Re: Dumb question re: processing 4x5
"darkroommike" <darkroommike@cableone,net > wrote in message
news:13hmulpn4gn8ncb@corp.supernews,com ...
> Depends on the volume but for trials (at least) get a 8x10
> paper drum, one that has dividers to separate 4x5 sheets,
> load it in your changing bag (note you may need to invest
> in a larger bag) and process on the tabletop in room
> light. i use a Unidrum and Uniroller for roll film and
> use an Omega Drum (Simmard) on the same base for the
> little sheet film I do. I presoak and the Uniroller seems
> ideal since it reverses direction automatically. The
> presoak extends processing times a bit but the constant
> agitation seems to shorten the processing times by about
> the same amount so I start with the "large tank" time and
> temperature and adjust if not satisfied with the contrast.
>
> Much has been written on the concept, lots of Google hits
> and the old Jobo newsletter are a goldmine of rotary
> processing info using theirs or any other rotary
> equipment.
>
> David Starr wrote:
>> On Sat, 20 Oct 2007 12:27:00 -0400, "Robert Chin"
>> <bchin_us@yahoo,com > wrote:
>>
>>> I'm sorry if this has been answered before. This is a
>>> legit question so please bear with me.
>>>
>>> My set up is not optimum. I do not have a dedicated
>>> darkroom (for now at least). I've done many many rolls
>>> of film over the years. I throw everyting into a
>>> changing bag, load up a reel and no problem.
>>>
>>> I'm getting ready to process 4x5 sheet film for the
>>> first time. It requires a bit more space to handle the
>>> sheet film than rolls. Since I do not have a dedicated
>>> darkroom, I can't fill the tanks with the necessary
>>> chemicals, leave them on a tabletop, and just lift the
>>> film holder from tank to tank in the dark.
>>>
>>> So my question(s) is/are simple: I've heard that
>>> because the processing tanks for 4x5 film take so long
>>> to fill, uneven development could result. Is this a real
>>> problem, or is it the opinion of someone really
>>> obsessive? Would I be better off making a light tight
>>> space to do this?
>>>
>>> Advice welcome from all.
>>>
>>> Thanks.
>> Can you fill the developer tank in advance, and lower the
>> film holder into it in
>> total darkness? If so, that takes care of the filling.
>> Then, you can, in the
>> dark, take the top off the tank, dump the developer and
>> pour in the stop
>> bath. - - - - - - - - - - - - - - - - - - - - - - - - -
>> - - - - - - - - - -
>> Retired Shop Rat: 14,647 days in a GM plant.
>> Now I can do what I enjoy: Large Format Photography
>>
>> Web Site: www .destarr,com
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>> - - - - - -
I also use Unicolor and Besler print drums for sheet
film. I have found that I can get "bromide streaks" on
occasion if the drums are rotated using the Unicolor motor
base unless they are taken off several times during
development and agitated sideways. Evidently there is not
enough turbulance in the flow of the developer to move the
reaction products away from the development sites in the
long direction of the drum. I've had this problem
specifically with Rodinal. Its likely it may not happen with
other developers but its worth beign aware of.
The streaks show up as lines of lighter density on
either side of dense highlights on the negative in the
direction of rotation.
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Richard Knoppow
Los Angeles, CA, USA
dickburk@ix,net com,com