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Dmorrison
16-Jan-2014, 20:59
In your opinion(s), what is the least amount of Developer needed to develop one sheet of 4 x 5 film (in ml); Ilford B&W HP5+ or similar.

If the container the sheet was housed were not much larger than the sheet of film, 5mm on all sides, that's about 51ml. Is this enough?
Or will it become exhausted due to its low volume? There must be some factors that I'm not considering, such as length of dev. time and
dev. used.

Please leave feedback.

Daniel :)

JW Dewdney
16-Jan-2014, 21:34
depends on the amount of active developer in the solution - you could dilute it WAYYYY lower (1:100 maybe even) and do a super long development on it (usually called 'stand' developing etc) ... best to experiment to find out what works for you though.

Mark Sawyer
16-Jan-2014, 21:54
I'm sure there's a minimum amount, but with any normal developer, you'll hit the limits of what it takes to evenly cover the film before you hit the volume limits. 51ml is plenty for a 4x5 sheet, at least volume-wise.

BTW, stand developing is based on lack of agitation more than high dilution. It's compensating nature depends on the developer exhausting as it sits there. The high dilution lets it exhaust the developer more, but the longer time lets more developer "fresh" diffuse in over time, so it's almost a wash. (Mind you, that's from my experience; others might argue the point...)

Dmorrison
16-Jan-2014, 22:02
My initial film developing will be using the Ilford HP5+ and some standard dev. D23 or D76 etc.
I figure that as long as the sheet is covered, it will develop--assuming it is more than simply wetting the sheet.
If the sheet were standing upright, in a box that was 5mm higher than the film, and 5mm thicker on both the front
and back gives a volume of about 51ml. This seems enough to me, but I'm new to 4 x 5 large format film. Everything
I've done has been roll to this point.

"She may not be very pretty now, but she was somebody's baby once." Bugs Bunny

JW Dewdney
16-Jan-2014, 22:07
Yes Mark but stand developing often involves super high dilutions. So that's why it was mentioned. I'm big on high dilution for acutance and frequent agitation myself.
I'm sure there's a minimum amount, but with any normal developer, you'll hit the limits of what it takes to evenly cover the film before you hit the volume limits. 51ml is plenty for a 4x5 sheet, at least volume-wise.

BTW, stand developing is based on lack of agitation more than high dilution. It's compensating nature depends on the developer exhausting as it sits there. The high dilution lets it exhaust the developer more, but the longer time lets more developer "fresh" diffuse in over time, so it's almost a wash. (Mind you, that's from my experience; others might argue the point...)

Dmorrison
16-Jan-2014, 22:15
Let's not stray from the main point here.
I'm trying to decide on a method for developing my sheets, and was thinking that tank was best?
Anyone have experience with using developing devices that use very little fluid? Tanks? Tubes? etc.

Thanks

Better to remain silent and be thought a fool than to speak out and remove all doubt. --Abraham Lincoln

BradS
16-Jan-2014, 22:47
well I routinely process six sheets of 4x5 in an Jobo tank - with 300~400ml of D23...so, yeah, I think that 50ml of D-23 per sheet is plenty.

I think you're going to have other problems with your "narrow box barely larger than a sheet of film" tank idea though. The most obvious is aggitation...

jcoldslabs
16-Jan-2014, 22:57
Daniel,

I use Cibachrome 4x5 developing tubes on a rotary base for all of my 4x5 (and smaller) sheet films. The drum's internal reservoir holds a maximum of 40ml so I have settled on HC-110 1:39 as my standard dilution. This means, of course, that I am only using 1ml of developer for each sheet of film, but I have had no problems with my development since I adopted this approach. In fact, it's produced the most even and consistent negatives of any method I've tried. The only drawback is that I can only develop one sheet at a time, but seeing as I prefer to process each sheet individually this has not bothered me.

Jonathan

Dmorrison
16-Jan-2014, 23:16
Daniel,
In fact, it's produced the most even and consistent negatives of any method I've tried.
Jonathan

What other methods have you tried? may I ask?

jcoldslabs
16-Jan-2014, 23:35
I started out using a JOBO 6 sheet 4x5 reel (2509n) in a tank with hand-inversion. Then I tried stand development in the same tank but abandoned that after a few bouts of bromide drag and/or uneven development in open sky areas. (Might have been user error.) Both of these methods worked fine, I suppose, but the level of consistency I get with the small drums is superior in my opinion. Plus, the low volume of chemistry required makes me happy; the 1500ml to fill the JOBO tank seemed like a waste for only six sheets.

I've never developed in trays or in tanks using hangers because I don't have a proper darkroom and daylight processing options have been a necessity. Also, I shoot a lot of odd sized films (3 1/4" x 4", 2 1/4" x 3 1/4", 9x12cm, etc.) and the small drums accommodate them all easily.

Jonathan

Dmorrison
16-Jan-2014, 23:42
To jcoldslabs...
I'm right across the river from you. Vantuckey.
Thanks for the info.
I've been doing some research for a while now, and it seems that if it can be managed, the tank method is suppose to yield better consistency and or results.
I don't mind going to a little extra trouble, if it means better results.
Daniel

Everyone is entitled to his own opinion, but not his own facts." - Daniel Patrick Moynihan

jcoldslabs
16-Jan-2014, 23:59
Good luck. Any method that gives you the results you are after is the right method for you.

Jonathan

Leigh
17-Jan-2014, 03:43
Everyone is entitled to his own opinion, but not his own facts." - Daniel Patrick Moynihan
Perhaps you should heed your own sig.

The fact that you want to do something, or that you like a particular idea, doesn't mean it's feasible.

Developers have minimum volume specs, normally presented on the datasheet. For example, Rodinal requires 10ml per 8x10 film, regardless of whether the dilution is 1:25 or 1:100 or whatever.

- Leigh

jb7
17-Jan-2014, 04:39
Published data sheets are a starting point- Jonathan is using 4ml of HC-110 concentrate per 8x10 area, and the datasheet specifies 6ml, yet it works for him- meaning his negs are developing to his required gamma, and probably to completion every time. So maybe a fact is different from a recommendation, or a data point.

I wonder what would be the difference, Jonathan, if you were to develop two identically exposed sheets, one at your normal time, and one at double? And if there's a difference between high key and low key negatives?

Over development has messed up more of my negatives than any other single variable, maybe I should start disbelieving the recommendations...

Leigh
17-Jan-2014, 04:42
Over development has messed up more of my negatives than any other single variable, maybe I should start disbelieving the recommendations...
Maybe you should refine your processing, to match that recommended by the developer manufacturer.

Development is a process. The results will vary based on many factors.

- Leigh

IanG
17-Jan-2014, 05:07
There's a minimum level of developing agent(s) needed to process a film and that means that the greater the dilution the larger the volume of developer needed to process the film effectively. Ilford did a lot of work into this in the 1950's for their PQ fine grain Photo-finishing developer Autophen, unlike D76/ID-11 where you need to discard developer as part of replenishment (to keep the bromide buil up low) Autophen used bleed top up replenishment and is very much more stable.

I have the figures somewhere I'll try and dig them out.

Ian

ic-racer
17-Jan-2014, 06:53
You can expose a sheet of film to a distant light (like across a room) and process that. Check density at corners, edges and a few places in the center to confirm uniformity. Exhaustion affects the middle of the sheet causing less density and mottling.

BradS
17-Jan-2014, 07:17
Developer is much less expensive than trying to go back and re-shoot many images.

This is an important point. I believe it is true for all of the materials we use in photography...and so, I am always a little baffled when people want to go with the cheapest film, developer, fixer, paper, etc....

Kirk Gittings
17-Jan-2014, 09:02
I totally agree. The OP's approach places at risk 50% of the effort required to get a good negative. The question should be more like "I am willing to do anything to help insure the proper development of my hard earned negatives. What can I do to maximize the possibility of successful development?"


Planning on using the bare minimum required will come back to bite you. A slight change in water, thermometer a bit off, somthing will come up and you will experience poor performance or failure.

Better to plan on more than the minimum so you have the safety factor to work with.

Developer is much less expensive than trying to go back and re-shoot many images.

Tony Evans
17-Jan-2014, 09:45
Example. Using Taco method, 4 sheets in 800 ml of 1:100 Rodinal Stand = 2 ml Rodinal/ sheet.

Salem Salem
17-Jan-2014, 10:02
If the container the sheet was housed were not much larger than the sheet of film, 5mm on all sides, that's about 51ml. Is this enough?


You're almost describing the Paterson orbital, which many people have reported using and many are happy with the results. (P.S. I have never used it myself because I've never had access to one).

IanG
17-Jan-2014, 13:40
You're almost describing the Paterson orbital, which many people have reported using and many are happy with the results. (P.S. I have never used it myself because I've never had access to one).

I used an Orbital in someone else's darkroom in the South West of Turkey (a member here), very easy and two of my favourite images. However I did ensure sufficient volume of developer.



Example. Using Taco method, 4 sheets in 800 ml of 1:100 Rodinal Stand = 2 ml Rodinal/ sheet.

That's what I was talking about earlier in the thread I think Agfa recommended 8-10ml of Rodinal concentrate per 35mm/120, 4x %"x4" or 10"x8". You can get away with 6ml if your using N (normal contrast) processing) with average subjects, 8-10ml gives a safety margin.

I use Pyrocat HD (Rodinal on Steroids) and when using my Jobo (inversion tanks) use 1+1 to 100 dilution but in a tray or Orbital use 2+2 to 100 which allows me to use less volume but still have sufficient developing agents.

Ian

jcoldslabs
17-Jan-2014, 13:58
I wonder what would be the difference, Jonathan, if you were to develop two identically exposed sheets, one at your normal time, and one at double? And if there's a difference between high key and low key negatives?

My normal development times for various films and the 1:39 dilution are figures that I have established over many years of shooting, testing and refining. I'm pretty sure developing twice as long would result in over-developed highlights, unless I was aiming for N+2 expansion.

I have often wondered if I would run into developer exhaustion issues with high key images (or really dense negatives), but I have not as yet. Below is an image I shot last month on 4x5 Acros 100. It is a fairly dense negative with lots of mid-tones and highlights but few shadow areas, yet it is very evenly developed and retains good highlight detail. This was developed in a 4x5 Cibachrome drum with 1ml HC-110 concentrate + 39ml water for 7 minutes. Alternatively, when I shoot T-Max film I prefer to use T-Max RS developer which I use 1:4 from concentrate (8ml dev. + 32ml water); this also gives me excellent results.

I would not necessarily recommend that anyone else use my method, however, at least not without testing it for themselves. It works for me and my way of shooting and processing, but others may find it problematic. My main reason for settling on 1:39 and not 1:31 (dil. B) is that the recommended development times for dil. B are often a bit short for my taste. And frankly, if the little drums held 80ml of chemistry I would gladly use 2ml concentrate + 78ml of water to be safe, but they don't.


http://www.kolstad.us/ebay/4x5-Acros-Parking-Garage-r3.jpg

Jonathan

Leigh
17-Jan-2014, 15:26
Example. Using Taco method, 4 sheets in 800 ml of 1:100 Rodinal Stand = 2 ml Rodinal/ sheet.
That's 8 ml/"sheet", since a sheet is defined as one 8x10 film or anything you can proof on one 8x10 paper.

- Leigh

koh303
17-Jan-2014, 19:19
This is yet one more of the "4X5 processing - how?" threads, so i will throw in my two cents:


When using rotatio -the Jobo 2520 (Multitank 2) only needs 270ml when loading 6 sheets. That means 65ml per sheet. Only slightly more then the OP's initial material question. The system is a tested and proven one with lots of resources and reference for support online and offline. This can be done on any flat surface, or a manual roller base, or a fancy processor.

If you only load 2 sheets, you only need 130ml in the tank (with the sheets loaded in the outer most slots.

sepiareverb
18-Jan-2014, 06:58
Developers have minimum volume specs, normally presented on the datasheet. For example, Rodinal requires 10ml per 8x10 film, regardless of whether the dilution is 1:25 or 1:100 or whatever.

- Leigh

When I first started with large format this was the second lesson I learned, after bellows extension. Then forgot it when I moved to 810. Second time was the charm for me, I have since always developed in trays with plenty of developer. No reason to start the darkroom process by skimping, it just makes every other step more difficult.

Bill Burk
18-Jan-2014, 09:09
a sheet is defined as one 8x10 film or anything you can proof on one 8x10 paper.

I like simple math like this.

Dmorrison
18-Jan-2014, 12:12
Well, thanks to everyone for the input--I appreciate it very much. I'm not trying to get away with murder here--I don't mind spending money on a good outcome. I merely wanted to learn
more about a process that I don't have much experience in. I'm going to make my own tanks, so I was looking for information regarding minimal fluid levels. I plan on automating the
process later, but the key here, I think, is the tank size/shape. All other variables will be taken care of with the automation; time, temp., agitation etc.

Thanks, Daniel

JW Dewdney
18-Jan-2014, 12:48
Daniel - I think that's a really smart way of doing things - so hat's off to you. I think it's admirable to go out and explore the frontier of what's possible first and then come back to a more conservative place - it will serve you incredibly well in the long run.

Dmorrison
18-Jan-2014, 13:05
Thanks JW.

I know that I will get this worked out. I've done things similar to this before, and through trial and error, find it wiser to start near the end result and start from
a path that will get me there. Having a clear idea of what needs to be accomplished will get me to where I want to be.

I figure that other than the developer used and it concentration, the only variables I have to contend with are the three mentioned above: time, temperature and agitation.
If there is something I haven't thought of, let me know. I'm speaking here of only the development stage, not everything leading up to it. Yes, exposure does affect
development time, but that would simply be a setting change in the automation device.

The goal here is to get very consistent results due to repeatability in the development stage. Just as one needs to measure out their developer/water mixture the
same way each time to get consistent results. The automator will basically allow me to repeat this part of the entire photo process consistently each time.

Thanks again, Daniel

koh303
18-Jan-2014, 15:52
Well, thanks to everyone for the input--I appreciate it very much. I'm not trying to get away with murder here--I don't mind spending money on a good outcome. I merely wanted to learn
more about a process that I don't have much experience in. I'm going to make my own tanks, so I was looking for information regarding minimal fluid levels. I plan on automating the
process later, but the key here, I think, is the tank size/shape. All other variables will be taken care of with the automation; time, temp., agitation etc.

Thanks, Daniel

What tanks will you be making?
Why not use an existing system?

koh303
18-Jan-2014, 15:54
The goal here is to get very consistent results due to repeatability in the development stage. Just as one needs to measure out their developer/water mixture the
same way each time to get consistent results. The automator will basically allow me to repeat this part of the entire photo process consistently each time.

Thanks again, Daniel

Dont look too far:
http://jobo-usa.com/jobo-analog-products/jobo-cpp3-processor

Bill Burk
18-Jan-2014, 15:58
I figure that other than the developer used and it concentration, the only variables I have to contend with are the three mentioned above: time, temperature and agitation.
If there is something I haven't thought of, let me know. I'm speaking here of only the development stage, not everything leading up to it.

Sensitometry? You will need to check how well the system is reaching your goals by exposing test strips, developing them, and then measuring them... Assuming you include that in your "system"... You will be able to quantify - and compensate for - any part of the system which is "out of control"

Dmorrison
18-Jan-2014, 16:55
What tanks will you be making?
Why not use an existing system?

I know about the Jobo system, and have used it in the past. What I'm looking to do is have a system that emulates tank
development as if done by hand. But that is consistently repeatable. Put the film in the tank, set the program for film type,
+/- development etc., and then push a button and walk away. Everything would be taken care of, including temperature control
during the entire process. Saved programs could be called to run a sequence on a type of film/developer/exposure combination.

This is my goal, and I know it will take some effort. I have experience in electronics, mechanics and robotics, so I feel confident
that I can do this project.

The sensitometry will be part of the tuning phase of programming; that's what will be so nice about the system. Simply change
a parameter in the program, push a button and check the results.

Thanks, Daniel

Bill Burk
18-Jan-2014, 20:20
If you feel ambitious you could add Nitrogen burst to the system...

Dmorrison
18-Jan-2014, 20:29
If you feel ambitious you could add Nitrogen burst to the system...

Not a bad idea, but the system will simulate the tank method that you would use if you were in a darkroom and doing this by hand. Like
lifting the sheet out of the dev. and tipping it to one side and then the other.

Now if using the N2 burst method gave better results, then I could see using it. As I've said, I don't have experience with developing sheet film--roll film only.
And a good inversion did quite well.

A work in progress, Thanks, Daniel

koh303
18-Jan-2014, 20:41
I know about the Jobo system, and have used it in the past. What I'm looking to do is have a system that emulates tank
development as if done by hand. But that is consistently repeatable. Put the film in the tank, set the program for film type,
+/- development etc., and then push a button and walk away. Everything would be taken care of, including temperature control
during the entire process. Saved programs could be called to run a sequence on a type of film/developer/exposure combination.

This is my goal, and I know it will take some effort. I have experience in electronics, mechanics and robotics, so I feel confident
that I can do this project.

The sensitometry will be part of the tuning phase of programming; that's what will be so nice about the system. Simply change
a parameter in the program, push a button and check the results.

Thanks, Daniel

This does everything you are talking about:
http://www.catlabs.info/product/jobo-atl-1000-autolab-compact-fully-automatic-processor

The onboard Eprom can easily be programmed to do pretty much anything you need.
The larger ATL (2,3,300 2X00) machines (which are readily available) are fully programmable, for temp/time/agitation speed and are launch and forget systems.

That said - good luck with your project - keep us posted on how it goes.Over the years there have been several such concepts to invent and create an automatic processor with various levels of automation, but none have ever yet come to life. I am holding fingers yours does.

Dmorrison
18-Jan-2014, 20:56
Well I took a look at the Jobo ATL units. Don't know if they would be as customizable as what I'm going to do--I'll have a LCD screen with
changeable parameters. You could call up any one a several programs that you save for film type, dev. type and +/- development.

It also looks like they are kind of expensive. I couldn't tell if they are still making them or not--all of the google references were to used
units. Looks like they are still making the CPP-3. But these are tubes, and I would like to use a tank, as I said, to simulate tank
processing. I'm sure Ansel Adams would have loved such a device.

Thanks for all of the input, Daniel

Dmorrison
18-Jan-2014, 21:06
I have just watched the video for the Jobo CCP-3. It is not as fully automated as I would like to create. They show the guy pouring chemicals into the tube,
and then tipping the tube up to drain. Sure it rotates the tube for agitation, but that and temperature control seems to be all it controls.

I'm working towards a unit that you set up, and then simply push the GO button, and when finished you would have a fixed and washed negative. My idea
would also be able to do up to 5 negatives at one time; given all five had the same development scheme. Otherwise, you can do one at a time.

I don't have a cost estimate yet, but do have some drawings and a rough idea what parts may cost. Of course, there's my time cost of building and
programming the micro-controller. But I'm looking at this as a labor of love; I love to tinker.

Thanks, Daniel

Bill Burk
18-Jan-2014, 21:10
I think Nitrogen burst is regarded as the pinnacle... But difficult engineering.

You know about compensating timers, right? I use CompnTemp, which feeds back actual temperature during the process and adjusts the real time to give a constant "time at target temperature" outcome, without me having to hold tight temperature tolerance in my process.

Dmorrison
18-Jan-2014, 21:25
I don't know of CompnTemp, but will look into it.

I plan on using a PID loop to control the temperature before and during the process of the actual developer, stop & fix baths. I could do something similar
as you describe, but it would be more complicated. Each program would have a set point for its temp. and only start the process once the temp. was reached.
So I could run one program that uses 68, and then another after that uses 70. I don't think that running the higher temp. process first would be as reliable.
I may find that I need to have some sort of cooling effect. If I did, I could run any process in any order without having to wait.

I did something very similar to this when I was brewing my own beer. I had my fermentation tank temp. controlled with both heat and cooling. It
maintained the 5 gallons of beer to within .5 deg. F. So I would probably just use that system in this project.

So, I'm already part way there.

Daniel

Bill Burk
18-Jan-2014, 22:06
The CompnTemp is similar in function to the older Zone VI compensating developing timers. It basically takes the traditional time/temperature charts into real-time.

I think it would be awesome if your system could do stand development just as easily as continuous agitation and everything in-between. (Agitate continuously first 45 seconds, then twice a minute for the first 5 minutes, then once a minute for the next 10 minutes etc...)

And I hope you don't make it a "push here dummy" system that insulates the user from the process, hopefully you will display what is taking place and program it with an intelligent interface...

To the original issue of highly dilute developer and the virtually huge corresponding tank required, maybe you can recirculate the dilute developer from a holding vessel that is larger than the actual developing tank.

You might also want to make it possible to alternate between developer and water (or 2 bath process) several times.

Dmorrison
18-Jan-2014, 22:23
I most certainly will have the user in mind. The user will be able to change any aspect of the program. Once set though, and then all you have to do is
"Push the button Max." (Get Smart)

I'm planning on having it set up so that you can change any of the parameters for a given process. Processes would include: pre-soak time, initial agitation
time, develop agitation/time, stop bath agitation/time, fix bath agitation/time and wash time. Any one of these could be left out or skipped.

Basically, this would be a robot that would do as you program to simulate the old tank dunk method. And in doing so would be very repeatable,
yielding consistent results.

Daniel

koh303
19-Jan-2014, 06:52
Any of theATL2X00 are fully programmable, with 32 channels,each with 12-14 fully independant stages (with time/temp/volume options for each). The machine fills the tank, rotates, temperes, rinses and dumps as you progrmmaed. All you do is select one of the 32 pre programmed channels and hit the start button. Some models can even replenish the 1.5L process bottles from larger storage bottles.
They have a 4X 20 LCD panel, though the on board processor can be hooked up to a larger control display (some users do that) and the processor it self is easily programmed in case you want to add anything (though after 30 years of production, they pretty much had everything keyed in).

All that said they are not "tanks" but Expert drums have been shown to produce the best over all results in sheet film processing. The machines also have a capacity of well over 10 rolls per run, or as little as one roll with no waste of chemistry.

These machines are available used, but we can get you a factory refurbished (all new components) unit as special order.
I can only dare to say, that the total cost of building your concept (without the time, effort and trails factored in) will be more then any ATL machine.

Leigh
19-Jan-2014, 07:16
I can only dare to say, that the total cost of building your concept (without the time, effort and trails factored in) will be more then any ATL machine.
Absolutely true. As an electrical engineer with over 50 successful products on the street, I'm well aware of the effort required to get even a simple product out of the lab and working properly.

- Leigh

Bill Burk
19-Jan-2014, 10:02
Absolutely true. As an electrical engineer with over 50 successful products on the street, I'm well aware of the effort required to get even a simple product out of the lab and working properly.

- Leigh

But doesn't Do-It-Yourself "Maker" type attitude make projects like these "no more expensive" than the usual photographer's journey of collecting the things for a darkroom?

Leigh
19-Jan-2014, 10:24
Hi Bill,

I didn't say there was anything "wrong" with the OP's idea.

I just cautioned that the effort involved may be significantly more than anticipated.

Whenever you combine electricity and water, there are some very strict guidelines to avoid getting killed.

- Leigh

Dmorrison
19-Jan-2014, 10:31
I'll look into the ATL2X00, but the other Jobo CCP2 that I looked at cost around $1800. I think I can spend less than that for parts; I do have a lot of stuff lying about.
Time is another issue. It certainly would take more time than buying one of the ATL2X00 units. And I may find that the saved time would be worth the outlay
in cash. It's always a balancing act.

Well I took some time to Google the larger Jobo, and found an ATL 3. Wow, that thing is big. And am I correct in assuming that these are no longer made? Looks
like it from what I can tell.

Thanks to everyone for your input, Daniel

Dmorrison
19-Jan-2014, 10:39
I found this one for $4950,
http://www.ebay.com/itm/Jobo-ATL-2500-film-processors-Qnty-2-/190984104290
buy-it-now. I'm pretty sure that I won't have to spend that much money in parts, but the time issue is still an unknown.
The concept of what I'm thinking of would be smaller also, less commercial in nature; more hobby oriented.

Thanks, Daniel

Bill Burk
19-Jan-2014, 11:32
Check with Greg Blank (forum member here), he may have an ATL-3 on consignment.

Dmorrison
19-Jan-2014, 12:01
Bill,

I don't really have the room for one of those beasts. My unit would be approximately 12w x 36L x 16h inches. The final size is yet to be worked out.
I kind of like the idea of doing this myself. We'll see.

Daniel

So, to recap my initial question: what would be the minimum volume of fluid for tank development, as if you were in a dark room dunking the negs
in the tanks?

Salem Salem
19-Jan-2014, 12:40
Here is my two cents (pennies) Until someone comes up with a definite answer. The data sheet for the ilford id-11 developer states that 1 litre stock in a deep tank would be exhausted and needs replenishing after processing 10 rolls or 40 5x4 sheets. So, 100ml a roll or 25ml a sheet. That is a layer of about 1mm in thickness of developer around the 4x5 sheet.

Leigh
19-Jan-2014, 12:58
So, to recap my initial question: what would be the minimum volume of fluid for tank development, as if you were in a dark room dunking the negs in the tanks?
How high is up?

The question cannot be answered because it depends entirely on which developer you use.

Your fixation with "minimum amount of developer" is totally at odds with your agitation method.
Trying to combine those will result in very uneven development.

You're not doing any original research here, Daniel.
This horse has been chased around the barn for 100 years.

- Leigh

Dmorrison
19-Jan-2014, 13:49
I'm not necessarily looking for the minimum amount because I want to save money, I would like to have an idea as to a near minimum
so that I can size my tanks accordingly. I'm sure that I will oversize them a bit anyway just to be safe.

Did they ever catch that horse?

Nothing here is set in stone as of yet, so this is merely advanced research of opinions. How's that for a dead horse?

Thanks to everyone for their opinions.

Daniel

Leigh
19-Jan-2014, 14:09
Poor horsies. ;-)

A suggestion regarding your agitation method...

You only need to raise the negatives about an inch, then put them back in the tank.
This minimizes the time the neg is out of the developer.

I've done an awful lot of tank-and-hangar processing in the last 50 years using that method, and never had a problem with inconsistency.

The only purpose of agitation is to move the used developer away from the film surface and replace it with fresh. it certainly does not require removing the negative completely from the tank, nor any other heroic action to refresh the chemistry.

- Leigh

Dmorrison
19-Jan-2014, 14:18
Leigh, This is exactly the kind of information that I need.
Please, more details. I was under the impression that you take the neg. up/out of the dev. and tip it to one side. Reinsert it
and then do it again but tipped the other direction. This should take no more than 4 seconds?

Given what you say, the N2 burst method would accomplish the same effect without removing the negs. from the dev. Not
a huge advantage for the added complication, though.

Please add any more thoughts on tank agitation methods that you have used, irregardless of the horse.

Thanks, Daniel

Leigh
19-Jan-2014, 14:41
There are certainly people who do use the agitation method you described.
I don't, because I see no advantage to it.

Some rules that I try to follow for tank development...

1) Film never leaves the developer. There's enough space between the top of the film(s) and the top of the tank to lift and lower the hangers without the film ever clearing the surface of the developer.

2) Slow. I lift and return gently, in only a second or two.

One problem people often encounter is uneven development around the film edges caused by developer surging around the hanger perimeter. I think this is frequently the result of the excessive movement involved in pulling film out and returning it.

Nitrogen burst is certainly the standard for commercial processing labs. It's likely impractical for a home system. I never tried it.

- Leigh

Bill Burk
19-Jan-2014, 17:51
Developers have minimum volume specs, normally presented on the datasheet. For example, Rodinal requires 10ml per 8x10 film, regardless of whether the dilution is 1:25 or 1:100 or whatever.

Daniel,

This is one of the basic issues with designing tanks for film processing. If you want to have a system that allows for Rodinal at 1:100 then you have to allow for a tank capacity of 1,000 ML per sheet of 8x10 film. And if you want to do stand development in such a system, then the tank has to be that large (I was thinking you could recirculate the developer from a reservoir, but then it wouldn't be stand developing). Even though it seems absurd to have that much liquid for one sheet of film, I think you need a big tank...

And give it a sturdy over-engineered lift or fill and drain mechanism.

Dmorrison
19-Jan-2014, 21:04
I'm thinking that the system should be designed in such a manner as to allow changing all aspects of agitation and development; I could lift
a little, or a lot. Agitate a little or a lot. A system that allows me many ways of doing these two things would allow me to adjust and tweak
forever.

I don't plan on doing 8 x 10, but I'll keep the size in mind during design so that I can allow that size in the future if I decide to go that route.

Bill, if I do use 1:100 concentration, won't I end up with 101 ml? It's been a while since chemistry, but I think that's correct. Or I could use
.5:50 and achieve the same thing. Correct me if I'm wrong.

I've not done any sheet film developing yet, but how touchy is the film with regards to the accuracy of the concentration of the developer?

Daniel

Bill Burk
19-Jan-2014, 21:29
It's not that complicated, it's more like cookbook math than chemistry...

Every developer needs a certain amount of active ingredient to get the job done... So with Rodinal which specifies 10cc per 8x10, you have to use 10cc of stock solution and you dilute it with the amount of water to reach the dilution you want.

Which can sometimes overwhelm a rotary processor lifting mechanism because you end up with a lot of developer.

Dmorrison
19-Jan-2014, 21:39
10 ml per sheet of 8 x 10 means 2.5 ml for a sheet of 4 x 5?

That is a fine point that I won't worry too much about now; I'll simply stay away from Rodinal in the beginning. To get me up and running I'll use D76 for ease of use.
Once I have that process down, I'll move on to other types of developer.

I can't believe that this one topic went on for 7 pages.

WIsh me luck, and thanks to everyone that had something encouraging to say. Daniel

Leigh
20-Jan-2014, 02:43
Daniel, forgive me for being blunt, but...

Have you ever actually developed and printed any film?
Some of your comments and concerns suggest that you have not.

Generally speaking, processing variations equivalent to about a half stop exposure change have absolutely no impact on the quality of the final print, with the possible exception of extremely dark detail in the shadows.

That's not meant to discourage experimentation, only to anchor your expectations in reality.

- Leigh

BradS
20-Jan-2014, 09:16
So, to recap my initial question: what would be the minimum volume of fluid for tank development, as if you were in a dark room dunking the negs in the tanks?

You've been given many decent answers. Ultimately, you should read the various manufacturers' data sheets. I would think this point obvious to somebody with the ambition to build what you've proposed.

...and, I still think that your main issue is going to be agitation. You mention lifting the sheet of film out of the tank an tipping the film...have you tried developing film this way by hand? Did you like the results? I would very strongly urge you to do some manual tests of what you think you'd like to automate to see if your idea is capable of producing acceptable results.

Dmorrison
20-Jan-2014, 09:50
As I stated in a previous post,--don't remember which page it was, didn't really expect this to go to 7 pages, I have not developed sheet film, but have developed
roll film since high school. That's over half a lifetime ago. Not having developed sheet film, I was merely trying to gather whatever information I could from all
of you experienced with sheet film. I've shot/developed so much Tri-X that I couldn't begin to guess.

I've read The Negative by AA. I understand the process in general as it applies to sheet film. I will be re-reading The Negative before I go
into fine tuning the process. I know that the first few boxes of film will be nothing more than test runs. I'm okay with this.

The main reason I came to this forum was just because I have not developed sheet film. You guys know, and are in the know.

This thread got a little off target, but I don't mind; many of you have given me plenty of good ideas, and encouragement. I may not have asked the precise
question to start this thread, but I think I got what I needed.

So, thanks again to all, Daniel

To Leigh: I have developed and printed film; I still have the first print that I ever saw appear before my eyes way back when. Technically not great, but I will
always treasure that print.

Leigh
20-Jan-2014, 11:41
Good luck with the project, Daniel. Let us know how it turns out.

I did keep my first print for a long time, but it was lost during the eruption of Krakatoa.

Give me a shout if you need any help with electronic or mechanical design, or technical drawings.
I have a lot of experience doing all of the above.

- Leigh

jcoldslabs
20-Jan-2014, 15:06
Or you could always build a developing bot out of LEGO:

http://petapixel.com/2014/01/20/using-legos-develop-film-automatically/

Jonathan

Dmorrison
20-Jan-2014, 19:22
TO: jcoldslabs
That is pretty much how my system would work, but a bit more rugged. I would use those rectangular tanks that Kodak made with their hangers. I have a few lying about.
I'm going to use linear ways with recirculating bearings, stepper motors and a servo or two. I have done some programming of the Parallax micro controllers, namely the
propeller. It has seven processors that can run concurrently. This will be very robust and flexible.

Don't mean to get off topic. I think that the beauty of the system is that every aspect of the process will be completely programable. I simply need a separate tank for each
fluid I want in the system. Just like our friend with the Legobot.

Keep those ideas coming, Daniel

Bill Burk
20-Jan-2014, 19:50
10 ml per sheet of 8 x 10 means 2.5 ml for a sheet of 4 x 5?

That is a fine point that I won't worry too much about now; I'll simply stay away from Rodinal in the beginning. To get me up and running I'll use D76 for ease of use.

Yes, and that 2.5 multiplied by 100... you get the point. People with these beautiful Jobo processors have broken their lift because even though the tanks are designed to work efficiently with just a small amount of fluid, they really wanted to use the highly dilute ratio for the effect they were after... I bring it up early in the design phase, so you can avoid that mistake other people have made.

D-76 takes 2 ounces for the 4x5 sheet. So at 1:1 you do 4 ounces liquid.

Dmorrison
20-Jan-2014, 19:59
TO: jcoldslabs
That is pretty much how my system would work, but a bit more rugged. etc.

Take a look at the video Bill. As stated above, my system would be more sturdy/professional.

The fluids would not be moved around; they would stay in the tank and the film would be moved along the conveyor belt, so to speak.

Daniel

Leigh
20-Jan-2014, 20:00
10 ml per sheet of 8 x 10 means 2.5 ml for a sheet of 4 x 5?
That is a fine point that I won't worry too much about now;
You're about to learn one of the harsh realities of product design.

The design IS in the details. The generalities do not matter at all.

You not only need to identify them, but to obsess about them before you try to make anything work.

Any damned fool can do a top-level design that looks great on paper.

- Leigh

Dmorrison
20-Jan-2014, 20:41
Leigh,

I guess that this is part of the obsession. I've been thinking about the implementation for at least 1.5 years. I've also collected some of what I need to make it
happen; motors, slides, tanks, hangers etc. I'm not entirely new to putting something together; I do some design work for the company that I work for, even
though I have no formal training. I've had some good ideas--according to my boss. Everything that I've done so far is still in use; cross my fingers.
I won't do anything until i've drawn it up in a CAD program first. I've also an EET certificate degree that allows me some confidence in the electrical arena.
But if I do have any questions I will contact you, if you don't mind.

The only generality that I'm thinking of is the programming of the micro-controller that will allow me to adjust the actions of the device infinitely.

_- Daniel

Leigh
21-Jan-2014, 04:30
With all this talk of infinite variability, the one point I find missing from the discussion is...

Why?

Why would you change the fixer stage? If the film is completely fixed, you're done.
If it's not, then extend the time and you're done. Follow the manufacturer's directions.

The same is true with stop bath.
Unless you want to go weirdo like a water stop, just use as directed and get on with your life.

These are examples of how you're caught up on the "gee-whiz" blinking lights aspect of the project
without giving any consideration to the rationale behind the design.

Certainly the process control and variability are highly desirable for the developing step(s), one or two
depending on whether you use a water pre-soak with a conventional developer or a two-part developer
like Diafine. But there's nothing of significance to be gained by changing any of the other steps.

This falls in the category of getting the donkey's attention by hitting him between the eyes with a clue stick.

- Leigh

Dmorrison
21-Jan-2014, 10:26
I was merely stating that the device would be infinitely flexible. I can do, or not do, whatever I want.
It's like the difference between having a switch, and a switch with a potentiometer.

Daniel