Re: Still life - DOF problem
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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Re: Still life - DOF problem
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.
Re: Still life - DOF problem
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.
Re: Still life - DOF problem
Quote:
Originally Posted by
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.
Bob, the 1/3d rule doesn't apply close up. It also doesn't apply at infinity.
Re: Still life - DOF problem
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
Re: Still life - DOF problem
Quote:
Originally Posted by
Dan Fromm
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.
Re: Still life - DOF problem
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.
Re: Still life - DOF problem
Quote:
Originally Posted by
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.
With what circle of confusion?
We don’t know if the op wants to make a contact print or a mural.
Re: Still life - DOF problem
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.