Aperture settings

[Rob one]

Afternoon everyone. After advice and tips from this forum, I'm still getting better with the photos. I seem to have one problem though, I can rarely get the aperture setting below f8, occasionally it will go as low as £5.6, but never below this. It doesn't matter what I set the shutter speed and ISO to, I've tried all sorts of settings but the aperture just will not go any lower. I like to take wildlife photos, so would like to use a high shutter speed, but because the aperture won't normally go below f8, if I try to use a higher shutter speed, the picture is very very dark. Does anyone out there know what I'm doing wrong, I hope the camera is not faulty, it's a canon EOS R100 mirrorless. Many thanks.

 

[480sparky]

What shooting mode are you in?

Understand that each of the three variables in the exposure triangle (shutter speed, aperture and ISO) are not mutually exclusive. Change only one and the exposure changes. You must alter another (or both) to balance the change.

I also think you're a bit confused with your terminology. "Below f/8 or f/5.6". What lens are you using? If the maximum aperture is f/5.6, then it physically cannot 'go below' that. This means the aperture blades do not close down at all when the image is taken.

 

[Rob one]

What shooting mode are you in?

Understand that each of the three variables in the exposure triangle (shutter speed, aperture and ISO) are not mutually exclusive. Change only one and the exposure changes. You must alter another (or both) to balance the change.

I also think you're a bit confused with your terminology. "Below f/8 or f/5.6". What lens are you using? If the maximum aperture is f/5.6, then it physically cannot 'go below' that. This means the aperture blades do not close down at all when the image is taken.

Hi thanks for the reply. My terminology probably is all wrong, I'm still learning, having a lot of fun, but still very much learning.

I'm in fully manual mode the lens is a 100 - 400.
Funnily enough I've just had another play with the camera, I set the ISO to 5000, aperture goes to f7, but I can get a shutter speed of 1/2000, I thought that if it's a sunny day the ISO should be low, about 200, I'm sure I read this on a few websites, I could be wrong of course, at 72yrs young it's not the first time I've been wrong, just ask my wife.

I shall keep plodding away.

Many thanks

 

[480sparky]

If it's the 100-400 4.5/5.6, then at longer focal lengths the maximum aperture would be f/5.6. You'd need to get closer to the 100mm setting to achieve f/4.5.

 

[smoke665]

Just out of curiosity, lens do you have? If this is the RF100-400, it's has a variable minimum aperture based on focal length from f/5.6 @ 100mm to f/8 @ 400mm.

The only way to get faster shutter speeds zoomed out to 400mm is to increase the ISO, or add supplemental light

 

[Rob one]

If it's the 100-400 4.5/5.6, then at longer focal lengths the maximum aperture would be f/5.6. You'd need to get closer to the 100mm setting to achieve f/4.5.

Many thanks

 

[Rob one]

Just out of curiosity, lens do you have? If this is the RF100-400, it's has a variable minimum aperture based on focal length from f/5.6 @ 100mm to f/8 @ 400mm.

The only way to get faster shutter speeds zoomed out to 400mm is to increase the ISO, or add supplemental light

I've increased the ISO to between 3,000 and 5,000, and tried a few shots in between, it works, great, I thought if it was a sunny day you set the ISO at about 200, definitely wrong. I shall keep plodding away, many thanks for your help.

 

[480sparky]

I've increased the ISO to between 3,000 and 5,000, and tried a few shots in between, it works, great, I thought if it was a sunny day you set the ISO at about 200, definitely wrong. I shall keep plodding away, many thanks for your help.

The notion of always using the camera's "native" ISO is required has ruined more images than about anything else. Modern cameras and processing apps are so apt at dealing with high-ISO noise using the lowest ISO is becoming more and more a non-issue.

 

[smoke665]

I thought if it was a sunny day you set the ISO at about 200, definitely wrong.

Noise in an image comes from random shot noise (random photons) in a scene and gain noise. When you increase the ISO, you're applying gain (amplification) which adds noise, however the random noise is also always present in shadow areas. So unless you expose your sensor fully those pixels in the shadow have nothing to record but the random photons. If you then boost the exposure post, you amplify all noise in the image, including the random. Exposing for a full sensor in camera, minimizes shot noise, so the only thing you're dealing with is gain, which is something newer cameras are better equipped to handle.

 

[cgw]

So basic. As patiently explained, you're dealing with slow max apertures on a variable aperture zoom. Constant aperture zooms are big, heavy and pricey for a reason. Think the OP needs to do a bit of "woodshedding" and sort it for themselves and return with specific questions.

 

[Rob one]

The notion of always using the camera's "native" ISO is required has ruined more images than about anything else. Modern cameras and processing apps are so apt at dealing with high-ISO noise using the lowest ISO is becoming more and more a non-issue.

I'm learning it's a very fine balance between all three of them, I've now just got to learn how to get rid of the noise and graininess, I shall get there, I've only been using the manual settings for a few months, so I'm definitely still learning. I shall just keep practising, but I'm enjoying every minute of it, and the buzz you get when you see that you've taken a brilliant photo, is just off the scale, mind you I'm taking about 30 shots to get a good one, at 72yrs young I wish I'd started this years ago. Many thanks for all your help.

 

[Rob one]

So basic. As patiently explained, you're dealing with slow max apertures on a variable aperture zoom. Constant aperture zooms are big, heavy and pricey for a reason. Think the OP needs to do a bit of "woodshedding" and sort it for themselves and return with specific questions.

Thanks

 

[Rob one]

Noise in an image comes from random shot noise (random photons) in a scene and gain noise. When you increase the ISO, you're applying gain (amplification) which adds noise, however the random noise is also always present in shadow areas. So unless you expose your sensor fully those pixels in the shadow have nothing to record but the random photons. If you then boost the exposure post, you amplify all noise in the image, including the random. Exposing for a full sensor in camera, minimizes shot noise, so the only thing you're dealing with is gain, which is something newer cameras are better equipped to handle.

Many Thanks