Дальномер

У кого есть опыт подобной переделки?
Мне досталось 2 камеры:
1) Москва-2, исправная (кроме дальномера - расклеились призмы) и в хорошем косметическом состоянии.
2)Москва-4 - потертая и с люфтами, переставил дальномер с нее на первую камеру, юстировку пока не проверял.
Четверку и хочу переделать в пинхол.

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Убей тело - и голова умрет!

Гм.. а как же вы таким пинхолом без дальномера снимать собираетеесь? :shock:

Там ведь дырочка такая тооооненькая-тоненькая, так что наводка на резкость просто ювелирная должна быть.

У пинхола НЕТ наводки на резкость - дальномер ему не нужен
дырочка высчитывается по формуле исходя из рабочего отрезка камеры - причём у москвы она будет достаточно крупная на вскидку 0,35 -0,40мм(более точно уже по формуле)

Теорию пинхолостроения почитал
Вопрос осталось лишь несколько вопросов:
Ампутировать целиком всю конструкцию с рычагами и мехом или просто удалить все линзы из объектива + затвор, а пихол встроить в крышку?
От расстояния между дыркой и пленкой будет зависеть только "фокусное расстояние" или что-то еще?
Что произойдет, если сделать отверстие заметно меньше расчетного? Упадет разрешение зи-за дифракции?

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Убей тело - и голова умрет!

затвор бы я как раз советовал оставить если конечно нет желания после каждого кадра закрывать крышку
пластинку я обычно ставлю на место последней линзы
в общих чертах -
ежели дырка маленькая то пойдёт дифракция и картинка будет неравномерной ежели дырка больше чем надо, то картинка получится размытая из за пропадания эффекта линзы

Да.. Век живи, век учись сказал подпоруччик Ржевский, доставая серебряный порсигар из кармана галифе, и перекладывая его в нагрудный карман френча

Вот тут на английском хорошая информация по изготовлению "дырки":

The Pinhole
The most important part of a pinhole camera is the pinhole itself. Precision made pinholes in brass shim may be bought, e.g. from the Pinhole Resource or the Swedish photo magazine Fotografi. Precision made pinholes in silver foil are avilable from images@airtime.co.uk. You will find a list of sources for pinhole sheets here. But for most purposes there is no reason why you should not make the pinhole yourself.
The hole is made in a thin piece of metal, brass shim (available in some car supply stores) or metal from the lid of small box or glass container (bought at a supermarket ). Some use aluminium foil from a disposable baking pan. Ordinary aluminium foil is too thin. My own experience is with brass shim and thin metal from container lids.
If the metal is taken from a container lid, it should be sanded carefully with ultra-fine emery paper (e.g. # 600) to remove any paint or varnish and to make it thinner. The hole is made with a needle. The edge of the hole should be sharp. The optimal diameter depends on the focal length of the camera, i.e. the distance from the pinhole to the film or photographic paper. Some formulas and charts are reproduced below. In general: the smaller the hole, the sharper the image. If the hole is too small, however, the image get less sharp because of diffraction effects (light is bent around the edge of the pinhole).
Place the piece of metal on top of some hard cardboard. Carefully poke a hole with a needle taking care that the hole is as round as possible. The needle may be put through a cork to make it easier to handle. Or you may put masking tape on the head of the needle. Hold the needle steadily in a 90 degree angle to the surface. Turn the piece of metal and sand the back side carefully with fine-grained emery paper to remove the burr or debris where the needle point has penetrated. (The edges of the pinhole should be sharp). Then place the metal on the cardboard back side up and cautiously spin the needle in the hole to make sure the hole is round. The hole can be checked with a magnifier or an enlarger. You can also use an enlarger or slide projector to check the diameter of the pinhole.

Formulas
According to Eric Renner at least 50 charts suggesting optimal pinhole diameters have been devised in the last 125 years (Renner 1995:118). In my own reading the last six years I have come across about fifteen charts or formulas, a few of which may be derived from the same basic formulas. It should be noted that the diameter of the pinhole is not really critical. But for every focal length there is an "optimal" diameter, i.e. a diameter which produces the sharpest possible image. The word optimal actually is not a felicitous term, since the pinhole photographer or artist may not be striving for the greatest possible sharpness. There are beautiful pinhole images which are intentionally softer than what is technically possible. A good pinhole image is something else than a blurred, out of focus, lens image.
Up to a certain point a small pinhole will produce a sharper image than a larger one. If the pinhole is too small, the image gets less sharp because of diffraction. The hole should be perfectly round, without ragged edges. It may be checked with a magnifier or an enlarger.
Joseph Petzval of Vienna apparently was the first, in 1857, to attempt to find a mathematical formula of the optimal pinhole diameter for the sharpest definition in a pinhole image. The British Nobel Prize winner Lord Rayleigh (John William Strutt, 1842-1919) worked on pinhole diameter formulas for ten years and published his work in Nature (1891). Lord Rayleigh's formula is still one of the formulas used to today. A number of others have been published since the 1880s.
Lord Rayleigh's formula for subject distances above 1 meter may be written as follows:
d = 1.9 * sqrt (l * f),
where d = pinhole diameter, l = wavelength of light and f = focal length or distance from pinhole to light-sensitive material.
For the wavelength of light different average values may be substituted. Often the value of the yellow-green spectrum is used, i.e. 0.00055 mm.
According to Renner (1995: 117) most formulas used today are of the following general form:
r = sqrt (l * c * f)
r = pinhole radius
l = wavelength of light
c = a constant, usually a decimal fraction between 0.5 and 1
f = focal length
Platt (1989:73) provides the following optimal pinhole formula:
d x d = f/k, where k is a constant of approx. 1300
Dobson (1991) provides this formula:
d = sqrt (f)/25
Lord Rayleigh's formula and those published by Platt and Dobson all give somewhat different results. Andrew Davidhazy of the Rochester Institute of Technology lists several other formulas in a posting on the net.
Four, slightly different, charts of optimal pinhole diameters are reproduced below. Some of the charts have been simplified by leaving out references to needle numbers. Holter's chart, published in Norwegian, has been translated by me. Platt's chart differs from the others by consistently giving smaller apertures.
Bogre (1988)
Focal length Best aperture diameter Equivalent f-stop Exposure factor for f/22
50 Mm 0.29 mm f/174 63 x
75 mm 0.35 mm f/213 94 x
100 mm 0.41 mm f/246 125 x
125 mm 0.45 mm f/275 157 x
150 mm 0.50 mm f/203 188 x
200 mm 0.57 mm f/348 250 x
250 mm 0.64 mm f/389 313 x
300 mm 0.70 mm f/426 376 x
Platt (1989)
Focal length (mm) Pinhole diameter (mm) f-stop
130 0.33 380
210 0.40 500
260 0.46 550
320 0.50 650
420 0.58 690
550 0.66 800
650 0.74 930
750 0.79 960
1000 0.91 1120
Holter (1990)
Focal length (mm) Pinhole diameter (mm) f-stop Exposure factor for f/16
10 0.14 70 20
20 0.20 100 40
30 0.24 125 60
40 0.28 140 80
50 0.31 160 100
60 0.34 180 125
70 0.37 190 140
80 0.40 200 160
90 0.42 214 180
100 0.45 220 190
150 0.54 280 300
200 0.63 318 400
250 0.70 360 500
300 0.78 380 560
350 0.84 418 700
400 0.89 450 800
Fuller (1992)
Focal length (mm) Pinhole diameter (mm) Approx. f-stop
50 0.26 200
75 0.32 220
100 0.45 240
150 0.55 270
200 0.63 320
250 0.71 350
300 0.77 390
350 0.83 420
400 0.89 450
500 1.00 500


It should be borne in mind that for most purposes the diameter is not really critical, as the different values in the charts above may demonstrate.

Взято отсюда:

http://photo.net/learn/pinhole/pinhole

Ув. CreativeMan к чему такие сложности(такая выкладка цифр отпугивает) - всё гораздо проще в рунете есть вполне дружественный сайт по пинхолам и прочему - www.pinhile.ru на главной странице у него как раз стоит калькулятор для расчёта дырки
также на форуме этого сайта можно всегда задать интересующие вас вопросы и выложить фото на всеобщее обозрение