DOF. Am I right in my assumption?

[Mike MT]

According to Jarrell, setting the lense to the widest view will give more dof. Using telephoto will decrease dof.

With this being the case, to get the best dof it makes sense then to set your camera 'closer' to the subject and widen the lense, than further away incorporating telephoto. But don't you need a higher f-stop to achieve good macro shots? The only way I can achieve higher f-stop is by using telephoto. Am I missing something? Do I need more light?

Thanks from a confused newbie S

M...

 

[Ching-Kuang Shene]

According to Jarrell, setting the lense to the widest view will
give more dof. Using telephoto will decrease dof.

Yes and No. DOF depends on (1) focal length, (2) aperture, (3) subject-camera distance, and (4) the hidden diameter of the circle of confusion. If the same camera is being used, (4) can be considered as a constant. So, here goes the rules:

(a) If (1) and (2) are fixed, shorter subject-camera distance produces shallower DOF;

(b) If (1) and (3) are fixed, larger aperture (i.e., smaller x.y in Fx.y) produces shallower DOF;
(c) If (2) and (3) are fixed, longer focal length produces shallower DOF.

Thus, it is likely that a telephoto lens may produce a larger DOF than a wide angle does, because there are three involving factors.

With this being the case, to get the best dof it makes sense then
to set your camera 'closer' to the subject and widen the lense,
than further away incorporating telephoto.

To get the best DOF, one should use a lens of very short focal length, very small aperture, and larger subject-camera distance.

But don't you need a higher f-stop to achieve good macro shots?
The only way I can achieve higher f-stop is by using telephoto. Am I
missing something? Do I need more light?

Because DOF is a function of 3 parameters, using a small f-stop on a telephoto may not be able to counter the impact of the focal length.

Take a look at the Depth of Field page of my 4500 user guide for more details.

CK
http://www.cs.mtu.edu/~shene/DigiCam
950/990/995/2500/4500 user guide

 

[JimTanCanada]

According to Jarrell, setting the lense to the widest view will
give more dof. Using telephoto will decrease dof.

With this being the case, to get the best dof it makes sense then
to set your camera 'closer' to the subject and widen the lense,
than further away incorporating telephoto.

The short answer is that you cannot get more DOF by using wide angle and moving closer. As long as the subject size as seen on the CCD is the same, the DOF is roughly the same. I think?

--
Jim Tan

 

[Mike MT]

The shot is about 15" from subject. 2 (Aperture) and 3 (distance from camera to subject) are fixed. My Aperture is 10.3 and I'm zoomed (is that longer focal length?) to max on optical zoom. According to what you've said, that means I have 'less' dof. Ok, gotcha.

Now, I do have a Ring Lite, but attached to the camera it's only good for VERY close (camera to subject) shots. If you recommend I should use it for macro, how do I achieve a smaller aperture w/ the wider lense (because the camera is closer to the subject)?

If you addressed this in the Ring Light tutorial on your site, I apologize. Must've missed it.

Thanks again for the help!

M...

According to Jarrell, setting the lense to the widest view will
give more dof. Using telephoto will decrease dof.

Yes and No. DOF depends on (1) focal length, (2) aperture, (3)
subject-camera distance, and (4) the hidden diameter of the circle
of confusion. If the same camera is being used, (4) can be
considered as a constant. So, here goes the rules:

(a) If (1) and (2) are fixed, shorter subject-camera distance
produces shallower DOF;
(b) If (1) and (3) are fixed, larger aperture (i.e., smaller x.y in
Fx.y) produces shallower DOF;
(c) If (2) and (3) are fixed, longer focal length produces
shallower DOF.

Thus, it is likely that a telephoto lens may produce a larger DOF
than a wide angle does, because there are three involving factors.

With this being the case, to get the best dof it makes sense then
to set your camera 'closer' to the subject and widen the lense,
than further away incorporating telephoto.

To get the best DOF, one should use a lens of very short focal
length, very small aperture, and larger subject-camera distance.

But don't you need a higher f-stop to achieve good macro shots?
The only way I can achieve higher f-stop is by using telephoto. Am I
missing something? Do I need more light?

Because DOF is a function of 3 parameters, using a small f-stop on
a telephoto may not be able to counter the impact of the focal
length.

Take a look at the Depth of Field page of my 4500 user guide for
more details.

CK
http://www.cs.mtu.edu/~shene/DigiCam
950/990/995/2500/4500 user guide

 

[Ching-Kuang Shene]

Now, I do have a Ring Lite, but attached to the camera it's only
good for VERY close (camera to subject) shots. If you recommend I
should use it for macro, how do I achieve a smaller aperture w/ the
wider lense (because the camera is closer to the subject)?

The SL-1 ring light has a weak intensity and may not be appropriate for day light macro shot. I normally used it in a very well-controlled environment. To get a small aperture, please try: set the ISO to 100 (rather than auto) and use long shutter speed. If noise does occur, consider the use of noise reduction. See the Sensitivity section of my 4500 guide for more details. I am currently testing a Samigon ring light, which is stronger than the SL-1. I will post my finding on my size when I complete this project.

If you addressed this in the Ring Light tutorial on your site, I
apologize. Must've missed it.

No, I did not address this on my site.

CK
http://www.cs.mtu.edu/~shene/DigiCam
950/990/995/2500/4500 user guide

 

[Mike MT]

Now, I do have a Ring Lite, but attached to the camera it's only
good for VERY close (camera to subject) shots. If you recommend I
should use it for macro, how do I achieve a smaller aperture w/ the
wider lense (because the camera is closer to the subject)?

The SL-1 ring light has a weak intensity and may not be appropriate
for day light macro shot. I normally used it in a very
well-controlled environment. To get a small aperture, please try:
set the ISO to 100 (rather than auto) and use long shutter speed.
If noise does occur, consider the use of noise reduction. See the
Sensitivity section of my 4500 guide for more details.

I read it and it did clear things up quite a bit. I'll try those settings.

I am currently testing a Samigon ring light, which is stronger than the
SL-1. I will post my finding on my size when I complete this
project.

I look forward to seeing the results.

If you addressed this in the Ring Light tutorial on your site, I
apologize. Must've missed it.

No, I did not address this on my site.

CK
http://www.cs.mtu.edu/~shene/DigiCam
950/990/995/2500/4500 user guide

Thanks again CK!

M...

 

[Frank S]

Am I missing something?

No. You have discovered that you cannot have your cake and eat it too. Routine stuff. Everything is a trade-off. Good pics depend on good technical decisions on how to best depict your intended result. There is no magic setting that is always right or that gets you "everything". You're the photographer. You decide the most important bit to capture and use the appropriate settings. Even if the unimportant bits are lost.

Hey, if it was easy, anyone could do it!

-Frank

 

[Alan Hartmann]

According to Jarrell, setting the lense to the widest view will
give more dof. Using telephoto will decrease dof.

With this being the case, to get the best dof it makes sense then
to set your camera 'closer' to the subject and widen the lense,
than further away incorporating telephoto.

The short answer is that you cannot get more DOF by using wide
angle and moving closer. As long as the subject size as seen on the
CCD is the same, the DOF is roughly the same. I think?

Michael Reichmann agrees with you, and that's good company to keep! ;-)
http://www.luminous-landscape.com/tutorials/dof2.shtml

--
Alan
http://www.pbase.com/abh
http://www.shutterfreaks.com/gallery/abh

 

[Mike MT]

Hey, if it was easy, anyone could do it!

-Frank

and I'm learning more every day! I never realized photography could be so complicated, and yet so simple, at the same time I LOVE this stuff!!

Thanks for the input Frank

M...

 

[Jarrell Conley]

Mike, sometimes it gets frustrating, don't it. Like Frank said, you can't have the proverbial cake and eat it. The main thing to remember is that dof is governed by the fstop you're using, i.e; f/2.8 = shallow dof and f/8=deeper dof AND it's governed by how far the subject is from the camera. So, if your camera is one foot away and you're shooting at f/5.6 you would get X dof. If you keep that same fstop and move the camera in to only 6 inches away, the dof gets narrower. In this example, you shot your dof down by moving in closer. The only recourse you have is to get more light on the subject so that you can change the fstop to an even smaller one, like f/8. That would give you deeper dof again. Remember though, that all the above is assuming that you do not change the focal length of the zoom, i.e; wide angle to telephoto. If you do that, then you've introduced the 3rd part of the equation.

It's something you just have to keep playing with. Set you up something like the batteries I used and take about 20 pictures at various settings and distances, but keep careful notes of what you changed. Pretty soon it'll all be second nature to you and when you look at a subject you'll know what to do.
Jarrell

According to Jarrell, setting the lense to the widest view will
give more dof. Using telephoto will decrease dof.

With this being the case, to get the best dof it makes sense then
to set your camera 'closer' to the subject and widen the lense,
than further away incorporating telephoto. But don't you need a
higher f-stop to achieve good macro shots? The only way I can
achieve higher f-stop is by using telephoto. Am I missing
something? Do I need more light?

Thanks from a confused newbie S

M...

--
How to embed photos in your message!
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Owner and user of 990 and 5700 and Photoshop. When looking at my pictures, never take it for granted I didn't enhance them....

 

[Frank S]

It's something you just have to keep playing with. Set you up
something like the batteries I used and take about 20 pictures at
various settings and distances, but keep careful notes of what you
changed. Pretty soon it'll all be second nature to you and when
you look at a subject you'll know what to do.
Jarrell

Yep. Actual testing is the best way to learn about DOF. And... what better way than with immediate feedback from a digital camera. I must have gone through a zillion rolls of film and 5-10+ years before I started understanding DOF well enough to be able to "play by ear", as it were. With digital, that learning curve should be MUCH shorter!

-Frank