Re: BL light box 'blues'

[Robert Newcomb <newcombr@uga.edu>]

Ken,
Before you saw any wood, if you're using a print frame, you could raise it up on some books or something, just get it closer to the lights, and see if the speed picks up without the banding.
Just a thought.
Robert 

---- Original message ----
>Date: Mon, 30 Mar 2009 18:59:06 -0600
>From: Ken Sinclair <photo1@telusplanet.net>  
>Subject: Re: BL light box 'blues'  
>To: alt-photo-process-l@usask.ca
>
>Hi Robert..
>
>That thought about sawing a couple of inches off the bottom of the  
>box had
>crossed my mind, but I was a bit worried about the greater  
>possibility of
>less even light with the tubes being the one inch apart. I'll try a  
>few more prints
>and see how it goes. If the long exposure times persist I'll take a  
>couple of inches
>off... and if there are any problems with 'banding', I can always  
>raise it an inch or so
>by adding some 'risers' on the sides and back since I still have some  
>strips of the half-
>inch baltic birch left over.
>
>Re: the BL tubes, I believe I read that while being a bit "less safe"  
>than the BLB, they are closer to
>the preferred wavelengths.
>
>
>Ken
>
>On 30-Mar-09, at 6:17 PM, Robert Newcomb wrote:
>
>>
>> I'm no expert, but you might consider moving the light closer to  
>> the printing frame. The inverse square law would indicate that if  
>> you half the distance you'd pick up two stops worth of exposure  
>> speed - I think.
>> And, is a BL lamp the correct one - should it be BLB?
>> Robert N.
>>
>> ---- Original message ----
>>> Date: Mon, 30 Mar 2009 14:48:59 -0600
>>> From: Ken Sinclair <photo1@telusplanet.net>
>>> Subject: BL light box 'blues'
>>> To: alt-photo-process-l@usask.ca
>>>
>>> Have recently decided to intensify my interest in non-silver, I
>>> constructed my
>>> new UV light-box using 10 BL tubes presently 5 inches above my
>>> printing frame.
>>>
>>> So that I could use the same negatives for both silver-gelatin,
>>> Cyanos and VDB
>>> I switched to Pyrocat as a developer... and I must admit, they do
>>> look "sweet".
>>>
>>> A few years ago my southern Alberta summer sunlight exposures for
>>> Cyanos were
>>> running around the eight minute mark... which expanded to around two
>>> and a half
>>> hours in the rather weak December sun.
>>>
>>> The exposure times I expected using the new 24" BL tubes are nowhere
>>> as short as I had
>>> hoped...  Cyanotypes seem to be requiring around 40 to 50 minutes
>>> while I have not
>>> yet reached the 'end-point' for acceptable VDB exposures, it seems as
>>> if 60 -70 minutes
>>> might be the absolute minimum.
>>>
>>> I do not have a stouffer wedge to assist reaching my standard
>>> exposure times, my patience is
>>> wearing (as my frustration level rises).
>>>
>>> I have just put a VDB out on the deck to enjoy some natural UV rays
>>> from the sun
>>> for a time comparison...
>>>
>>> Are my BL light-box test exposure times "out of line" with times
>>> experienced by others?
>>>
>>> Ken
>>>
>>> Quando omni flunkus moritati (R. Green)
>>>
>
>Quando omni flunkus moritati (R. Green)
>