Technique for increasing depth of field

[JohnF]

Recently I was photographing detail on a tree trunk on 5x4 with a 150 mm lens.
Predictably, close in, depth of field was very small. I had thought that increasing the distance of object to lens, moving the camera back and using a longer focal length, might give me extra depth of field whilst framing the composition as before. Checking depth of field tables reveals the same depth of field in both scenarios i.e. the gain in depth of field from doubling object distance is negated by the smaller depth of field of a lens of twice the focal length.
So it seems the only way to achieve greater depth of field is by a shorter lens or by moving the camera further away, and in both cases cropping to arrive at the same composition. But does not cropping result in a smaller perceived depth of field?
Grateful for any comments.

[xkaes]

If you back up and use a longer lens -- or backup and use the same lens and then crop -- you end up with the same result.

Your best option is to stop down. Is that a problem?

On some subjects you can't get all you want in focus by stopping down. Sometimes you can change the field (or angle) of the DOF by swinging and/or tilting the lens, but that depends on the subject.

[Alan9940]

Everything xkaes said, plus sometimes you just need to choose what's in sharp focus and what you're going to let go a little. Stopping down will certainly help, but then you run into diffraction issues. It's all a trade-off, really.

[domaz]

If you scan digitally, focus stacking might be another way to get more depth of field without stopping down. Although you would need to make likely at least 3 exposures for that to work.

[Michael R]

Cropping also decreases depth of field because in the end depth of field depends on the your chosen circle of confusion, which depends on magnification/viewing distance.

So… basically the easiest way to increase depth of field is to view a print from further away :).


Recently I was photographing detail on a tree trunk on 5x4 with a 150 mm lens.
Predictably, close in, depth of field was very small. I had thought that increasing the distance of object to lens, moving the camera back and using a longer focal length, might give me extra depth of field whilst framing the composition as before. Checking depth of field tables reveals the same depth of field in both scenarios i.e. the gain in depth of field from doubling object distance is negated by the smaller depth of field of a lens of twice the focal length.
So it seems the only way to achieve greater depth of field is by a shorter lens or by moving the camera further away, and in both cases cropping to arrive at the same composition. But does not cropping result in a smaller perceived depth of field?
Grateful for any comments.

[ic-racer]

“The” technique to increase the impression of more depth of field with a view camera is to align the focal plane with the subject. If the subject is a complex shape or space, then align front and rear standards parallel and stop down to the limits of diffraction.

[Doremus Scudder]

ic-racer's advice is good. While repositioning the plane of sharp focus in the subject doesn't really increase depth of field (a common misconception here, I'm afraid), it can result in getting all the important parts of the subject closer to that plane of sharp focus, which can then allow you to use a more optimal f-stop to get the DoF you want.

The way to check is to choose "near" and "far" focus points, focus on them and then note the spread (the distance on the rail/camera bed between sharp focus on the two points). Now, apply your movements to reposition the plane of sharp focus and do the same thing. If the spread is smaller, you've made an improvement.

FWIW, there's a great article on finding the optimum f-stop on the LF home page here: https://www.largeformatphotography.info/fstop.html that may be helpful in your situation.

Also, don't hesitate to stop down when doing close up work. You're likely not planning on making a huge print anyway, so diffraction won't be a huge issue. Using f/64 with a 4x5 camera still will get you a really nice 8x10 print.

Best,

Doremus

[JohnF]

Thanks for the thought provoking responses with ideas for me to try.
I was exposing at f32 with f45 available to me but avoided because of diffraction, so might be worth trying to assess any benefit. I will also try with some movements.
I shared my image with club members. Some found the soft focus areas distracting, others felt the soft areas enhanced the sharply focussed textured areas in the image! I fell in with the latter but was curious enough to seek advice. Thanks again

[JohnF]

Doremus,
Thanks for the link. Some bedtime reading!

[xkaes]

Hey, just a thought. Try a pinhole -- f300 or there about.

http://www.subclub.org/fujinon/pinhole.htm

[JohnF]

Certainly an option. I have a pinhole on a Lensbaby Edge 35 mm format, and a newly delivered Pinsta 5x4 pinhole camera which is designed to take Harman Direct Positive Paper but would take sheet film

[Michael R]

Not comparable though. Nothing is in sharp focus through a pinhole, and a pinhole is not a way around diffraction.


Certainly an option. I have a pinhole on a Lensbaby Edge 35 mm format, and a newly delivered Pinsta 5x4 pinhole camera which is designed to take Harman Direct Positive Paper but would take sheet film

[Bernice Loui]

Possible to share that same image here?

There is only one plane of focus that can be where the lens is focused from subject to image plane (film or digital imager), "stopping down the aperture" results in perceived to be in focus in the plane areas in front and behind the actual plane of focus. Camera movements can aid lots in placing the actual plane of focus where it needs to be.. within limits. Spend some time with these examples of what view camera movements can and cannot do to aid in altering and controlling where the actual plane of focus is placed.
https://www.largeformatphotography.info/forum/showthread.php?164126-Importance-of-camera-movements-gt-Alan-amp-others-long-amp-Linhof

Knowing, understanding and accepting these very hard and real limitations of how this optics and camera stuff works is part of how images can be composed, crafted and applied as the foundation of a creative-expressive image.

Out of focus areas is neither good or bad, it depends absolutely on what the image maker is striving to achieve in the image, example.
227846

Image with lots of perceived to be in focus areas.. where is the actual plane of focus?
227847


Then there are "sorta focus" lenses.. that can present an illusion of "depth".
227848


The image goals are...
Bernice




Thanks for the thought provoking responses with ideas for me to try.
I was exposing at f32 with f45 available to me but avoided because of diffraction, so might be worth trying to assess any benefit. I will also try with some movements.
I shared my image with club members. Some found the soft focus areas distracting, others felt the soft areas enhanced the sharply focussed textured areas in the image! I fell in with the latter but was curious enough to seek advice. Thanks again

[JohnF]

Here is the image which I should have shown in the original post.
Looking at it once more, I am not sure camera movements could help in increasing the depth of field. Am I correct?
227874

[Ulophot]

It appears to me that you are correct; movements would probably not serve here. A front swing to the right with a change of focal plane toward the center distance of the left-hand bark might give you a little advantage in the central area, but the depth behind the bark would probably be less sharp, since you're already beginning to lose focus at the closest tip of the bark. Perhaps others with more experience will correct me.

[xkaes]

Not comparable though. Nothing is in sharp focus through a pinhole, and a pinhole is not a way around diffraction.

Really?

[xkaes]

Here is the image which I should have shown in the original post.
Looking at it once more, I am not sure camera movements could help in increasing the depth of field. Am I correct?
227874

Just a guess -- f8.0?

[Bernice Loui]

Where was the lens focused to in this image?

This appears as a curved recesses area inside the tree trunk. Front tilt might aid in focusing the top area, but limited. Better solution to this image is to back up, to project a smaller sizes_lower magnification ala image ratio on film, then use a smallish aperture.

Given the image content, stopping down past f45 on 4x5 might be the solution, with the trade offs of applying f45. Possible example of larger film is not better.


Bernice




Here is the image which I should have shown in the original post.
Looking at it once more, I am not sure camera movements could help in increasing the depth of field. Am I correct?
227874

[Michael R]

Movements won’t help here. Stop way down.


Here is the image which I should have shown in the original post.
Looking at it once more, I am not sure camera movements could help in increasing the depth of field. Am I correct?
227874

[JohnF]

Where was the lens focused to in this image?

This appears as a curved recesses area inside the tree trunk. Front tilt might aid in focusing the top area, but limited. Better solution to this image is to back up, to project a smaller sizes_lower magnification ala image ratio on film, then use a smallish aperture.

Given the image content, stopping down past f45 on 4x5 might be the solution, with the trade offs of applying f45. Possible example of larger film is not better.


Bernice

Lens focussed on bright bark half way down right edge. I was at f32 with only f45 available additionally on my 150 mm Symmar.

[martiansea]

Lens focussed on bright bark half way down right edge. I was at f32 with only f45 available additionally on my 150 mm Symmar.

Longer lens is what you need here for a shot like this with more depth of focus. Should try 210mm.

[lassethomas]

Longer lens is what you need here for a shot like this with more depth of focus. Should try 210mm.

It bares to be repeated, there is no such thing as a free lunch when it comes to depth of field.
The only thing that really matters is the aperture.
Focal length is irrelevant if you weight in magnification.
Trust me, if you choose a longer or shorter focal length, and then move further away or closer to the subject to get the same magnification as before (i.e the same crop sort of), then you are also getting the same depth of field as before.

Physics makes you pay for what you eat.

[Vaughn]

Lens focussed on bright bark half way down right edge. I was at f32 with only f45 available additionally on my 150 mm Symmar.

Looks like you focused too far forward, if I understood your description. My 'trick' is to pick a place to focus, then slowly close the aperture and watch my near and far points come into focus. In most situations, if I have placed my focus in the right spot, the near and far points will come into focus at about the same time (aperture). If the near point comes into focus way before the far point, I move the focus back a little and check it again.

In such situations diffraction is insignificant compared to focus...head to f45!

[JohnF]

Looks like you focused too far forward, if I understood your description. My 'trick' is to pick a place to focus, then slowly close the aperture and watch my near and far points come into focus. In most situations, if I have placed my focus in the right spot, the near and far points will come into focus at about the same time (aperture). If the near point comes into focus way before the far point, I move the focus back a little and check it again.

In such situations diffraction is insignificant compared to focus...head to f45!

I believe my thinking was that knowing the depth of field was going to be very limited, I risked having nothing in focus unless I concentrated on the important part of the image. It’s easy enough to re-visit the tree and play around with the technique you are describing. Incidentally, do you practice the back and forth focussing at widest aperture, or stopped down? I find assessing sharp focus on the ground glass is much more difficult at small apertures.

[Bob Salomon]

I believe my thinking was that knowing the depth of field was going to be very limited, I risked having nothing in focus unless I concentrated on the important part of the image. It’s easy enough to re-visit the tree and play around with the technique you are describing. Incidentally, do you practice the back and forth focussing at widest aperture, or stopped down? I find assessing sharp focus on the ground glass is much more difficult at small apertures.

Focus ⅓ rd into the scene. If doing close or macro us ½.

[Tin Can]

Bob is correct as usual

I often use https://www.dofmaster.com/charts.html

and others for visualization

I put small flashlights in dark corners to check image size

Shoot tiny format...

[Vaughn]

I believe my thinking was that knowing the depth of field was going to be very limited, I risked having nothing in focus unless I concentrated on the important part of the image. It’s easy enough to re-visit the tree and play around with the technique you are describing. Incidentally, do you practice the back and forth focussing at widest aperture, or stopped down? I find assessing sharp focus on the ground glass is much more difficult at small apertures.

I am not 'back and forth' focusing. I am just slowly closing the aperture while studying the GG. I pick my near point and far focus points and watch both as I close down. If that mountain in the back and the bush close in front of me both come into focus at the same time, I know I've placed my plane of focus in the 'right' spot. If the mountain comes into focus while the bush is not yet become sharp, then I need to move my focus plane closer to the camera.

[JohnF]

Thanks for the clarification

[Doremus Scudder]

Situations like this is where the "near-far" focusing method really helps. Choose the closest and farthest points in the scene you want. Focus on each, note the position on the camera rail and then simply position the focus halfway between the two extremes (in distance on the camera rail).

And, if you're using the method described in the article I linked to earlier, you can use the focus spread to find your optimum aperture. EZPZ and reliable. I swear by this method.

The only real possibility for error in in choosing the focus points. When in doubt (is that piece of bark there closer than the knot on the right?) focus on both and see which one is actually the closest or farthest (most/least bellows draw). I use wooden field cameras and have simply printed out millimeter scales onto label stock and affixed them to the camera bed.

Best,

Doremus

[Bernice Loui]

If the lens (focal length/type greatly irrelevant) was focused as noted on the right hand bark circled with arrow, improved areas of perceived focus can be enhanced by focusing on the part of this tree circled with the arrow on the left as noted.
227899

Keep in mind the area/plane/point of perceived to be in focus grows more away from the lens as the lens aperture is reduced (that focus "1/3" in idea). In the case of large lens aperture the area in perceived focus is about equal towards then away from the actual area/plane/point of focus.
227900

Image klepped from, then notes added in orange.
https://www.edmundoptics.com/knowledge-center/application-notes/imaging/depth-of-field-and-depth-of-focus/


Lens type/focal length is not really relevant as this is innate to lens behavior controlled by the way Nature (Physics) is... and Nature will NOT be denied or ignored.


Bernice





Lens focussed on bright bark half way down right edge. I was at f32 with only f45 available additionally on my 150 mm Symmar.

[Bernice Loui]

Assessing sharp focus on the GG require a good loupe (4x to 7x, more is not better), good dark cloth and a learned skill. Practice, Practice, Practice as with any developed skill this will be difficult initially and will improve with time and development.


Bernice




I find assessing sharp focus on the ground glass is much more difficult at small apertures.

[Vaughn]

Thanks for the clarification

You are welcome. If you use my method, the focus will probably be right where Doremus' method will land you. I believe my way is just a visual way of doing the same thing (as I have not had the scales on my cameras and I learned about that method late). I have used the method Doremus mentioned with the 11x14 to help get me very close...that much real estate is not easy to manage.

To aid my eyes, I have racked the focus in and out to help judge when something is in perfect focus on the GG. But f64 and be there!

[JohnF]

Thanks Bernice and Doremus - really helpful. Now to get back to that tree. Oh, it has started a week’s worth of rain here in the north of England. Guess I am going to have to set up some indoor focussing challenges!

[JohnF]

So a little indoor practice today. I fixed a centimetre scale to the bed of my Wista 45DX, and estimated the distance between near and far focus on the scale.
For near infinity far distance, I moved the focus to 1/3 way in, and for macro focus half way, assessing the effect as aperture stopped down in stages, as described above. It did, of course, work very well as you all suggested. Very satisfying. Also added in some swing and tilt on a receding wall. It is starting to feel more intuitive. Thanks once more, one and all.

[Doremus Scudder]

So a little indoor practice today. I fixed a centimetre scale to the bed of my Wista 45DX, and estimated the distance between near and far focus on the scale.
For near infinity far distance, I moved the focus to 1/3 way in, and for macro focus half way, assessing the effect as aperture stopped down in stages, as described above. It did, of course, work very well as you all suggested. Very satisfying. Also added in some swing and tilt on a receding wall. It is starting to feel more intuitive. Thanks once more, one and all.

With the "near-far" focus technique, you should always position the focus at a point on the (nice new) scale you have on your camera bed halfway between the near and far extremes. It makes no difference if you are working close or far.

The whole "focus 1/3 into the scene" method is used with actual camera-to-subject distances and is really just an approximation of where the plane of sharp focus is positioned anyway. So, if you've got a 4mm focus spread, you'd position the focus right in the middle of that, i.e., at 2mm in from the extremes.

I use Wista DXs and SWs too, FWIW, and use the engraved lines on the brass rail as reference marks on my scales.

Best,

Doremus

[Bruce Watson]

Recently I was photographing detail on a tree trunk on 5x4 with a 150 mm lens.
Predictably, close in, depth of field was very small. I had thought that increasing the distance of object to lens, moving the camera back and using a longer focal length, might give me extra depth of field whilst framing the composition as before.

There are limited controls available for controlling DOF. View cameras have one that smaller formats lack, and that is camera movements.

My experience is not everyone's experience; my work isn't what everyone does. And all the rest of the disclaimers. That said, I found that for me there were just four main ways to control DOF. My order of preference:

1) Camera movements. First thing I would do is place the plane of exact focus where I wanted it to be. The art in this is defining the concept "where I wanted it to be" for your own work. It's often not intuitively obvious, and it takes practice -- but mostly learning how to do this takes a lot of film. The more photographs you make, the better you get at it. It took me hundreds of sheets of film before I felt like I really understood how to use camera movements. But every photographer learns in his/her own way and own time.

2) Aperture. Once the plane of exact focus is established, I pick an aperture that will give me sufficient DOF (on *both* sides of the plane of exact focus). Depending on the composition and what I want from it, I would often go an extra stop. I determined a long time ago that diffraction was nearly meaningless for me in LF, but things being in focus and/or out of focus could make or break an image. So I was always willing to stop all the way down if that's what the image needed. Group f/64 (https://en.wikipedia.org/wiki/Group_f/64) wasn't wrong. Just sayin'.

3) Perspective. Said another way, where you place the camera. I hardly ever positioned a camera with DOF in mind; only the image mattered.

4) Lens choice. For a given camera position and subject position, shorter lenses give you more DOF than longer lenses. That said, I hardly ever did this -- I always wanted to keep cropping to a minimum.

Within this limited palette of controls there is a huge range of possibilities.

[Bob Salomon]

There are limited controls available for controlling DOF. View cameras have one that smaller formats lack, and that is camera movements.

My experience is not everyone's experience; my work isn't what everyone does. And all the rest of the disclaimers. That said, I found that for me there were just four main ways to control DOF. My order of preference:

1) Camera movements. First thing I would do is place the plane of exact focus where I wanted it to be. The art in this is defining the concept "where I wanted it to be" for your own work. It's often not intuitively obvious, and it takes practice -- but mostly learning how to do this takes a lot of film. The more photographs you make, the better you get at it. It took me hundreds of sheets of film before I felt like I really understood how to use camera movements. But every photographer learns in his/her own way and own time.

2) Aperture. Once the plane of exact focus is established, I pick an aperture that will give me sufficient DOF (on *both* sides of the plane of exact focus). Depending on the composition and what I want from it, I would often go an extra stop. I determined a long time ago that diffraction was nearly meaningless for me in LF, but things being in focus and/or out of focus could make or break an image. So I was always willing to stop all the way down if that's what the image needed. Group f/64 (https://en.wikipedia.org/wiki/Group_f/64) wasn't wrong. Just sayin'.

3) Perspective. Said another way, where you place the camera. I hardly ever positioned a camera with DOF in mind; only the image mattered.

4) Lens choice. For a given camera position and subject position, shorter lenses give you more DOF than longer lenses. That said, I hardly ever did this -- I always wanted to keep cropping to a minimum.

Within this limited palette of controls there is a huge range of possibilities.

But you left out the most important step.
Learn what point to focus on.

[Bruce Watson]

But you left out the most important step.
Learn what point to focus on.

That is perhaps the most difficult thing. Many an LFer starts out thinking that the plane of exact focus needs touch the main point of interest in the photograph. But if you make enough photographs to learn how movements work, you sooner or later disabuse yourself of that idea. It's hard for newbies (and not a few oldsters) to wrap their heads around the concept: Just because it's the central point of interest of the photograph doesn't mean it intersects the plane of exact focus. Or is even all that close to it. Can be, but doesn't have to be.

[pdmoylan]

“4) Lens choice. For a given camera position and subject position, shorter lenses give you more DOF than longer lenses. That said, I hardly ever did this -- I always wanted to keep cropping to a minimum.”

Bruce, it’s easy to take for granted that a wider Angie lens gives more DOF, but in reality, at the same aperture and the same magnification, all lenses have the SAME DOF. So if you use 90mm or a 300mm, if the subject fills the frame exactly the same amount, DOF will be the same, though perspective differences caused by different angles of view will be obvious.

This is an important understanding when you are attempting closeup work in particular, often overlooked.

Another suggestion is to look under the dark cloth with your loop and carefully look at the area in focus as you stop down the lens. For all practical purposes, the view gets too dark beyond F 16.

Adjust your point of focus accordingly.

Be a contrarian when necessary and stop down to f 45 or more if it gives you the image you imagine.

Pdm

[JohnF]

Leslie Stroebel publishes the following table in the latest edition of View Camera Technique.
Distance ration is the ratio of len’s to near focus and lens to far focus, and focus fraction is the ratio of travel of the lens on the camera bed from the near point as a fraction of the total travel from near to far points:

227945

[Doremus Scudder]

"1) Camera movements. First thing I would do is place the plane of exact focus where I wanted it to be. The art in this is defining the concept "where I wanted it to be" for your own work..."

I agree that placing the plane of sharp focus optimally is essential to optimizing depth of field. Really, though, camera movements don't do a thing to increase depth of field. What they can do is better position the plane of sharp focus so that you don't need so much depth of field to get everything acceptably sharp in the print, which means you don't have to stop down as much.

Practice helps to get a sense of where the plane of sharp focus is best placed. I try to visualize where that plane goes in the scene so that it's closest to all the various elements that I want in sharp focus. I then choose three focus points that lie on my visualized plane and use these to apply the movements. Sometimes this is easy; just look at what's closest or farthest from the camera position. Often, especially if lots of tilt/swing have been applied, it's not so intuitive what is "in front of" and "behind" the plane of sharp focus. It the plane of sharp focus is closer to horizontal than vertical in the scene, then "in front of" becomes "above," and "behind" becomes "below" the plane of sharp focus.

In cases like this, it helps to find several candidates for the near-far focus points, focus on them, and note the distances on the scale on the camera bed to find which really use the most/least bellows draw to get into sharp focus.

This is also a good way to check if the movements you've applied are optimum. Check the focus spread with no movements applied. Then apply the movements and see if the focus spread is smaller. Remember, the smaller the focus spread, the larger the optimum aperture for the desired depth of field will by. Try several positions of the tilt/swing to see which one gives you the smallest focus spread and choose the one that gives you the best optimum aperture.

Best,

Doremus

[Ulophot]

[QUOTE= If the plane of sharp focus is closer to horizontal than vertical in the scene, then "in front of" becomes "above," and "behind" becomes "below" the plane of sharp focus.
[/QUOTE]

How does that happen? Is there a flip in relative positions at 45 degrees? I'm trying to visualize why that would be the case.

[lassethomas]

Well, as already stated I think, all the movements in the world won't increase depth of field.
And visualizing what happens when you apply either tilt or swing takes some training. When depth of field becomes a cone and eventually front and back becomes above and below or right and left.
And when you apply both tilts and swings complexity multiplies and at least my mind directly has severe problems visualizing and controlling the result.

So don't overdo it. Learn to early identify scenes and compositions where movements are non productive or at the very least of very limited value. They are perhaps more common than we think. And then just stop down to get what you want i focus.

That said, I love the near-far method. It really works, movements or no movements. Thanks Doremus for pointing that out and convincing me.

[Michael R]

Depth of field boundaries tilt with the plane of focus.

227956



How does that happen? Is there a flip in relative positions at 45 degrees? I'm trying to visualize why that would be the case.

[Bruce Watson]

“4) Lens choice. For a given camera position and subject position, shorter lenses give you more DOF than longer lenses. That said, I hardly ever did this -- I always wanted to keep cropping to a minimum.”

Bruce, it’s easy to take for granted that a wider Angie lens gives more DOF, but in reality, at the same aperture and the same magnification, all lenses have the SAME DOF.

Learn to read. I didn't say a thing about magnification being equal. I said "for a given camera position and subject position". If camera position is the same, and subject position is the same, different focal length lenses will render different magnifications. Duh.

[Doremus Scudder]

How does that happen? Is there a flip in relative positions at 45 degrees? I'm trying to visualize why that would be the case.

Philip,

It's simply that the plane of sharp focus has been moved to an almost horizontal position. The graphic Michael posted show the principle very well, but let's put that into practice.

Imagine a scene with a long, flat foreground that has on little rock close to the camera along with some small bushes/trees. Then there's a range of low mountains in the distance. One might want that little foreground rock in sharp focus and the distant mountains as well.

So, one would pick focus points for applying movements that lie at about the middle of the foreground rock for near and halfway up the mountain range for far. Then front/back tilts would be used to position the plane of sharp focus so that it intersects those two points. (Note: this set of focus points is for working with the camera movements; we aren't focusing the camera yet.)

After this, you can see that the plane of sharp focus is now much closer to horizontal than vertical. Maybe even more horizontal than Michael's graphic. So the next question is, where are the near-far focus points for determining focus spread and optimum depth of field? Since the plane of sharp focus is almost flat, there is no longer a real "in front of" or "behind," rather things that stick up above the plane of sharp focus are now the nearer, and things that are under it are farther, in terms of the geometry of the optics.

An object that is the highest above the plane of sharp focus is going to be the near focus point. This could be a foreground tree or the top of a foreground boulder, but it could also be a more distant, very tall tree. Conversely, an object that is lowest underneath the plane of sharp focus is going to be the far focus point. This is likely the base of the distant mountain range, but there may even be a valley of some sort that's even lower somewhere in the scene.

At any rate, identifying those near-far points is important for making sure you get the right focus spread and the right aperture.

Hope that's clear,

Doremus

[Doremus Scudder]

Learn to read. I didn't say a thing about magnification being equal. I said "for a given camera position and subject position". If camera position is the same, and subject position is the same, different focal length lenses will render different magnifications. Duh.

Bruce,

Don't be too harsh... I think many of us assume that we want a particular framing, so when using a shorter focal length lens from a particular camera position, would end up cropping the final image, thereby magnifying it, in order to get the original framing we had in mind. In such a case, the magnification introduced by the cropping cancels out the improved depth of field achieved by choosing a shorter focal length lens exactly and we end up with, essentially, the same image with the same depth of field.

Only if we can live with the wider view and the different composition in the uncropped image do we have an advantage, and that's only because the final image is smaller, i.e., not magnified as much.

Best,

Doremus

[pdmoylan]

Learn to read. I didn't say a thing about magnification being equal. I said "for a given camera position and subject position". If camera position is the same, and subject position is the same, different focal length lenses will render different magnifications. Duh.

My comment was intended to help the op, and since you did not mention magnification, I thought it helpful to buttress your comment. Not sure how one can get emotionally bruised when I was not criticizing, nor countering your comment. Getting out an photographing may relieve the injudicious antagonism. The OP is here to learn, we understand you probably know all of this.

For years this was a relatively safe and civil forum. Let’s try and buck the contrary trend.

[Eric Woodbury]

Is there a telecentric lens available for large format? These change the rules on depth-of-field. DOF is no longer an issue, but everything is a trade. Only one magnification.

Therefore, use what you have, focus on what's most important, stop down, keep the contrast up. Add a sharpening mask if you must.

[Michael Kadillak]

I am not 'back and forth' focusing. I am just slowly closing the aperture while studying the GG. I pick my near point and far focus points and watch both as I close down. If that mountain in the back and the bush close in front of me both come into focus at the same time, I know I've placed my plane of focus in the 'right' spot. If the mountain comes into focus while the bush is not yet become sharp, then I need to move my focus plane closer to the camera.

Vaughn nailed it. Put your focal plane in the correct orientation and watch the GG. If you have to high intensity LED flashlights are cheap these days to check yourself as you stop down. I put macro correction wafers and even bandaids from my backpack at various points in the scene to check it on the GG. I would shoot this with my 210 mm Computar/Kowa and an 8x10 all day long. The scene is not that complicated as long as you properly put your plane of focus in the correct place.

[xkaes]

With a lot of my scenic work where I need exact points -- near and far -- in focus, I determine the distance for each point with a tiny, inexpensive rangefinder. I then look up the f-stop AND the "center" distance I will need to achieve that using the DOFMaster for the lens I'm using. I then use my rangefinder again to select an easy-to-see point in the scene at that "center" distance -- and focus on it on the ground glass -- and stop down accordingly. Piece of cake, but becomes less and less useful the closer and closer you get -- i.e. close-up & macro work. My DOFMaster dials are made for normal distances, but, since you design them yourself, you could set them up for close-up use.