The hot streaks would not happen every time. Maybe one out of twenty negs. But I could never predict it, other than to know it would happen when I could least afford it.
The culprit seems to be the concentric ribs on the interior of the drum instead of the longitudinal ribs. I would get changes in the amount of stain right around the rib. It can be very subtle. In fact I have a few negatives that show no uneveness to the naked eye, but you sure as hell can see the streak when you print them in platinum. Some of the other problems I had I eventually corrected through some technique changes. One was to use quite a bit of volume to minimize oxidation effects. I typically would use 1000ml for 2 7x17 sheets in the drums. I also used a 2:1:100 or 2:1:150 dilution for pyrocat, which also would help minimize any runaway base + fog problems.
Let us know how that goes.
Originally Posted by Donsta
It's interesting to note that the concentric ribs can be avoided - you can place a sheet of 12x20 into a 3063 drum either lenghways or sideways - it sits in place just fine (I tried both and could find no imperfections either way). I haven't spent enough time playing with 7X17 sheets - but will get round to it. I did not, however, do a Pt test print to check for UV visible only hot streaks. I may do an overexposed Cyanotype test print (cheap and should show up any UV transmission problems too). Clay - which drums were you using? As far as I can tell, the 3063 drum is a single piece, so that may help.
For 8 x 10 and 7 x 17 negatives I use a 16 x 20 tray. My total volume of dev is around 100 ozs depending on dilution and developer, so 6-8 films are covered well. By using the large tray I can slide the bottom sheet clear of the stack before I start to pull up. This minimizes the chance of the edges in the stack from dragging against the film emulsion. Film is FP4. I understand the efke 100 sratches easily, so I'd probably start with 4 films.
Originally Posted by clay
Many years ago ((early 90s?) when people first started experimenting with rotary type processing with staining developers of ULF film, including Jobo and film drums, there were numerous reports of development artifacts, ranging from streak patterns on the film that corresponded to the direction of rotation to stains that seemed to correspond to the ribs of the drums. I also heard reports of lines such as the one you describe that were not visible to the eye but would definitely show up on the print with UV processes. Quite a number of people concluded from these experiences that rotary processing was not worth the problem and returned to tray.
However, as I have stated many times, standing there in the dark for long periods processing film is not something I like to do so spent a lot of time thinking about my own technique and examing the results. I don't pretend to have all of the answers but here are some of my thoughts on the way to get very even development with rotary processing. Some of the things I see you do already so I suspect that the difference in our results is equipment, not technique.
1. Use a fairly large amount of developer solution as this minimizes the effects of developer speed up when crossing over any dividers that may be in drum. For example, I use 2 liters of solution per sheet of 12X20 film, quite a bit more than necessary (about 4X as much in fact).
2. Rotation should be as slow as your equipment will allow, down to 5 RPM if possible. Fast rotation is very risky, not only because it increases oxidation that gives higher general stain but also because it can create hot spots.
3. Rotation should be in both directions so it is important to use a motor base that reverses direction.
4. Lift the drum or tube off the motor base frequently and give the film vigorous sideways agitation. It is very important to start this pattern of agitation very early in the cycle, say within 15 seconds or so of the beginning of development, because any patterns of unevenness always start during the first seconds of development and increase with time. Anything you can do to inrtroduce a random pattern to development is useful in breaking up laminar flow patterns that can cause hot spots.
5. If you are using Pyrocat-HD increase the proportion of Solution A to B in the developer, and use a fairly weak dilution. I personally use a 1.5:1:100 but I can see that 2:1:150 might actually work better (more developer exhaustion and edge effects but less oxidation).
Regarding those lines on the film that are not visible to the eye but show up during printing I have also seen this, but in my case I concluded that this was due to coating irregularities of the film during manufacture, not development technique.
I have also concluded, for my own conditions, that the ribs that run lengthwise in print drums do not create any development artifacts, so long as 1) the film is pre-soaked, 2) speed of rotation is kept to 5 RPM or less, 3) a large amount of total solution is used, and 4) a fairly weak dilution of developer is used, with more Solution A than B.
In spite of my very positive experiences with rotary processing I would encourage others to actually test how even your film is developed by sacrificing a few sheets of film by exposing them to an even light source and then developing with several techniques, say in a tray, in a tube or drum on a motor base, or in a tube that is used in a water bath as with BTZS type tubes. I know from my own tests that I get the most even development in the following order: best in smooth walled tubes in a water bath, after an initial pre-soak, second best in drums on a motor base, and last in tray development. Which convinces me that the key to even develpment is slow but continuous random agitation. From my tests I would conclude that the best method for 7X17 film would be the use of BTZS type tubes (which one could easily make from ABS plastic), with agitation by rolling them in a water bath. But there are some practical considerations which make the use of tubes of this size much more difficult than in smaller sizes such as 4X5 and 5X7.
But I have to admit than even if the order of even development was reversed I would still use the drums because of my dislike for working in the dark.
Last edited by sanking; 07-20-2005 at 12:33 AM. Click to view previous post history.
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Well, I share the distaste of working in the dark and shuffling negatives. I used to get so many gouges that I just did one negative at a time and that took forever! That's why I switched to a JOBO. Problem is, even at the slowest setting there is no way I can get 5 RPM. I'll have to keep my eye out for a Bessler\Unicolor with the Uniroller base. I assume, Sandy, that it has bi-directional rotation and can go as slow as 5 RPM?
My next choice would be stand development with tubes, but I'd prefer the easy of the roller base. My JOBO spoiled me. If the Bessler roller will handle the JOBO expect drums, I may not need my JOBO anymore.
I'll be doing 7x17 in very low volumes so tube processing could be a viable option - I may even try both to see the difference first hand.
If anyone sees the roller base come up on eBay, please keep me in mind if you can.
My next challenge will be 'seeing' in 7x17, something other than the obvious wide landscapes I hope. I have a few things in mind. But then I have a lot of things in mind and time is not so plentiful<g>.
One very practical solution for 7X17 film is to develop it in open ended 3" diameter PVC tubes. You could just roll the tubes around in an open tray in the dark, or you could buy or make a tank that could be covered for development in the dark. In fact, if you made the tank deep enough so that the developer would cover the tubes you could choose to either develop you film with normal agitation or with extreme minimal or stand agitation. With a tank of reasonable size this method would allow you to develop 4-6 sheets of film at a time, which makes it a very viable method.
Originally Posted by mikewhi
One could also do the same thing with 12X20 film but the size of the tubes and the amount of developing solution that would be required for this size begin to approach the impractical. Not impossible, though.
Photos of how 2 sheets fit perfectly in the Jobo 2850 drum. These aren't an expensive drum. 2 8X20 sheets fit the same way but go all the way to the far rib. I get perfect even development every time. No insert needed. I don't think the 1220 would work in this though.
Just recently I started developing 8X10 negatives. I use Cibachrome base that I modified with a DC motor. I use model RR transformer to power the base. I found that I can turn drum at less then 5 rpm's and have a switch to reverse rotation which I do three times during 8 min developing time. I could have gone and made larger wheel inside the base to rotate even slower but so fahr the negatives are very good. I use Efke PL100
2:2:100 dilution with 250 ml of Pyro HD. I use Cibachrome drum for a single sheet of 8X10 film.I imagine you can use any size drum. The negatives are very sharp and contrasty , anfortunatelly I do not have noting to compare it with. I love the results.
Just my 2c worth
Looking is a gift, but seeing is power.
Originally Posted by jimgalli
I got into Carson City yesterday morning. I have a lot of gear with me and I'm ready to shoot!
Regarding your post, are those 7x17 negatives. They look like they fit well. How much chemistry do you put in there to cover the negative? Do you process it on a JOBO or rotary processor or do you do it by hand?
BTW, I setup my 7x17 for the first time today. My friends have a great view in their back yard and I see across Carson City to the mountains beyond. I put on my Nikor-W 360, Schneider Symmar-S 480 and my Cooke Triple Convertible XVa. All of them cover the format easily. With the Cooke, all 3 focal lengths will easily cover the 7x17 with a ton of room for movements. When I put on the rear element alone (about 476mm) I could adjust the front rise\fall to their maximum and never got any cut-off. When I slid the rear standard left\right the bellows cut into the optical path before I ever reached the limits of the lens. This Cooke lens is amazing. I have my 305 G-Claron with me but I haven't tried it out yet.
My friends and I are talking about a multiple day trip down to the Bristlecone Pine area. I will go down south ahead of them by a few days and then we'll tool around in my Jeep. There is that great drive down from the Bristlecone Pine on a pretty steep 4WD road that drops all the way down the valley.
Before I head south from Carson, I'll contact you to see if we can hook up and make that drive you mentioned. If not, just dropping by or meeting somewhere to say 'hi' would be great.
I brought 25sh of 7x17 HP5 along with my 8x10 and 5x7 outfits so I'll have plenty to shoot with.
I'll be processing the 7x17 when I get back and I'll pick up one of these 2850 drums. I don't need inserts with this drum?