Question about lens tilt on 4x5

[Halide]

Thanks again for the additional info - I will visit the links and get a better grasp on the solution for lens tilt.

I use my Epson flat bed scanner to post images on the web and for doing digital proof sheets of my negatives - my dark room time is better spent on printing. As nice and quick as digital printing is I still only print on graded papers with chemicals in the darkroom.

Regards,
Len

[Taija71A]

Thanks again for the additional info - I will visit the links and get a better grasp on the solution for lens tilt...

Len... Just in case you are not familiar with this info...


* New Material
* Recent Additions
* About The INs and OUTs of FOCUS
* About FOCUSING the VIEW CAMERA
* The Scheimpflug Rule
* The Hinge Rule
* View Camera Focus
* View Camera Depth of Field


http://www.trenholm.org/hmmerk/


Enjoy!
--

Tim.
________

[Jim Jones]

When Ansel Adams photographed Mt. Williamson from almost the exact same spot (within inches), he had the advantage of a slightly higher vantage point, the platform on top of his vehicle. The longer lens, the 19" element from a 12.5" Cooke triple Convertible, at f/32 would have increased DOF over your capture. His 8x10 ground glass might have made precise focusing more precise.

[StoneNYC]

When Ansel Adams photographed Mt. Williamson from almost the exact same spot (within inches), he had the advantage of a slightly higher vantage point, the platform on top of his vehicle. The longer lens, the 19" element from a 12.5" Cooke triple Convertible, at f/32 would have increased DOF over your capture. His 8x10 ground glass might have made precise focusing more precise.

Wouldn't 8x10 and a longer lens at f/32 have actually given a shallower DOF than the OP had?

Please forgive the question if I'm confused, I'm also new-ish to LF and still learning. So it's a question not a statement.

[Eric Leppanen]

As has already been noted, applying movements such as tilt is only the first step in the focusing process. Unless further refinements are made, you will frequently get images where the foreground and background are in sharp focus, but other elements are soft, as is the case with your image.

I also have been using the Paul Hansma formula contained in the LF focusing link referenced in Doremus' post. It enables precise control of what is in focus, and what is not. It does require having a millimeter extension scale on your camera (on my wooden field cameras I would print one out on adhesive paper and attach it to the camera body). As far as re-shooting your image, the process would work as follows:

- Set front tilt so that your foreground and background are simultaneously sharp. Pick foreground and background points that are not quite at the extremes of your desired area of sharpness, as this will make better use of the available depth of field later on in the focusing process. For example, in your image apply tilt so that a point near the top of the mountain is in focus, rather than the very top.
- Focus on the point farthest below the plane of focus that you want in focus, and record where it lies on your millimeter scale. This will frequently require sampling a variety of points in the image, since it may be difficult to immediately determine which point is farthest below the plane.
- Focus on the point farthest above the plane of focus that you want in focus, and record where it lies on your millimeter scale.
- Lock in your focus exactly midway between the two focus points you just recorded.
- Based on the distance between the two focus points you recorded, set your f-stop using the Paul Hansma table. In my experience it is rare that f/22 will provide sufficient depth of field when shooting complex subjects with 4x5. Most of the time I'm around f/32 to f/45.

If you want to work quickly, you may want to skip the near/far focus stuff and just apply movements and stop down as much as circumstances permit (that is what Jack Dykinga does). This requires an experienced feel for placing the plane of focus optimally, and means regularly stopping down to f/45 to f/64. Even then, there are going to be some subjects where stopping down to even f/64 won't produce enough depth of field. Alternatively some folks determine the required f-stop by stopping down while evaluating the image on the ground glass, although evaluating focus using a dim, stopped down lens is not my idea of fun.

Personally, I like spending the additional time optimizing the focus point and f-stop. I know exactly what is in focus, and what is not. I'm confident that everything has been done to minimize diffraction (avoiding f/64 is definitely worthwhile for enlargements) and optimize shutter speed.

[Doremus Scudder]

Eric,

I, too, like to optimize sharpness and limit diffraction as much as possible. This allows the making of larger prints before unacceptable lack of sharpness creeps in.

I have pasted-on millimeter scales on all my cameras that don't have them already, plus I have a sticker on all of them with the optimum f-stop for different focus spreads. Sometimes I don't bother to focus on anything except my chosen near and far points. I then read the spread, set the aperture and make the photograph. I'm spending less and less time looking at the ground glass these days and more time composing and framing without the camera.

The trick with this method is to accurately identify the near and far focus points. When movements are applied, these can be in less-than-intuitive locations. Having a mental picture of where in the scene the plane of focus lies helps immensely.

Best,

Doremus

[lbenac]

I think that this might illustrate what was discussed. The focus plane goes from my wife's head in the foreground to my cousin at the top of the mountain but ignores anything under that "plane".



Cheers,

Luc

[Halide]

When Ansel Adams photographed Mt. Williamson from almost the exact same spot (within inches), he had the advantage of a slightly higher vantage point, the platform on top of his vehicle. The longer lens, the 19" element from a 12.5" Cooke triple Convertible, at f/32 would have increased DOF over your capture. His 8x10 ground glass might have made precise focusing more precise.

Hi Jim,

Thank you for the input - I was wondering if anyone was going to recognize the location of the image. I frequently take photo trips to the eastern Sierra and if the weather/lighting is unique when I am near Mt Williamson I will drive up to the location to make an image. As accurate as Ansel Adams records were I believe he may have confused his published "set up" for this image- He made a number of visits to the site before he got his final image. I came to the conclusion it is very unlikely he took his published image from the roof of his station wagon. The site has a very restrictive location to position a vehicle - those boulders you see in the image are part of a 4 mile wide 15 mile long boulder field of granite left behind from the last north American ice age (they were deposited by receding glaciers from the Sierra Nevada) and for the most part (except where a few roads have been cut) haven't moved for quite some time. The access to the site is a small narrow (6 ft wide - 20 yard long) spur road. I regularly make images from the roof platform of my truck if the image needs separation from the foreground. On my first visit I went up on my platform to make the image (as Ansel Adams described he did) but the perspective from the roof top is way too high and there is a huge boulder that blocks the view (of his foreground rocks) if the image is taken from this spur road). I know it sounds like I am a lunatic to contradict Ansel Adams, (he always made good notes of his images) - it is just highly likely he published the wrong record for this image.

For grins I have attached a "happy snap" of my truck with its platform -( It was taken at the site while I was for the light to change).

[Halide]

I think that this might illustrate what was discussed. The focus plane goes from my wife's head in the foreground to my cousin at the top of the mountain but ignores anything under that "plane".



Cheers,

Luc

Hi Luc - That image is very slick! - until I got help from the forum I didn't think something like that was possible.

Regards,
Len

[lbenac]

For grins I have attached a "happy snap" of my truck with its platform -( It was taken at the site while I was for the light to change).

I like your truck :-)