Registration Punch? No?

[cyrus]

OK so there was an 8x10 Condit registration punch on Ebay, with 1 bid for $200, and no one else placed a single bid on it. The delivery cost was OK, and the seller has a perfect record.
I thought these things were as rare as hen's teeth and somewhat desirable?

[jeroldharter]

That is just for a punch. Not dirt cheap. I do see them pop up from time to time.

[mdm]

You are a god.

[Drew Wiley]

The punch isn't much good unless you have a precisely matching pin bar or pin glass,
or preferably a set of them. Some of the later punches had adjustable spacing. I've
passed up any number of these deals. I've got an immaculate new diagonal punch right now that I still have to mfg the matching components for. Might not ever get around to it. Still have other sets in good working order. It's a lot easier to get gear for really big film sizes, which were formerly used in conjunction with graphics copy cameras. Extremely small differences in pin spacing can spoil registration. Condit used
micropins which had the tiny 1/16" inch pin slightly off-center from the 1/8" base, so
that they could be every so slightly rotated for exact adjustment, before the expoxy
set. Still, if one was smart, they ordered spare pin glasses or bars up front, along with
the original punch. Condit kept punched mylar strips of everything they made; but post
ordering wasn't always completely sucessful. The biggest problem right now is finding
any kind of thick anti-newton glass which can be successfully drilled without chipping.
I've acquired a number of small diamond bits and lubricants to test, but am not terribly
optimistic. I did find an alternate way of doing it, without resorting to pins outside the
glass itself, which will either crop some of the image or necessitate taping a supplemental registration strip (easy to do, but one more potential source of misregister if multiple masks have to be generated).

[nolindan]

You don't need to use a pin bar - loose pins work just as well, if not better. You do have to be a bit more careful though. The pins on a pin bar can be fixed or they can be loose and slide along the bar. The bar makes it harder to mislay pins, helps keep the pins from tilting and can speed production.

The punch should make one round hole and one rectangular/slotted/oblong hole in the direction of the round hole. The round hole co-locates a point between the films, the second oblong hole co-locates the angle between the films. Oblong pins are available for use with oblong holes, but aren't a necessity. If your system makes two round holes then the second pin should be a 'diamond pin'. Fixed-spacing punches are cheaper and less flexible than punches with adjustable hole spacing.

Using all round holes with all round pins can be done only using loose pins - and even then it isn't a good idea. Round pins and a fixed pin bar is a recipe for disaster: the coefficient of expansions of film, pin bars and punch bases are all different and buckled film is a certainty. Using oblong holes means the pin locations can vary an 1/8" or so and the films will still be in register.

If you are working with large (20x24) films then a third oblong 'tail' hole on the other edge of the film is made at right angles to the other two holes.

On a budget you can get away with a round pin, a diamond pin and a perfectly ordinary paper punch. The punches that make holes at the top of the page sometimes make smaller holes - an advantage with 4x5 negatives.

[Drew Wiley]

Nichoas - that's how graphics punches work, not punches for typical small sheet film
like 4x5 or 8x10. If you have different coefficients of exp/contr then you are using the
wrong kind of film entirely! Remember, most camera film punches work with enlargement in mind, while graphics punches are generally only for contact work; so the significance of even tiny errors is itself equally enlarged, and then repeated with each sucessive steps. I have both kind of punches.

[cyrus]

The punch isn't much good unless you have a precisely matching pin bar or pin glass,
or preferably a set of them. Some of the later punches had adjustable spacing. I've
passed up any number of these deals. I've got an immaculate new diagonal punch right now that I still have to mfg the matching components for. Might not ever get around to it. Still have other sets in good working order. It's a lot easier to get gear for really big film sizes, which were formerly used in conjunction with graphics copy cameras. Extremely small differences in pin spacing can spoil registration. Condit used
micropins which had the tiny 1/16" inch pin slightly off-center from the 1/8" base, so
that they could be every so slightly rotated for exact adjustment, before the expoxy
set. Still, if one was smart, they ordered spare pin glasses or bars up front, along with
the original punch. Condit kept punched mylar strips of everything they made; but post
ordering wasn't always completely sucessful. The biggest problem right now is finding
any kind of thick anti-newton glass which can be successfully drilled without chipping.
I've acquired a number of small diamond bits and lubricants to test, but am not terribly
optimistic. I did find an alternate way of doing it, without resorting to pins outside the
glass itself, which will either crop some of the image or necessitate taping a supplemental registration strip (easy to do, but one more potential source of misregister if multiple masks have to be generated).

I just tape the mask and neg together - solves a lot of problems