High ISO

richard plumb

Distinguished Member
took some photos at my son's birthday party yesterday. Some activities were outdoors in the sun, so I had no problem at low ISO at good shutter speeds. But then the games went indoors to a sports hall.

Very low light and I had trouble getting a decent shutter speed even at ISO 1600 at f4 (the fastest my 24-105 would go). I'm annoyed I didn't bring along my new 60mm 2.8 macro as the length was about right and the extra stop would have helped (but not completely). As it was I was about a stop underexposed at 1/100 second which still wasn't quite quick enough for jumping children.

The result was very noisy images - lots of random colour noise, very nasty and pretty much unusable IMO.

Is this something that the 350d is particularly bad at? Are newer bodies much better at handling high ISO noise? As it is I'd avoid ISO 1600 completely, which renders it pointless even having it.

Any other suggestions? All a 2.8 lens would have done would have let me be at least the correct exposure at 1/100, but I'd still have needed 1600 ISO, and even 3200 would have helped get the speed up.

oh, and a couple of examples - guess which is which :/



 

hot-fuzz

Distinguished Member
Would not whacking the f-stop up a bit have helped ?
You would get a larger DOF and the shutter speed would increase a bit if you went up to (and not over 8 or so max).

Having never taken indoor sports shots i may be talking out of my rear end, but i seem to get better shots when i need a faster shutter speed and lower ISO if i put the f-stop up a bit.
 

grantsteve

Well-known Member
Would not whacking the f-stop up a bit have helped ?
You would get a larger DOF and the shutter speed would increase a bit if you went up to (and not over 8 or so max).

Having never taken indoor sports shots i may be talking out of my rear end, but i seem to get better shots when i need a faster shutter speed and lower ISO if i put the f-stop up a bit.
The higher the f-stop goes means the less the 'eye' of the lens opens up. So at f4, Richard has his lens wide open (as wide as it goes) and so was letting the most amount of light available into the lens.

With a higher f-stop, say f8 as you suggest, less light would be allowed into the lens and the shutter speed would be slower to allow the shot to expose properly.

Higher f number = smaller opening. Odd isn't it :confused:

... You were right with the DOF bit though ;)
 

Radiohead

Well-known Member
Even a 5D can look noisy if the shot is underexposed - it is something of a myth that with Canon's you can shoot pretty much carefree and have noise free images.

You've found out why f4 lenses aren't really fast enough indoors the hard way here, even a 2.8 lens would have struggled and that's why indoor sports shooters often use 1.4's, 1.8's and 2's. You might have been close enough to get good results using a powerful flash like the 580EX, but that second shot looks like the focal point is on the kids in the background rather than the one in the air - what drive and focal point were you using. AI Servo rather than One Shot, and continuous drive? Another factor here is perhaps running into the limits of the 350D's AF module which is again why indoor sports shooters will use 1D series bodies. Not suggesting for a minute that people turn up to birthday parties with £5k set-ups, but simply that you might be going over what the 350D is capable of. A 30D would struggle in there with an f4 lens on. Looking at the histogram would help, expose to the right, and bump up the exposure compensation if need be.
 

richard plumb

Distinguished Member
I think I had that one manually focused on the take off board. Not completely convinced with my 350d focus generally - it seems to focus in front of where I'd like.

Not sure how I could expose to the right when the situation was too dark in the first place? i.e at f4 and 1/100 the meter was showing approximately 1 stop under exposed. I didn't want to drop the shutter speed down any more to get a 'correct' exposure as everyone would have been blurry. rock and hard place spring to mind

Same with exposure compensation. Surely all that does is adjust shutter speed compared to what the meter is suggesting?

I think a 30D (or 40D) would be nice simply to have more faith in the autofocus. I don't have the money or the opportunities to invest in 1.4 or even 2 lenses, so my 60mm 2.8 will have to do. Hopefully the 40D is at least usable at 1600 ISO, which would be ok in those situations 1/100 f2.8. I don't expect to be shooting anywhere darker than that - it was very dim.

Perhaps a nice 70-200 2.8 non-IS in a year or two if I'm feeling flush. Maybe upgrade from my 70-300 IS
 

jonnypb

Member
The 50mm 1.8 and 1.4 are pretty good at indoor shots. you can get the 1.8 for £50 or the 1.4 for £185ish. I had the 1.8 initially then went to the 1.4 as the AF was far better, USM, better built and slightly faster
 

stevegreen

Well-known Member
Did you shoot in RAW? I shot in the dark at the Shrewsbury Folk festival and at the Green Man festival over the past two weekends and though I managed to get away with ISO-800 at times at Shrewsbury I was stuck on ISO-1600 at the Green Man (images on my Flickr should you want to have a look) If you look at the images from the Green Man they appear a lot noiser than those at Shrewsbury (the ISO-1600 ones anyway) and that is because I used the colour noise reduction on the RAW file in post processing.........quite impressed.

I expose to the left on all of my shots and recover the details in post processing, however, you can go too far and recovering the exposure in PP will add a lot more noise in some cases making some shots un-useable.
 

AceAceBaby

Novice Member
Here's one from the weekend. Night time, f/2.8 but with a kenko 1.4x TC which I believe costs a stop, so f/4?

It shows the noise at ISO1600 on a Canon 30D

this was the Jpeg from the Camera (I haven't processed the RAWs) resized and cropped in MS Office Photo Editor, no PP.
 

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