From: Sandy King (sanking@hubcap.clemson.edu)
Date: 02/01/01-09:37:16 PM Z
Hi Ellen,
The ABS plastic tubes work fine for 4X5 up to 8X10 negatives (1 1/2" - 3"
ID tubing) but I would not recommend it for 16X20 negatives. For one thing
I am not even sure you can get ABS tubing large enough for a 16X20. The
largest size I have seen is 4" ID. That fits in one 12X20, barely. However,
there is another problem with the larege sizes;the cap is so big you can
not easily snap it on and off as you can with the smaller sizes. The result
is that you have to use one of the screw-on end caps and that makes it very
difficult to pour in and discard rapidly the chemistry.
Best bet for you in my opinion is to buy one of the 16X20 Unidrum or
Beseler (or perhaps there are others) print drums. I see them all the time
dirt cheap on ebay, and used motor bases also appear frequently at good
prices. The motor bases are of two types:one type reverses direction, while
the other type always goes in one direction. I use the former type and
don't know how the second might work.
Sandy King
>Sandy (and all of you who might have advice!),
>
>I have been developing 16x20 negatives in trays, and I
>am having the same problems that you mentioned, ie -
>the scratching and uneven development. I am looking to
>improve this process, and so I was wondering what kind
>of drums you use to develop your large format negs?
>Anything affordable?? I was going to just take a trip
>to the hardware store and see what I could come up
>with. Any recommendations??
>
>Regards,
>Ellen Sigunick
>
>
>--- Sandy King <sanking@hubcap.clemson.edu> wrote:
>> Nelson Goforth wrote:
>>
>>
>> >I tried the BTZS tubes for three sets of negatives
>> (mostly doing the tests
>> >to determine proper dev time), and liked them save
>> for one problem - I got,
>> >on at least one neg per batch of 6 - flaking of the
>> emulsion. One small
>> >flake (not a scratch, but an irregular flake) that
>> had come loose and then
>> >laid back down on the emulsion.
>> >
>>
>> What caused the flaking of the emulsion in your use
>> of the BTZS tubes is a
>> mystery to me but but this is a very unusual
>> problem. What film was it?
>> Some films have very soft emulsions that will flake
>> off rather easily, FP5+
>> for example.
>>
>> I don't use BTZS tubes but I do develop in tubes, in
>> tubes made from ABS
>> plastic for 5X7 and 6.5X8.5, and in print developing
>> drums for 7X17 and
>> 12X20 film. I find this type of development highly
>> consistent and reliable.
>>
>> Phil Davis pionered the use of film developing tubes
>> because tray
>> processing was simply too inconsistent for
>> sensitometric use in his BTZS
>> sensitomety workshops. As is commonly known, uneven
>> development is very
>> common with tray processing, for a variety reasons I
>> won't go into here.
>> Persons with refined technique who understand the
>> nature of the problem
>> inherent in tray processing can come close, but in
>> my opinion not exceed,
>> the level of eveneness possible with rotary
>> develoment in tubes.
>>
>> I switched from tray processing to tube processing a
>> number of years ago
>> and have never looked back. I prefer it for the
>> following reasons.
>>
>> 1. Most of the film processing can be done in the
>> daylight. After many year
>> of working with photography I have a profound
>> aversion for standing around
>> in the dark for long periods of time.
>> 2. With the larger film, which is rotary processed
>> in tube on a motor base,
>> I am free to do other things while the film is
>> developed.
>> 3. Development in tubes has almost entirely
>> eliminated the problem of
>> scratching and gouging of the film that plagued my
>> tray processing.
>> 4. Development in tubes by rotary processing gives
>> more even development
>> than tray processing.
>>
>>
>> Sandy King
>>
>>
>
>
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