I have seen this in a batch of sodium sulfite I bought. I would pick them out with tweezers, but I'm sure I missed some. There weren't many, but I would spot them from time to time. Actually the only time I worried about them and picked them out was when making an VitC type developer. The developers like BTTB and such I didn't pay much attention to it.
Barry Thornton's two-bath question about time and temperature
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It could be anything number of things even including silver, depending on how much you’ve used/re-used the solution. Filtering is always a good practice. Other than that I would not worry.
I'm about to develop two sheets of TMX 4x5 film contacted with a step tablet to generate a couple of curves. Since it is a tabular grain film, I'm going to assume, right or wrong, that even with the BT2B developer or just a divided developer in general, that the film will be just as sensitive to a one-degree change in temperature deviation as with using any one shot developer. For curve evaluation, I want to keep that variable consistent with how I'm developing TMX in XTOL currently, which is 68F..........currently waiting on both baths A & B to reach 68F.
I'm thinking I'll do 4min 30sec time for both A and B baths. As far as agitation goes, I'm going to follow BT's words and not agitate in bath B since it is a sheet film and should not be subjected to those sprocket streams he mentioned, and I'll not use a pre-wash. For bath A, I'm thinking I'll agitate just as I do for XTOL, 10 sec initial with 5 sec every 30 sec. However, I've got some time due to waiting on the tempering bath, if someone with more experience with T-grain films and using BT2B can suggest a better time and agitation scheme, I'll be watching.
I'm thinking I'll do 4min 30sec time for both A and B baths. As far as agitation goes, I'm going to follow BT's words and not agitate in bath B since it is a sheet film and should not be subjected to those sprocket streams he mentioned, and I'll not use a pre-wash. For bath A, I'm thinking I'll agitate just as I do for XTOL, 10 sec initial with 5 sec every 30 sec. However, I've got some time due to waiting on the tempering bath, if someone with more experience with T-grain films and using BT2B can suggest a better time and agitation scheme, I'll be watching.
Standardizing your temperature is wise. Temperature changes will definitely impact the results - especially the contrast - remember, bath A is a complete developer so it should be treated the same way you would a single bath process (ie temperature, time, agitation all matter).
Bath B agitation is a wild card. Typically I’d suggest using whatever standard agitation you use for regular processing, but you’ll have to judge uniformity for yourself and decide what works.
With Kodak sheet films pre-soak vs no pre-soak shouldn’t matter as long as you are consistent because obviously it will have an impact on the amount of development you get in bath A for a given time (typically a pre-soak will speed up development). Obviously if you are tray shuffling a pre-soak is the norm.
I found that with some films I occasionally got patchy, uneven development if there was no agitation at all in Bath B.
Noted. thanks
And to be clear, I am specifically talking about sheet films, tray developed.
Well, the temp reached its mark and so I had to start...........the negatives definitely have some issues. Perhaps it is the warning that @retina_restoration mentioned, idk. But I will not produce curves from these negatives. I taped these to a window to use the bright snow outside for the backlight. These are TMX and are differentiated by one being exposed at box speed and one being exposed at 1/2 box speed. I chose a half box speed example because I currently rate TMX at EI50 in XTOL 1+0 and wanted to compare with BT2B. For the ISO100 sheet the issue is the straight angled higher density line through steps 6 to 8. For the EI50 sheet the issue is from steps 11 to 16. Trust me I have never in my years seen either of these types of issues on any sheet that I have ever tested.
I'll reiterate the particulars:
- the sheets were developed in an SP445 tank; the negatives are oriented to you as they would be in the tank's film holders, one sheet per holder; I did not put two sheets on one holder.
- development was 4.5 min x 4.5 min at 68F
- bath A agitated by 10 sec initial agitation with 4 inversions (forward to backward) every 30 sec after that. Agitation was exactly like I do for TMX in XTOL..
- bath B received no agitation.
I don't have BT's books so I'm wondering if there are any specific notes as this process relates to T-grain films. A question I have is.....is it possible that this occurred in bath A and not bath B? Does a T-grain film need more time in bath A for complete soaking of the emulsion? Idk, just my thoughts. I'd be interested in other's thoughts.
I have already exposed two more sheets in the same manner but wanted to hear other's thoughts before deciding on a time and agitation scheme and I'll develop tomorrow. I'm giving myself 6 sheets to get this BT2B processing to a point I can call it successful, two down four to go. If not by then, then it'll have to wait a while.
I'll reiterate the particulars:
- the sheets were developed in an SP445 tank; the negatives are oriented to you as they would be in the tank's film holders, one sheet per holder; I did not put two sheets on one holder.
- development was 4.5 min x 4.5 min at 68F
- bath A agitated by 10 sec initial agitation with 4 inversions (forward to backward) every 30 sec after that. Agitation was exactly like I do for TMX in XTOL..
- bath B received no agitation.
I don't have BT's books so I'm wondering if there are any specific notes as this process relates to T-grain films. A question I have is.....is it possible that this occurred in bath A and not bath B? Does a T-grain film need more time in bath A for complete soaking of the emulsion? Idk, just my thoughts. I'd be interested in other's thoughts.
I have already exposed two more sheets in the same manner but wanted to hear other's thoughts before deciding on a time and agitation scheme and I'll develop tomorrow. I'm giving myself 6 sheets to get this BT2B processing to a point I can call it successful, two down four to go. If not by then, then it'll have to wait a while.
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I suspect you’ll find that the Tmax films will misbehave if you do not agitate at least one or two inversions per minute. Carry on.
What film did You used 120 or 135 for graphs? For rollfilm fog density is too big. In my own experiments fog density is formed in the first bath and slightly depends oт time, agitation and temperature of second bath.
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135.
In general chemical fog has a lot to do with alkalinity. If the second bath is highly alkaline (for example, carbonate) one can expect more fog.
Depending on what alkalinity one settles on for the second bath, some refinement of the developer would be something to explore (as I mentioned in a previous post when it comes to these two-bath developer methods the developer is not necessarily “optimized” but usually more generic).
I did not cross my mind til now but perhaps my last few posts appear to be hi-jacking the thread a bit as it is not specifically referencing the temp issue that is the point of the OP, my apologies to the OP for that. Can a moderator move my post #183 to a new thread with an appropriate title?
But have you stood film for 4.5 min without agitation before?
The OP has assured me that I am not hijacking his thread and so to continue. I test my 4x5 film using procedures in the "AA Guide to Basic Techniques of Photography, Book 2" by Schaefer. So if you have that book, it should look familiar.
With my 2nd test sheet of the BT2B developer I was able to obtain a clean, uniform negative with 4.5 min in each bath. @retina_restoration warned of the possible problem with no bath B agitation but I wanted to give it a try as BT said it was "ideal" with films without sprocket holes, now I know. However, it's not abundantly clear to me if this is specifically because of it being a tabular-grained film or if it is a general issue with all films when there is no bath B agitation. That said, the issue did clear up with the bath B agitation you see implemented in my notes on the graph below. In trying to keep with BT's statement, the agitation was kept fairly minimal at 10 sec initial and just 5 sec every 60 sec in the B bath.
The film was rated at box speed. I prefer viewing the x-axis in relative log exposure units to display the zones separated by major divisions of 0.3 units of exposure that coincides so nicely with how we use our shutter speeds, aperture rings, and ISO dials on our meters. The original ISO 100 curve does not reach a 0.1 density until a whopping 1 and 2/3+ stops down the road on the log exposure scale, a major loss of speed. So, in keeping with Schaefer, to reach the preferred 0.1 density at Zone I, each step density is shifted 0.5 log exposure units back to the left and the shifted curve is re-drawn to show its relative position on the log E scale at Zone I.......if it had been rated at EI32. The negative is definitely soft like it is supposed to be, perhaps too soft.
The 1.2 density line is my visual for comparing my "Normal" single bath development time of 7min 30sec with TMX (rated at EI50) in XTOL 1+0. I target a Zone VIII density of 1.2 for "N" development, for a density range of 1.1 from zone I to VIII. I've read that expansions and contractions are not doable per se with divided development but that the gradient can be manipulated with how long it stays in bath A. I think this screams for more development in bath A and would be interested from those with more experience with divided developers as I'm a newbie with it.
With my 2nd test sheet of the BT2B developer I was able to obtain a clean, uniform negative with 4.5 min in each bath. @retina_restoration warned of the possible problem with no bath B agitation but I wanted to give it a try as BT said it was "ideal" with films without sprocket holes, now I know. However, it's not abundantly clear to me if this is specifically because of it being a tabular-grained film or if it is a general issue with all films when there is no bath B agitation. That said, the issue did clear up with the bath B agitation you see implemented in my notes on the graph below. In trying to keep with BT's statement, the agitation was kept fairly minimal at 10 sec initial and just 5 sec every 60 sec in the B bath.
The film was rated at box speed. I prefer viewing the x-axis in relative log exposure units to display the zones separated by major divisions of 0.3 units of exposure that coincides so nicely with how we use our shutter speeds, aperture rings, and ISO dials on our meters. The original ISO 100 curve does not reach a 0.1 density until a whopping 1 and 2/3+ stops down the road on the log exposure scale, a major loss of speed. So, in keeping with Schaefer, to reach the preferred 0.1 density at Zone I, each step density is shifted 0.5 log exposure units back to the left and the shifted curve is re-drawn to show its relative position on the log E scale at Zone I.......if it had been rated at EI32. The negative is definitely soft like it is supposed to be, perhaps too soft.
The 1.2 density line is my visual for comparing my "Normal" single bath development time of 7min 30sec with TMX (rated at EI50) in XTOL 1+0. I target a Zone VIII density of 1.2 for "N" development, for a density range of 1.1 from zone I to VIII. I've read that expansions and contractions are not doable per se with divided development but that the gradient can be manipulated with how long it stays in bath A. I think this screams for more development in bath A and would be interested from those with more experience with divided developers as I'm a newbie with it.
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1) I have found that for my needs, many (most?) films perform better at a minimum of five minutes in Bath A, and in some cases I extent the time in A to 6.5 minutes. I don't exceed 5 minutes in Bath B. I have experimented with increasing the time in Bath A as much as 8 minutes and it had no negative effects on a film like Tmax 100. (Click to see example)
High contrast, slow speed films like Ferrania Orto perform beautifully at the standard 4.5 minutes in each bath. It tames some of the contrast without making negs look "soft". See example here.
2) I have also found that BTTB reduces effective film speed by about 1 and a half stops for many films. For certain circumstances, that is excessive, but with how I work, it's not unreasonable in many cases where I use a tripod and long exposures. The Ferrania Orto produced great negs at 25 ASA, so just one stop under box speed.
3) I find certain films really sing in BTTB and others produce mediocre images. Fomapan 400 and 100 produce beautiful negatives in BTTB.
High contrast, slow speed films like Ferrania Orto perform beautifully at the standard 4.5 minutes in each bath. It tames some of the contrast without making negs look "soft". See example here.
2) I have also found that BTTB reduces effective film speed by about 1 and a half stops for many films. For certain circumstances, that is excessive, but with how I work, it's not unreasonable in many cases where I use a tripod and long exposures. The Ferrania Orto produced great negs at 25 ASA, so just one stop under box speed.
3) I find certain films really sing in BTTB and others produce mediocre images. Fomapan 400 and 100 produce beautiful negatives in BTTB.
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I posted this in another thread re BT's suggestion for agitation in Part B:
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Adox HR-50 bulk arrived......which developer?
Ok, so aren't Hr-50 and Scala 50 worthwile to buy and use? I don't know Scala 50 & HR-50 to be the same thing. But I said, that I found much better CMS20 or Spur. For low grain I mean. I don't like in HR-50 that it have narrow correct range (example bracketing) & specific color sensitivity.For...
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Nice examples on your Flickr images, especially the TMX at 8 min in bath A; how did you agitate in bath A for that 8 min.?
You've misread Thornton. He did not say no agitation at all was ideal. He said not agitation for the first three minutes was ideal. Here's the complete excerpt—the sentence about "no agitation is ideal" must be read in relation with the sentence that came before (emphasis mine):
The technique is the same for all versions of the two bath. Bath A contains only the developing agents and preservative and sometimes a restrainer. Bath B contains the accelerator, and sometimes a restrainer. The film is developed in Bath A with agitation every half or full minute -its not critical. Actually little development takes place. Mostly the film is becoming saturated with the developing solution.
However, some development does take place and agitation is important to prevent streaking. The solution is then poured off and saved. Drain the tank well but don't rinse or use a stop bath. Then pour in Bath B, and after a quick rap of the tank on a hard surface to dislodge any air bells, let the tank stand still with no agitation for three minutes or so when all development has ceased. Note, though, that while no agitation is ideal, and usually works well for unsprocketed roll film (120/220), there can be streamers from 35mm sprocket holes. This seems to vary with different kinds of tanks, different films, and the local water characteristics. Do your own experiments to determine the minimum agitation you can achieve without streaking before committing a crucial film to the process. Perhaps try one minute intervals to start with.
In the second bath the developer soaked into the film emulsion is activated by the accelerator. In the highlight regions where the developed silver will be densest, the developer available in the emulsion is soon exhausted and development halts, thus automatically limiting the density of the negative at that point.
Well I guess I did............so any agitation at all in bath B should not be until at least 3 min have passed, then can agitate to some degree until completion? Is that how I should understand that?
30 seconds to start, and five seconds every minute thereafter.
Yes, that's the agitation routine I use with BTTB and I get no streaking or unevenness. If it ain't broke, don't fix it. I have a new batch of BTTB mix for the cottage where I'm at now. I also mixed up a batch of Karl's 2B-1 to try with 35mm HR-50. I'll see wish one works the best for me. I'm also going to take my old 4X5 box camera for a spin the next sunny day we have and we'll see how these two divided developers work with Foma 100 and that old 1898 camera.I posted this in another thread re BT's suggestion for agitation in Part B:
Adox HR-50 bulk arrived......which developer?
Ok, so aren't Hr-50 and Scala 50 worthwile to buy and use? I don't know Scala 50 & HR-50 to be the same thing. But I said, that I found much better CMS20 or Spur. For low grain I mean. I don't like in HR-50 that it have narrow correct range (example bracketing) & specific color sensitivity.For...
That's how I read it. But I'll admit it's not clear.
Further down in the article, after giving the formulas for each baths, Thornton states "Try about 4 minutes in each at about 21º C for roll films; 5 for sheet"—which seems to imply that you should (or can) agitate after three minutes. But earlier, in the part I quoted, he indicates that "all development has ceased" after three minutes "or so". Now why keep the film in the developer for one to two aditionnal minutes if "all development has ceased"?
Hard to say how long Thornton actually used this developer formula. His experiments leading to it, based on Stöeckler's formula, are well described in Edge of Darkness, but immediately after giving the formula (with a few variations regarding sodium metaborate amount in bath B), he starts talking about his experiments with pyro (after Gordon Hutchings PMK formula), leading to a single bath/two bath pyro developer he called DiXactol—for which he does not give the formula.
Photographers' Formulary sells it:
Dixactol© & Dixactol Ultra© Film Developer
Developer Dixactol Film Photography Chemicals
There are a few old threads on Dixactol on Photrio.
I should add that with bath B and 120 film I've tried both one inversion after pouring, then nothing until the 2:30 minute mark, as well as no inversion after pouring and 2 inversions at the 2:30 minute mark and haven't seen a difference.
I posted this in another thread re BT's suggestion for agitation in Part B:
Adox HR-50 bulk arrived......which developer?
Ok, so aren't Hr-50 and Scala 50 worthwile to buy and use? I don't know Scala 50 & HR-50 to be the same thing. But I said, that I found much better CMS20 or Spur. For low grain I mean. I don't like in HR-50 that it have narrow correct range (example bracketing) & specific color sensitivity.For...
I did a second sheet yesterday with a different bath B agitation than #2 above. I agitated 30 sec initial and then 30 sec at the 2 minute mark in bath B, but it produced the exact same curve as what resulted from #2.
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