A Manual for NuvoFocus (Final release version)
NuvoFocus
Two big attractions of a Tech Camera are; the availability of the best optical quality lenses; and capability of 'movements' - shift, tilt, swing.
Two big challenges of a Tech Camera to a photographer are; difficulty to focus accurately; and less than ideal means of composing the images.
NuvoFocus was designed to solve the first challenge; means of accurate focusing with or without lens TILT, SWING, or CAMERA TILT.
A quick comment on built-in screen of DBs:
It is my humble opinion that no matter how great a built-in display of DBs becomes, with or without LiveView, it will not meet the expectations of most photographers with Tech Cameras. Display screen is TOO SMALL since we are accustomed to staring at 30" high resolution screens, with 100% view at a click of mouse. We cannot go back composing and focusing on 3.2" screen when an iPad gives us 9.7" screen and an old 4x5 View Camera gave us 6 +" ground glass.
I do not have any better solution. For now, I am content with lugging 13" Retina MacBook Pro and tethering to DB for fine adjustment of my composition, and relying 100% on NuvoFocus for accurate focusing.
A Simple Argument for Precise Focusing:
It may seems silly to some that a photographer should use 'mathematical' formulae to get a focus setting while creating 'art with soul'. My only argument would be, 'IT IS A TOOL' just like paint brushes or color pigments for artists.
It is a step which allows a photographer to make her workflow simpler and to take advantages of her lenses and DB for better results.
Distance Measurement:
A Disto is preferred device, especially, if Lens Tilt is to be used. It can be handheld for Simple DOF but should be mounted on a tripod if Lens Tilt is used.
The specification claims that Disto can measure distance range up to 100 meters but I haven't been successful any farther than 40 - 45 meters in actual field application. I did measure an object (aluminum Street sign) that was 65 meters away but the range is more limited with 'natural objects' such as tree trunks or rocks.
HFD (Hyper Focal Distance) with CoC of 20.4 microns and f = 8 is 50 meters for SK90, 61 meters for SK100, and 88 meters for SK120. Which means, a Disto may not cover the needed distance measuring ranges for lenses longer than 100 mm or so.
In Lens Tilt application, it is not necessary to select 'FAR' object at greater distance since we are using
'Wedge of DoF'. The boundary of acceptable DoF extends to 'Infinity' within defined angles.
For example shown in
post # 84, the vertical range between 3.04 meter above and 0.5 meter below the ground level is within the boundary of acceptable DoF at a horizontal distance of 10 meters from camera, therefore, roughly 60 meters above and 10 meters below the ground level will be within the boundary of acceptable DoF at a horizontal distance of 200 meters from camera.
It is an absolute necessity to have a 'Fixed Mounting Platform' for both camera and Disto in order to measure accurately the needed distances for Lens Tilt. See
Post # 77 for explanation and an example.
My workflow using NuvoFocus for Lens Tilt:
As I indicated earlier, I tether my DB to a Retina MacBook 13 for critical composing.
1. Select a right focal length lens for the selected composition.
2. Frame the image using whatever method you use. Tilt the camera if needed but no tilt of the lens yet. Review image on built-in display just to see if four edges are properly located.
3. Fixed the camera height and the camera tilt (if you are using it). Measure and note the camera tilt angle and the Disto height.
4. Aim at Near Object point with Disto laser point using Cube's pitch control. Measure X, Y location. Repeat the same for Far Object point.
5. Reset the camera to the tilt angle that you noted before (so camera is again set for the desired composition).
6. Enter the data into NuvoFocus; Disto height, camera tilt angle, camera focal length, near and far object location coordinates.
7. Set Lens Tilt angle and the calculated Focus Distance (and Index Setting with Lens Equation) per NuvoFocus output.
8. Take picture and review the composition.
9. You may want to adjust your composition.
10. Many adjustments can be done by 'shift R/L and raise U/D' instead of changing camera height or camera tilt angle. No adjustments are needed to the lens tilt or focus setting when you do 'shift'.
11. If you decide to use different focal length lens, let say 47mm instead of 35mm to tighten the composition, only thing you have to do is to select other lens in the program. No new measurement are needed. Change the lens, adjust the lens tilt angle and focus setting, and shoot. You have another pin prick sharp image.
Jae Moon