Stupid Question About Focusing

[Vixen]

It may be that being indoors, on auto, your camera makes aperture larger (ie smaller number) & increases ISO to keep shutter speed high enough for handheld and available light. It's hard to give the "right" answer for the situation without knowing the details. But basically, if in auto, you are letting the camera make the decisions regarding settings and it does not necessarily give you the effect you would like.

If you wish to dictate what you want you need to learn to use manual settings, and as the others have pointed out, it is aperture that determines depth of field, so consider learning about depth of field and maybe experiment using Aperture Priority Mode.

 

[Blacktop]

Flashpot. I did an experiment for you so you may further understand , what happens when you play with your aperture settings. I shot 4 shots at different apertures , at the same focal length.(55mm) The only thing that changed was the aperture. I shot it with the same camera and lens that you have.
See how the background, in this case the mixing board, gets less and less blurry as the aperture gets smaller. (larger number)

1st shot F/5.6
2nd shot F 7.1
3rd shot F10
4th shot f22

 

[Flash Pot]

Best thing to do is experiment.
Pick a subject to shoot. Maybe a flower pot or something.

Put your camera on aperture Priority, and start with the largest aperture. (smallest number). In your case that would be F/3.5 at 18mm
Then take a shot.
Work your way up with the numbers , at each step take another shot, all the way till the numbers wont go any higher.
Then compare each shot and see how the background is affected, just by changing the aperture size.

Excellent advice! I will try this and see what happens

It may be that being indoors, on auto, your camera makes aperture larger (ie smaller number) & increases ISO to keep shutter speed high enough for handheld and available light. It's hard to give the "right" answer for the situation without knowing the details. But basically, if in auto, you are letting the camera make the decisions regarding settings and it does not necessarily give you the effect you would like.

If you wish to dictate what you want you need to learn to use manual settings, and as the others have pointed out, it is aperture that determines depth of field, so consider learning about depth of field and maybe experiment using Aperture Priority Mode.

Thanks for the tips!

 

[Flash Pot]

Flashpot. I did an experiment for you so you may further understand , what happens when you play with your aperture settings. I shot 4 shots at different apertures , at the same focal length.(55mm) The only thing that changed was the aperture. I shot it with the same camera and lens that you have.
See how the background, in this case the mixing board, gets less and less blurry as the aperture gets smaller. (larger number)

1st shot F/5.6
2nd shot F 7.1
3rd shot F10
4th shot f22
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Outstanding! It is much easier to learn for me with visuals! Thank you!

I love this place!!

 

[Blacktop]

No problem, glad I could help. When I first started out with DSLR's (a few months ago) , I had a hard time understanding aperture as well. Once you figure it out, it will just click and all make sense.

 

[Flash Pot]

No problem, glad I could help. When I first started out with DSLR's (a few months ago) , I had a hard time understanding aperture as well. Once you figure it out, it will just click and all make sense.

Like I said, I thought auto mode just gave me a shot like a point and shoot. I had no idea i should adjust the aperture for focal points. I kinda feel overwhelmed by it all, but if I can just piece it together by understand bits like this it should become easier! Thanks once again for your help, much appreciated!

 

[Blacktop]

Like I said, I thought auto mode just gave me a shot like a point and shoot. I had no idea i should adjust the aperture for focal points. I kinda feel overwhelmed by it all, but if I can just piece it together by understand bits like this it should become easier! Thanks once again for your help, much appreciated!

Ok, now you are confusing me. When you say auto mode, are you talking about auto focusing, or are you talking about the Auto setting on your camera, where the wheel is on top?

If you are talking about the latter, then yes, the camera will pick the aperture and the shutterspeed on it's own.
Try shooting in A mode(aperture priority). Then you can change the Aperture.

On the wheel on the top of your camera the letter A, does not stand for Auto.
You may want to re read your manual.

Also if you want to shoot in Auto mode, there are 8 Auto mode settings. One is without flash, the other is with flash. Plus six more that are self explanatory

On the wheel,Auto mode with flash Is the Green setting that says "auto mode"
the one underneath is the Auto Mode without flash.

 

[480sparky]

When you're in Auto Exposure, you can't change the aperture. The camera has total control.

You need to go to any of the other exposure modes to be able to change the aperture. How depends on the mode chosen.

 

[Blacktop]

Yes, I believe Flashpot might be confusing Auto Focus, with Auto Exposure.

 

[Horoscope Fish]

Like I said, I thought auto mode just gave me a shot like a point and shoot. I had no idea i should adjust the aperture for focal points. I kinda feel overwhelmed by it all, but if I can just piece it together by understand bits like this it should become easier! Thanks once again for your help, much appreciated!

Shooting in full Automatic (Green Auto setting on the Mode Dial) surrenders all control regarding the shot to the camera. Not that that's a bad thing, but... The camera is not human and is programmed to take a middle path in all things in hopes that most of the time photos will turnout "okay". And by "okay", I mean shots with decent exposure overall. If you want creative control, you have to wrench control away from the camera and take the helm your own self. Doing this requires you know a few things.

If I were you, I'd spend some time reviewing the basics what photographers refer to as The Exposure Triangle; composed of Aperture, ISO and Shutter Speed. You'll need to understand these three concepts, and how they interact with one another, frontwards and backwards. The importance of these three concepts, and their interconnectedness, can not be over-stated.


....

 

[Flash Pot]

Ok, now you are confusing me. When you say auto mode, are you talking about auto focusing, or are you talking about the Auto setting on your camera, where the wheel is on top?

If you are talking about the latter, then yes, the camera will pick the aperture and the shutterspeed on it's own.
Try shooting in A mode(aperture priority). Then you can change the Aperture.

On the wheel on the top of your camera the letter A, does not stand for Auto.
You may want to re read your manual.

Also if you want to shoot in Auto mode, there are 8 Auto mode settings. One is without flash, the other is with flash. Plus six more that are self explanatory

On the wheel,Auto mode with flash Is the Green setting that says "auto mode"
the one underneath is the Auto Mode without flash.

Yes, I was talking about the auto setting with the wheel. Sorry if I confused you and everyone else!

 

[Flash Pot]

Shooting in full Automatic (Green Auto setting on the Mode Dial) surrenders all control regarding the shot to the camera. Not that that's a bad thing, but... The camera is not human and is programmed to take a middle path in all things in hopes that most of the time photos will turnout "okay". And by "okay", I mean shots with decent exposure overall. If you want creative control, you have to wrench control away from the camera and take the helm your own self. Doing this requires you know a few things.

If I were you, I'd spend some time reviewing the basics what photographers refer to as The Exposure Triangle; composed of Aperture, ISO and Shutter Speed. You'll need to understand these three concepts, and how they interact with one another, frontwards and backwards. The importance of these three concepts, and their interconnectedness, can not be over-stated.


....

So I am guessing that middle path in auto mode will always bring into focus the subject I am targeting and the background will always be blurred?

 

[480sparky]

So I am guessing that middle path in auto mode will always bring into focus the subject I am targeting and the background will always be blurred?

Not always.

The problem with Auto Exposure is the camera doesn't know what your intentions are. It only knows, "Get a correct exposure." Not "Get THE correct exposure."

Let's use the Sunny 16 Rule as an example. But first, we'll need to set some parameters. Let's limit ourselves to only full stops, aperture between 4 and 22, and ISO 100-400.

The Sunny 16 Rule, at ISO 100, says a correct exposure would be f/16 and a shutter speed of 1/100. At ISO 100, the other correct exposures would be:

1/1600, f/4.
1/800, f/5.6
1/400, f/8
1/200, f/11
1/50, f/22

At ISO 200, we have:
1/3200, f/4
1/1600, f/5.6
1/800, f/8
1/400, f/11
1/200, f/16
1/100, f/22

And at ISO 800:
1/6400, f/4
1/3200, f/5.6
1/1600, f/8
1/800, f/11
1/400, f/16
1/200, f/22

So with the above limitations, there's a choice of 21 'correct exposures' the camera can make.

And if you bring in more available apertures and ISOs, and break it down further with half- or third stops, the possibilities increase exponentially. A single image could have hundreds of 'correct exposure' choices. Since the camera cannot be programmed to read your mind, it calls upon it limited 'knowledge' and makes many assumptions.

The only way to break out of this rut is to learn to take control of your camera.

 

[Horoscope Fish]

The problem with Auto Exposure is the camera doesn't know what your intentions are. It only knows, "Get a correct exposure." Not "Get THE correct exposure." ... Since the camera cannot be programmed to read your mind, it calls upon it limited 'knowledge' and makes many assumptions. ... The only way to break out of this rut is to learn to take control of your camera.

Well said, especially the part about exposure.

 

[Flash Pot]

Not always.

The problem with Auto Exposure is the camera doesn't know what your intentions are. It only knows, "Get a correct exposure." Not "Get THE correct exposure."

Let's use the Sunny 16 Rule as an example. But first, we'll need to set some parameters. Let's limit ourselves to only full stops, aperture between 4 and 22, and ISO 100-400.

The Sunny 16 Rule, at ISO 100, says a correct exposure would be f/16 and a shutter speed of 1/100. At ISO 100, the other correct exposures would be:

1/1600, f/4.
1/800, f/5.6
1/400, f/8
1/200, f/11
1/50, f/22

At ISO 200, we have:
1/3200, f/4
1/1600, f/5.6
1/800, f/8
1/400, f/11
1/200, f/16
1/100, f/22

And at ISO 800:
1/6400, f/4
1/3200, f/5.6
1/1600, f/8
1/800, f/11
1/400, f/16
1/200, f/22

So with the above limitations, there's a choice of 21 'correct exposures' the camera can make.

And if you bring in more available apertures and ISOs, and break it down further with half- or third stops, the possibilities increase exponentially. A single image could have hundreds of 'correct exposure' choices. Since the camera cannot be programmed to read your mind, it calls upon it limited 'knowledge' and makes many assumptions.

The only way to break out of this rut is to learn to take control of your camera.

Thank you for the insightful post! I have a long ways to go but with this great group of folks it will be much easier.

 

[donaldjledet]

Like I said earlier a great place to learn. Like I mostly shoot in aperture or shutter mode.

 

[Vixen]

If you were inside with low light, on auto your camera will have problems focussing because of low light conditions. Not sure if that applies to your situation, but if you DO find yourself in low light and trying to auto focus, then it helps to use a torch to light your subject while the camera focuses, then take the torch away for the shot.

 

[Horoscope Fish]

If you reeeeeally feel like getting your geek on, and you've been warned, Google "Phase Detection Autofocus" and "Contrast Detection Autofocus". Digest all that information and you'll better understand why your DSLR has trouble sometimes getting to focus-lock in low-light situations. At that point I'll need you to come back and explain it all to me.

....

 

[Flash Pot]

If you reeeeeally feel like getting your geek on, and you've been warned, Google "Phase Detection Autofocus" and "Contrast Detection Autofocus". Digest all that information and you'll better understand why your DSLR has trouble sometimes getting to focus-lock in low-light situations. At that point I'll need you to come back and explain it all to me.

....

Oh no, I have better things to do with my life