Re: Mamiya 645/w135 back vs. HIE

["Elton N. Kaufmann - Cycloid Fathom Group" <cycloid@xxxxxxxxxxxxxxxxxx>]

Nate:
A short time back I complained about a similar pattern of fogging and the
list quickly enlightened me.  (By the way, thanks to those on the list who
helped - I've been quite negligent about letting the list know what
valuable advice I've found here.)  It's most likely not the camera at all,
but the agitation during processing that generates excessive turbulence
(i.e., more agitation than the average) at the sprocket holes because those
holes disturb the liquid flow in the area.  I reduced my agitation to one
gentle inversion plus one 360 degree slow roll of my Patterson tank per
minute (currently using Xtol 1:1 or D-76) and the problem was greatly
reduced.  I too saw it primarily at the top of the frames (noticed most
easily due to the otherwise clear skies in the scenes).
			Good Luck
					EltonK



>Date: Sat, 30 May 1998 09:13:22 -0500
>From: Nate <nkeith@xxxxxxxxxxxxxxxxxxxxxx>
>Subject: Mamiya 645/w135 back vs. HIE
>
>A short time ago there was a thread regarding ir light leaking through a
>Bronica back.  I do not recall the specific symptoms or details, but I
>suspect I am having a similar problem and would like to confirm this.
>My apologies for rehashing this previous topic:
>
>On a recently developed roll of HIE, I noticed that some of the images
>have what appear to vertical fog patches extending from the sprocket
>holes.  It is more noticible from the top down than the bottom up, and
>with those negatives that are more dense.  I have not noticed any
>fogging from the horizontal sides.  There is no apparent fogging when
>using Tri-X 400 in 35mm format.
>
>My suspicion is that IR light is leaking through the top and bottom if
>the back/body line and the patches are created extending from the
>sprocket holes since the holes are less of a medium for the light to
>travel through.
>
>Any thoughts, and what was the solution in the other instance, i.e.,
>what type of not IR transmitting cloth/cover could be used, etc.
>
>Thanks,
>
>Nate
>
>
>- --
>Nate Keith
>Eden Prairie, MN
>USA
>
>Visit NatelanD ImageS at http://www.pioneerplanet.infi.net/~nkeith

Exhibiting fine-art and editorial photography
Cycloid Fathom Gallery
Elton N. Kaufmann, Chairman
P. O. Box 8129
Downers Grove, Illinois 60517-8129
USA
cycloid@xxxxxxxxxxxxxxxxxx
http://www.cycloid-fathom.com/gallery/
ftp.cycloid-fathom.com/group/uploads/

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