Still life - DOF problem

[PatrickMarq]

As test for learning how to develop my film I took a still life, also now as we cannot go out this will be my subject for a while.

The setup 4X5 Chamonix, with 150/5.6 lens Aperture f45.
Distance to te flowers about 20”
The distance between the flowers and the frame about 10”

I cannot get the two sharp, I’m I doing something wrong or is this not possible. Normally I do landscape or architecture.

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First image focus on the frame, the second image focus on the flowers

Thx
Patrick

[C. D. Keth]

That may just not be possible on that lens or at that stop. I can’t think of anything in the way of movements that would help you out.


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[Dan Fromm]

You seem to have focused on the frame. At the magnification you're working at, DOF is roughly (got that, folks, roughly) symmetrical about the plane of best focus. Try focusing midway between the front of the blooms and the frame.

[Bob Salomon]

Larger aperture to avoid diffraction and take one focused 1/3rd between the flowers and the mirror and one half way between.
Focusing on the flowers means that you are loosing all of the DOF in front of the flowers.

Your lens should be diffraction limited at 22.

[Dan Fromm]

Larger aperture to avoid diffraction and take one focused 1/3rd between the flowers and the mirror and one half way between.
Focusing on the flowers means that you are loosing all of the DOF in front of the flowers.

Your lens should be diffraction limited at 22.
Bob, the 1/3d rule doesn't apply close up. It also doesn't apply at infinity.

[Bernice Loui]

Composition not gonna work for trying to hold focus front to back. Stopping down to f45 or using camera movements will not get front & back "in focus". In this case your best option is to move back, make the composed image smaller on the ground glass then to film. Moving in, close up will greatly aggravate this problem.

Alternative is to change the composition by placing the tall objects at the back of the image with the shorter items in the front of the image. This is more effective as camera_lens tilt produces a curved plane of focus toward what is considered the back or rear or furthest away object.

Idea is to arrange a image composition that can be held in reasonable focus with the lens wide open, then apply minimal camera movements to achieve enough improvement in overall focus at full lens aperture. Once these basic criteria are met, then stop down the lens only as much as needed to achieve good-reasonable overall focus_this is done by looking at the GG with the lens stopped down to taking aperture.


All the best and enjoy this adventure :)
Bernice

[Bob Salomon]

Bob, the 1/3d rule doesn't apply close up. It also doesn't apply at infinity.

That’s why I also said half way.

[Ulophot]

Just quantify, one DOF calculator online shows DOF at 25" for the 150mm lens at 5.4". Variations in calculating DOF could increase or decrease this number, but it is nowhere close to the 10" you need. LF does have its specific challenges. As Bernice noted, increasing the distance will increase the DOF, but then the relative sizes of the flower group and picture frame, hence their alignment, will also change.

[Bob Salomon]

Just quantify, one DOF calculator online shows DOF at 25" for the 150mm lens at 5.4". Variations in calculating DOF could increase or decrease this number, but it is nowhere close to the 10" you need. LF does have its specific challenges. As Bernice noted, increasing the distance will increase the DOF, but then the relative sizes of the flower group and picture frame, hence their alignment, will also change.

With what circle of confusion?
We don’t know if the op wants to make a contact print or a mural.

[Drew Bedo]

I may not fully understand your creative vision. . . .but I am sure that, as Seinfeld's George Costanza famously said, " Its not you, its ME."

To get both in focus, I would raise the whole camera some, then use some tilt and stop down. You may be able to get both the frame and the blooms sharp. As sharpness falls off going down the stems it will be less noticeable. It may be that you will have to accept some compromise in this.

I myself have a visual disability and sharp focus is always a challenge for me. One strategy that I regularly use is to place a target in the composition. I often use a bar code panel from some rtail package. The target is placed in the composition and focus checked. Then the target is moved to another part of the shot and I go back under the dark cloth. This goes on till I get it right or decide to change the set up. One drawback: Sometimes I get so enthusiastic about finally putting the shot together that the target gets left in the shot.

If you don't see it on the ground glass it is not there.

[darr]

Focus 1/3 to halfway in, tilt if it helps, and shoot stopped down with fingers crossed.
Me, I’d focus stack with my medium format digital tech gear and be done with it.

I get this is a learning process, so consider this a valuable lesson on learning the limits of large format and why the evolution of photography has led us to the current digital processes. It’s all image making no matter how you get there.

Blurring out the background and bringing the focus on the flowers might make a more aesthetically appealing composition.

Best to you,
Darr

[PatrickMarq]

for me now it’s more a learning process, I’m taking pictures sinds 1980 with 35mm and MF, I know perfect there limitations but with LF I have only done landscapes and architecture. So now I’m a bit out of my comfort zone.
For the time being I can experiment a lot.

[Jody_S]

Seems fairly straightforward to use an online DOF calculator for the exact numbers you need, and you'll have to use a tape measure and place a target where you figure out your focus has to be to get both the foreground and background in focus. Then remove the target, say a prayer, and shoot.

[Bob Salomon]

Seems fairly straightforward to use an online DOF calculator for the exact numbers you need, and you'll have to use a tape measure and place a target where you figure out your focus has to be to get both the foreground and background in focus. Then remove the target, say a prayer, and shoot.

Or just get the pocket size Rodenstock depth of field/Scheimpflug calculator and follow the numbered steps. No measuring or targets needed for formats from 35mm to 810. No batteries either, just finger power.

[Tin Can]

Time, to post this again

I set this up in studio 2018, then tried a few lenses and formats to get it all in focus using DOF Master (https://www.dofmaster.com/dofjs.html)

As I lose notes, I think it is 8 feet from the upside down neg to the wood circle, My 8X10 camera was 6 feet from the closest object, the neg again.

I used a tiny flashlight to find corners and check focus. Spent a week setting it up.

The smoke machine was a failure, but kept it

Titled "2 minutes to Midnight" as in WWIII. Everything in image has meaning to me, more lately.

Scan of contact print 1 of 25 made.

https://live.staticflickr.com/7802/47492097241_cb85236cf2_b.jpg (https://flic.kr/p/2fmHpUM)2 min 360 2019-03-24-0001 (https://flic.kr/p/2fmHpUM) by TIN CAN COLLEGE (https://www.flickr.com/photos/tincancollege/), on Flickr

[Jody_S]

Or just get the pocket size Rodenstock depth of field/Scheimpflug calculator and follow the numbered steps. No measuring or targets needed for formats from 35mm to 810. No batteries either, just finger power.

Can you explain in simple terms how the calculator allows you to focus at some calculated point between the flowers and the frame without placing a target to focus on? I'm intrigued, that would be a really useful skill.

[Bob Salomon]

Can you explain in simple terms how the calculator allows you to focus at some calculated point between the flowers and the frame without placing a target to focus on? I'm intrigued, that would be a really useful skill.

You focus on the near point. Focus on the far point and it will tell you where to position the rear standard between the two as well as what f stop to use and how much tilt would be required.

[Jody_S]

So if you have one of those fancy cameras with scales and degree indicators you can just dial it all in, whereas I have to adjust rubber bands and chewing gum to make those adjustments.

[Bob Salomon]

So if you have one of those fancy cameras with scales and degree indicators you can just dial it all in, whereas I have to adjust rubber bands and chewing gum to make those adjustments.

Don’t need scales on the camera. You can use a small ruler and protractor to use a camera without scales. It will also tell you the magnification, and any required exposure compensation.

Using an online calculator you would also need the displacement on the focusing between near and far points.

[Bob Salomon]

Don’t need scales on the camera. You can use a small ruler and protractor to use a camera without scales. It will also tell you the magnification, and any required exposure compensation.

Using an online calculator you would also need the displacement on the focusing between near and far points.

Here it is on B&H. It shows one side. The other side is also a calculator.

https://www.bhphotovideo.com/c/product/155145-REG/Rodenstock_260700_Depth_of_Field_Calculator.html/reviews

[Chester McCheeserton]

Bob, the 1/3d rule doesn't apply close up. It also doesn't apply at infinity.

Why doesn't 1/3 rule apply close up? Or at infinity?

[Chester McCheeserton]

I always found diffraction on film highly overrated, If your goal is to make a contact print, I'd guestimate 1/3 of the way from the closest flower to the wall and stop down to F64.

If enlarging, I'd back up, focus on the same spot, shoot it at F32 and crop. Or get a 210 lens.

[Chester McCheeserton]

Focus 1/3 to halfway in, tilt if it helps, and shoot stopped down with fingers crossed.
Me, I’d focus stack with my medium format digital tech gear and be done with it.


+ 1 or even with a full frame small sensor.

[Dan Fromm]

Why doesn't 1/3 rule apply close up? Or at infinity?

That's how the calculations come out. Do them.

Oh, and by the way, one third of infinity is infinity.

[Tin Can]

and beyond

[Pere Casals]

First image focus on the frame, the second image focus on the flowers


Use this DOF calculator, it makes a good calculation of the theoric circle of confusion with different settings. Using it a bit you will get a clear idea on how "Focus management" is optimized.

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Anyway each lens has a particular behaviour in the DOF, there is a graph named Through Focus MTF that plots the "blur level" through the depth, some proficient cinematographers use those graphs to understand how a particular lens works.

http://cinematechnic.com/optics/super-baltar

[ic-racer]

https://www.largeformatphotography.info/fstop.html

[Drew Bedo]

Sure, measure and calculate . . .its all good.

But check it out on the ground glass. I took a workshop at Santa Fe3 years ago (mid-1990s) and one thing really stuck with me. /the instructor said to us, "The ground glass is truth." and "If you don't see it there, it isn't there."

So check it out. I use a set of bar codes to check focus in diffident spots of a composition. Stopping down haqrd does make it dim. I turn on extra hot lights to let me see what-is-what , then turn them off to expose with strobes or natural light.

I guess what I am saying is use all the tools and techniques you have.

[Jody_S]

I use a set of bar codes to check focus in diffident spots of a composition. Stopping down hard does make it dim.

I've found LED flashlights work well when you have to do this stopped down or with an f16 lens indoors. The ones with 5-6 individual LEDs, if you can make out each individual LED on the ground glass then it's in focus.

[C. D. Keth]

I've found LED flashlights work well when you have to do this stopped down or with an f16 lens indoors. The ones with 5-6 individual LEDs, if you can make out each individual LED on the ground glass then it's in focus.

The small size maglites work well, too, the ones with a regular incandescent bulb. You can unscrew the lens and set the flashlight into the lens housing so the whole thing stands up like candle.


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[enotheisen]

Does your front standard tilt? If it does, set the focus on the frame and tilt to get the flowers in focus.

[Drew Bedo]

Back in the day . . .way back, the Graflex press cameras had an added-on range fildet (Kalart ). /there was an additional accessory light that could be attached to the eyepiece. /this projected two spots of light. As the RF was focused on a target subject, the two spots would come together, When they superimposed, the subject was in focus.

More recently, folks have substituted an LED laser for the little flashlight. While this doesn't address the DOF issue, something along this line of approach might supplement your efforts to accurately place the plane of focus.