Not enough light.....

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Hi,

I am quite new to using a DSLR but slowly getting to grips with it all. I am not sure if I am imagining things but i`m almost convinced the camera is not letting as much light in as it did when it bought it 2 months ago and I am starting to think there is something wrong with it. I am using a Canon EOS 550D with 55-250mm lens.

I have checked the online light calculators and also the sunny 16 rule but it doesnt seem to add up right. For example, the sunny 16 rule says on heavy cloud/overcast day like today then f5.6 @ iso100 and shutter 100. If I use these settings the image is almost black!

What I am looking for is real world feedback from other camera users. Today is a very grim/grey/cloudy dull day. If you were to go outside and take a picture at f5.6 iso 100 what shutter speed do you need to use to get a properly exposed picture? Thanks in advance for any feedback on this.
 
Short (unhelpful) answer:
This is winter in Britain, Sunny 16 does not apply here!

What does your camera's meter say?
 
It's pretty difficult to guess what sort of shutter speed is needed to compliment a given aperture and ISO without knowing what you're focussing the camera on and what metering mode you're using etc.

Have you got a shot with the exif data to hand ?

Try putting it in AV mode - select f5.6 & ISO100 and see what shutter speed the camera gives you.

For the record - I just checked by the back door pointing at frosty grass

100mm / ISO100 / f5.6 = 1/30 shutter speed

In this sort of weather (dull) I'll be using ISO800 at f5.6/400mm to get anything near to 1/400
 
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Thanks for the quck reply! I am using AV mode on the camera with the lens wound out to 250mm. I am using f5.6, iso200 and the shutter is calculating itself to 1/20 - 1/30. According to sunny 16 I should be able to use a shutter speed of 1/200! Also this online calculator http://www.calculator.org/calculate-online/photography/exposure.aspx it says on heavy overcast days with sun not visible (like it is today) it should be ok at 1/250! Thats why I asked for real life comparisons instead of using something online as a guide.
 
Well that sounds about right to me.

f5.6 / 250mm / ISO 200 = pretty slow shutter speed on a dull day.

In this dull light you want to be getting that ISO up to retain a respectable shutter speed.

Obviously if you're shooting statues and using a tripod then it's not a problem.
 
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Yes, now I have some feedback to compare against it does seem about right. Thanks for that btw :)

Its just when you see something online and its saying on an overcast day it should still be possible to get 1/200 at iso 200 f5.6 then it make me start thinking if something was wrong! lol Just goes to show once again you cant always believe what you read and the actual facts win! Since posting this I also spoke to a friend with a 450D and that also calculates the shutter speed to around 1/30 at iso 200.
 
The other thing to check is that you don't have a load of + exposure compensation dialled in by accident. This would further slow down your shutter speed however it would be giving you bright over exposed images.
 
No, generally I dont use any sort of exposure compansation. Maybe occasionally but 99% of the time its just set to the middle.
 
camera meters on 18% grey.

so you should get a grey card, spot metering and point the camera at the grey card in AV to take a reading.

being winter in UK, I would say you need to add 2 stops to your sunny 16 calculations. 1 stop in summer. eg, in very sunny days, f11 is a better bet than f16.
 
The human eye compensates for light, so even on a sunny day in winter the actual light level is quite a bit lower than in the summer, however to our eyes it seems the same, the human brain has excellent exposure compensation built in to it's image processing.
 
Set your camera to P mode and Auto ISO....if the shutter is below 1/30 make sure you put the camera on a tripod of flat surface before hitting the button...whats the picture look like now? Also double check your metering mode....make sure its not spot...
 
There's a massive amount of difference between an overcast day in the middle of summer, when the sunny 16 rule would apply, and an overcast day in the depths of winter. The sun just doesn't get high enough in the sky to provide the same levels of light that you would experience in summer, so when using f/5.6 and ISO 200 your shutter speed is going to be quite a bit slower than dictated by the sunny 16 rule.
 
I have never understood why anyone would use S16 Rule with a modern camera, and I don't want the benefits/uses explaining to me :D, as metering systems are usually quite good and compensation easily dialled in.

I'm pretty sure that at for example fx, ISO 100 and 1/xxx you'll get very different exposures and images if shooting a beach scene under clear blue sky or a squirrel sat in a tree.
 
woof woof said:
I have never understood why anyone would use S16 Rule with a modern camera,
Click to expand...


Same here. It takes about 2 seconds get your metering spot on in the VF, and even if you feel it's off, it takes a slight adjustment of one or other of the three main factors. ISO, shutter speed, f stop.

After a bit of practice you can almost get it right from the off without looking at the meter, just take a tester and work from there. On a dull day in Ireland you want to be at ISO 800, even at 2.8, to get anywhere around 1/200. Whoever said on a dull day at f/16 and ISO 100 they get 1/30 must live in the tropics!
 
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same here too, I can see the sense of it on a manual film camera with no meter but irrelevant now.
 
I've just tried my 7D and Sigma 24-70 f2.8 USM outside at f5.6, ISO 100 and 70mm on frosty grass and the shutter speed was between 1/200 and 1/320. When aimed at a frosty tree over the road and including sky in the background the SS was down to 1/100. There's still a fair bit of mist about although the sun is shining, it would be a nice day for shooting if it wasn't still -2 degrees out there.
 
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