The Case of the Dirty Thumbprint

We're staying with the 4x5 TiTAN pinhole for the moment - another one from our walkabout in Portstewart last week.  This time looking West, past Dominican College in the foreground towards Downhill and Magilligan Beach.  If you look closely you can just about make out the hills of Donegal way in the distance, centre-right.

Portstewart Bay via Fomapan 200, ID-11 and MG Classic fibre paper. 30 second exposure.

 

As before, there was a good bit of magic required in the darkroom - burning in of sky and left-side of water then more selective burn-in of the lighter waves.

Ah go on then, I'll say it - you know I'm dying to.  Not bad for no lens.

I'm not suggesting this next bit is necessary but if you click on the image and get it larger on your monitor you might notice something odd.  I did!  But only when I scanned the print and saw it full-screen. Then I took a closer look at the print and yes, in oblique light it is there.  What am I talking about?  The artefact that looks suspiciously like a thumbprint, North-West of the centre of the print.  I'm going down to the darkroom where the negative is to take do some further investigations.  Don't go away...

OK I'm back, none the wiser.  There is nothing on the negative that I can see.  I can't imagine it is a thumb-print on the negative anyway, as it's so close to the centre of the negative and there's no way I'd ever grip a 4x5 negative like that.  I've checked the enlarger lens (clean) and the negative carrier.  I use a glass carrier for 4x5, which is necessary if you want a flat negative (which you do!).  Although the DeVere carrier is able to take glass top and bottom I only use glass on the bottom and rest the negative on it.  I've no need for glass on the top as with the LED head that I use there's no heat and no chance of the negative 'popping'.  It's old picture frame glass and on close inspection it's not perfect - there are marks on it.  But...I don't think sufficient to cause the artefact here.

I've spent most of the last 24 hours thinking about this one and I think I know what happened. I use a 4-blade easel, which is a thing of beauty and like the DeVere likely to withstand the next earthquake to hit Ireland (hopefully in a few millennia).  The blade mechanism lifts up and the paper butts up to two bumpers, on the top and left sides before the blades are lowered to keep the paper in place.  With fibre paper there can be quite a curl when it is removed from the box and it doesn't just sit cleanly against the bumpers.  What I usually do is stick a thumb, or finger in the middle of the paper to keep it in place while with the other hand I lower the blades.  I reckon my thumb (or finger) has become contaminated with fixer from a previous print...

I haven't noticed this artefact before and the reason for that is that up until very recently I've used nitrile gloves when working at the wet side of the darkroom, which more or less guarantees that your hands stay clean.  You do go through a lot of gloves in one print session, though.  What with the COVID situation and the massive demand for nitrile gloves (especially in the early days of the pandemic) I decided the sensible thing to do was go back to using tongs.  But I've developed the habit of lifting the paper out of the fixer by the tongs but then using my fingers to transfer it to the wash.  I mustn't have washed my hands properly before going back to do the next print.   I think that's what's happened.  So...I'll tighten up my workflow and go back to using gloves.  We'll see if that does the trick.