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garysa Feb 16, 2012 11:46 PM

Canon 7D - Noisy photos
 
3 Attachment(s)
Hi

I have recently bought a Canon 7d and while I seem to be getting the hang of it I am finding that when I take photos mainly in shutter priority the photos come out very noisy (see attached)
The attached photos were shot at F/5.7, 1/1328 sec, Sopt Metering, Focal length 135mm

I have reset the camera to factory defaults but still same problem so it must be me.

Please can someone help as I like taking photos of birds and need to get this sorted out

Thanks

Gary

peripatetic Feb 17, 2012 2:21 AM

They are not noisy, they are underexposed by around 3 stops.

I would suggest you avoid spot metering until you know the basics of photography first.

Fortunately with digital you can check your exposure as you go, look for some articles on how to read the histogram.

Also some basic books on understanding exposure and metering.

garysa Feb 17, 2012 2:41 AM

Thanks for this. Just so you know I had to take the exposure down as it was very sunny and had a complete blow out at normal exposure. So I clicked down a stop at a time until there was no more blow out. Then I sat and waited for the kestrel to arrive hoping that all would be ok. When you view the picture at full resolution there is an incredible amount of noise in the photo.

I will try today to do the same but with normal exposure. Hopefully the kestrel will visit again today.

SIMON40 Feb 17, 2012 4:34 AM

1 Attachment(s)
Looking at the skies in your pictures,I'd say the conditions you were shooting are consistent with regards lighting. Maybe switch to aperture priority and shoot wide open,giving you the most shutter speed possible with a given iso setting.
I would also use evaluative metering- as using spot metering can be tricky with a moving subject. Just deliberately over-expose- maybe by a stop- to bring the bird into the realms of decent exposure- sometimes accepting over-exposure in the sky is necessary to bring detail into a small subject. Just keep an eye on the shutter speeds- making sure you have at least 1/500th sec- ideally more.
Here's one such example taken on a 20D in aperture priority- wide open at 270mm,f/6.3,1/1600th sec,iso 400- with a +2/3 of a stop using evaluative metering. To be honest I could've done with more over-exposure to bring more detail in- but I think you get the idea... :)

garysa Feb 17, 2012 5:21 AM

Thanks very much Simon. Some great ideas and I will try them. I usually shoot in aperture priority but thought I needed to switch to catch the bird in flight.

MartinSykes Feb 17, 2012 5:37 AM

I think you want to try fully manual for this - you'll have complete control over the exposure then. You do need a high shutter speed but I think you might also need to stop down the aperture a bit so you get a decent depth of field as the autofocus might struggle a bit with a small, fast-moving target.

wave01 Feb 17, 2012 5:46 AM

what was the iso setting
to me its just under exposed

garysa Feb 17, 2012 5:58 AM

ISO was 200

Unfortunately when I reduced the size so that I could post it here you cannot see just how noisy the image actually is.

peripatetic Feb 17, 2012 8:19 AM

Images display a lot of noise when they are 3-stops underexposed.

dr_spock Feb 17, 2012 10:07 AM

I think under-exposing with the 7D can cause noise.

Aperture: f/5.7
Exposure Time: 0.0008 s (1/1328)
ISO equiv: 200
Exposure Bias: -1.33 EV
Metering Mode: Spot
Exposure: shutter priority (semi-auto)


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