Opinion on the book, "Focusing the view camera" by Merklinger?greenspun.com : LUSENET : Large format photography : One Thread
I read this book and was fascinated by it, however, he represents everything as theory's only. I am very compelled to beleive the "hinge" rule he talks about the whole book. Has anyone else read and tested his focus concepts? Success in the field? Things you would disagree with?
-- Bill Glickman (Bglick@pclv.com), January 13, 1999
I suppose there are people that are more intuitive and others that are more rational. Some go on to be great poets and some become brilliant physicists. Some combine both. I'm no great photographer, but Merklingers book is way to technical and complicated if you ask me. Which I guess you did. You can see what you're doing on the ground glass and judge the tilt and swing yourself. It takes a little experience and it's easier in some light conditions than others but you can see it right there rather than stand outside the dark cloth and calculate it.
-- Sean yates (firstname.lastname@example.org), January 13, 1999.
I hate to disagree with Sean because he's been so helpful to me in other posts but Merklinger's book has saved me all kinds of agony regarding tilts. It does take a while to read and understand because M is being very careful to build a good case. But I believe every word and I also encourage you to look at his other book, Ins and Outs of Focus. After reading these books carefully I have really come to like the guy and what he has done. He runs very useful experiments to test what he is saying. I got extremely frustrated reading about the Scheimpflug rule in other texts because it leaves out a major component of what is needed to set your tilt. Just because your two standards intersect say six feet below the camera does not mean you know what angle your plane of focus will subtend. It only tells you that your plane of focus will pass through a point six feet below your camera. Maybe it flies straight up from there. Maybe it points down. Who knows? Merklinger's book and technique will tell you. As Sean points out, you can see it all on the ground glass but I have spent an awfully long time playing with tilts and focus to get something close to but not exactly what I wanted in focus when my eyes finally gave out and I quit trying in a given photo. Merklinger's book is inexpensive and I suggest you get ahold of a copy.
-- Erik Ryberg (email@example.com), January 13, 1999.
I recently purchased and read both of these books. I think they are a good reference to have. But I find them more an "armchair" photography reference, not so useful for me in the field. I am not the type to carry a calculator, charts, protractor, etc. I have a hard time in most situations determining what the "J" distance is: being somewhere between 20 & 50 feet underground of the camera for a typical situation. Still, I have found "Focusing the View Camera" to be valuable to undersand the tradeoffs in tilt and depth of field and knowing when and how much to apply. It makes you to realize how sensitive the tilt is and how it is effected by focal length. I would not carry all those tables in my pack, along with a protractor to set 1.38 degrees of tilt to the front standard...... Being pragmatic on what works for me in the field, Focusing with a loupe on the ground glass, selecting the 2 near/far points on the selected plane of sharp focus, is what works best for me. The beginner tends to try and use too much tilt. For depth of field estimation, I find the simplest approach is to focus on the nearest and farthest objects and measure this distance on the front standard in millimeters. ( I don't actually measure it, I know how far the focus knob must rotate to move per mm) For a CoC of .05mm: If the change in focus is 2.2mm use f/22, etc. If change in focus is 3.2mm from nearest to farthest point, use f/32, For a CoC of .1mm: If change in focus is 2.2mm use half that: f/11. This is real easy to remember, works for all focal lengths, no calculator or tables. When you get to know how far your fine focus knob moves, you can estimate without coming out from under the cloth. Before I started using this method, I found just stopping down and using the loupe to determine when things get sharp worked well. Though this can be a problem in dim lighting. These methods have correlated very well with what ends up on the film.
I don't doubt that one could use his methods and that they work, but for me, I would still need to confirm I had everything exactly right on the ground glass, so I just skip the tilt angle table lookup and setting, and go directly to the ground glass. Mr. Merklinger states in his book that he has not done much LF work. Adjusting tilt by "trial and error" is hard when you are just starting, but gets easier with a little practice: you get a feel for it and don't overshoot so much. I use the "focus on the far, tilt for the near" method. With 2-3 itterations (I have base tilt) its set. I am glad to have and read his books and they will stay in my reference library, but I have not found the need to take the tables in the field.
-- Gary Frost (firstname.lastname@example.org), January 13, 1999.
Sorry if I gave the wrong impression or offended. I have no doubts about the validity or soundness of Mr. Merklinger's work, that he builds a well-reasoned, cogent argument, etc. I imagine I would buy it as a reference text at some point, or check it out of the library. However, I don't see it as an invaluable tool. I just feel (i.e. emotion rather than thought) that it's too much to deal with when you're shooting and what you need is right there in front of you.
When I started out I sat down and calculated all the hyperfocal distances for my lenses at their various apertures for a given C.of C. and so on. But I don't use those tables in the field, to awkward and time consuming and too distancing from the "organic" process of making an image, more thought, less feel/experience. But again, my opinion is worth what you paid for it. By the by, Linhoff has made a depth of field scale for years based on measuring the focus spread and now apparently they make an angle calculator as well, available from B&H I think.
-- Sean yates (email@example.com), January 13, 1999.
As I (still) have no LF experience yet, my comment is more general :
I recently read carefully through Merklingers series of articles on DOF for non LF (i.e. no movements) cameras which are presumably covered in his book 'The Ins and Outs of Focus'. After struggling for a number of years with DOF and soft landscapes using wide angles in 35mm I was enthralled. Being a theoretical physicist I soaked it up, worked it all out myself and did a bunch of in camera tests. The result being that I have fundamentally changed the way I think about and take these kind (large DOF landscape) pictures. Unfortunately in the articles that I read, he does not take the diffraction limit fully into account in his analysis. This leads to somewhat erroneous conclusions, in particular that you must always stop down a large number (7 in his case) of stops to achieve maximum sharpness at infinity, hence effectively eliminating the notion of a hyperfocal distance. In fact you can revise the definition of hyperfocal distances and for small apertures (f/22 and below) they are quite reasonable. He always used f/8 for which his conclusions are mostly correct.
As for the practical usefulness of his full approach when you have camera movements... I might tend to agree with a few others here. But his thought process about obtainable sharpness and DOF is in my professional opinion correct, while most other stuff I read in photography books is technically questionable at best.
-- Richard Ross (firstname.lastname@example.org), January 14, 1999.
I agree with Merklinger that using the "standard" CoC and Hyperfocal will produce a "worst case" resolution at infinity and if sharpness at infinity is important, don't use the hyperfocal. Certainly for most situations better resolution at infinity can be obtained by using a smaller CoC. My method of achieving this is to use the hyperfocal distance of a wider aperture (1 to 2 stops) than what I actually set the camera. (ie. set hyperfocal for f/8 and shoot at f/16, effectively using a smaller CoC.) Still you can run into diffraction issues if you carry this too far, and some situations you may need,(or even want...) to let some part of the picture go soft. Whether it is foreground or infinity is dependent on the subject.
-- Gary Frost (email@example.com), January 16, 1999.