys are willing to help point me in the right direction

[LaPistola]

Well it does depend on the camera but a 5D is very good and reports good quality at higher ISO's. With my 50D it's given that anything above 800 will give noticeable noise. Really you only need to shoot at 1600 when there is little or no light, you have no tripod and can't use flash.

To get better quality shots you need to slow your shutter, use wider apertures and use a tripod. This may mean manual shooting mode.

[jet_kit]

Hi Aneela,
I'm not sure I can wholly endorse La Pistola's comments.
Quality does not come from long exposures and wide apertures.
The first thing you need to understand is the triangle of exposure. The objective is to get the right amount of light on the sensor to give you the correct exposure. This is done by juggling the shutter speed with the aperture setting. Higher speeds will allow less light in that lower speeds and this is offset by using larger or smaller apertures. This is further adjusted by use of the ISO settings; This effectively adjusts the sensitivity of the sensor and lower numbers need longer shutter speeds or larger apertures.
The higher the ISO setting the greater the chance of noise interfering with your images, so you should try to use as low a setting as your type of photography will allow.
A very basic rule of thumb might be: Outdoors, bright sunshine, fairly static subject. ISO 200 with a shutter speed of 1/200 @ f11 Check out the histogram and adjust any one of these as necessary to get a good spread over the graph.
The next thing to consider is the optical performance characteristics of your lens. Every lens has a 'sweet spot', that aperture setting where the lens will produce the sharpest image. It will not be at either end of the scale, so try to avoid the widest couple of apertures and the smallest two - the rest should be fine.
Now, your shutter speed. This is dictated by your subject. If you're shooting racing cars or low-flying aircraft, you're going to need a fast shutter speed. Perhaps something around 1/500 and adjust your aperture to suit.
However, if you find the light is bad but you still need a fast shutter speed and you haven't got a large enough aperture, you will have to increase your ISO setting to compensate.
OK. So, here are the rules. ISO 400 lets in half as much light as ISO 200 and ISO 100 twice as much. 1/500 lets in half as much as 1/250 and 1/125 twice as much.
When it comes to apertures it starts to get a bit tricky. The theoretical widest possible aperture is f1, f1.4 lets in half as much light as that and f2 a quarter as much. These are referred to as 'Stops' and they run (rather bizarrely) f1.4, f2, f2.8, f4, f5.6, f8, f11, f16, f22, f32. Each of these steps means half as much light as the one before and needs a corresponding increase in shutter speed (or ISO) to compensate.
I hope this has made it a little clearer. It takes a little while to get your head round it, but it will be worth the effort in future as this is the basic photographic principals that it's all built on. Feel free to continue to post any questions you may have, even if it's just to say that all this makes no sense. We're here to help.

[LaPistola]

My point Jet is in low light you use an higher ISO but the higher the ISO the more noise you get in your photo and by sharper images the poster meant (I assume) less noise, the OP also posted in the beginners section so I thought a simple answer was required. Also the OP is using a 5D which reports low noise at ISO's of 1600 so the OP must be shooting in some really low light situations.

So to try clarify what I meant. To be able to shoot at lower ISO's (less chance of noise and better quality of images) in low light you need to get light to your sensor for longer which is achieved by slowing your shutter down, widening your aperture will let more light in so helping keep the shutter speeds down.

I mean this as a question and not in defense or obnoxious but are there any situations where someone with a higher spec camera would be shooting moving subjects, flash not permitted and in a low enough light that requires more than say 800 ISO?

[mondmagu]

Chris is spot on,the triangle of shutter speed, aperture and iso is important to understand.When possible use a low iso setting because increasing this will introduce noise into your shots.
I personally adjust aperture or shutter speed to get the shots I want,only upping the iso as a last resort,but also the lens quality has a lot to do with this as well.
If you get the opportunity, join a club and do a basic course in photography to get a grip of the fundamentals.

Des

[jet_kit]

Originally Posted by LaPistola

My point Jet is in low light you use an higher ISO but the higher the ISO the more noise you get in your photo and by sharper images the poster meant (I assume) less noise, the OP also posted in the beginners section so I thought a simple answer was required. Also the OP is using a 5D which reports low noise at ISO's of 1600 so the OP must be shooting in some really low light situations.

So to try clarify what I meant. To be able to shoot at lower ISO's (less chance of noise and better quality of images) in low light you need to get light to your sensor for longer which is achieved by slowing your shutter down, widening your aperture will let more light in so helping keep the shutter speeds down.

I mean this as a question and not in defense or obnoxious but are there any situations where someone with a higher spec camera would be shooting moving subjects, flash not permitted and in a low enough light that requires more than say 800 ISO?

Hi LaPistola,
I understand completely what you trying to say. My concern was that to a beginner (and let's not forget that's the forum we're in) it might be interpreted exactly as you wrote it: Low shutter speeds and wide apertures = High quality, and that isn't necessarily the case.
I know my response was long-winded, but I felt it was important to get the message across regarding interactivity of the various controls at our disposal.
The answer to your question is simply; Yes, possibly. This is why we have such control - to enable us to capture whatever we want under all manner of conditions.

[greenwing]

Originally Posted by LaPistola

I mean this as a question and not in defense or obnoxious but are there any situations where someone with a higher spec camera would be shooting moving subjects, flash not permitted and in a low enough light that requires more than say 800 ISO?

Most certainly. this guy is one of many that I see asking for more resolution and more ISO capability. He regularly shoots the high-end Nikons (D3s, D700, D800) at 1600 ISO and more.

Chris

[cosmicma]

with a 5d mk2 iso 3200 can give good results as long as you expose to the right ( as people say )
in other words make sure your exposure is a little on the bright side rather than being under exposed
high iso and under exposure will more or less always show noise when you try to correct the exposure in whatever software of choice you use
shooting in RAW will give more flexibility that shooting in JPG when it comes to editing your photo's

another thing to consider is if your looking at your photo's at 100% ( pixel peeping ) you will generally see noise even at 1600 iso in low light conditions but when printed the noise will be virtually unnoticeable

i find ( in my case ) a lot of noise problems with the 5d mk2 at higher iso is down to under exposure and trying to recover the detail within an editor
if the exposure is spot on noise even at iso 3200 is not enough to be concerned about