Depth Of Field

[happyg]

i see it a lot in macro, but how do you increase dof when shooting macro? is it the type lens you use? or another secret?
thanks indvance for help
ann

 

[Big Mike]

Stop down the lens (use a smaller aperture).

If your subject is not moving, you could take multiple shots with the focus at different distances, then combine the shots to get a deeper DOF that would otherwise be possible.

 

[William Petruzzo]

DOF is controlled by your aperture. The smaller your f/stop number (the larger your aperture), the more shallow your DOF will be. The larger your f/stop number (the smaller your aperture) the greater your DOF will be. The only true way to increase DOF is to lower you f/stop number. Most consumer lenses won't drop below f/3.5. In this case, you can simulate a shallow DOF by using a longer focal length. Anything over about 70mm will give a more shallow effect to your DOF.

 

[KmH]

Most people want to know how to decrease the DOF and that's why bpetruzzo answered the way he did.

Big Mike got you taken care of on increasing your DOF buy using smaller apertures and or using focus stacking. Smaller apertures mean longer shutter times though unless you increase your ISO.

Subject to lens distance effects DOF too and that's why it can get so very shallow doing macro with the subject so close to the lens.

Using a telephoto macro lens helps to some degree by getting the lens a bit further from the subject.

 

[Samanax]

If your subject is not moving, you could take multiple shots with the focus at different distances, then combine the shots to get a deeper DOF that would otherwise be possible.

Known as "Focus Stacking".

 

[benhasajeep52 51]

Just to be clear on DOF.

Think of it this way. The bigger the F number the larger the depth of focus will be. The smaller the F number the less range will be in focus.

Now, there is also another variable to this. The closer you are to an item the shallower the DOF will be given the same setting. And example of this would be taking a flower picture from 8" away. At f/5.6 you may get a dof of 2". If you keep the aperture at f/5.6 but move the camera back to 12" away. The DOF may increase to 3" ( just an example).

In the situation of Macro where you want to fill the frame as much as you can. The best way to get a larger DOF is to increase the F# higher than what you just used (bigger #, the more in focus). Another example would be a flower macro where only half of it is in focus when you used f/5.6. Going to F/8.0 or maybe even f/11.0 may be needed to get it all in sharp focus.

 

[happyg]

i just got back to site...i was about to ask what focus stacking was, thanks everyone for your replies, it all helps!!!!! that focus stacking seems a bit much for a beginer like me tho....looks easy tho.
thanks again
ann

 

[William Petruzzo]

Most people want to know how to decrease the DOF and that's why bpetruzzo answered the way he did.

That's what happens when I don't completely read the first post.

 

[KmH]

Been there, done that.

 

[happyg]

a quick thank you to all that replied to me, i really apprciate it
ann

 

[Overread20]

A few points ot add to the above.

Remember that whilst you can use a smaller aperture (bigger f number) to get a greater depth of field you can't just take the lens down to its smallest aperture and shoot there - after around f16 diffraction will start to occur and that can start to noticably soften your images (depending on camera used and lens).

Also since using smaller apertures means less light getting into the camera there are a few ways to counter to get your shutter speed up to either capture a moving insect or to counter handshake if shooting handheld

1) Raise the ISO - typically you don't want to take this too high otherwise you will get a lot of noise into your shots

2) Flash - good flash control for macro work is a great release and allows one to shoot with a nice low ISO and a fast shutter speed at smaller apertures - it will take practice and good flash lighting is not easy to get perfect, but its a valid and well worth considering skill

3) Boost ambient lighting - reflectors are great for reflecting more sunlight onto a shadowed image or to add yet more light to the scene - they are also light and cheap so they dont get in the way nor act as a great burden - though they do not work best in windy weather For macro you can also use smaller reflectors rather than having to use the larger people sized ones.

As for focus stacking its great fun to do give it a try at some point and if you find a sleepy insect (early mornings or after cold rainstorm) it can let you get some outstanding results when applied right

 

[TamiyaGuy]

Also, bear in mind that at macro distances, the depth of field is TINY, literally millimetres. For this reason, it's a good idea to stop down your lens' aperture to what you might normally consider quite small, as taking a macro photo at f/5.6 will mean that, odds are not even your whole subject will be in focus. Also, you can try to align your camera so it is perpendicular to your subject, rather than 45 degrees on. (this works well with butterflies).

 

[happyg]

<img src="http://www.thephotoforum.com/photos/data/500/medium/IMG_3420rs.JPG" />

here is a shot i just took, using the advise given...i could not figure out how to insert it in here...i will have to read that later today, but here is a link to here in the gallery. i used a 100mm f2.8 and i use a canon 40d. i like the way it came out, but some of the flower jsut isnt in focus yet. i know i need to step back to get the whole flower, i was jsut testing lens i got yesterday as a gift from a friend. feedback always welcome, this photo is untouched except for resizing it to put online.
thanks
ann