Obtaining maximum DOF - DPChallenge Forums

09/07/2006 04:24:05 PM · #1

I'm asking this because I was trying a few things with manual focus primes and ended up confusing myself...

I have a scenario where my subject is about 4ft away, but I want both the background (a lake with swans) *and* the subject to both be in focus.

So I set the lens to F11 and focussed on the background, but that threw the foreground subject out of focus. What's the correct way to achieve this? - I'm sure I've done it before, but just can't remember the best aperture, and where to set the focus (do I focus to infinity, or focus on the foreground subject?)

50mm f1.8 by the way.

Message edited by author 2006-09-07 16:24:42.

09/07/2006 04:27:02 PM · #2

The smaller the aperture (the larger the f number), the greater the DOF), so stop down all the way. You could also try focussing between them, to get them both in the DOF. You will not have maximum sharpness on either though.

Canon EF 16-35mm f/2.8L USM

09/07/2006 04:28:17 PM · #3

The max is F16 on that lens right? ... I'm interested in this too. All I can think is the the distance between you and the subject needs to be greater -- which of course makes everything smaller ... It would be easier with a higher F lens like a zoom I think (f29 is a nice high number)
I think this shot would be tough with this particular lens.

Message edited by author 2006-09-07 16:32:10.

Falc

Canon EOS-1D Mark III

09/07/2006 04:29:04 PM · #4

When you say it threw theforeground out, did you check it by looking at the image or just through the view finder?

If you were just looking through the viewfinder then the lens was probably wide open at f1.8. Its only when you fire the shutter that it stops down to f11 and gives you the deeper depth of field.

violinist123

Canon EOS-6D

Canon EF 24-70mm f/2.8L USM

09/07/2006 04:29:55 PM · #5

Originally posted by jhonan:

Should be a chart that came with your lense in the instruction manual. It will tell you given any F stop what the minimum and maximum points are of the focal range for that setting. Focal length of the lense plays a large part (I don't remember the math). Anyway look in the manual or just experiment, but focus on your foreground subject and the aperture setting will take care of the rest. One of them in your book should say min focal length X ft. Max: infinity.

09/07/2006 04:30:52 PM · #6

Originally posted by metatate:

The max is F16 on that lens right? ...

It's a Nikon Series E 50mm f/1.8 Max aperture is F22, focus goes from 60cm to infinity.

09/07/2006 04:32:51 PM · #7

Originally posted by jhonan:

Originally posted by metatate:
The max is F16 on that lens right? ...

It's a Nikon Series E 50mm f/1.8 Max aperture is F22, focus goes from 60cm to infinity.

Putting the aperture on f22 will give you the maximum DOF. DOF is also greater the further away you focus, so you could try standing further away.

w24x192

Canon PowerShot S50

09/07/2006 04:32:54 PM · #8

When's someone going to mention hyperfocal distance?

09/07/2006 04:33:20 PM · #9

i would try f22 with a tri-pod --- get as far away as you could tolerate.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

09/07/2006 04:34:51 PM · #10

Originally posted by w24x192:

When's someone going to mention hyperfocal distance?

Hyperfocal distance = distance at which to focus for maximum possible DOF.

Here's a link

Here's another link

GeneralE

Canon PowerShot S3 IS

09/07/2006 04:35:29 PM · #11

Originally posted by w24x192:

When's someone going to mention hyperfocal distance?

I meant to about eight posts ago, but didn't because I can never explain it right.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

09/07/2006 04:35:31 PM · #12

Remember that the area in focus will be about 1/3 in front of the focus point and 2/3 behind. Based on the hyperfocal distance you figure out where to focus the camera.

Now to figure out the hyperfocal distance .....

talmy

Nikon D300s

Nikon AF-S DX Zoom-Nikkor 16-85 f/3.5-5.6G ED VR

09/07/2006 04:37:46 PM · #13

Originally posted by w24x192:

When's someone going to mention hyperfocal distance?

Good question!

Doesn't need to be calculated. Just set the focus ring so that infinity is at the mark on the DOF scale (thank goodness these old lenses had that scale!) then everything will be in focus from infinity to the minimum distance (which is also indicated by the other mark on the DOF scale).

Canon EF 70-300mm f/4.5-5.6 DO IS USM

09/07/2006 04:38:17 PM · #14

a funny link

cpanaioti

Canon EOS-40D

09/07/2006 04:38:34 PM · #15

Good article...

//www.vividlight.com/articles/2314.htm

Message edited by author 2006-09-07 16:38:47.

violinist123

Canon EOS-6D

Canon EF 24-70mm f/2.8L USM

09/07/2006 04:39:00 PM · #16

Originally posted by talmy:

Originally posted by w24x192:
When's someone going to mention hyperfocal distance?

Good question!

Doesn't need to be calculated. Just set the focus ring so that infinity is at the mark on the DOF scale (thank goodness these old lenses had that scale!) then everything will be in focus from infinity to the minimum distance (which is also indicated by the other mark on the DOF scale).

Actually I went looking and this lense doesn't have the scale on it. Else I've been lied to by the mighty Internet. But what are the odds of that...

"AF 50mm 1.8 52 1.5' (0.45m) HR-2 hood.6/5 element design. No distance scale window."

Message edited by author 2006-09-07 16:40:16.

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

09/07/2006 04:39:23 PM · #17

At a 4-foot subject distance, there is no way to get both the subject and background in focus within the constraints of the camera and lens you're using. You'd need roughly f/64 to achieve what you want.
Use a shorter focal length, like 24mm. That will enable you to get from 4 feet to infinity in focus at f/16. Downside is, your subject will be smaller in the frame.
FWIW, here is the calculator I used to get these numbers. I used a fixed CoC of 0.016mm, which is slightly more conservative than choosing a camera directly.

09/07/2006 04:42:17 PM · #18

The lens has a scale which looks like this (thanks for the links btw);

Yea... now you mention it I was going to ask how to use these DOF index markers...

Canon EF 24-70mm f/2.8L USM

09/07/2006 04:42:33 PM · #19

21ft at f16-22 for 50mm approx.

Look Mom I'm LEARNING!!!

Originally posted by metatate:

a funny link

Message edited by author 2006-09-07 16:43:59.

violinist123

Canon EOS-6D

09/07/2006 04:43:20 PM · #20

Originally posted by jhonan:

The lens has a scale which looks like this

I'm going to sue the Internet...

fotomann_forever

09/07/2006 04:43:36 PM · #21

Originally posted by GeneralE:

Originally posted by w24x192:
When's someone going to mention hyperfocal distance?

I meant to about eight posts ago, but didn't because I can never explain it right.

Yeah, not easy to explain in a few sentences.

talmy

Nikon D300s

Nikon AF-S DX Zoom-Nikkor 16-85 f/3.5-5.6G ED VR

09/07/2006 04:43:42 PM · #22

Originally posted by routerguy666:

Originally posted by talmy:

Originally posted by w24x192:
When's someone going to mention hyperfocal distance?

Good question!

Doesn't need to be calculated. Just set the focus ring so that infinity is at the mark on the DOF scale (thank goodness these old lenses had that scale!) then everything will be in focus from infinity to the minimum distance (which is also indicated by the other mark on the DOF scale).

Actually I went looking and this lense doesn't have the scale on it. Else I've been lied to by the mighty Internet. But what are the odds of that...

Recent lenses leave the scale off because nobody manually focuses anymore. :-( Are there any Canon MF lenses that work on digital bodies?

I recently purchased a (used) 24mm F/2.8 Nikkor AI lens (manual focus) and use this hyperfocal trick all the time -- it's difficult to focus a wide angle lens because of the large depth of field -- and it works great -- sharpest pictures of any of my lenses that incorporate that focal length.

09/07/2006 04:44:59 PM · #23

Originally posted by jhonan:

The lens has a scale which looks like this (thanks for the links btw);

Yea... now you mention it I was going to ask how to use these DOF index markers...

The markers just show from where to where the DOF extends for a certain aperture and focus distance.

09/07/2006 04:46:45 PM · #24

Originally posted by talmy:

Originally posted by routerguy666:

Originally posted by talmy:

Originally posted by w24x192:
When's someone going to mention hyperfocal distance?

Good question!

Doesn't need to be calculated. Just set the focus ring so that infinity is at the mark on the DOF scale (thank goodness these old lenses had that scale!) then everything will be in focus from infinity to the minimum distance (which is also indicated by the other mark on the DOF scale).

Actually I went looking and this lense doesn't have the scale on it. Else I've been lied to by the mighty Internet. But what are the odds of that...

Recent lenses leave the scale off because nobody manually focuses anymore. :-( Are there any Canon MF lenses that work on digital bodies?

I recently purchased a (used) 24mm F/2.8 Nikkor AI lens (manual focus) and use this hyperfocal trick all the time -- it's difficult to focus a wide angle lens because of the large depth of field -- and it works great -- sharpest pictures of any of my lenses that incorporate that focal length.

For Canon you can buy apadters that allow one to use old manual lenses like the M42 Pentax screw mount.