How to set the appropriate depth of field using apperture mode?

[eleftherios_skoutaris]

<p>Greetings to all the photo lovers out there!<br>

I have just started taking lessons in photography. I'm thus a newbie and I'm using an old Nikon D80 camera with a zoom in-out lens of 18-200 mm.</p>

<p>My current problem is that I cannot manage to achieve any variation of depth of field with my camera by changing the apperture values.</p>

<p>For instance, I set my camera to apperture mode. I place two objects in a distance of 1,5 meters from one another (or else have an object close to me and landscape in the background). When I take a shot with different apperture values, starting from f5.6 to 32, there is no change of the DoF in the photo. I should expect a very short DoF in the former case and becoming larger ( until everything in focus) in the latter. This is not happening...</p>

<p>Furthermore, what confuses me is that I can adjust the focus on the objects I am shooting using a rotating barrel of the lens from 0.5 to infinity (has a DX mark on it).</p>

<p>Therefore, I learn in the class that I can change the DoF by changing the apperture, but in my case this is not happening and on the other hand I can just grab the rotating barrel and set the DoF by myself manually...</p>

<p>What am I missing here? I must be doing something wrong with my camera. Thank you in advance for your precious help!</p>

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[paddler4]

<p>This sounds like you may be confusing the location of the point of focus with depth of field. What changes when you rotate the focusing ring is how far away the lens focuses. This is not depth of field. Depth of field refers to the RANGE of distance around that focus point within which the image appears sharp. For any given focusing distance, depth of field is controlled by aperture. You will get a small, narrow range with a wide aperture and a larger range with a small aperture.</p>

<p>Here are a few things you can read:</p>

<p>http://www.cambridgeincolour.com/tutorials/depth-of-field.htm</p>

<p>http://toothwalker.org/optics/dof.html</p>

[john_wheeler6]

<p>Hi Eletrherios<br>

The perceived DOF depends on more than the Aperture. It also depends on the focal length of the lens being used, distance to subject in focus as well as the size of the print and viewing distance.<br>

I suspect one of two issues is going on for you so use the case where you have a single item 1,5 meters in front of you and focus on that item first<br>

1) you may be using too low of a focal lenght so everything will look in focus even for Aperture set to 5.6. Zoom to the 200mm and focus on the single object and then try different Apertures<br>

2) If the above does not change anything then I think you might be no seeing a difference because you are judging the DOF from the viewfinder. The aperture in of the lens is left at its maximum value until you take the picture. If you want to preview the DOF with the viewfinder, you need to press the DOF preview button on the camera (the lower button near the lens mount). The image will get darker for smaller when the button is pressed (less light getting in with smaller aperture) yet you should be able to see the DOF change with that approach.<br>

-------------<br>

That's my best guess at what is going on for you. Hope this helps.<br>

PS - Note that the DX on the lens just means this lens is made for DX sensor type cameras. The closer in ring on the Nikon 80-200mm lens is for changing focus point manually.</p>

[AlanKlein]

<p>Can you post the two pictures with the Exif data?</p>

[hjoseph7]

<p> Shooting at F5.6 with a cropped camera is like shooting at f8 on a full frame camera. You might try using a faster lens which would give you more variation in your DOF. </p>

[eleftherios_skoutaris]

<p>Thank you all for your answers and time dedicated answering my post.</p>

<p>@Dan M. You are right I was confusing the focusing with the depth of field. This is clear to me now thanks to you. The links are tough reading.<br>

<br />@John Wheeler. Thank you very much John, indeed as you said when the subject is better zoomed by using a high focal length then when changing the aperture, I used f5.6 and f10, I could see the difference in the DoF at the background.<br>

@Harry Joseph. Yep I have to look into the differences between the two camera types. By googling a bit it seems that mine is a cropped one.<br>

<br />My question was very basic and thanks a lot to all for answer I got to learn more :)</p>

[eleftherios_skoutaris]

<p>Thank you all for your answers and time dedicated answering my post.</p>

<p>@Dan M. You are right I was confusing the focusing with the depth of field. This is clear to me now thanks to you. The links are tough reading.<br>

<br />@John Wheeler. Thank you very much John, indeed as you said when the subject is better zoomed by using a high focal length then when changing the aperture, I used f5.6 and f10, I could see the difference in the DoF at the background.<br>

@Harry Joseph. Yep I have to look into the differences between the two camera types. By googling a bit it seems that mine is a cropped one.<br>

<br />My question was very basic and thanks a lot to all for answer I got to learn more :)</p>