out of focus?

[james silverman]

I still havent managed to master the focusing of the camera i am using a 5x4 monorail toyo view and have stuck a paper ruler on my rail with double sticky tape. Ihave been testing using the "visual" method to focus first on the far object, then on the near object using a lupe, and then split the difference on the rail. I find it difficult to focus without being wide open at 5.6 ..then i stop the lens down to f22 and am finding out of focus images.



I would rather use a method which is simple and uncomplicated.

It is working out really expensive my testing with no satisfaction...

any advice welcome?

[Frank Petronio]

If you are doing typical near-far landscape photos, are you using a front forward tilt along with "splitting the difference"?

I tend to rely on what I see on the ground glass, using a loupe and a tightly closed dark cloth. I allow time for my eyes to adjust so that I can see what things look like stopped down, but I always determine the main plane of focus - and set the tilts/swings - with the lens wide open. If I don't see the effects of the movement in action at 5.6, then stopping down isn't going to promise that my images will be in focus (unless I get lucky.)

More often than not, I don't preview the image stopped down - if it is good at 5.6, and I am using a modern lens that doesn't shift its focus when stopped down (most don't) - then I don't bother.

[Peter Collins]

James,
If you could be a bit more specific about "out of focus images," the forum might be of considerable help. For example, tell us if there is a plane of sharp focus anywhere in the field of view, and if there is, where is it relative to where you expected and wanted it. Also, is this a problem with the camera and all the lenses you have (or, do you have only one lens)? How deep (in feet) do you desire the depth of sharpness to be, and how far is the camera from the near object? What is the focal length of the lens used in this example?

[Chris Mallison]

What focal length lens are you using? Depending on how close the closest object is, f22 may not be stepping down enough, especially on a 210mm lens or similiar. A well-regarded photographer said at a workshop that he just about always stops down to f45. Granted, this was for 8X10, but the lens in question was approx 110mm. As mentioned above, with a tilt, f22 could be adequate in many circumstances. The general principle of focussing "in the middle" seems valid. But even with my 90mm on 4X5, I've started using f32 more and more.

[Glenn Kroeger]

James:

Have you tried any shots at f/5.6? It is possible that your ground glass and film holders are not correctly registered. I always shoot a test target to make sure the ground glass and fresnel are correctly positioned.

[Alan Davenport]

What lens are you using? Some lenses, esp. single elements of convertible lenses, can exhibit a shift in focus when stopped down (vs wide open.) Also may be caused by uncorrected chromatic or spherical aberration.

St. Ansel talked about focus shift in one of his books. One solution is to mark the amount of shift on the camera bed, then fudge the focus by that much before taking your shot. See "The Camera."

[Jim Rice]

I've never attempted the "split the difference" method of focusing. I determine what elements I want to be in focus (sometimes it involves compromise) and use front movements to get there. Once I have done what I could with movements, I stop down to fill in the spaces. I almost always shoot between f 22 and f 32.

[Jim Rice]

Oh, and I also double check everything with the loupe after I stop down, even though I'm sure that my lenses don't exhibit focus shift.

[Glenn Kroeger]

You can try all of the techniques mentioned above, but if your ground glass or fresnel are mislocated, you will never get properly focused images.

[Tom Perkins]

You may find it useful to get some strong reading glasses, 3x or 4x, instead of using the loupe. Then you can watch what is going on. Keep going back and forth, and making small adjustments to focus and tilt, until you have it nailed. Don't stop it down until you have the focussing part done. If you can get ahold of a polaroid holder and box of film, it would be cheaper than testing transparencies, and more immediate than processing your own film, although processing your own is probably cheaper. Take your time and just kind of explore the world with the ground glass. Save the loupe and the scale for after you get a handle on the way the instrument works. Good luck.