First Work with 8x10 Blade

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October 30 - November 1, 2006

Finally back at it.  The good news is that the fall shows were good enough for me to afford an 8 x 10 coating blade. 

I started back at the exact spot that I left in emulsion recipe tweaking.  Knowing myself and my memory, I left notes and post-its all over my darkroom and desk.  It worked.  I would have sworn I had forgotten everything I had figured out, but I followed my bread crumbs and cooked up perfect emulsion.  That says a lot about the usability of the recipe and process.  The fragmentation and complexities of most photographers' lives require a lot from any process.  It must deliver the technical goods, yet be agreeable to putting down and picking up again, without unacceptable loss of time or materials. 

Once again:  Thanks to Ron Mowrey for getting the ball rolling.

The 8 x 10 blade is in some ways almost a different animal than the 4 x 5.  I expected that it would just be "more" (emulsion and paper).  Because of its length, it is a challenge to pull it evenly down the paper. (The 4x5 blade almost pulls itself.)  I haven't eliminated this uneven pull "chatter" at the beginning of  coating.   That is hopefully just a matter of practice (and I've only coated 12 sheets of paper so far).  If not, it will require a piece of paper considerably larger than 8 x 10 to contact print an 8 x 10 inch negative.  As it is, there is more than enough good surface in the center of an 11(h) x 10(w) inch piece of paper for a 5 x 7 negative.  For my current work space, this requires 11ml emulsion.

I started out with by calibrating the blade with spark plug gappers (at 6 mil).  This works great with the smaller blade, but couldn't seem to produce an even flow-thru gap along the length of the longer blade, so I decided to eyeball the calibration.  I loosened the set screws, and in good light, adjusted the blade so that it showed the slightest  and equal gap on each side.  Works wonderfully!  It is possible my gap is a little big, but I think I'll play with emulsion viscosity before I change it.  That leads into an issue that is obvious from a technical p.o.v. but makes reporting ongoing research a challenge.

There are a multitude of overlapping variables involved with the process.  I am working right now with Fabriano paper - just 'cause I love the stuff.  It is only slightly absorbent, not enough to cause problems with the smaller coated surface.  With the 11 x 9 inch coated surface, the paper swells- bowing and popping.  With the thicker emulsion layer, which I love for the dmax and gloss,  the emulsion can pool in the valleys.  This is visible as a discoloration after processing (at least with warm tone developer).  So...I need to set up a dichotic tree to evaluate the variables.  Emulsion viscosity (temp and/or gelatin concentration), sizing options, developer effect,  and others that will no doubt come to me at 3:00 in the morning.

Well, back to it.



Full sheet (11 x 10 inch) missing the right edge in order to fit on my scanner.

TMAX 5 x 7 original negative, XTOL developer

Note the "chatter" at the top and "out of emulsion" at the bottom.  I'm aiming for as little waste as possible.  To evenly coat all the way to the bottom, it is necessary to use enough excess to scrape off at the end of the pull.

Developer: ZonalPro HQ Warm Tone, 1:10

Acetic acid stop

Plain hypo fix, two-bath.

10 ml selenium/liter archival wash aid



Image-only crop of above, fiddled with in Photoshop to try to convey the exact color of the original.  Close miss (at least on my monitor) The color has a tad more of that not-quite purple brown of selenium toning.

As always, any foggy appearance is a scanning artifact.  I've decided against the technique used by many pt/pd printers - to print the image on commercial glossy paper, and use that for the scans.  It's a legitimate option if you're trying to convey an image.  But for me, this is about the process.  My negatives of rocks, trees, and running water are just fine, but at the end of day, they really are just negatives of rocks and trees and running water.  This is about silky blacks and clear whites and all the grays in between - on paper you want to stroke.


November 2, 2006

Developed in Dektol 1:2, 2 min.  Much softer appearance to print (lower contrast and sharpness).

Toned one print in selenium (20 ml/lit archival wash).  There is a noticeable cooling.

Besides the color difference, the two prints point out the variation within a batch.  The top print shows some mottling through the left edge.  There's no indication that the emulsion is uneven, so either the paper surface itself is affecting things, or emulsion defects don't have to be visible to make their presence known.  Playing with sub coats and/or sizing should help with answers.

The bottom two pictures are crops of yesterday's HQ warm tone and today's Dektol, both selenium toned.  These are straight scans, no adjustments or sharpening.  The scanner exaggerated the color difference, but the thing to note is how much softer the Dektol print is.


Dektol 1:2

Selenium: 2ml / liter archival wash



Dektol, no toning




Dektol, selenium (20 ml / liter archival wash)




ZonalPro HQ Warmtone, selenium (10 ml / liter archival wash)










November 3, 2006

In the daylight this morning, looking at two of the worst prints from both the HQ and Dektol sessions,  I realized how much info is in these "failures".

(Tech note: When I am preparing my paper for coating, I punch a hole in the lower right hand corner.  I have allowed an inch salvage for handling on that edge, so that I know I won't be getting finger prints of the coating surface even after I take off the cotton gloves.  This also makes handling in dim, red light much less fraught.)

The idiosyncrasies of the scanner will finally work to advantage.  The emulsion defects are more obvious than 'in person'.  In the HQ print, you can see where the emulsion pooled and cooled in a thicker layer.  The HQ developed this out as brown.  Where the emulsion started running out at the end of the pull, mottling is very evident.  I forgot to check the placement of the negative on the paper in the contact frame before I exposed.  I drew the arrows in the margin right after coating.  In the reflection of the safe light, thin patches are easy to see.  They disappear as the emulsion dries.  On the other hand, pooling is only obvious after the emulsion has started to dry.  After the rest of the paper is dry (about a half hour in my darkroom), these areas are still glossy, and I either draw a circle around the small areas or note in the margin that larger areas have pooled. 

Dektol didn't discolor the area of thicker emulsion.  In the daylight, a slightly thinner area of emulsion is visible at the top of the sheet. It's barely visible as you tip the print in and out of the light, and was not visible right after coating, but obviously the difference is significant enough to produce the mottling.  In the future, I will try to position the negative towards the bottom of the paper.


ZonalPro HQ Warmtone developer: (no metol - doesn't affect non-warm tone commercial papers - I use it because I've become sensitive to metol), selenium toned

The small, white spot in the lower right corner was smutz on the contact frame glass.  It shows as clean white, which is a good indicator that the emulsion doesn't have a fogged base density.

(note: original wider than scanner)



Dektol:  The thicker emulsion pool is visible because it's so much glosser, but there is no discoloration after development (center of paper, right side).  Mottling on the upper edge is visible even though the thinner emulsion is just barely.  The black dot next to the left side of the main truck is probably a gel "slug" that got through filtration. 



















(Tech. note:  Spouse and I built a simple tile warming cabinet from scrap furniture grade plywood, insulated just on the top and bottom.  The slats hold single 12 in. sq. granite tiles at about 85F, temp maintained by old fan-less food dehydrator - seems about right, but more important, it's a consistent temperature that allows me to calibrate (more or less!) the coating viscosity.  I tape the paper on each tile and after coating carefully set it aside and take a new, warm tile and paper to coat.  I don't touch them again until everything is dry.  The "set aside" area is just two painted boards set on the washing sink and along the opposite wall on two cabinet doors propped open; very low tech, but easily set up and taken down.  The real advantage is that everything is clean, dry, and warm at the start of coating, stays that way, and the process moves along quickly. 

The safelight shines on the wet paper in the dark and makes emulsion imperfections very visible.)



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Denise W Ross Photography