Rotary processing and developer choice

[Joseph O'Neil]

I've never used Acros, but for almost all my B&W films, including at one time, a couple boxes of Fuji Neopan in 4x5 (my sister used to live in Japan, and i had her ship me a coupel boxes once), I use HC-110 in my Jobo 2500 tank, and I have the same base as you do.

The stuff keeps forever, and i use the straight syrup. I also find a pre-soak in near manditory in my case, and you can get good tonality with HC-110 if you weaken it down a lot. The traditional Dil-B is waaaaaaay too strong I find. You'll have to experiment a bit to get things the way you like it, but can be done.

Also, I've used PMK Pyro to good effect in the Jobo 2500 drums. In fact, you can use just about any developer you want - the trick is to adjust times and solutions. I find, overall, to go with a weaker solution than you would with an inversion or hard rubger tank or tray development, and then adjust times accordingly.

The constant rotation/mechanical action of the drum on the base can have the effect of increasing your contrast, so I find instead of fighting that effect, count on it, and adjust your development accordingly. Otherwise with any developer, especailly something like HC-100, if you are not careful, you can make just about any sheet of film look like a litho print.

One last thought - with tray or hard rubber tanks, I would use replensiher and reuse chemistry. For the Jobo tanks, I have found out the hard way - at least for me - when it comes to developer, one shot is the way to go to keep good results and consistancy. I find I can re-use my fix for a period of time, but always one shot for th edevleoper, regardless of what developer I am using.

good luck

joe

[Bruce Watson]

How about my actual question on whether rotary and inversion get the same results from any developer? Are any important developer properties lost or gained with constant agitation? That's what I want to know.

Think of agitation as a spectrum. On one end you have constant agitation (rotary). On the other end is no agitation (stand developement). In the middle a range of intermittant agitation techniques (tank inversion, lift-and-tilt with hangers, etc.).

People use these different techniques to get different effects. For example, stand development is often used to create a compensating effect -- local developer exhaustion slows down the density increase in the highlight areas resulting in a lower Dmax and thus a lower contrast negative. Basically, you can't do this with constant agitation.

On the other hand, constant agitation does a better job of even development. You can see this particularly in areas of even or small tonal gradients like sky areas. Constant agitation does a better job of creating consistant results from batch to batch also, particularly if the agitation is from a motor.

Some developers do better with some techniques than others. For example, a two bath developer like Diafine will work poorly in with constant agitation. The first bath will be flushed out of the emulsion too quickly; the second bath won't continue the development process alone.

Developers that oxidize quickly (PMK comes to mind) will probably give somewhat better results with other (non-rotary) agitation techniques as well.

So, "Are any important developer properties lost or gained with constant agitation?" The answer is yes. Which properites you gain and/or lose is a function of film and developer. Whether it matters to you is a function of your individual aesthetic.

Personally, I use XTOL 1:3 with a Jobo and a 3010 drum. I don't normally use all five liters in a year. If I question its age I toss it out and mix up another batch. XTOL is cheap. When in doubt, toss it out.

[paulr]

If you like the compenating effect of intermittent agitation, you can come closer to that by using weaker dilutions with constant agitation ... or, as Bruce says, any developer that tends to exhaust quickly for other reasons.

Another consideration is evenness/freedom from streaking. If you have the jobo expert drums, this may not be an issue. But no other kinds of drums provide perfectly even flow.

To promote evenness, higher concentration developers or ones that don't exhaust quickly will have a bit of an edge. Also, developers using agents that are less inhibited by oxidation products will give more even results. A simple test is this: is the developer known for encouraging edge effects? If so, it's a lot more likely to cause edge density buildup problems with rotary processing.

[Dirk Rösler]

Thanks for all the information. I shall stick with Xtol.

Bruce, when you do 1:3, how much stock solution do you use? I have been using 100ml per 35mm roll or per 4 4x5 sheets which for the 2500 with 12 sheets makes 300ml. Since the max liquid is just under 600ml, I cannot get beyond 1:1 but would also return to 1:2 or 1:3 as I did with 35mm to get the effect that Paul eluded to.

[sanking]

A simple test is this: is the developer known for encouraging edge effects? If so, it's a lot more likely to cause edge density buildup problems with rotary processing.

Is this what you really meant to write? If so, what sort of edge density buildup problems would one expect from an an acutance developer that enhances edge or adjacency effect when used with rotary processing. My understanding is that edge density buildup would be less with rotary processing than with intermittent agitation with acutance developers.

Sandy King