Not sure I have understood your question but answering what I think you are asking these two URLs should help:.

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

Http://www.dofmaster.com/doftable.html.

Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

If you can make an image background unfocused (i.e. shallow depth of field) by using a larger aperture, the image will stand out more from the background (e.g. portraits, flowers, etc.)..

If you are shooting landscapes in which you want everything in focus use a smaller aperture.

Galleries: http://www.dheller.net/photo/..

I think you're asking: 'What do I have to do to either get everything in focus, OR have only one thing in sharp focus and everything else nicely blurred.'.

Everything in focus:.

You will generally want to make the aperture (lens opening) smaller. The smaller the aperture, the higher the f/number such as f/8, f/11, f/22, etc. This is called 'stopping down' the lens..

Example: You're shooting with a lens set at 200mm. The subject is a man standing on the beach with the city in the background. The man is 15ft in front of you..

Put your lens at f/22 and the man AND the city in the background will generally be in focus. It doesn't matter if you focus the camera on the man OR the city in the background because the DOF (depth of field) is really deep with the lens stopped down to f/22. EVERYTHING between the man and the city in the background, is in focus, no matter what you focus on .

Example #2: Using the same situation above, if you changed your aperture to f/2.8, and focused on the man, then the background would be blurry and the man in sharp focus..

Example #3: Using the same situation above, if you chance your aperture to f/8, BUT WALKED CLOSER TO THE MAN UNTIL YOU WERE 10 FEET AWAY, and focused on the man, ** the background would STILL be nice and blurry and the man would be in sharp focus..

Basically: If you want everything in focus, use stop the lens down (as much as you can without requiring a low shutter speed due to the lens opening (aperture) being so small)..

If you want 1 thing in focus, and everything else blurry, then open up the lens (use a wide aperture) f/1.4, f/1.8, f/2, f2.8, or f3.6 for example..

This was taken at f/1.8 with a 50mm lens.

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*you'll notice* that the CLOSER you get to a subject when using a long lens 200mm or longer, you'll be able to focus on that subject and still easily blur the background, even when using an aperture of f/8..

This shot was taken indoors as a studio shot. I really like 200mm for studio type work (which isn't the norm), but whatever works for you! There isn't a right or wrong. f/4 at 200mm was used here..

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Long lenses allow you to blur the background a lot easier!.

If you're shooting at wide angles (less than 50mm), then it becomes harder to blur the background (but a lot easier to get everything in focus). You'd have to get really close to a subject to blur the background when shooting wide angle..

This was shot at f/3.2 and 32mm....

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This was shot at f/7.1 and 17mm...

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I hope I was able to help out .

Teila K. Day..

Can you try a less sloppy question? As you can see, you have us confused..

Are you talking about numbers such as 4, 8, 11, etc engraved on either side of the main focus mark?.

BAK..

Alright, sorry the question was sloppy (which I admit it was)....

Alright, I understand aperature, and smaller aperatures (between 8 and 22 generally) will provide more depth of field while larger aperatures (1.4-4 persay) will keep you focused on one subject and give you good background blur....

My question is, in this book they talk about setting the lens to infinity so everything is in focus, numbers at the front of the lens... how does this work to help accomplish the above goals (using a portrait with background blur vs a landscape where you want everything sharp)?.

Thanks,.

-TBRI..

The short answer:.

Use your shortest focal length available on your (zoom) lens..

Use the smallest aperture (biggest f-number, using aperture priority)..

Stand as far back from your subject as your concept permits..

Then, focus on your subject..

All should be in focus, except for the very immediate foreground..

In short:.

The smaller the f-number (the wider the aperture), the closer to the subject, and the longer the focal length being used (zoom or fixed lens), the shallower your depth of field (down to millimetres)...

What your'e talking about is "Hyperfocal Distance"..

This is very easy to demonstrate, but not to explain in writing, here..

In order to use it, you need a lens with an engraved focus distance scale, depth of field scale, manual focus, and manual aperture selection. I can't see any easy way of doing it with your typical "zoom" lens, or even a fixed focal length EF type lens...

BTW, an acquaintance (who lives near a beach and who owns over 1,000 35mm film cameras, a collector) regularly puts a film through one of his "pets" -the subject is usually a good sunset- told me that he "never' focuses through the viewfinder but always uses the hyperfocal distance method instead. I have to admit both the clarity and the subject matter of his photos are superb!..

Mikelis wrote:.

What your'e talking about is "Hyperfocal Distance"..

This is very easy to demonstrate, but not to explain in writing, here..

In order to use it, you need a lens with an engraved focus distancescale, depth of field scale, manual focus, and manual apertureselection. I can't see any easy way of doing it with your typical"zoom" lens, or even a fixed focal length EF type lens..

Easily explained, it's different from camera to camera so you have to find some table for your particular setup..

What it's all about is that at some focal lentgh and aperture, there is a focusing distance x, that when you set focus there you will have focus from x/2 to infinity..

Lets say at 50mm and F8, some table/calculator on the web somewhere might show you that if you focus at 10m you will have focus from 5m to infinity. That means, hyperfocal is the way to get the largest possible DOF for a certain focallength and apterture setting..

Oh, and heres a calculator by the way....enter your settings and out comes, among others, hyperfocal distance, for many cameras.http://www.dofmaster.com/dofjs.htmlhttp://sebastianfoto.se/..