PDA

View Full Version : Printing with Jobos?



cyrus
10-Jan-2012, 19:31
How do you folks who develop BW prints with Jobos or tubes do it? There is so much information about a print that is provided by watching a print develop in a tray that I can't image how you could develop without it. For example I always count the time it takes for certain events to occur in the tray:

1- the over all base tone starts to become apparent

2- the shadows to start,

3- how long it takes for the midtones to complete from then,

4- and from there I watch how long it takes the highlights to catch up.

(This is in addition to the normal print basics check of finding blackest black, etc.)

Changing an enlarger setting (exposure time, contrast) affects how long it takes from one event to another, how far apart the peaks of the highlights/midtones/shadows are, and how high they get. If I see for example that it takes a normal time for the base tone to show up, but then the shadows come in dramatically, the midtones much slower, and the highlights never budge from base white, then I know that contrast is too high.

How do you do this in a Jobo if you can't see the printing process? Must require a lot more trial and error.

cyrus
10-Jan-2012, 20:04
How do you folks who develop BW prints with Jobos or tubes do it? There is so much information about a print that is provided by watching a print develop in a tray that I can't image how you could develop without it. For example I always count the time it takes for certain events to occur in the tray:

1- the over all base tone starts to become apparent

2- the shadows to start,

3- how long it takes for the midtones to complete from then,

4- and from there I watch how long it takes the highlights to catch up.

.

For got to add


5- How long until all obvious changes stop, and the print "settles down" - I develop for 3 secs and like to see this happen at about half way

Drew Wiley
10-Jan-2012, 20:21
No different than anything else. Use a standardized temperature, maybe in this case
standardize to 68F (20C). Make your test strip. Turn the RPM relatively low if possible. Fill and drain as quickly as possible. Try 2 min dev for fiber based prints,
then a brief acid stop bath. If the time needs adjusting just do another test strip.
I think trays are generally easier, but utterly ignore all that stuff about trying to see
in near darkness when some subtle detail becomes emergent. After the test strip is
rinsed I put it in a toaster oven for about 20 sec to dry it completely to judge the
results. With drums you will have to monitor your solution volume and preferably
use it one-shot. A smaller drum can be useful to conserve chemistry with test strips
if all the other parameters remain basically the same.

Larry Gebhardt
10-Jan-2012, 20:28
Just use fresh chemistry and a consistent time and your prints will come out well with the Jobo. That's how I do it in a tray as well. I will vary the development time a bit if I know the developer is old. Then I use a multiple of the emergence time (#1 as you described it) which I test on the first print. Then I sue that time for the rest of the tests and prints. But for a Jobo that won't work.

I think it's a recipe for disaster to alter the development time in response to how the print is developing. I always keep the time consistent and vary the time or contrast at the exposure step.

cyrus
11-Jan-2012, 10:29
I think it's a recipe for disaster to alter the development time in response to how the print is developing. I always keep the time consistent and vary the time or contrast at the exposure step.

Not development time - exposure time. I adjust exposure and contrast at the exposure stage, based on how the shadows in the print develop whilst in the development stage. But I don't adjust development time - it is always 3 min for me.

I guess I have been spoilt with my LED safelights which are bright enough for me to see these details about the print as it develops.

cyrus
11-Jan-2012, 12:28
Pg. 96 of "The Print" describes Factorial Development. Earlier on page 95 he states that "rich blacks require full development" of the print. That's what I was learned. Right or wrong, it kinda makes sense. You should be able to achieve "full development" in drums or trays.

http://www.scribd.com/doc/43861132/The-print-Ansel-Adams

**

Yes full development is necessary - the blackest black. I don't change the development time, I change the exposure time and the contrast. Viewing how the print develops provides that info on contrast and exposure.

For example, the time it takes from when the deepest shadow kicks in, to the time that the midtones come out - knowing this time is quite important in how I expose.

cyrus
11-Jan-2012, 15:38
Could you give a working example of this? Though, my safe-lights are not bright enough to evaluate a print, knowing the steps would indeed be of interest to me. Many thanks in advance.

Well I'm not sure how else to describe it. I place the print in the developer, watch it develop and start counting. There is a predictable pattern that occurs each time. Even in the low light of my LED safelights, you can still see the important things and time their occurrence.

The development process is first the shadows come then the midtones and the highlights develop last. Time these events.

The darkness-brightness is a function of exposure time. The speed at which the max highlights/shadows/midtones are achieved relative to each other is a function of contrast.

If there is too much exposure then everything is too dark, and when the shadows first start to develop they look like a blob of blacks and destroy the detail that first appears. So you know to reduce exposure time.

The time it takes for the shadows to complete and then the midtones to fill in, is an indicator of contrast. If there's decent time interval then you've got the shadows and midtones spread out enough to get the fullest range of tones in between. On the other hand if the midtones are mostly done developing as soon the shadows finishing development too then you know your midtones are too close to your shadows and need to be separated, by lowering contrast.

I usually like to have all the obvious changes finish by about 90 sec, which is half the time that the print is in the developer. For the second 90 secs, all that's left is that the shadows are very incrementally getting darker, hitting max black.

cyrus
12-Jan-2012, 11:14
Thanks cyrus, I should try to attempt this on my own. Though I'm sure plenty of practice will be required. Do you know of an online reference for this evaluation process? I'm digging through my books. Would this an element of the Zone system or like method?

No, it is really just a thing I picked up after developing prints for a while. There is a distinct pattern of event that occur everytime a print goes into the developer which you start to recognize if you pay attention, and once you're familiar with the pattern you can also see how changes to the enlarger exposure settings result in changes to the development process.

I started enlarging a step wedge, and noticed how changing contrast/exposure would open up or block up tones, and how it affected contrast. It was very good way to learn what's really going on, and so how to control it.

Larry Gebhardt
12-Jan-2012, 11:38
Not development time - exposure time. I adjust exposure and contrast at the exposure stage, based on how the shadows in the print develop whilst in the development stage. But I don't adjust development time - it is always 3 min for me.

I guess I have been spoilt with my LED safelights which are bright enough for me to see these details about the print as it develops.

I see. I've never tried to make exposure adjustments based on how the print comes up, so putting a print in a drum wouldn't limit me. I guess for you you would just need to change how you adjust things to only looking at the finished print. I know - not helpful.

I'll have to try your method and see if it can save me some paper and time.

D. Bryant
12-Jan-2012, 21:34
No, it is really just a thing I picked up after developing prints for a while. There is a distinct pattern of event that occur everytime a print goes into the developer which you start to recognize if you pay attention, and once you're familiar with the pattern you can also see how changes to the enlarger exposure settings result in changes to the development process.

I started enlarging a step wedge, and noticed how changing contrast/exposure would open up or block up tones, and how it affected contrast. It was very good way to learn what's really going on, and so how to control it.

You are really doing this the hard way, read Drew's post again. trays are fine but judging print density by safe light isn't. I use a Thompson safe light with the appropriate filter and have plenty of light after it has warmed up.

For rough adjustments your method works but not for fine nuanced adjustments which require viewing of a dry print under appropriate lights. If you print frequently with the same paper you can make judgments about the print in the wash tray once you gain your dry down vision or by using a wet step wedge in the wash tray for comparison.

If you are proofing, quickie printing is fine; for fine printing there really aren't any short cuts.


I thought you were doing gravure printing ...

cyrus
13-Jan-2012, 11:17
You are really doing this the hard way, read Drew's post again. trays are fine but judging print density by safe light isn't. I use a Thompson safe light with the appropriate filter and have plenty of light after it has warmed up.

For rough adjustments your method works but not for fine nuanced adjustments which require viewing of a dry print under appropriate lights. If you print frequently with the same paper you can make judgments about the print in the wash tray once you gain your dry down vision or by using a wet step wedge in the wash tray for comparison.

If you are proofing, quickie printing is fine; for fine printing there really aren't any short cuts.


I thought you were doing gravure printing ...

I don't know what a Thompson safelight is, but I do have a Thomas in my darkroom though I prefer my amber LEDs right over my sink, which are mucho bright and quite safe (since they emit only on a single wavelength.) Judging density of a print during development can be done just fine if you're only comparing it to the density of another print that was also in development. I just need to see if it is more dense or less dense. Once I've made up my mind about how the print should appear I use this technique to know how and when my changes to exposure are going the right way, and whether there are potentials left in the negative that I haven't used yet (for example, to get more of a contrast separation.)

I should point out that I didn't invent or create this process of "reading" the print while it is developing - this was standard practice, at least back when I was being taught.

cyrus
13-Jan-2012, 11:28
I see. I've never tried to make exposure adjustments based on how the print comes up, so putting a print in a drum wouldn't limit me. I guess for you you would just need to change how you adjust things to only looking at the finished print. I know - not helpful.

I'll have to try your method and see if it can save me some paper and time.

I don't know if it will necessarily save paper but it does give quite a bit of feedback during the printing process that gives me (at least) a better sense of what the possible range of contrast/exposure settings are and how they can change the print.

cyrus
13-Jan-2012, 15:11
By the way something else I was taught: to see if there's any more detail in your shadows that you can bring out, I was trained to put the print on a lightbox. The small amount of light that comes through the paper has a way of lighting up the shadows, and you can cleary see details in there.

jm51
14-Jan-2012, 10:16
How do you folks who develop BW prints with Jobos or tubes do it? There is so much information about a print that is provided by watching a print develop in a tray that I can't image how you could develop without it.


People manage to develop film ok without inspection. :)

cyrus
14-Jan-2012, 17:30
People manage to develop film ok without inspection. :)

Yeah but developing film by inspection is REALLY hard! :p If more people could do it, they would.