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sully75
2-Aug-2010, 11:44
Seriously folks...

I'm planning on running my own tests some time soon, but I'm interested in anyone's personal tests of rotary vs. non rotary development. I believe I've heard that rotary development overdevelops the highlights and may promote uneven development. I've tried taco style and rotary development with a Bessler drum on a unicolor base, a couple of times with a duplicate negative, and I can't say that my results have been that different.

That said, I still don't know what I'm doing, so it's hard for me to say. I'd rather not invest too much time going down the wrong road though. I like taco style because it gives me a little additional control if I want to + or - a development time, and I've been able to experiment with stand development. But the Bessler drum is great because you can sort of set it and forget it, it's very convenient. It also is great for quantities. So...I will probably continue to do both.

Has anyone run their own tests and what were your results in comparison? It seems like many people here are using rotary development, but I'm interested in all opinions, rants, tyrades, etc.

Thanks!
Paul

Brian C. Miller
2-Aug-2010, 12:16
The first real question would be, is the film being processed in a device that was meant for rotary film processing?

A lot of the rotary film processing that I've read about on this forum has been done with equipment that was never intended for it. If the equipment wasn't designed for processing sheet film, then why should someone be disappointed when the results aren't stellar?

I have a Jobo 4x5 Expert drum, the 2509N, and of course tray development. I've also tried a Yankee tank, and I'm not going to use that ever again.

I have used the 2509N with my CPE2, and I had some issues with (mainly) loading. I don't remember doing a test specifically for uneven development like I did with my Yankee tank. The Jobo Expert drum has been flawless. Tray development (with my slosher) has been flawless.

sanking
2-Aug-2010, 12:50
Seriously folks...

I'm planning on running my own tests some time soon, but I'm interested in anyone's personal tests of rotary vs. non rotary development. I believe I've heard that rotary development overdevelops the highlights and may promote uneven development. I've tried taco style and rotary development with a Bessler drum on a unicolor base, a couple of times with a duplicate negative, and I can't say that my results have been that different.

That said, I still don't know what I'm doing, so it's hard for me to say. I'd rather not invest too much time going down the wrong road though. I like taco style because it gives me a little additional control if I want to + or - a development time, and I've been able to experiment with stand development. But the Bessler drum is great because you can sort of set it and forget it, it's very convenient. It also is great for quantities. So...I will probably continue to do both.

Has anyone run their own tests and what were your results in comparison? It seems like many people here are using rotary development, but I'm interested in all opinions, rants, tyrades, etc.

Thanks!
Paul


Rotary development , if done correctly with the right equipment, can not be beat for even and smooth development of film. The very best method of rotary, IMO, is in BTZS tubes where the tubes are rotated in a tray of water. This is the method introduced and used by Phil Davis because it was the only method that provided the kind of even development and consistency needed for his BTZS workshops. One of the reasons this method works so well is that agitation is almost totally random and varies a lot as the tubes bob up and down on each side as they rotate on the other axis.

Rotary development that is totally mechanized, especially with very fast rotation, may produce development artifacts like bromide streaking. Bob Carnie of Elevator Digital mentioned recently that in order to avoid streaks he always agitates manually for the first minute or so of development. That would also work well when developing film in print drums on motor bases.

If even development is one of the major pros of rotary development, reduced film speed and reduced accutance are the cons. Film will give more effective film speed when it is developed in dilute solutions for a long time with reduced agitation. This type of development also usually produces more acutance (= greater sharpness).

And yes, I have tested all of this, many times over. Based on my experience and testing I always use rotary development for film testing when even development and consistency is most important, and minimal agitation or two bath development when maximum shadow detail and sharpness is wanted.


Sandy King

Jay DeFehr
2-Aug-2010, 15:20
I agree with everything Sandy says above. Randomness is the key to even development. The taco method, despite its humble nature, provides for very random development because the film itself produces turbulunce that prevents any kind of patterned development. I prefer the taco method to BTZS type tubes, because the taco method is a true daylight process. Developing for maximum acutance is mostly a curiosity for me, and as a result, I have many images that are too sharp for my taste. Rotary development takes some of the edge off, but not much. An acutance developer will not produce soft-edged images, even with rotary development, but it helps a little.

Lachlan 717
2-Aug-2010, 15:36
Is there any value/use in changing the rotational speeds during the development to avoid any artefacts (mimicking, I guess, the random movements mentioned above)?

Kevin Crisp
2-Aug-2010, 15:39
I just develop in trays, two sheets at a time. I glued a little plastic piece in the bottom of the tray that keeps the sheets from ever hitting each other. (Two legs of the tripod thing that comes with delivered pizza.)

For agitation I follow the lift the edge of the tray method Kodak recommended for TMAX development in publication F- something. This is basically a fairly mild form of constant agitation, repeated as a three part motion every 8 seconds. Since the sheets of film have room to move around in their halves of the tray it is quite random. It is plenty repeatable for me and fairly mindless activity I can easily do while thinking about other things in the dark. Even with So. Cal. development times down into the less than 5 minute range I have no problems with evenness.

I am not knocking rotary development, I've just been completely satisfied with trays. I have no need for a 'daylight process.'

sully75
2-Aug-2010, 15:52
Possibly silly question: I wonder if there is something to put in the circuit of a unicolor base to randomize it a bit more. I have the reversing base, and the speed it rotates at doesn't seem excessive, but I wonder if slowing the speed some and/or introducing some vibration might help.

sully75
2-Aug-2010, 15:52
or, what Lachlan said.

sully75
2-Aug-2010, 15:55
If even development is one of the major pros of rotary development, reduced film speed and reduced accutance are the cons. Film will give more effective film speed when it is developed in dilute solutions for a long time with reduced agitation. This type of development also usually produces more acutance (= greater sharpness).

And yes, I have tested all of this, many times over. Based on my experience and testing I always use rotary development for film testing when even development and consistency is most important, and minimal agitation or two bath development when maximum shadow detail and sharpness is wanted.


Sandy King

Hi Sandy,

For the record, what developers are you using, particularly for your two bath and minimul agitation development? Could you give examples of the types of scenes that might recomend one over the other? I'm thinking you would go for even development in a scene with a lot of sky, and your two bath in a high contrast scene with a lot of shadow detail, but could you elaborate on that decision?

thanks
Paul

sully75
2-Aug-2010, 15:57
I agree with everything Sandy says above. Randomness is the key to even development. The taco method, despite its humble nature, provides for very random development because the film itself produces turbulunce that prevents any kind of patterned development. I prefer the taco method to BTZS type tubes, because the taco method is a true daylight process. Developing for maximum acutance is mostly a curiosity for me, and as a result, I have many images that are too sharp for my taste. Rotary development takes some of the edge off, but not much. An acutance developer will not produce soft-edged images, even with rotary development, but it helps a little.

Hi Jay,

Just wondering, are you doing 5x7 taco style by any chance? I'm currently doing 2 negs in a stainless tank but I was wondering if anyone is doing 4 negs, 4x5 style, in any kind of tank.

Thanks
Paul

sanking
2-Aug-2010, 17:18
Hi Sandy,

For the record, what developers are you using, particularly for your two bath and minimul agitation development? Could you give examples of the types of scenes that might recomend one over the other? I'm thinking you would go for even development in a scene with a lot of sky, and your two bath in a high contrast scene with a lot of shadow detail, but could you elaborate on that decision?

thanks
Paul

In addition to Pyrocat-HD and -MC, which I use for both minimal agitation and two-bath development I also like divided D23 as a two-bath developer, and for stand and minimal agitation schemes very dilute solutions of HC-110, Rodinal and FX-2 work well.

When exposing sheet film I usually note the contrast range of the scene for that sheet and choose a development time to achieve the desired contrast. I typically use two-bath development with all of my medium format roll film since each roll may contain scenes of different contrast. If the scene is one with a lot of open, even sky the best method of development is the one that gives the most even development, and that is continuous rotary development.

Sandy King

Michael Rosenberg
2-Aug-2010, 17:49
To test for uneven development, expose two sheets of film each to a white/light colored towel evenly lit at Zone VI and VII. After giving appropriate development to achieve similar densities (it really does not have to be exact) use a densitometer and measure from each of the edges of the negatives to the center.

I had developed in tanks (using Kodak holders) for many years, and when I started doing high key photographs I saw some anomalies in printing the negatives. I did this test and saw a big difference. I got a Jobo and have not looked back since.

Mike

Jay DeFehr
2-Aug-2010, 19:15
Paul,

I develop 3 5x7 sheets, taco style, in an older Paterson tank that holds 3 120 reels. I'm testing an insert that makes the taco method simpler and more convenient, and a diy tank for 8x10 to develop 6 sheets. I'll post more when I have a finalized design.

Sandy,

your last post made me curious: under what circumstance would you use Pyricat HD instead of MC?

sanking
2-Aug-2010, 19:41
Sandy,

your last post made me curious: under what circumstance would you use Pyrocat HD instead of MC?

Jay,

People ask me that question a lot. The two developers give very similar results, though in fact they are quite different in terms of the chemistry. I generally use Pyrocat-HD with minimal agitation and semi-stand type agitation, and in trays with slow shuffle agitation, and Pyrocat-MC with rotary processing of ULF film in tubes. In these conditions MC gives slightly greater acutance and slightly less general stain than HD. I use both with two-bath development.

If I were to classify the two I would call Pyrocat-HD an acutance type developer that gives very smooth creamy type tonal rendition and Pyrocat-MC a hugh acutance type developer that gives a slightly more wiry look. However, the exact look of both is determined by dilution and type of agitation. For example, with two-bath development both MC and HD become very high acutance developers that produce high micro-contrast.

Sandy

sully75
2-Aug-2010, 20:36
Sandy, more questions:

Why do you use the other developers instead of pyrocat? I'd use pyrocat if it weren't for the toxicity (I develop in my bathroom, with roomates). What's your non-pyrocat favorite?

sanking
2-Aug-2010, 21:12
Sandy, more questions:

Why do you use the other developers instead of pyrocat? I'd use pyrocat if it weren't for the toxicity (I develop in my bathroom, with roomates). What's your non-pyrocat favorite?

Mainly because I am curious to know how things work. I also play around with different ideas for formulas to see if I can improve some aspect of development. And anything I come up with I always compare to D76 1:1 and at least one other traditional developer.

My favorite non-pyro developer is D23, which I have used primarily as a two bath developer.

Sandy King

Jay DeFehr
2-Aug-2010, 21:37
Thanks, Sandy.

Tom Kershaw
3-Aug-2010, 02:29
Mainly because I am curious to know how things work. I also play around with different ideas for formulas to see if I can improve some aspect of development. And anything I come up with I always compare to D76 1:1 and at least one other traditional developer.

My favorite non-pyro developer is D23, which I have used primarily as a two bath developer.

Sandy King

Sandy,

How do you react to comments that Pyrocat-HD developers don't offer any real benefits over D-76?

Tom (Pyrocat-HD user on occasion)

Brian Stein
3-Aug-2010, 03:53
I'd use pyrocat if it weren't for the toxicity (I develop in my bathroom, with roomates).

Ummm I dont see toxicity as that big a deal. Maybe I am just insensitive to the threat, but once the stock is made up you are not dealing with loose chemicals and I am quite happy with a good sluice down after working with it. For making up the stock i do take care with the pyrocatechin etc but this is an infrequent event so doesnt really make much of an impression on me.

sully75
3-Aug-2010, 04:55
Hi Sandy,

Do you have a link to your two bath d23 formula somewhere?

Thanks
Paul

Ron Marshall
3-Aug-2010, 06:25
Hi Sandy,

Do you have a link to your two bath d23 formula somewhere?

Thanks
Paul

A divided D23 link:

http://unblinkingeye.com/Articles/DD-23/dd-23.html

sanking
3-Aug-2010, 06:32
Sandy,

How do you react to comments that Pyrocat-HD developers don't offer any real benefits over D-76?

Tom (Pyrocat-HD user on occasion)

I have two main reactions.

First, all developers are about 90% to 95% alike. It is in tweaking the final 5% to 10% that we change the result. If people don't see a difference in that final 5% to 10% there is nothing I can do about it.

Second, even if there were no difference in results I don't see anyone claiming that D76 is actually better, only that it is just as good. And if that is so we can still make a good case for pyro developers because they have much longer shelf life than mixed D76, and most other traditional developers. Also, pyro developers like Pyrocat-HD cost a lot less per liter, whether you compare cost mixing your own or compare costs of prepared kits.

Sandy

Brian Ellis
3-Aug-2010, 09:54
. . . I prefer the taco method to BTZS type tubes, because the taco method is a true daylight process. . . .

I don't know what the taco method is, in 20 years or more of photography this thread is the first time I've ever heard the term. But I've always considered the BTZS tubes to be a daylight process, in the sense that you put the film and developer in the tubes in the dark, put the top on the tubes, and turn the lights on. From there on out everything through the wash is done in room light. Is the taco method more of a "daylight process" than that?

Brian C. Miller
3-Aug-2010, 10:54
I don't know what the taco method is, in 20 years or more of photography this thread is the first time I've ever heard the term.

Previous post about "taco" method (http://www.largeformatphotography.info/forum/showthread.php?p=612011&highlight=taco#post612011).

Basically, the film is held in position like a taco using a either rubber band, or beads on a monofilament line to chemicals access to the back of the film. Using a rubber band leaves a line on the film, which will need a second fix bath.

(I've never used the taco method myself.)

Drew Wiley
3-Aug-2010, 11:04
I prefer tray dev for convenience, and believe I get more even results, but have done well with drums too. There is no "best" method, just preferences and acquired skills.
I have also used many developers for different purposes, but am unquestionably in the
pyro camp when it comes to general purpose film developers.

Jay DeFehr
3-Aug-2010, 11:37
Brian,

Using BTZS type tubes, one must turn out the light to dump the developer and pour in the stop bath, and again to pour out the stop bath and pour in the fixer. With the taco method, none of this is necessary, and more than one sheet of film can be processed in one tank. I don't like the BTZS tubes, but I've used them, and they are capable of excellent results.

Sandy,

I know you've posted many times your assertion that all developers are 90-95% alike, and I think I know what you mean by this, but I also think it can be misleading. First, how do you arrive at these percentages? It the same as saying we share 95% of our genes with Chimpanzees, for instance. It seems you could as easily say that all developers are mostly alike, and avoid the implication that there is some empirical, quantifiable basis for your contention. Maybe I'm picking nits, but it seems to me to depend on how one considers the issue. If one compares characteristic against characteristic (film speed, grain. sharpness, gradation being the primary ones, but development time, shelf life, number of solutions, toxicity, economy, etc., being some others) one could reasonably argue that some developers are very significantly different than others. I personally would not claim that a ppd-based ultrafine grain, large tank, replenished developer is 90% identical to a single agent, one-shot, tanning/staining, acutance developer, or that a high contrast lithographic developer is 90% identical to a POTA type developer. I think your claim misrepresents the diversity of film developer formulation. I could more easily accept that developers within a given category are essentially similar, but even here, there are important differences.

For those interested in introducing some randomness to their developing drums' agitation, consider the following:

Find a piece of suitable material (anything flexible, that can be shaped) about 2" wide, 8" long, and 1" high, and taper the ends to make the top form a smooth curve. I use styrofoam, but just about anything will do. Tape this to one end of your drum, where it contact the roller of the base. Now, when it rotates, the hump will elevate one end of the drum to break up any linear flow patterns. If your base is a reversing type, I don't think this is even necessary, but it can't hurt!

Henry Ambrose
3-Aug-2010, 12:17
You can simply lift the drum for a few seconds and replace it on the rollers and/or swap the drum end for end a few times during development. Its easy, this ain't rocket surgery.

hendrik faure
3-Aug-2010, 12:51
i have done rotary devellopement long time in a JOBO equipment, this needs repair so i devellop at a a time 6 sheet 8x10 inch film (in Rodinal) no problem except few scratches and i can not tell, which results i prefer - not caring about the last 5% of difference. the machine is more comfortable of course and i need not hold my hands in chemistry
hendrik

Jason Greenberg Motamedi
3-Aug-2010, 13:03
...Using BTZS type tubes, one must turn out the light to dump the developer and pour in the stop bath, and again to pour out the stop bath and pour in the fixer. ...

I have found that turning off the lights between developer and stop with tubes isn't necessary. If you can prevent light from shining directly on the film (open the tubes and hold the open sides away from light source) and you quickly (~10 seconds) roll the open tubes an acid stop, there is no perceptible fogging. When I first heard about this I was skeptical, and ran a simple experiment: I used two sets of film, one piece unexposed and one lightly flashed. Set 1 ("control," if you like) set was stopped in tube in the dark, and the other ("treatment") under a 60w bulb. Using a densitometer I was unable to find any significant (in keeping with the rest of my "experiment" think I defined this as .05 stop) difference. Once it is stopped the film in can be fixed in full light.

sanking
3-Aug-2010, 13:38
Using BTZS type tubes, one must turn out the light to dump the developer and pour in the stop bath, and again to pour out the stop bath and pour in the fixer. With the taco method, none of this is necessary, and more than one sheet of film can be processed in one tank. I don't like the BTZS tubes, but I've used them, and they are capable of excellent results.

(snip...snip...snip...snip)

I know you've posted many times your assertion that all developers are 90-95% alike, and I think I know what you mean by this, but I also think it can be misleading. First, how do you arrive at these percentages? It the same as saying we share 95% of our genes with Chimpanzees, for instance. It seems you could as easily say that all developers are mostly alike, and avoid the implication that there is some empirical, quantifiable basis for your contention. Maybe I'm picking nits, but it seems to me to depend on how one considers the issue. If one compares characteristic against characteristic (film speed, grain. sharpness, gradation being the primary ones, but development time, shelf life, number of solutions, toxicity, economy, etc., being some others) one could reasonably argue that some developers are very significantly different than others. I personally would not claim that a ppd-based ultrafine grain, large tank, replenished developer is 90% identical to a single agent, one-shot, tanning/staining, acutance developer, or that a high contrast lithographic developer is 90% identical to a POTA type developer. I think your claim misrepresents the diversity of film developer formulation. I could more easily accept that developers within a given category are essentially similar, but even here, there are important differences.




Jay,

About processing with the BTZS tubes. When you use the tubes as they were originally intended to be used everything can be done in daylight as soon as you pop the tube over the cap that contains the developer. You develop one sheet in one tube and the amount of developer needed is very low, about 50 ml per 4X5 film. This is a totally different method of development than the "taco" method. You don't even have to turn on the lights to remove the cap and place the tube in a stop bath. Some find it hard to believe but the film will not fog if you just pop the cap in regular room light and place it immediately in the stop bath. This has been confirmed many times by people who know what they are doing.

About the percentage all developers are alike. The 90% to 95% figure is not an assertion but figures of expression and are not to be taken literally. Moreover, my comments were meant to pertain only to main stream pictorial type developers, not highly specialized ones like POTA for micro film or for developing in the tropics. Whatever the percentage my point was that the 5% to 10% difference, or whatever % you like, is meaningful, otherwise why would someone like me spend so much time trying to optimize results?

Sandy King

Jay DeFehr
3-Aug-2010, 14:18
Sandy,

Maybe I'm overly cautious when using BTZS type tubes, but I still fond them cumbersome in use when more than one sheet is developed. This is just my personal preference. I disagree that the taco method is "totally different" than BTZS tube development. Both methods are based on continuous random rotary agitation, and both methods permit the use of minimal solution volumes. I would say the differences are superficial and the similarities substantial. The differences are about convenience, and have no effect on the development of the film. In other words, nothing need be changed for one method or the other, regarding solution volumes, solutions, development times, etc., and there will be no measurable affect on the film developed attributable to the differences in the two methods.

I agree that 5% can be meaningful, as it is in the case of our genetic similarity to chimps, but we use so many numbers in quantifying our processes, it can be misleading when we use them as figures of speech. Thank you for clarifying.

sanking
3-Aug-2010, 14:44
Sandy,

Maybe I'm overly cautious when using BTZS type tubes, but I still fond them cumbersome in use when more than one sheet is developed. This is just my personal preference. I disagree that the taco method is "totally different" than BTZS tube development. Both methods are based on continuous random rotary agitation, and both methods permit the use of minimal solution volumes.

Perhaps I am not understanding what you mean by "taco" method. I assumed this method was when you placed rubber bands around the film and then placed several sheets of film so constrained in a larger tube or drum, which you then covered with a light proof cap. Is the "taco" method different, or perhaps there are several flavors of "tacos".

Sandy King

sully75
3-Aug-2010, 17:06
yeah, Jay...I don't think continuous agitation is generally part of the taco method. I think you load a normal reel tank taco style and then develop the way you would if you had reels in the tank.

Jay DeFehr
3-Aug-2010, 17:12
Sandy,

You're correct; the taco method utilizes daylight spiral tanks for sheet films bent into a taco shape and secured by a band. The above aside, development by either method is essentially similar; randomly rotating agitation with minimal solution volumes. Unless there's something unique about BTZS development that escapes me?

Brian Ellis
3-Aug-2010, 18:22
Brian . . . Using BTZS type tubes, one must turn out the light to dump the developer and pour in the stop bath, and again to pour out the stop bath and pour in the fixer.

No, that's not how they're used. You turn the lights on when the tubes are capped and they stay on from that point forward. That's the method Phil Davis taught in his workshops (I attended two) and that's what I did for at least ten years and hundreds of sheets of film. As development is nearing completion start removing the tubes from the water jacket, take the tops off one by one and quickly dunk each tube into the stop bath. Then take the tubes out of the stop bath, remove the film, and place it in the fix tray. All with the lights on. If you were turning lights on in between developer, stop, and fix off you were taking some unnecessary precautions.

Of course I'm not trying to convince you to use the tubes, you'll use whatever method you like and that works for you. The BTZS tubes are one method, the one I happened to like, but there are certainly other methods that work as well and that others like. I'm just explaining how the tubes are used.

Ed Brock
3-Aug-2010, 19:32
I've taken the taco method one step further for those of you unfamiliar with the method. I fully enclose the tacos in mesh tubes and stack them in the Paterson roll film tanks - up to 5 in one layer around the fill tube. I process 10 5x7 sheets or 12 4x5 sheets in the deep tank. I do mostly 5x7 and now have a stack of empty film boxes about a foot high all processed with this method and so far all without a processing failure. The method allows complete control of agitation along with temperature monitoring etc in daylight.

sanking
3-Aug-2010, 19:50
I've taken the taco method one step further for those of you unfamiliar with the method. I fully enclose the tacos in mesh tubes and stack them in the Paterson roll film tanks - up to 5 in one layer around the fill tube. I process 10 5x7 sheets or 12 4x5 sheets in the deep tank. I do mostly 5x7 and now have a stack of empty film boxes about a foot high all processed with this method and so far all without a processing failure. The method allows complete control of agitation along with temperature monitoring etc in daylight.

I am having a hard time understanding this but it sounds interesting. What kind of mesh tubes are you using?

Sandy King

Jay DeFehr
3-Aug-2010, 20:07
Paul,

When I devised the taco method, several years ago, I used both continuous rotary, and intermittent agitation, and have regularly used both since then, along with stand development. I'm gratified to know others find the method useful, and are making useful modifications of the method, like Ed's mesh tubes. I have some ideas of my own along these lines, and hope to find time to work them out. I still use the taco method occasionally, for intermittent and stand development, but I usually use Jobo Expert drums for rotary processing, unless I want to develop a single sheet, then it's back to the taco!

jon.oman
4-Aug-2010, 09:52
I am having a hard time understanding this but it sounds interesting. What kind of mesh tubes are you using?

Sandy King

I would be interested in more detail also!

Jon

sully75
4-Aug-2010, 10:22
woah...Jay. I didn't know you invented it. I guess it's what you say it is then. :)

Jay DeFehr
4-Aug-2010, 10:41
Paul,
A lot of people are using a lot of variations of a simple method I introduced several years ago. I'm happy to see people using their own variations and evolving the method.

Jon and Sandy,

I think some people are using the kind of fiberglass mesh used for window screens, but I suspect there is a variety of suitable materials.

sully75
4-Aug-2010, 11:24
Jay, keep up the good work. You must have a good brain!

BradS
4-Aug-2010, 11:42
Paul,

When I devised the taco method, several years ago....(snip)

Jay....my mom developed sheet film using the taco method in the kitchen when I was a kid (back in the 1970's) . She learned it from an old salt at the newspaper where she worked....

Jay DeFehr
4-Aug-2010, 11:50
Brad,

I think my concept of the taco method is fairly accurate, since I introduced it. Your mistaken about the method, and it's possible variations. The taco method can certainly be used as you described, but it's definitely not limited to that use. I've developed hundreds of sheets of film using the taco method and rotary agitation in various kinds of tanks, Paterson included. If one uses the black plastic cap included with the tanks, there is no/minimal leakage during rotary agitation. The taco method can be used to develop from one to 18, or more sheets of film (see Ed's post above), in no more time than it takes to develop by any other method, and much faster than many.

Jason Greenberg Motamedi
4-Aug-2010, 11:54
Perhaps your invention was serendipitous, because I was taught something very similar to what you describe in an LF class I took in college (1986?).

Jay DeFehr
4-Aug-2010, 12:05
Jay....my mom developed sheet film using the taco method in the kitchen when I was a kid (back in the 1970's) . She learned it from an old salt at the newspaper where she worked....


That's cool! I'm not surprised someone else thought of the same technique, as it seems so logical it suggests itself.

sanking
4-Aug-2010, 12:43
That's cool! I'm not surprised someone else thought of the same technique, as it seems so logical it suggests itself.

On the same subject back in the 1970s I developed large prints (40"X50") wrapped in a mesh screen which was then inserted into a tube about two to three inches in diameter. I don't believe the screen was fiberglass because the developer could soak through the mesh. The mesh and tube was sold for about $20.

Sandy King

John Kasaian
4-Aug-2010, 12:56
I've hed excellent results with Unicolor print drums & base.
Terrible results wth a Dev-tech.
I like trays for ortho where I can work under a red light and see the image appear.
IMHO working with panchro film in total darkness is about as interesting as watch dust balls form under the furniture, but I do like the results and if I didn't have a Unicolor that would be my preferred method (unless a rich relative bought me a Jobo)

Drew Wiley
4-Aug-2010, 13:20
There was actually a mesh and tube commercial semi-automated processor made, up
to 30x40 print size if I recall. Doubt I still have the brochure, but maybe.

Ron Marshall
4-Aug-2010, 13:22
Paul,

When I devised the taco method, several years ago

I thought Al Gore invented the Taco method, or was that the internet?

Jay DeFehr
4-Aug-2010, 14:05
I'm not surprised others before me have used similar methods, but when people refer specifically to the "taco method", I assume they're referring to the method I introduced, and called the "taco method". Whatever one chooses to call it, the method can be useful in a number of ways.

arunrajmohan
4-Aug-2010, 14:36
I'm not surprised others before me have used similar methods, but when people refer specifically to the "taco method", I assume they're referring to the method I introduced, and called the "taco method". Whatever one chooses to call it, the method can be useful in a number of ways.

Amazing. I did not expect a conversation on the merits of rotary versus non rotary method of development to become a debate on who invented the "taco method". As far as I can remember Jay DeFahr was to first to mention such a method online. Mention in real or virtual print could be termed as 'publication'. Obviously many have used the technique of stuffing the film in tubes and 35mm film development tanks and even a similar technique was taught at some place.

Ok, back to the merits of ...

-Arun

Jim Michael
4-Aug-2010, 14:39
Seems the biggest difference would be in the amount of control over agitation. Is there a rotary equivalent to stand processing?

Jay DeFehr
4-Aug-2010, 15:07
Continuous agitation, rotary or otherwise, lies at the opposite end of the agitation spectrum from stand development, and there is a range of options in between these two extremes. I consider both 5 seconds per 30 seconds, and 10 seconds per minute, standard intermittent agitation. Any agitation less frequent than 10 seconds per minute, I refer to as Low Frequency Agitation. I'm not aware of anyone using agitation more frequently than 5 seconds per 30 seconds, but less than continously agitating, so in descending order of frequency there is: continuous, standard intermittent, low frequency, and stand. Low frequency agitation encourages compensation, edge effects, and enhanced local contrast. The risk of LFA is uneven development, streaks (bromide drag), mottling, etc. The advantages and disadvantages of contiunous agitation are essentially the opposite of those for LFA. I use the entire range of options depending on the effects I want. Continuous agitation is by far the most convenient option for me, since I have an automated processor, but restlessness, curiosity, and other vices keep me using the other options on a regular basis. Some developers are better suited to one option or another, but in general, I'd say the best option is the one that produces the desired result.

Kevin Crisp
4-Aug-2010, 15:28
Trays were my idea.

BradS
4-Aug-2010, 15:47
and I invented the Jobo.

Henry Ambrose
4-Aug-2010, 16:13
I welded the first hangers and tanks in my garage.

Henry Ambrose
4-Aug-2010, 16:14
snipped....

Is there a rotary equivalent to stand processing?



Yes, I pull the plug.
It stands very still then.

Ron Marshall
4-Aug-2010, 17:01
and I invented the Jobo.

Yes, but did you mention it online first?

Jim Michael
4-Aug-2010, 17:10
Well, of course I'm thinking of a chemical equivalent to stand processing that works during continuous agitation, e.g. some type of restrainer that inhibits processing near the sites with higher exposure.

Jay DeFehr
4-Aug-2010, 17:20
Jim,

the closest one can approximate the effects of stand development with rotary processing is by using a 2-bath developer. Development happens very quickly in the second bath, with the developer- hungry highlights exhausting their local supply of developer absorbed in the emulsion, while the shadow areas continue to develop until the developer there is exhausted, too. This disproportionate development is sometimes referred to as compensating development. And since development is completed so quickly, there is little time for the developer to migrate between regions of high and low densities, so acutance can be very high. This is the only way I use Hypercat with rotary development.

sanking
4-Aug-2010, 18:49
Well, of course I'm thinking of a chemical equivalent to stand processing that works during continuous agitation, e.g. some type of restrainer that inhibits processing near the sites with higher exposure.

This happens in two-bath development, with some developers. There has already been a fairly long thread on the use of Pyrocat-MC as a compensating developer, with most of the emphasis on two bath development. See http://www.largeformatphotography.info/forum/showthread.php?t=52913&page=15&highlight=pyrocat-mc

Not much was made of the fact in that thread but two-bath development with MC produces very high micro contrast from edge effects. This is apparently due to the mechanism that Jay described in a previous message.

I would point out that divided D23 and divided D76 do not produce this kind of microcontrast with two bath development. You may like the results with these developers but microcontrast is lacking, at least by comparison to MC. This is due to the fact that some of the alkali is generally in Solution A and you don't have the kind of sudden developer exhaustion that you will see in a two bath pyrocatechin developer that works at a high pH with a carbonate accelerator.

For many years I have been a proponent of stand or semi-stand development with dilute solutions for scenes of very high contrast. I would today always choose two bath development for those kind of scenes.

Sandy

Jim Michael
4-Aug-2010, 19:40
Jay and Sandy, thanks for that. I'll have to look into those 2 bath developers a little more.