Advice please on focusing with movements
So I made my first large format foray with my 8 X 10 combo legend.
I Shot an old building that had a nice range textures.
I used my 165mm Schneider Super Angulon and applied a bit of tilt to correct for a Vertical element in the scene .
I used an incident meter held at the face of the building to meter the scene .
For HP5+ at 40O I Used F16 at 1/250 as per my meter .
I developed in XTOL 1: 1 for 12 minutes in a tray .
The negative and contact print look great !!
Except for the depth of field and Focusing.
I had thought that My depth of field Was Sufficient based On an app that Calculates Such things On my phone but apparently not.
So can anyone offer any advice for my second foray this weekend ?
Hi, I'm not able to say what you did wrong, but I would revisit your decision to use tilt on this building. What aspect required tilt, and did you tilt the front or back? Did you check focus on the ground glass with a loupe? Doing so should help avoid these situations in the future IMHO.
Tell us about how you were focusing.
Did you check multiple parts of the ground glass with your focus loop?
f16? Not much depth of field there. Try f45, or even f64 if contact printing. Does your app use the formula of Hansma?
The OP was photographing a building so they were probably correcting for key-stoning.
Originally Posted by Karl A
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Right, f16 for 8x10 ain't much. I would think more DOF is needed.
Just as a comparison, 165 f/16 on 8x10 is about the equivalent of 30mm f/2.2 in 35mm or 45mm f/3.5 in 645: ie not much...
An awful lot of electrons were terribly inconvenienced in the making of this post.
First, if you are correcting for keystoning, (i.e., making sure the verticals are parallel and not converging), then you should be (preferably) setting up the camera level and parallel to the building with both standards in "zero" position or (basically the same, but fiddlier) tilting both standards; the back to fix the convergence and then the front to bring it parallel to the back for focusing reasons; if the front and rear standards aren't matched to the plane of sharp focus, you'll have problems... more later.
Originally Posted by bascom49
Whoa Nellie! You use f/16 with a 165mm lens on 8x10 film and expect any depth of field? I shoot 4x5 mostly, and a lot of buildings, f/22 is the largest aperture I would ever use (that translates to f/32 on your 8x10) and I use f/32 a good percentage of the time (f/45 for you). With minimal enlargement or contact printing, you can easily use f/64. Most LF lenses give best performance at around f/22 anyway.
Originally Posted by bascom49
I don't know what app you are using to determine depth-of-field, but it kind of sounds like it is designed for 35mm cameras, not LF.
Originally Posted by bascom49
Here's my method of focusing (it is very different from looking through a viewfinder and twisting the focusing ring on your lens...):
I usually have my camera position and framing determined before I set up my camera. I set up and then choose the lens which best fits my framing visualization without cropping it too small. I then point the camera at the subject and rough focus and basically position everything where I want it, ... no fine focusing yet ...
If I am interested in making sure vertical or horizontal lines do not converge, I make sure the camera back is parallel to the surface(s) I want parallel by first using the levels on my camera to roughly level the camera and then using the grid on my ground glass and the tripod head to get 1) the center line vertical (side-to-side tilt w/ the tripod head) and then the verticals on the sides of the frame parallel (front-to-back tilt w/ the tripod head) and finally, bring the horizontals on the edges of the frame parallel (if needed) using pan on the tripod head. I have thus positioned my camera back correctly. I then use rise and shift to frame the building as I wish. Note, no tilts or swings have been applied.
If I am not interested in making sure parallel lines do not converge (which actually is rather rare...), I set my camera up in zero position and just point it at the subject.
Now, I begin focusing. I first determine which plane in my subject I want to focus on. This is chosen to optimize depth-of-field and does not necessarily correspond to a plane on any object in the scene. However, in the case of a building being photographed frontally, it will usually be the face of the building. I then choose three or four easily-identifiable points on this plane as far away from center as possible.
Since I have a camera with base tilts, I always focus the point at the bottom of the ground glass first. I then check the point at the top of the ground glass (yes, bottom of the scene) to see if it is in focus. If not, I need to apply tilt. If I have the camera back in the correct position already for preventing convergence of parallel lines, I cannot tilt that standard (or swing it either if the horizontals have been brought parallel), so I have to use lens tilt to bring both top and bottom focus points into sharp focus. I then repeat this process with the focus points on the sides, not using back swing if the horizontals have already been brought parallel.
Now, I find the nearest and the farthest points in the scene that I want to be in sharp focus. I focus on them alternately and not the focus spread in millimeters on the millimeter scale I have pasted on the focusing rails of all my cameras.
I then consult my table of optimal f-stops for acceptable depth of field for the format I am using (usually 4x5 inch) and maximum enlargement size I anticipate (up to 20x24 in most cases) and choose the proper aperture from the table. It is usually from f/22 to f/45.
Now you are asking: What table? Where do I get one? etc.
Go here: http://www.largeformatphotography.info/ and read the articles, "How to focus the view camera" and "How to select the f-stop." Take your time and digest and understand all of this and you'll never have another question about focusing and depth-of-field. Yep, it is long and a bit technical, but well worth your time.
Watch this and all will become clear: http://www.youtube.com/watch?v=0JU-eHpk97Y
The f64 club was called that for a reason.
Thanks for the help
l am planning on returning to the same location this weekend and using all of your generous advice .