How do I increase d.o.f.

[AaronJAnderson]

Trying to learn how to adjust things manually to get more desirable results. After all, that's why I bought a DSLR.

I'm shooting with the kit lens (18-55)
Take this photo for example, shot at 55mm in AUTO mode.

I would like more of the image to be in focus. What do I need to do? Adjust ISO and F stop?

 

[PhotoXopher]

Get out of Auto mode and switch to manual or Aperture priority and open the lens up.

 

[HeY iTs ScOTtY]

use a large aperture

 

[Big Mike]

Get out of Auto mode and switch to manual or Aperture priority and open the lens up.

Yes, switch to Aperture Priority mode but you want to 'stop down' the lens...not open it up.

The DOF is controlled main by the lens aperture. The larger the aperture, the more shallow the DOF...so the smaller the aperture, the deeper the DOF. Now keep in mind that a smaller F number is a larger aperture and thus a higher F number is a smaller aperture.

So in Aperture mode, you could choose something like F11 or F16 etc. That should give you a lot more DOF. However, when the aperture gets smaller, the shutter needs to stay open longer...and if the shutter speed is too long (slow), then you will get blurry photos unless the camera and subject are perfectly still (use a tripod).

DOF is also controlled by the focal length. A shorter focal length (zoom) will give you a deeper DOF. The distance from the camera to the subject also has an affect on DOF...the farther away you are, the deeper it gets.

 

[AaronJAnderson]

use a large aperture

That's a big F number, which is a small opening in the lens, correct?

 

[Big Mike]

use a large aperture

He want's more DOF...so he needs a smaller aperture (high F number)

 

[farmerj]

"Open the lens" would be using a Larger aperture. This is actually a "smaller" number, like f/3.5 or therebouts.


To get MORE DOF, you would use a smaller aperture or larger number like f/22 or greater.


http://www.dofmaster.com/dofjs.html

 

[AaronJAnderson]

Get out of Auto mode and switch to manual or Aperture priority and open the lens up.

Yes, switch to Aperture Priority mode but you want to 'stop down' the lens...not open it up.

The DOF is controlled main by the lens aperture. The larger the aperture, the more shallow the DOF...so the smaller the aperture, the deeper the DOF. Now keep in mind that a smaller F number is a larger aperture and thus a higher F number is a smaller aperture.

So in Aperture mode, you could choose something like F11 or F16 etc. That should give you a lot more DOF. However, when the aperture gets smaller, the shutter needs to stay open longer...and if the shutter speed is too long (slow), then you will get blurry photos unless the camera and subject are perfectly still (use a tripod).

DOF is also controlled by the focal length. A shorter focal length (zoom) will give you a deeper DOF. The distance from the camera to the subject also has an affect on DOF...the farther away you are, the deeper it gets.

That makes sense. I'll give it a shot when I get home.

Should the ISO be adjusted along with that or will I get satisfactory results just changing the f stop?

 

[Moglex]

That makes sense. I'll give it a shot when I get home.

Should the ISO be adjusted along with that or will I get satisfactory results just changing the f stop?

If you switch to aperture priority mode the camera will change the shutter speed to allow for the smaller aperture.

This means that unless your camera is attached to a tripod you need to be careful that the speed does not drop below around 1/125th second. If it does then you will need to either find some more light or increase the ISO so that the shutter speed is 1/125 or greater..

(It *may* be possible to hand hold the lens at 1/60th especially if you are at the wide angle end of the lens' range but 1/125th is safer.)

 

[HeY iTs ScOTtY]

sorry i missed the part that said you want the image in focus my bad...smaller aperture lol. (larger number)

 

[PhotoXopher]

My bad, I misread what he wrote as well... I guess I'm used to people asking about the other way around

 

[Battou]

use a large aperture

That's a big F number, which is a small opening in the lens, correct?

Yes, that is exactly what he means, that will increase the DoF. This will require a longer Shutter speed or higher ISO.....you would prolly be better off adjusting shutter speed to compensate as much as possible. When the shutter speeds get too long to handhold (roughly 1/30) then bring up the ISO.

 

[Joves]

That makes sense. I'll give it a shot when I get home.

Should the ISO be adjusted along with that or will I get satisfactory results just changing the f stop?

You will only want to adjust your ISO to a higher setting if the shutter spees is too slow for handheld or, if you use a tripod then it doesnt matter on a static object like your subject.
My suggestion though is since it is digital, start out wide open lower numbers, then adjust one stop and, shoot it, then do the same through all of the numbers and, compare photos. It will be a good way for you to see how things affect an image. You can do the same with ISO as well.
Back in the old film days when I was learning we didnt have a delete or review button and, had to take notes for each shot to learn what works and, what doesnt.

 

[benlonghair]

That makes sense. I'll give it a shot when I get home.

Should the ISO be adjusted along with that or will I get satisfactory results just changing the f stop?

I would reccomend getting "Understanding Exposure" by Bryan Peterson. Understand that ISO 100 to 200 is a 1 stop change meaning that changing from ISO 100 to ISO 200 is equivelent to going from 1/100 sec to 1/200 sec or going from f/8 to f/11. They're exactly the same. (Each cuts light entering the camera by half or in the case of ISO the sensitivity of the sensor.)

The difference is the effect you get from each change. F stops add or subtract DoF. Shutter speed effects motion blur and such. ISO just adds noise (in my experience).

Hope this helps.

 

[Big]

Haha I think it's funny to read the "smaller number, no wait, the larger number, or is it..." I'm not making fun of anyone because I'm guilty of it myself so don't take it personal.

Edit: If Noyze reads this... your avatar is awesome! :thumbup: