Pin registration system preferences

[interneg]

For those who use pin register systems, do you find the small pins within the film margins (Condit, Inglis) better/ more precise than bigger pins on a taped on strip (Radeka, Durst)? I'm in the process of assembling a carrier for my 8x10 enlarger (a De Vere 5108) & wanted to get a sense of what people feel works better for more heavy duty sequential work. My own sense is that the fine pins tend to be more precise overall, but the bigger pins tend to be easier to enact on equipment in terms of adaption/ assembly - in the main this will be for printing colour neg using RGB filters as well as working with separations for various processes.

[Drew Wiley]

I have a complete Condit micro-pin system, including registration punches, contact frames and glasses, etc. I've personally adapted glass for my Durst and own 8x10 registration carriers to match this. Registered CARRIERS are NOT necessary for basic masked printing, only for things like sequential color separation negatives like you're interested in. Offset-diameter micro-pins might now be impossible to find; but similar diameter stainless pins can be acquired from McMaster. Drilling the glass and correctly aligning these pins is tricky, but a doable procedure which can be described if necessary. I am unfamiliar with the DeVere system, so can't help you there with respect to carrier modifications.

[interneg]

I'm making a light source & carrier that more closely matches my needs - I have various dislikes about the later De Vere carrier (especially the hinges) & its pin register variant is a bit improvised in my view. The main headache is how easy it is to drill suitable holes in a coated glass like Schott Mirogard - at a guess something along the lines ofa lapidary drill bit will be needed to safely drill the glass.

Regarding the eccentric pin, I take it that it was designed to describe an arc as it rotated to allow for ultra precise matching to the punch? There are a number of approaches I can see that would achieve the same result - I notice the Inglis carrier achieved the same end by using a small plate holding the fine pin & a bigger pin attached to the holder - it describes the same arc. Making a suitable pin with the offset would be downright easy for the toolmaker I'm going to work with on this project, so I'm not particularly concerned about it.

One other question for Greg: would you happen to have the 5108 manual? There's a very specific question I have about the neg stage to column spacer on the DVB/ DVW model - if you don't, don't worry - I'll bother John Boyce of Odyssey about it sometime this week.

[Eric Woodbury]

I'm no specialist on this topic, but if you want a quality 1/4" punch, it is generally available from ebay. It's an ACCO Products 2-hole punch from the 30s on through 50s. A nice sharp solid pin. Cuts a good hole. Made in USA.

196540

[Peter De Smidt]

I have one of the older 504 pin-registered carriers, the ones without the plastic hinges. I use it on my newer 504, even though the carrier is thicker than the new one. To do so, I made 1/4" metal spacers to replace the ones in the head. They simply have to be a bit longer to allow the thicker carrier to be insert. De Vere uses Kodak-style pins. A while ago I was able to buy some from Stossur. I probably have some spares.... To be honest, though, I didn't get much in to masking, and so I use on older non-pin-registered carrier in my 504.

[Drew Wiley]

Eric - that's not the kind of punch in mind. Even if it was 1/4", that diameter would have to be absolutely precise, and the spacing between the two punch holes has to be reliably consistent within a few thousandths of an inch every single time. Something like that is readily available from Ternes Burton or Olec Stoesser. But unless you're just punching a taped-on strip of film, a 1/4" hole takes an unacceptably drastic amount of meat out of the edge of a negative.

[Drew Wiley]

Interneg - drilling thin coated glass is risky to say the least. There are miniature solid carbide bits from McMaster-Carr that might do it on a precision drill press without almost zero chuck wobble. The special type of glass Condit used for drilling has not been available for a long time. What I've done instead is to split a thin brass register strip into two halves with a missing bit of space in the middle. Then I've every carefully ground a precision shallow groove in the glass with an on-edge small rubberized abrasive Dremel wheel (McMaster). Then the two opposite halves of the pin strip are set into the groove with wet 2-ton thin epoxy while firmly attached to a prepunched piece of film. Keep the epoxy off the top of the strip or film itself. Weigh or tape everything down perfectly flat for at least 24 hrs. Clean up any epoxy overage with acetone. This is a simple procedure in concept, but more like being a surgeon in its finickiness. But it sure beats chipping or shattering the glass with a drill bit.

[Pere Casals]

Interneg - drilling thin coated glass is risky to say the least.

Today this is easy:

https://www.youtube.com/watch?v=E1QaQHjCAv4
https://www.youtube.com/watch?v=1TEhYy4AcfM

CNC waterjet made holes may be a bit conic, so a polishing may be required later.

[interneg]

Today this is easy:

https://www.youtube.com/watch?v=E1QaQHjCAv4
https://www.youtube.com/watch?v=1TEhYy4AcfM

CNC waterjet made holes may be a bit conic, so a polishing may be required later.

It's an abrasive jet, the spray is not good for coated optical surfaces. I looked at laser cutting but I think it would be prohibitively expensive. I'm not entirely sure what was special about the glass that Condit used.

[Pere Casals]

It's an abrasive jet, the spray is not good for coated optical surfaces.

The glass surface is protected with any adhesive plastic layer, no problem. The CNC is very precise, and holes and dimensions are well in place, single thing is that the cut is not exactly perpendicular to the surface because of effects in the jet, some advanced machines inclinate a bit the jet to perfectly compensate that angle while the head is moving in any direction.

Waterjets have an operation cost of (perhaps) around $200 per hour, but that job would be cut in less than one minute, so most of what would be invoiced is machine preparation cost and bureaucracy.

[Drew Wiley]

Waterjet would not be realistic. Micro-laser is hypothetically possible, but would be a specialty service, probably pricey for a one-off. Condit offered a thick anti-Newton glass that was soft and drillable, making That's been unavailable for about 30 yrs now. Later AN glass is quite hard and brittle; so is coated optical glass. But coated glass doesn't do it for me; I still get rings.

[Pere Casals]

Waterjet would not be realistic.

:) Drew, it's beyond realistic: it's real.

How can you say "not realistic"? You can even make a butterfly: https://www.youtube.com/watch?v=1TEhYy4AcfM

Why "not realistic"?

_____


Single thing is that you should use very flat glass, if not you get rings (those you mention) way easier. The glass used to make mirrors is very flat, but glass sold to make windows it may not be well flat.

[interneg]

I have the manual, what is your question?

Does it specify whether the bench/ wall models have a different (narrower) spacer casting between the neg stage and the column runner compared to the floor standing model?



Waterjet would not be realistic. Micro-laser is hypothetically possible, but would be a specialty service, probably pricey for a one-off. Condit offered a thick anti-Newton glass that was soft and drillable, making That's been unavailable for about 30 yrs now. Later AN glass is quite hard and brittle; so is coated optical glass. But coated glass doesn't do it for me; I still get rings.

I'll possibly ask Kienzle - they supply glass for the various Leitz Focomat II enlargers that use quite a thick piece of glass in their carriers. I'd be interested to know what the minimum quantity needed to get a suitable glass made would be - mainly because I suspect Condit made use of a suitable product already on the market rather than having the glass completely custom made.

[Drew Wiley]

Condit used an AN Belgian glass unavailable for a long time now. Isn't made, period. But if you can work with plain glass, ordinary 1/4" thick float glass works fine. But don't use anything tempered - too tricky to drill precisely. There are plenty of sources for flat optical glass if you want to go that route. As usual, Pere is making sheer guesses.

[Pere Casals]

As usual, Pere is making sheer guesses.

Drew, LOL :) what sheer guesses? Please point what sheer guess.

My dry plate coating glass platform was cut with a waterjet.

Minimum hole diameter with a waterjet is usually 1mm, with 0.1mm precision, registration precision is not influenced by that precision, this is not a guess, but a fact. Of course tempered glass is not suitable for cutting.

[Drew Wiley]

Yes, you could dimensionally size glass using waterjet. But any glass shop anywhere can do the same thing with common equipment. I can do it in my personal shop with even tempered glass. I wouldn't trust just anyone to size optical glass. But you refute your own premise when you state 0.1mm hypothetical precision - that's like a shotgun where you need a sniper rifle; in other words, not nearly precise enough. Enlarge things a bit, and even unsharp masking misalignment becomes a visual distraction, not to mention the far more demanding applications for punch and register gear like color separations. And in sequential film operations, errors become cumulative.

[Pere Casals]

your own premise when you state 0.1mm hypothetical precision - that's like a shotgun where you need a sniper rifle; in other words, not nearly precise enough. Enlarge things a bit, and even unsharp masking misalignment becomes a visual distraction,

Drew, register precision does not depend on the holes in the top glass, but on the holes in the film/mask, aren't you aware ?

Imagine that the holes in the top AN glass are 2mm larger than the pins, no problem !!! what keeps negative-mask alignment are the holes in the film/mask and the pins.

____

Now let me explain how to DIY make a Top Quality ANR glass:

https://www.youtube.com/watch?v=XZ8FP0vJGMU

You need this (amazon):

196629

You protect one side of the glass with any adhesive plastic, then you dilute the "etching cream" with plain water until it works at some 1/10 of the speed shown in the video, so it would take 100min instead 10min to do the same.

You submerge your glass in the soup until etching suits your taste. Done !!!

You may submerge as many glasses you want until you are tired...


Safety sheet says that it contains:

BARIUM SULFATE 0.0 - 6.0% 7727-43-7
SULFURIC ACID 0.0 - 9.0% 7664-93-91
SODIUM BIFLUORIDE 7.0 - 12.0% 1333-83-1
AMMONIUM BIFLUORIDE 21.0 - 27.0% 1341-49-7

[Drew Wiley]

What kind of gibberish is that, Pere? All the spacing has to precisely align regardless - punch, pin glass, pins on carrier, if a registered carrier is involved. Go tell an automotive machine shop that you don't care if the cylinder holes and the pistons are precisely matched or not. But you apparently thought I was talking about a top glass. NO. I recommend and use AN glass on BOTH sides of the carrier sandwich. Pin registered bottom glass was once a standard offering by Condit; and there was a logical reason for that. But Contact frame glass itself also needs to be drilled, and is ideally thick AN glass. But since that's no longer available, one can substitute a thin sheet of mylar, frosted both sides, between the slick frame glass and the negative in the contact frame. That trick obviously won't work when enlarging. I wonder how much of these "done" snake oil projects you've ever actually undertaken. Somewhere around zero, it seems. There's more to an effective Anti-Newton surface than simple etching. If you don't do it just right, you'll get a pattern showing on the mask or interneg or whatever. But you just posted a product designed for essentially frosting glass. All glass etching is based on hydrofluoric acid. Even if that worked, you'd have to polish it up quite a bit to make it fully clear again.

[Pere Casals]

What kind of gibberish is that, Pere? All the spacing has to precisely align regardless - punch, pin glass, pins on carrier, if a registered carrier is involved.

Drew, this is funny, lets go...

If the "registered bottom glass" moves this is irrelevant, the single thing that's important is that the negative and the mask are precisely aligned by the register, the position of the top and bottom glass is irrelevant if the negative/masks are kept aligned, weren't you aware?



I wonder how much of these "done" snake oil projects you've ever actually undertaken.

:):):)

Drew, don't get angry, man.

I'm working hard to control BW printing with digital CAST masking on LF negatives...

You have not participated in this thread: https://www.largeformatphotography.info/forum/showthread.php?154485-Darkroom-Printing-CAST-a-powerful-method-for-advanced-curve-control

Also let me explain that this proofing tool https://www.largeformatphotography.info/forum/showthread.php?150045-New-darkroom-calibration-software is ready for action. By now I can predict the density of any spot in the sandwich and, since last weekend, also on the paper.

Now I'm working to sucesfully proof CAST masks, I advance at good pace in that.

This is not snake oil... "if" one day you try a CAST mask you will be aware.


Drew... look, I virtually bend the paper curve like I want...

[Drew Wiley]

Well, I'm glad you're having fun and finding a technique applicable to your own intentions. But you're into zonal masking, not precision image alignment by any means. The original question by Interneg was in reference to matched color separations; and all hell breaks loose if everything during that kind of procedure is not precisely aligned to begin with. And that's far easier to accomplish using classic punch and register film gear than via scan and post-alignment options, though I do know an electrical engineer who designed a pin-registered film recorder, and it takes real 8x10 film; but that's way beyond the skill level of most of us to make.

[Pere Casals]

The original question by Interneg was in reference to matched color separations; and all hell breaks loose if everything during that kind of procedure is not precisely aligned to begin with. And that's far easier to accomplish using classic punch and register film gear than via scan and post-alignment options

Of course...

Anyway for color separations the important thing is that the sheets have to be well registered, if the top ANR glass is moved 0.5mm left or right... this is irrelevant, as it's transparent.

[interneg]

No, but the conversion kit doesn’t include one, so the spacing must be the same. I believe the bench model has a baseboard just as deep as the floor model, but not as wide. I may be wrong as I have not seen a bench model in person.

I've solved the mystery as far as I can tell - the neg stage spacer casting on the cream painted machines seems to be shorter than that of the 504/507 etc, but the grey/ black painted machines use a similar casting to the 504/507 for the neg stage spacer and a longer lens stage spacer to centre the lens about 3.5" further out - which seems reasonable to me if you're regularly making really big prints, especially in the 32x40" range. From what I've seen, the bench model had a baseboard about the same as all the other 5-series De Veres - 24x24".

[Drew Wiley]

I just noticed that Heiland is introducing a film punch and register system, but haven't looked at the details, just the picture of the gear.

[interneg]

I just noticed that Heiland is introducing a film punch and register system, but haven't looked at the details, just the picture of the gear.

That was partly what spurred me on with this thread - and in the picture it does look like the Durst carrier has drilled glasses. That said, I think I'll probably start with something more along the lines of what Inglis came up with - ie pins just at the edge of the glass & accept a very small image area loss in return for a much more straightforward build. Do you happen to know roughly what the diameter of the body of the Condit pins was?

Pere's 'system' appears to be nothing more than the age-old delusion that acquiring darkroom printing ability is just one technological crutch away. Many companies sold all kinds of heavily marketed whiz-bang devices to do the same sort of things & none were or are as good as a well trained set of eyes.

[interneg]

I can see that it is reasonable that the 5108 is longer than the smaller models, and it also seems reasonable that the floor model and bench model of the 5108 would be identical so that parts are interchangeable.

The interchangeability is mixed... There's a pretty big re-configuration to go from wall/ bench to floor standing or vice versa - essentially the pulleys inside need re-strung differently. Would you be able to measure the width of the spacer casting? I can pm a picture of the part I need the dimensions of if needed.

[Pere Casals]

Pere's 'system' appears to be nothing more than the age-old delusion that acquiring darkroom printing ability is just one technological crutch away. Many companies sold all kinds of heavily marketed whiz-bang devices to do the same sort of things & none were or are as good as a well trained set of eyes.

Interneg, your are not well informed:

Look, in practice I control the paper curve like I want, beyond grade I easily control toe/shoulder extensions and gradients, this is before burning/dodging/etc.


PD: take a look... https://www.largeformatphotography.info/forum/showthread.php?154485-Darkroom-Printing-CAST-a-powerful-method-for-advanced-curve-control

[Drew Wiley]

Pere - you're simply barking up the wrong tree on this thread. I thought you already posted a separate thread on your plan for zonal masking. Here we're talking about pin registration devices for actual film, in order to accomplish a somewhat different objective. Pan film can be used not only for gradiant masking, but for very detailed hue corrections as well as precise color separations etc. Different subject.

[Drew Wiley]

Interneg - micro-pins on earlier Condit gear varied a bit (I'm talking in the thousandths), but we're specified as 1/16 inch. In later decades the quality control was quite consistent, and I find precise 1.5 mm diameter pins to be a more suitable substitute matched to later punches.

[Pere Casals]

Pere - you're simply barking up the wrong tree on this thread. I thought you already posted a separate thread on your plan for zonal masking. Here we're talking about pin registration devices for actual film, in order to accomplish a somewhat different objective. Pan film can be used not only for gradiant masking, but for very detailed hue corrections as well as precise color separations etc. Different subject.


Drew, if you read well you'll see that I was answering a direct interpelation made by the OP.


Selective digital masks are also often registered, and they can have a remarkable USM effect depending on diffusion. Also many of the masks you are considering for registering are also zonal, in particular HLM and SCIM types.


:) Take this with humor: let's see what's barking an entire forest, more than a tree, a whole Yosemite : https://www.largeformatphotography.info/forum/showthread.php?154331-Backpack-for-Hiking-with-an-11x14-View-Camera&p=1518383&viewfull=1#post1518383 Not complaing at all, but the counter !! realy funny !!!

[Drew Wiley]

Pere - barking up the wrong tree is a figure of speech - it's when a dog is sitting there looking up a tree and barking, but the squirrel is actually in a different tree. The original question of this thread was concerning color separation negatives and how to precisely register them - and those aren't meant to be diffused !!!!!!!! Unsharp masking might be employed in a supplementary sense; but your method is useless for the stated application itself. It is also incapable of very fine detail control color-wise. A completely different ballgame. You apparently have b&w VC printing in mind.

[Pere Casals]

this thread was concerning color separation negatives and how to precisely register them - and those aren't meant to be diffused !!!!!!!!

OP says negative printing and color separations, and the first thing may use diffusion.

Digital masking can be very useful for RA-4 optic printing. I allows "through the negative quality" while it adds some of the "hybrid flexibility". Imagine a wedding shot, a white dress would impose a color balance, but beyond that you may want (say) a cooler background and warmer skin tone, you may do that by editing a color correction mask in Ps that corrects color locally and dodges certain areas. You save time and materials. In that case you need some diffusion to hide the inkjet spots in the mask. Then you have solved most of the print, it may be left some manual burning.

[Drew Wiley]

That seems to be the wrong post, Pere, so I can't comment. What you're missing in this whole conversation, because you're still hypothesizing about all this, is that in color printing, masks are used not only for contrast control or curve modification, but for color correction too, in advance of separation negatives, or in combination with them, or just by themselves when separations are not in mind. It makes little sense to do half of this via scan and the other half via film contact directly. Besides, unless you're generating especially big digital separations, it's far easier to register thing everything using actual film the whole way. The method you espouse would be clumsy at best attempting hue correction in fine detail and not just overall areas. But you are obviously welcome to experiment. I've only been actually doing this kind of thing for the past forty years, so what would I know?

[interneg]

Greg - good to get a double confirmation on the Condit pins - if you could send me a picture of the punch, I'd be interested to see how it changes between 4x5 & 8x10 settings.

Drew - you're hitting the nail on the head with what's wrong with Pere's approach. It's imprecise in register, overly time consuming/ effortful for the end result vis-a-vis what a competent printer can do in a few minutes (which is not to deny that Alan Ross's approach using yellow & magenta selective masking has some usefulness in long edition printing with complex negatives) & starts from the (wrong) position of making a notionally 'correct' print rather than one that looks 'right' - which is, I think, the fundamental fault of the BTZS approach as practiced by many - it's fine if you need an exact replica of something like a car part or a painting etc, not so good for creative approaches. Essentially its adherents seem to spend an awful lot of time imposing a top-down set of technicalities on image-making rather than using it as a means to analyse/ standardise a film/ paper/ exposure/ process that makes a 'good', as opposed to 'correct' print - often, I suspect, because of an unwillingness to open up to the hard work and artistic understanding necessary to get better at printing. Attempting (and failing) to turn complex human understanding and behaviour into reductive tables of numbers has been an irresistible technician's temptation for many centuries.

[Drew Wiley]

Well, creativity also depends on one having a bit of fun doing things the way one wants to, whether entirely realistic or not, otherwise a procedure becomes tedium. So I can't dictate rules to anyone else. But some methods are indeed much more efficient than others in terms of getting from Point A to Point B without a train wreck. Now as to pin diameters, the problem with anything a bit over 1/16th is that some films swell with humidity, and once that tiny hole becomes too tight, it will break open when forced onto a pin. But shrinkage of film can be even worse. Alas, for awhile polyester base color film choices were scant, and we had to make due with dimensionally unstable acetate base. A barely undersized pin like 1.5mm seems more practical to me. Mine were very precisely made in Italy, but purchased through McMaster. I have no idea who made Condit's offset pins, but the source and quality obviously differed over time. All those pins ended up in the hands of Jens of DurstPro when he purchased Condit, and have hence disappeared into the blue like him. Larger offset pins are available from American Circuit Technology, but then you'd have to match everything to their own standard. They do offer custom mfg, but people like me who pretty much has everything necessary anyway, and might buy only two or three pins some day, are hardly realistic candidates. I guess it wouldn't hurt to ask them what a minimum quantity order would be for 1/8" barrel / 1/16" off-center upper pin configuration. Maybe they've done that size before, maybe not.

[Drew Wiley]

Pere - with respect to merely masking color neg film : in the case of a basic contrast-reduction mask, you can go diffuse. But if you need a contrast-increase mask (a distinct possibility when working with low contrast color neg film), you first want a sharp contact interpositive, prior to your unsharp mask. I guess you could hypothetically reverse an image after a scan, going directly negative to negative in PS, but you'd have to figure that out on your own. But that still leaves you with the difficulty of color-resolving fine detail without registration headaches. A pin-registered film recorder could solve this automatically, but that's a pricey option. Have fun.

[Pere Casals]

But if you need a contrast-increase mask (a distinct possibility when working with low contrast color neg film), you first want a sharp contact interpositive.

OK, I understand what you say, with diffusion a CRM increases acutance, instead with a Contrast Increase Mask what diffusion does is adding some blur.

We usually never require a Contrast Increase Mask in BW in optic printing because we instead rise the paper grade... but OK, we may want a contrast increase mask in RA-4

In theory we can digitaly edit a mask that both increases contrast and acutance when diffused, in the digital edition we have powerful tools like the highpass filter that can be subtracted from the original image and later layered on our mask, this is in theory, I'll dig in that...

Personally, I've advanced a lot in digital masking with BW, I found it extremly powerful. My next step will be trying that for RA-4, I suspect that it would also deliver a nice flexibility.

"Throught the negative quality" combined with some of the hybrid flexibility may be a powerful combination !

This woud also require registering, tinny marks are placed in the negative boundaries, this allows an easy alignment of the mask with the negative, and correcting the mask size to perfectly match (we only need to inkjet print the marks). When alignment made the digital mask is registered with the negative, for convenience, to not have to align anymore the mask again with the bino loupe.

[interneg]

Pere - I know you like to throw around the acronyms used by the Radeka et al school of masking, but before you deny the usefulness of sharp highlight 'bump' masks in BW, please go and at least read up what they and Ctein have to say about their uses.
Furthermore, inkjet masks are useless for any sharp masking above contact size because of the stochastic screening - indeed, the granularity of any sharp mask film is an important consideration that must be made. And that's before we consider the inherent effects on contrast that a halftone screen has.

[Pere Casals]

Pere - I know you like to throw around the acronyms used by the Radeka et al school of masking, but before you deny the usefulness of sharp highlight 'bump' masks in BW, please go and at least read up what they and Ctein have to say about their uses.

Interneg, if you read well I've not denied that, as I was not speaking about masks intended to selectively modify ("Bump") highlights, I was saying that Contrast Increase Masks (counter of a Contrast Reduction Mask, CRM) are not usually made for BW printing, because by increasing paper grade we do mostly the same without making a mask.


Instead CRM may often be needed to deal with extreme DR in the scene.




Furthermore, inkjet masks are useless for any sharp masking above contact size because of the stochastic screening - indeed, the granularity of any sharp mask film is an important consideration that must be made. And that's before we consider the inherent effects on contrast that a halftone screen has.

Interneg. Unsharp masking. In unsharp masking the faint interpositive mask always has to be diffused anyway, to get higher acutance. Using a diffuser layer is the usual situation in masking, and this allows using an inkjet mask.

[Drew Wiley]

Pere, I think you'll eventually discover two serious problems with inkjet masks when it comes to COLOR printing, besides the necessity to manually post-register them. This method is nowhere near as sharp or accurate as film by contact, even slightly diffuse. Second, black inks suitable for printing on transparent substrates aren't truly black, but carry some kind of hue bias. This is a significant problem where you only want some shading effect, as in fact is the case with most contrast masking. You will probably have to take a hard look at ink selection and experiment. So things get a little more complicated than using your prescribed method for black and white printing. But, as usual, you're welcome to carry this to its logical endpoint, and see whether or not it's sufficient for your own needs. It seems more like an unnecessary detour to me, with a bridge or two out along the way. But if you enjoy this approach, see where it takes you.

[Pere Casals]

This method is nowhere near as sharp or accurate as film by contact, even slightly diffuse.

Inkjets deliver 6 lp/mm aprox, which is sharper than the diffusion in a USM, so no problem.




Second, black inks suitable for printing on transparent substrates aren't truly black, but carry some kind of hue bias.

This is not a problem, we may correct hue of the black ink with the CMY inks we also have.




But if you enjoy this approach, see where it takes you.

We'll see :)

Approaching optic RA-4 these days is uncommon and it may look weird...

[Drew Wiley]

Wrong. You fail to understand the serious gamut limitations of your ink choices, and how very minor hue tweaks in a mask have a disproportionate effect in a color neg mask. it's like power steering in a car, and needs to be quite subtle. Ink is not transparent like dyes. You're dependent upon the distribution of tiny spots of it. With more than one step or mask or whatever, this is also additive in effect. Making very subtle tweaks in an alleged black is not going to be easy using other inks which are themselves opaque. Think of mixing paint, and how paint is not ideal for a window if you want light to cleanly pass through. A big display transparency might be an acceptable application for inkjet, but in this case, you're working on small scale, especially if you are contemplating 120 Ektar. Inkjet masking is like using an axe in a surgery which mandates a scalpel. It's you're ballgame; but it seems sooooo much simpler just using real optical film the whole way. Can't any dealer abroad ship you some Ektar sheet film?

[interneg]

Pere - if you had actually gone and read both sources you would see that no one makes anything other than sharp or near sharp contrast or highlight boost masks. Why? Because if you don't make them sharp, you'll get haloing. And that's even nastier in colour. Furthermore, your insistence on not needing absolute register is nonsensical if you are working using separation filters to print colour neg: let's imagine you need to mask the green exposure, but not the red or blue: how do you get the neg out the enlarger, attach the mask & back into the exact same place? Or you are printing an RA-4 print using sequential separation negs from transparencies, where you can't get their registration wrong either?

And before you go wibbling off about various light sources, please accept that there are very good reasons to use RGB separation filters to print colour with.

[Pere Casals]

and how very minor hue tweaks in a mask have a disproportionate effect in a color neg mask.

A durst color head has 170 shows levels per channel, the inkjet has 256... I don't see the problem.

Do you set fractions in the 170 Durst levels?


Furthermore, your insistence on not needing absolute register is nonsensical

Here, Burkett rgistering with a bino, min 11:43: https://www.youtube.com/watch?v=doNGi8HeKQ4

Alan Ross explains how to align digital masks on WB negatives, with color it's the same.






Or you are printing an RA-4 print using sequential separation negs from transparencies, where you can't get their registration wrong either?

Still I've never printed a single RA-4, I'm an absolute rookie in that, but I'm assembling a fully capable RA-4 darkroom, and it is what I will learn now.

I've had a great success with digital masks in BW with VC paper, with that innovative mask generation method (https://www.youtube.com/watch?v=FOz92KnCsHA)...

Now I'll try to develop a method for digital masking for RA-4, probably I'll have to overcome some difficulties, in the same way I posted the C.A.S.T. method if finally I'm succesful with optic RA-4 digital masking then I'll post my findings, for the moment I can say it if it work well, but I'm optimistic.

By the way, try the C.A.S.T. if you can ... you won't be disappointed.

[Drew Wiley]

You're sure off base on that comment! A Durst dial might have 170 markings on the dial, but its fully adjustable in between. 256 ???? - that's as abominable as the web palette itself. An ordinary paint store color chip rack has far more colors than that. Be careful what you think Burkett actually does - that's a very oversimplified demo video for sake of just giving a generic hint. He actually uses a rather sophisticated, costly punch and register system. Otherwise, he would have gone bonkers long ago. Alan Ross is not a color printer, though he might have done a bit of it over time. I dunno. His masking method is a dead giveaway about his printing priorities. He's after endpoint zonal range control - something else, not mutually exclusive from this conversation, but not really addressing it either. Making acceptable masks is like hunting pumpkins - they seldom fight back; but making accurate color separation negatives is like fighting dragons, and there's no room for error. But otherwise, good hunting to you, and I hope you do get some hands-on experience with RA4 soon.

[interneg]

A durst color head has 170 shows levels per channel, the inkjet has 256... I don't see the problem.

Do you set fractions in the 170 Durst levels?


You really don't get this, do you? They are not metrics on the same absolute scale.



Here, Burkett rgistering with a bino, min 11:43: https://www.youtube.com/watch?v=doNGi8HeKQ4

Alan Ross explains how to align digital masks on WB negatives, with color it's the same.


Those are unsharp masks. Not what we are talking about. Try doing this with multiple separations. Not going to happen. Pin register means no fiddling with microscopes etc. You punch the film, the masks etc & they should all be in the same place every time. That's the point. Wasting materials because of registration problems is what I want to eliminate.





By the way, try the C.A.S.T. if you can ... you won't be disappointed.

It's a technique that's about as old as masking techniques of any sort - all it's doing is a mild variant on what the colour separation world would resort to if necessary. I tend to take the need to acroynm-ise standard if slightly obscure techniques as an admission of charlatanry on the part of the claimant. It's also an enormous waste of time if you know how to exploit multigrade paper via flash/ fogging exposures. Finally, if you are making negatives that are so difficult to print that they absolutely need hugely complex masking, you'd be better off consigning them to a drawer and actually getting the basics of negative exposure and process sorted.

[Pere Casals]

You're sure off base on that comment! A Durst dial might have 170 markings on the dial, but its fully adjustable in between.

Don't tell me that you find a difference from 23.3 to 23.7 in the dial !!! :)

[Pere Casals]

It's a technique that's about as old as masking techniques of any sort - all it's doing is a mild variant on what the colour separation world would resort to if necessary. I tend to take the need to acroynm-ise standard if slightly obscure techniques as an admission of charlatanry on the part of the claimant. It's also an enormous waste of time if you know how to exploit multigrade paper via flash/ fogging exposures. Finally, if you are making negatives that are so difficult to print that they absolutely need hugely complex masking, you'd be better off consigning them to a drawer and actually getting the basics of negative exposure and process sorted.

OK, don't try it...


196878



I tend to take the need to acroynm-ise standard if slightly obscure techniques as an admission of charlatanry on the part of the claimant.

Interneg, you are as rude as always :) you can do nothing to heal that... :) :) :)

No problem, let me reiterate that "this is only an small addition to Alan Ross selective masking, it's just looking at the same from another point of view: We make a mask to effectively deformate the paper curve to suit our desire."


So with some standard Ps presets we obtain a "de facto" modified paper curve, which is the same than the AR selective masking but by using a gradient map we distribute grades continuously across densities. The single thing I invented is using a gradient map to automatically asign colors to gray levels, just an small improvement that's new.

You may get the above AZO curve (those plots by Mowrey), a regular ilford classic curve or anything in between.

Probably you may not understand the power of having a custom curve for the paper, but this is not my problem.

[Drew Wiley]

Pere - you'd be amazed at how fussy I can be with color. The dial markings are just a starting point, and I only have those on one colorhead anyway, the CLS300 CMY on my L184 chassis. My other color enlargers are true RGB additive with a different kind of control entirely. Even cc gradation values differ between different systems, some with tighter spacing, some with wider; and in this respect, RGB behaves a bit differently than CMY anyway. But the color channels on my additive enlargers are so pure that, even though these are for sake of simultaneous exposure, I can still selectively use the separate RGB channels to make respective RGB color separations that are every bit as pure - even better than, traditional 29 red , 62 green, and 47B blue filter results. I just don't have a lot of time to do that kind of thing, however. Lots of ongoing projects. In fact, I'm making these posts in between session of drywall and paint work in our bathroom remodel. Don't want to do anything in the darkroom at the moment because it's our forest and brush fire season, and the electrical power risks getting cut off if there's a major fire inland with transmission lines potentially involved. Our oak trees don't have any fire-resistant cork like some of yours do! But it's mostly beetle-killed pines at risk, along with native chaparral rich in flammable natural creosotes etc. There's quite a cloud of smoke about 50 miles to the north at the moment.

[Pere Casals]

Pere - you'd be amazed at how fussy I can be with color. The dial markings are just a starting point,

Let me some time to test it... still I've to print my first RA-4... we'll see, from preliminary tests it looks to me that selective color correction masks can be done with inkjets, for RA-4, to control area dominants and saturation. We'll see...

[Drew Wiley]

Yeah, there's no crime in trying. Even if it doesn't work out, you might learn something useful for a different application. But if you somehow get lucky enough to stumble onto a clean matched punch and mask registration frame at a reasonable price, grab it.

[Pere Casals]

But if you somehow get lucky enough to stumble onto a clean matched punch and mask registration frame at a reasonable price, grab it.

Well, I'll have to make it... it has has to fit in the Nega 138 ...

[Michael Clark]

Well, I'll have to make it... it has has to fit in the Nega 138 ...

Pere Casals if you ever able to make the nega 138 work for mask registration let us know how you did it !!!

[interneg]

Pere Casals if you ever able to make the nega 138 work for mask registration let us know how you did it !!!

Durst did it themselves - GRAHAL & GRANE are the parts. The problem is finding the punch that matches them. They replace the NEGA 138 in its entirety. Essentially GRAHAL is a precision metal block that locks to the chassis & the GRANE registered carrier then slides precisely & repeatedly into that. If you have access to precision machining, they are not hugely complex parts to make a version of.

[Pere Casals]

Pere Casals if you ever able to make the nega 138 work for mask registration let us know how you did it !!!


If you have access to precision machining, they are not hugely complex parts to make a version of.

I've designed a version for 4x5 only in the Nega 138 that requires only two precision drills on a metal plating, the rest, glass included will be cut with a waterjet:

(It looks like if the plating is blocking the image but's only an effect from perspective)
196891

196892

196893


It uses 1.5mm pins and the sheet is punched in the 5" side, for a 20% better alignment.

The top glass is ANR 4mm, its weight is to keep the thing flat. I'll DIY the ANR glass: https://www.largeformatphotography.info/forum/showthread.php?154670-Pin-registration-system-preferences&p=1521082&viewfull=1#post1521082

If somebody wants the drawings please PM. This is the Landscape version, the Portrait version varies in the base glass drills. The DWG file for the cuts can of course be edited tu suit any pin diameter and distance.


So by just replacing the base glass in the NEGA 138 we have a 4x5 registered carrier, with al confort/convenience a Neg 138 sports, I love the Nega 138

I'm thinking in a 5x7 carrier that would require some modifications in the NEGA 138 frame, as the base glass is just 13x18cm, modifications would be small, but before "damaging" a NEGA 138 I want to think it well.

[Drew Wiley]

I have a GRAHAL/GRANE which I modified to match my 4X5/5X7 Condit punch system, but have never used it yet because I've been concentrating on 8X10 images; and I have separate registration equip for that size. But there's no need for registered carriers in basic masked color printing where the final mask is taped in register to the original, but only when you need sequential exposures in register, like for color separation use.

[interneg]

glass included will be cut with a waterjet:

...

So by just replacing the base glass in the NEGA 138 we have a 4x5 registered carrier, with al confort/convenience a Neg 138 sports, I love the Nega 138


Having used 138s on a day to day basis for years, you're missing a fundamental issue: the NEGA 138 isn't designed for registration to the enlarger chassis & if you can't solve that problem, any pin register system will be extremely limited in its usability. The GRAHAL locks to the chassis and the GRANE registers to pins in the GRAHAL. You will have an easier time designing a base unit that locks to the enlarger and a carrier that registers to that than trying to modify a NEGA 138.

I still don't think water cutting is a good idea anywhere near optical surfaces - the cutting material is much the same stuff used to grind lenses.

[Drew Wiley]

Agreed. The Nega 138 is perfectly suitable for enlarging a neg or chrome with a mask already taped in register to it. But it is worthless for attempting to make sequential exposures in register with one another, and would be an exercise in futility to attempt to modify for that purpose. I have at times made my own registration carriers, but starting from scratch. Any decent machinist could do it if an appropriate design was communicated to them. The tolerances have to very tight, yet still allow precise positioning with thermal exp/contraction issues already factored in. Condit made their own registered carriers for various popular enlargers. Matched Durst components are now hard to find; and their own punches are nearly nonexistent. I saw one of the later deluxe 138 register carriers for sale on EBay earlier this year, the model which replaced the GRAHAL/GRANE system. Somebody eventually bought it; but they must have had a rude surprise when they discovered they needed a matching perimeter component to make it actually work, and it wasn't included - probably long lost.

[Pere Casals]

I still don't think water cutting is a good idea anywhere near optical surfaces - the cutting material is much the same stuff used to grind lenses.

interneg, let me reiterate, you place a protective/adhesive plastic film on the glass surfaces, that film won't even be damaged but, is the film is not perforated you know that now corindon particle reached the glass.

In fact risk of scratches is at the bottom, from the steel blades supporting your material:

196925
https://my.wardjet.com/waterjet-support-systems

So a protective material should be also placed under, say a thin cellular plastic sheet. I use it to cut (often polished/satinated) AISI 304.

[interneg]

So a protective material should be also placed under, say a thin cellular plastic sheet. I use it to cut (often polished/satinated) AISI 304.

So, once again the truth emerges: you've never had glass cut with a water jet. I've just spoken with a local specialist glass supplier who water cut all sorts of glass for engineering & technical purposes & their comment was that they were unwilling to cut a smaller than 6mm hole. Which is not much use for either a 3.5mm hole for the pin body or clearing the 1.5mm pin itself in the top glass.

[Pere Casals]

So, once again the truth emerges: you've never had glass cut with a water jet. I've just spoken with a local specialist glass supplier who water cut all sorts of glass for engineering & technical purposes & their comment was that they were unwilling to cut a smaller than 6mm hole. Which is not much use for either a 3.5mm hole for the pin body or clearing the 1.5mm pin itself in the top glass.
Interneg, now Im a bit busy, later I'll explain you about that....

For the moment use google a bit to get informed

[Pere Casals]

So, once again the truth emerges: you've never had glass cut with a water jet.

Interneg, in post 17 I explained it to you, I have cut glass with waterjet: https://www.largeformatphotography.info/forum/showthread.php?154670-Pin-registration-system-preferences&p=1521034&viewfull=1#post1521034




So, once again the truth emerges: you've never had glass cut with a water jet. I've just spoken with a local specialist glass supplier who water cut all sorts of glass for engineering & technical purposes & their comment was that they were unwilling to cut a smaller than 6mm hole. Which is not much use for either a 3.5mm hole for the pin body or clearing the 1.5mm pin itself in the top glass.

LOL, what an specialist !!!

Look, to cut a hole (or to start cutting in the middle of the sheet) first the machine makes a perforation operation (nozzle distance to material is changed), this hole has some 1mm, once perforation is made the nozzle adjusts to the cutting height and starts movement.

A (say) 10mm hole is made by the nozzle making the perforation in the "circunference" of the hole, and then it describes a circle...

...but to make a (say) 2mm hole the procedure is different, once the perforation is made the nozzle starts describing circles of growing diámeter, say each circle being 0.5mm larger than the previous one until reaching the desired size.

I cannot believe that your "technical engineering expert" was not aware...



Which is not much use for either a 3.5mm hole for the pin body or clearing the 1.5mm pin itself in the top glass.

See the design:196951

The position of the register pins are determined by the precision holes drilled in the metal plating, that metal plating is fixed to the glass with larger bolts, the small holes in the glass are to let pass the pins through the glass not to keep the pins in position.

Is it that difficult to understand?

[Drew Wiley]

Pere is describing an optional pin positioning method on the perimeter frame rather than the glass. This works, but crops away more edge of the negative itself unless a punched register strip is taped to the film to give extra width. It becomes more a liability in a registration contact frame than carrier application, but if necessary can be done in that case too if drilling the glass itself is unrealistic.

[Pere Casals]

Pere is describing an optional pin positioning method on the perimeter frame rather than the glass. This works, but crops away more edge of the negative itself unless a punched register strip is taped

Not necessary... see this:

196956

The pin is 1.5mm

[Drew Wiley]

I've been there, done that, Pere. It's relatively tricky not to have a bit of meat around the pin itself, but if you can pull it off, congratulations. For certain precisely composed originals with nominally sized glass, that kind of spacing is just too much of the image edge to sacrifice. But it might simplify design. With smaller format originals using LF punches and pin glasses, you need a taped register strip anyway, so there's no penalty in that case. The Durst system only worked with a secondary register strip, but was oversized to begin with.

[Pere Casals]

Drew, see it, it does not take more than any register system, the register strip it's always a possibility anyway... When I finish a ATL 2500 rebuild I've in course then I'll make that register, I'll show it to you...

[Drew Wiley]

Thank you, and good luck. Unfortunately, I'm not likely to experiment in this manner anymore myself, because I already have the personal equipment I need.

[interneg]

Pere - as usual, it was none of your assumptions. The people I spoke with can deliver higher accuracy than you have quoted for water jet, but said that the big problem with fine holes is cracking at the point that the jet contacts the surface of the glass. Only at about 6mm can you cut away enough to safely be rid of the initial cracks - that said, they supply to industries where cracks that propagate could result in life or death situations, so I can see their caution. Perhaps you'd like to show us the fine holes you had cut in glass and tell us who did the work rather than flinging around CAD drawings?

I think the last avenue I'll explore before resorting to something along the lines of Durst or Inglis's use of pins in the metalwork of the carrier & accepting a small image area loss is the latest generation double sided glass drills - apparently they can reliably cut 3mm holes.

[Pere Casals]

apparently they can reliably cut 3mm holes.

From 6mm to 3mm you have moved a bit.

Let me explain you that in a Waterjet several parameters can be adjusted for a job, beyond cutting speed.

You may vary:

>> nozzle aperture
>> water pressure
>> abrasive type
>> abrasive granularity


With lower water pressure, an smaller aperture and a low granularity abrasive you make a perfect 1.5mm hole, it takes a bit more time but if only two holes are to be made... what you end paying is machine preparation for a lower speed work.


Look, your "engineering & technical expert" does not want to exchange the nozzle and the abrasive for you... , and you ended saying that only 6mm holes can be made...




show us the fine holes you had cut in glass

In post 17 I told that I only have cut linear, but in the workshop I order my regular WJ cuts I asked, and I've been shown samples of 1.5mm holes well made on glass, this is the reason why I made my register design with 1.5mm pins.

[Drew Wiley]

You'll still need a bit of wiggle room to adjust the pin spacing as the epoxy sets up, or you'll never achieve perfect register. That was the convenience of off-center pins on a larger barrel.

[Pere Casals]

You'll still need a bit of wiggle room to adjust the pin spacing as the epoxy sets up, or you'll never achieve perfect register. That was the convenience of off-center pins on a larger barrel.

Yes... I was considering allowing one the pins to shift, to tension just a bit the sheet... This would make less critical the distance between pins...

Also I was considering the film sides touching some top-left edges to make the register... I don't know if that was ever succesfully used...

[Drew Wiley]

Corner/side alignment guides are typically used on the register punch rather than pin glass, where they're unnecessary. And yes, simply having one hole in the glass a tiny bit oversized would allow the task of precise pin spacing.

[Pere Casals]

And yes, simply having one hole in the glass a tiny bit oversized would allow the task of precise pin spacing.

But in that case two metal platings are necessary, one for each pin, and a guide has to be provided for the floating plating...

let me draw it...

[Drew Wiley]

Durst once had something analogous.

[interneg]

In post 17 I told that I only have cut linear, but in the workshop I order my regular WJ cuts I asked, and I've been shown samples of 1.5mm holes well made on glass, this is the reason why I made my register design with 1.5mm pins.

Having now spoken with multiple specialists in both high precision glass cutting & optical glass supply, none of them recommended water cutting for holes of the sort needed, and definitely not in an optical surface (they all made unhappy noises at mention of water cutting of that nature). The latest generations of double sided glass drills can however apparently deliver an excellent hole with no blowout at 3.5mm, which is a reasonable size to make the shank of the off-centre pin compliant with. It's not going to be cheap, but if it allows something close to Condit's elegant and simple solution, then I'll be happy.


Corner/side alignment guides are typically used on the register punch rather than pin glass, where they're unnecessary. And yes, simply having one hole in the glass a tiny bit oversized would allow the task of precise pin spacing.

Just to double check, were both of the pins in the glass off-centred on their shanks, or just one of them?

[Pere Casals]

can however apparently deliver an excellent hole with no blowout at 3.5mm, which is a reasonable size to make the shank of the off-centre pin compliant with.

I don't see the problem, you may see in many videos how glass is smoothly perforated and smoothly cut: https://www.youtube.com/watch?v=a_qMKKwvzz8 , but if they cant... no problem, if the pin is retained by the metal plating then the glass hole may be larger than the pin:

197017



It's not going to be cheap,

In my case, cutting the two glasses will be under $20, I often rent that machine for some $200/h, and if you see the videos this can be done in less than 5min.

_____________________

This is my reviewed design, the idea is placing a punched sandwich and then tensioning the left plate before tightening the (not shown) bolts, so the good inter pin distance will be adjusted:

197018

197019

_____


197021

[interneg]

That glass is about 60% thicker & is having a considerably different machining operation done - the thickness of the glass is apparently quite important for successful water cutting & the quantities cut relative to acceptable final pieces is also important. The video mentions neither of these, yet every supplier I've spoken with has taken the time to explain that these are important factors.

More importantly, the design of the punch is far more critical to the success of the whole system than too many moving parts in the pinned glass. You want to be able to permanently lock down the pinned glass to match the punch - thus the epoxy'd in off-centre pins in the Condit approach.