Delta 100 pinholes / emulsion issues in 4x5...
Ugh, ran another ten sheets today and I am having a heck of a time with Delta 100 in 4x5 in terms of pinholes / emulsion coming off in specks. I am running either Xtol 1+1 or HC-110 B in rotary / Jobo 3010, no special distilled water, temps within 1/2 a degree. I am using Ilford Stop bath and Kodak fix. It's definitely emulsion though, I can see the marks in the emulsion with a 15X loupe...very Efke-like behavior although rarely in the middle of the sheet, opting for corners or edges, really odd.....
It's the only sheet film I have this problem with.....and I have always had it, thought it was dust for awhile...
What the freak is going on?
I would contact Simon directly - they will probably ask you to send the film to them and they can put it under the electron microscope to give you the best answer.
Once a photographer is convinced that the camera can lie and that, strictly speaking, the vast majority of photographs are "camera lies," inasmuch as they tell only part of a story or tell it in a distorted form, half the battle is won. Once he has conceded that photography is not a "naturalistic" medium of rendition and that striving for "naturalism" in a photograph is futile, he can turn his attention to using a camera to make more effective pictures.
I remember this problem being discussed before and was pinned down to too strong acid stop bath.
Thanks, I'll try a dilute mixture next time around....
Originally Posted by Mark Layne
I don't use an acid stop bath -- just water. Actually, I've never used an acid stop bath for film both Kodak and Ilford films including Delta 100 4x5. It has worked with no problems for over forty years. I do use acid stop for paper .
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The issue of using a stop bath and pin holes is that a function of film size? I have been using Kodak's stop bath for years and have had no pin holes in my film but the largest film I use is 120. I ask this question because I just inherited a 4x5 camera and I would rather not get frustrated with pin holes from the get-go.
I'm curious to see where this goes. I've used Delta 100 for years in 35mm and 4x5 with Kodak Indicator Stop Bath (standard acetic acid stop bath) and never had anything like this happen. I could half understand a stop bath issue if OP was using a developer with a Carbonate alkali (although I'd still be surprised) but that is not the case.
I've not had this problem. I use Delta 100 (4X5) with Xtol 1+1 in a CPE+ and do not pre rinse or use a stop bath. I use several changes of water in place of a stop bath and TF4 to fix, FotoFlo and hang to dry.
Dear PKM 25,
Firstly I am always concerned and very sorry when anyone has a problem with one of our products, even if you use an acetic acid based stop bath you should never get pinholes on any ILFORD film product, emulsion being removed from any base requiries some kind of traumatic chemical or temperature based event.
90% of QC enquiries relating to marks of any type on any of our films are related to dust or contaminants preventing development, but you say 'emulsion' is being removed and you have no temperature variation.
As you are probably aware we do not recommend pre-soaking any of our films, in our opinion this is just not required, you do not state if you pre-soaked, BUT regardless, as long as its not an excessive pre-soak that should not affect in any way the performance of the film.
I have checked to see if we have any outstanding QC complaints on DELTA 100 Sheet film and we have none, none outstanding on any DELTA Film product, so as one of the above suggested you should send a sheet of the affected film to us for examination, just send it by post to Technical Service at Mobberley please include your e.mail address, a description of what has happened, your process and the batch number off the box and an unexposed sheet as well from the same box if you have it, you said you can see 'the emulsion' off with a 15 x Lupe, I do not doubt for a second that is what you think you see, but it probably is not, unless its actually reticulation it may well be interference with one of the coated layers, the only way you can actually tell is by using an Electrom Microscope which is what we will use.
You will get back an explanation of what we think it is, that will start with one of three statements :
1 ) Cause justified : A problem has occured with the manufacture of the product.
2 ) Cause not certain : We are unable to determine how or why a problem exists with the sample.
3 ) Cause not justified : A problem was encountered post manufacture.
Simon ILFORD Photo / HARMAN technology Limited :
I know you are a very experienced photographer and darkroom worker PKM, but just in case anyone else looks at this later on what he means is "even more dilute"! The standard dilution with Ilfostop is 1+19 and I use it myself at that concentration without a problem, as do zillions of other people.
Originally Posted by PKM-25
It will be interesting to discover what the problem is caused by, as the whole process you described seems pretty optimal. Very good support from Ilford, as usual