ULF Minimal Focusing Discussion

[Michael Kadillak]

Disagree. Yes, the 8" vertical makes things less worrisome with regard to the tops of trees, but is still a problem to be considered.

Specifically what is your problem to be considered with the 8" vertical because I do not see any problems in this scenario at all? You have plenty of coverage even if you decide to square up the GG camera back to vertical and start the film plane selection iteration from inception all over again if perspective of the trees is determined to be an issue. Picking the tops of the trees or 3/4ths up the trees for the back film focus plane is inconsequential since the results will not materially change one iota.

[Michael Kadillak]

And I'll toss in: Flim flatness

Oren, thanks for your words of wisdom. The only time I go down to f90 is when I have a lens that has one...tho if possible I use F45 or f64. I always use all the movements, tho often I set them at their neutral position. A habit I picked using a 4x5 for years with no indents -- I don't assume that neatly zeroed out movements are what I need, or don't need to make an image. It's all on the GG.

After learning photography under the redwoods, I am always amazed how different it is in the 'grand landscape', such as my month in Zion. Instead of ferns 5 feet away and redwoods back there a 100+ yards away, the closest foreground might be 20 feet or more, f22 seems to work just fine and most of my meter reading are about the same. Plus the legs of my Ries slide easily.

11x14 Carbon Print -- dang fern in the foreground moved in an unfelt breeze. Would have been fairly sharp otherwise.

Great image. I could see a modest front swing being deployed in this image for myself intuitively given the orientation of the front two tree elements, but whatever you did you managed overall DOF very effectively.

[Corran]

My issue is defocus in the tree tops, same as shooting a horizontal 8x10 with a 305mm, a consequence of too much tilt. I simply disagree with the statement "There is no such thing as too much forward tilt." I certainly have found many instances where there is indeed too much front tilt - in fact I made that mistake constantly when I first started with LF and learned to stop tilting so much.

[Michael Kadillak]

My issue is defocus in the tree tops, same as shooting a horizontal 8x10 with a 305mm, a consequence of too much tilt. I simply disagree with the statement "There is no such thing as too much forward tilt." I certainly have found many instances where there is indeed too much front tilt - in fact I made that mistake constantly when I first started with LF and learned to stop tilting so much.

If you tilt without intent of being on a designed film plane then I would agree with you. Tilt without purpose and intent has problems written all over it as you intimately already know. Then put the top of the trees in the film plane along with the foreground rock and you would still be 100% perfect in this situation. From the beginning on this topic I suspect many photographers have not engrained a systematic approach for how to go about selecting a film plane in their photography and fall victim to "winging it" which from my point of view is at the core of feeling the need for f90. Been there and done that. Never again! Take the time to employ a repeatable and structured method for precision focus plane selection when making LF and particularly ULF photographs because without this structure intentionally or unintentionally you are in fact inducing risk into your process and the prices of admission to this arena is too great for these conditions to coexist. The beautiful thing is that when you do in fact proceed with structured purpose and intent and stop down one or two stops and the image looks like an etching on the GG, it will put a smile on your face each and every time.

[Corran]

But what about the midrange distance and/or bottoms of the trees, in that instance? In fact, what I generally do is as you describe, and then find the relatively "best" focus area to get most of the scene in focus stopped down a little (as much as I can before the image is so faint as to be basically un-seeable), understanding that more DOF will be apparent at the back of the focus area. When stopping down a minimal amount, I have seen issues at the base of the trees in an image like this, in smaller formats.

Anyway, if you had said that perhaps f/64 would be "enough," that would be one thing - I agree that maybe f/90 is slight overkill, as a safety factor to get everything inside the DOF, but f/32 for a shot like this to me is entirely too small, if the intent is to have it all inside the focus area. Now if I were oriented to a flat plane and wanted background objects to be a little bit out of focus to separate them from the foreground, that would be understandable, but in this case I would personally never consider shooting wider than f/64. And all of this "risk" to make sure the sheet of film retains more detail despite contact printing, is anathema.

[Corran]

Basically this is how I understand the DOF issue with regard to f/32 (yellow) vs. f/90 (blue), when focused on the plane as described (red). The rear blue rectangle would be my image area. Just a crude drawing in PS:



I could test this relatively speaking by shooting such a scene with my 6x17, some tilt, and f/9 and f/25 apertures. As you say, 8x20 is expensive so I am not really interested in shooting some of my remaining sheets in such a test, but the 6x17 should be similar in DOF with a 90mm lens.

For those shooting 8x10, or larger, do you use f/stops smaller than f/32??

[Michael Kadillak]

But what about the midrange distance and/or bottoms of the trees, in that instance? In fact, what I generally do is as you describe, and then find the relatively "best" focus area to get most of the scene in focus stopped down a little (as much as I can before the image is so faint as to be basically un-seeable), understanding that more DOF will be apparent at the back of the focus area. When stopping down a minimal amount, I have seen issues at the base of the trees in an image like this, in smaller formats.

Anyway, if you had said that perhaps f/64 would be "enough," that would be one thing - I agree that maybe f/90 is slight overkill, as a safety factor to get everything inside the DOF, but f/32 for a shot like this to me is entirely too small, if the intent is to have it all inside the focus area. Now if I were oriented to a flat plane and wanted background objects to be a little bit out of focus to separate them from the foreground, that would be understandable, but in this case I would personally never consider shooting wider than f/64. And all of this "risk" to make sure the sheet of film retains more detail despite contact printing, is anathema.

The point here is that visually one needs to break away from the stoic visions of the 1/3 and 2/3rds focusing as static "fixed" events (ie non-view camera limitations) and make the necessary transition to dynamic focus planes an integral benefit of utilizing view cameras that grow as a function of distance into the image area. In this instance (to my comment earlier about it being perfect that the foreground was so close) because in this photograph the film plane must deeper into the image area (ie sufficient forward tilt necessary) this contributes to the improvement of the effective depth of field above the film plane chosen by 1/3th increasing into the image area and 2/3rds below the chosen film plane increasing into the image area would unquestionably be more than adequate to cover all of the image area in sharp focus at no more than f32 where these components exists in this image. The beautiful thing here is that the GG never lies and the verification of adequate image area being included within the cone of chosen film plane can quickly be ascertained by a simple stop down visual check.

[Michael Kadillak]

Basically this is how I understand the DOF issue with regard to f/32 (yellow) vs. f/90 (blue), when focused on the plane as described (red). The rear blue rectangle would be my image area. Just a crude drawing in PS:



I could test this relatively speaking by shooting such a scene with my 6x17, some tilt, and f/9 and f/25 apertures. As you say, 8x20 is expensive so I am not really interested in shooting some of my remaining sheets in such a test, but the 6x17 should be similar in DOF with a 90mm lens.

For those shooting 8x10, or larger, do you use f/stops smaller than f/32??

If the scene is nearby, take the same lens at the same location and put the film plane 3/4ths up the trees and on the foreground rock so these two components are sharp and lock your camera down and stop down to f22 and f32 and watch the entire image area come into perfect focus. You do not have to burn film to validate this event.

[Corran]

Assuming one has adequate adjustments for reciprocity so as to have a proper exposure and development, I just don't see why it matters, to shoot closed down a bit more. If you can see diffraction on a contact print by eye then you have some crazy good eyesight. I don't personally believe it.

Speaking of eyesight, I am near-sighted and sometimes in low-light I really struggle to see the focus. I can't reliably see the image on any of my cameras at f/22.

[Michael Kadillak]

Assuming one has adequate adjustments for reciprocity so as to have a proper exposure and development, I just don't see why it matters, to shoot closed down a bit more. If you can see diffraction on a contact print by eye then you have some crazy good eyesight. I don't personally believe it.

Speaking of eyesight, I am near-sighted and sometimes in low-light I really struggle to see the focus. I can't reliably see the image on any of my cameras at f/22.

Reciprocity has nothing to do with this discussion. We can safely assume that completely irrespective of all image election variables, whatever f stop and shutter speed one chooses, proper reciprocity correction should be standard operating procedure.

From a technical perspective LF and ULF is the epitome of the art of compromise. How one balances these conditions to secure the shortest shutter speed along with the best film resolution while carrying along premium image quality, desired print tonality and sharpness is our credo.

Diffraction effects with stopping down at the smaller end of the scale are enormous (an exponential effect) and rather visually easy to qualify. Just shoot the identical scene with a series of progressive smaller f stops and print them identically and look at them side by side. Even wet on the viewing plate over the darkroom sink the degradation in image quality presented is simply enormous. For me it was enough to make me cringe in discomfort. If you do not have the qualifying reference to convey how things go into the ditch at lower f stops you can be easily hoodwinked into unqualified complacency and that is most unfortunate.

If you have problems with stopping down take advantage of technology to solve this issue. LED flashlight advances are such that you can acquire a 500 lumen mini flashlight for $25 that you can use to illuminate your scene to verify the quality of your image stopped down. When you can properly see your image, all is well. Sometimes just the linear improvement of the focus (say from f9 to f22) is sufficient to feel confident that at f32 all is well allowing you to proceed forward.