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#11
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Adjust B&W paper development time when using Uniroller?
Phil Glaser wrote: Patrick Gainer wrote in message Ordinarilly, 2 minutes are sufficient, 1 minute is not enough. Higher concentration will decrease the time. The instructions for my paper, Ilford Multigrade IV RC Deluxe, say that with Multigrade developer diluted 1:9, 1 minute is the recommended time. Are you suggesting that these instructions are wrong (it would clearly not be the first time a photographic material manufcaturer's instructions were wrong . . . ) --Phil Sorry, I wasn't clear. I was referring to my setup, using trays. The developer I normally use, which is home brew, needs 2 minutes to get the maximum black and normal contrast. If it is too dark after 2 minutes, reducing the development will not make a better print. The time for your setup is 1 minute, so I would say if you fell that less than 1 minute would be better, there is a good probability that the exposure was too much. |
#12
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Adjust B&W paper development time when using Uniroller?
The following will not apply to drum development, but it may be of
interest in this thread. To be sure full development is reached, especially as the developer is used and becomes weaker, Adams used a procedure he called 'proportional development'. (I'm 99% sure that was the term he used, but I can't find it in one of his books right away.) Once he determined the development time needed for a given developer when it was fresh, he noted the time it took the image to first come up in the tray. As the time for first appearance of the image increased, he would increase the total development time by the same percent. For example if a developer requiring 150 seconds for total development needed 20 seconds for first image appearance when fresh, then when it weakened to the point that it needed 24 seconds, he would increase the total development time by that same 20% to arrive at 180 seconds. Bob ----------------------- Phil Glaser wrote: Hi, For the first time this evening I developed a B&W print in my Uniroller drum on a motorized Uniroller base. I am using Ilford Multigrade IV RC "Deluxe" with Ilford Multigrade developer. Having never used a Uniroller before (and being unable to find directions for B&W print processing with it on the web), I just followed the paper's instructions for dish developing, using a dilution of 1:9 for one minute. This first print was a series of test exposures starting with 2 seconds at f/11. Now I realize that agitation and development time do not affect paper in the same way as they do film, and that saying 2 seconds at f/11 is completely relative to the density of the negative. Nonetheless, I was rather shocked to find that the the print came out absolutely completely black -- absolutely nothing came through, not even a hint of that 2 second exposure. So I experimented with the development time for the uniroller, and found that if I developed for only 20 seconds with constant drum agitation, I got relatively more of normal image (normal given that I was still over exposing the print by two stops -- see below). Now this is all very disorienting to me (I feel as dizzy as I myself were spinning in that drum!). I mean, it seems like I eventually got an ok print when developing it for 20 seconds (the final exposure time for this particular print turned out to be two stops less than where I started, half the time, and down from f/11 to f/16). But I'm working with a questionable negative, and am unsure if what I don't like about the final print is the negative, or whether something about the print process is mudying the print. Given my set up, I don't have a way of developing in trays and comparing the results with what I'm getting from the Uniroller. I AM SO CONFUSED!!! Is there a rule of thumb for print development time with a Uniroller? Should I try working with the multigrad developer in a more diluted form (ilford suggests 1:14 as an alternative to 1:9)? And does anywone know where I can find information about using a Uniroller for B&W processing on the web? Thanks! --Phil |
#14
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Adjust B&W paper development time when using Uniroller?
What kind of enlarger are you using. If its not a color head type
what filter are you using? Note that the speed of variable contrast paper without a filter is twice what it is with the filter. If you are using a color head and still get overly short times try adding some yellow to get a neutral density effect. I am using a Besseler 23C II with a non-color head. The borders are nice and white, so no fogging. Listen, I am sorry to have stirred this all up (no pun intended) because I now realize that it was indeed an exposure problem. The shot was a picture of a scene that I had contrtived with a luminance range adequate to tell whether my _film_ developing time was correct (i.e., highlights not blocked, etc.). In the course of placing the shaddows in zone II, I deliberately "underexposed" (as far as my light meter is concerned) by three stops, but neglected to realize that my highlights (which were seven stops away from the shaddows according to the light meter) were now _also_ underexposed by three stops. So my negative was just TOO THIN. Moreover, I was printing on 5x7 paper. I don't know by what factor that should reduce print exposure time, but it must reduce it somewhat. I had been doing 8x10 for a while and neglected to take that change into consideration. I think everything is ok with my equipment, paper, and developer. It is just my inexperience in evaluating negatives (and calculating correct negative exposure) that led me astray here. Thanks! --Phil |
#15
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Adjust B&W paper development time when using Uniroller?
"Phil Glaser" wrote in message
om... snip Moreover, I was printing on 5x7 paper. I don't know by what factor that should reduce print exposure time, but it must reduce it somewhat. I had been doing 8x10 for a while and neglected to take that change into consideration. Exposure (all other conditions identical) is proportional to the surface ratio of projected images: if you double the surface, you double the exposure to obtain the same densities. In your case, going from 8x10 to 5x7, you should reduce exposure by roughly 1 stop. I developed a lab software, you may try it for educational purposes: http://www.bonavolta.ch/hobby/en/photo/labsoft.htm Third tab of the dry side part does this kind of calculations. I think everything is ok with my equipment, paper, and developer. It is just my inexperience in evaluating negatives (and calculating correct negative exposure) that led me astray here. Test strips are a good way to go ... :-) Thanks! --Phil Regards, -- Claudio Bonavolta http://www.bonavolta.ch |
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