jim_jones3

<p>When shooting at right angles to the sun, a polarizing filter helps darken the sky in both a b&w and a color photograph. This works better with a fairly long focal length lens than a wide angle.</p>

<p>To be consistent with the other pinhole diameters in your information, the diameter for a 135mm focal length in the 35mm chart should be about .5mm, not your .39mm.<br> There may be little need to include the image circle data. Some pinhole photographers are content with greater image circles than listed.</p>

<p>The formula for optimum pinhole imaging has been debated for well over a hundred years. I use PinholeDesigner <a href="http://www.pinhole.cz/en/pinholedesigner/">http://www.pinhole.cz/en/pinholedesigner/</a> with a user constant of 1.4 instead of the Lord Rayleigh constant of 1.9, based on my experience and preference in pinhole images. Others may have different experiences and preferences. For wide angle pinholes, that user constant is sometimes increased to improve image corner sharpness at the cost of some center sharpness. Lord Rayleigh apparently based his formula more on scientific theory than on pinhole photography. Pinhole image sharpness near the optimum pinhole diameter is limited both by geometric optics and wave mechanics, resulting in ambiguity between the two theories. One way to experiment with varying pinhole diameters is to use a 35mm camera with pinholes at several times the normal lens distance and a target that simulates the subjects one prefers. This permits multiple testing on one convenient strip of film with an image in which the pinhole blur is relatively large.<br> Some of the charm in pinhole photography is its contradiction of hard science. Do your own thing, and let the magic begin!</p>

<p>Cameras come and go, but the right tripod is a lifetime investment. I've owned perhaps a dozen tripods over the past 65 years, but for 42 years have mostly used original Tiltall tripods for cameras up to 5x7. They cost under $100 online. The permanently attached 3-axis head saves the expense and potential loss of stability of aftermarket heads. With the legs fully extended, the platform is only 57 inches from the ground. However, the center column gives another 12 inches, and is rigidly clamped with a collet instead of the less solid side screw. Tiltall uses a standard 1/4 inch tripod screw. A quick detach system can be mounted if one wants to sacrifice the advantages of the original camera mounting system. I have no experience with the currently imported Tiltall products.</p>

<p>Your first camera may well not be what experience will demand as you become more proficient. Therefore, don't spend too much money now. That beginning camera can become a backup camera if you upgrade. It's good to have one that you can also use where you don't want to risk your best camera. I chose the cheapest Nikon DSLR because lenses and other accessories from my Nikon film cameras fit it. Years later it still does all I need. Even a second-hand point-and-shoot camera and a capable photographer are capable of prize winning photos. If possible, do speak to the instructor so you won't be handicapped by an inappropriate camera.</p>

<p>To further complicate the problem, the required DoF varies with different subjects. Edward Weston sacrificed sharpness in favor of greater DoF in some of his macro-photographs by using tiny diffraction limited apertures. Because of the subjects, form and luminosity were more important than apparently perfect sharpness. Soft focus lenses also complicate DoF calculations. DoF considerations are more art than science.</p>

<p>One of the several books on large format or view camera photography might be more valuable than mere videos. Book publishers are more selective and professional than Youtube. The information is usually more comprehensive and better organized. However, a few operations may be better presented in a video. John Shriver's suggestions in the first reply are accurate. For large format, knowledge is cheaper than equipment and film. Spending time learning about the subject is more practical than spending money without knowledge. When you understand all of the options available in large format photography, a few hundred dollars might get you started in 8x10 images that at best would be only slightly better than those printed from smaller cameras. You could also spend a few thousand, and have gained no more.</p>

<p>Probably many of us have downloaded the USAF 1951 chart and printed it at various sizes. One source of information on the chart is http://www.takinami.com/yoshihiko/photo/lens_test/pdml-procedure.html. In this link, the width of the large black square should be 35.5mm for the resolution figures to be correct.</p>

<p>My few purchases from Japanese sellers have been flawless. Do check feedback.</p>