Brian Pritchard

I understand that Film and Photo will close at the end of March and that Deluxe Denham will cease film processing on the 21st March. Brian

The masks come from coloured couplers in two of the layers. The coupler that produces the cyan dye is coloured magenta and the layer that produces the magenta dye is coloured yellow. Together they make the orange colour. The layer that produces the yellow dye is colourless. The masks correct for unwanted transmissions in the dyes. There isn't an appropriately coloure coupler for the yellow dye and also the yellow dye does not have any great unwanted absorptions. If you are interested I have a page on my website with some film samples that show the individual layers with and without masking. http://www.brianpritchard.com/why_colour_negative_is_orange.htm These pictures were made at the Kodak research laboratory in Harrow on specially coated samples as there ia no other way to see the individual layers. Brian

Whilst this is true of colour negs and interpos, black and white dupe negs and duplicating positives were quite often printed as combined picture and sound. If the duplicates were for foreign versions to be printed abroad, they were often printed in level sync so that the duplicates could be edited. Brian

Dirk is quite right, of course. You can't make a CRI from an Ektachrome original. You have to make an 'normal' internegative. However if you are looking at a negative it will be masked and you wouldn't be able to see that the blacks are green without using a video analyser, the black areas would be white in the negative. Again it wasn't normal to make 35mm Ektachrome dupes. Would it be possible to post a frame scan so we can see what you are looking at? Brian

The latest information that I have is that Technicolor closed it's Pinewood lab in April 2013 but that Deluxe are still doing release printing at Denham. Brian

Yes Greg, the higher the fog level the lower the maximum black with reversal processing. Hopefully the maximum black is capable of losing a bit of density without unduly affecting the picture quality too much. Brian

Gregg The J1/74 46 911 is the footage number. The + could well be the date code (1969) Brian

Second thoughts, as it is camera stock it might be cemented stripe so that it can be cleaned. You can't clean paste stripe with solvents as it will come off. You might still be able to read the edge code even if it is cemented stripe. Brian

You could develop up a short section, the only problem might be the balance stripe covering up the edge print. If so you can remove the stripe, if it is paste stripe, with a solvent such as perklone. You might find methylated spirit will work. If it is a cemented stripe (rather unlikely, I think) then the solvents will not remove them. Brian

Richard I know that Tony Scott at Film and Photo has quite a few Model C Spares. It would best to give him a call on (0) 208 993 0037 if you can't find anything locally. Brian

Thinking about it further, I think you need a punch tape in the reader for the machine to run. Brian

Richard You must make sure that the film break rollers are held up into position, you usually do this by putting rubber bands to the roller above. The machine shuts down if the film breaks. You can only operate the trims manually. They move the 1 to 50 by 22 points. Only the light valves will work from the RF cue detector or the notch detector. It is possible that the other cables are FCC information from the motor. What you really need is the Model C manual. I am not sure when I will be in a lab next but when I am I will check for you if you can wait. Best Wishes Brian

The BFI/National Archive don't do work for outside customers but, of course, this might change in the future. They do have the capability to do 16mm B/W work. Film and Photo can do A&B roll printing in both 16mm and 35mm. They use Schmitzer Model C printers and can do grading. I work there occasionally and recently graded some A&B's to make interpos's for them. I understood that Nowhere had a 16mm Debrie printer that people are able to use but that information might be out of date. Prestech run a fairly complete service in B/W and colour in 16mm and 35mm. Their main work is Archival preservation work but also do other work. They also have a very comprehensive digital setup including scanners and recorders. Brian

There are at least 4 places still doing 16mm printing or are able to do 16mm printing in the UK. Film and Photo, Prestech, Nowhere and the Bfi National Archive. Brian

You also need the colour head if you are using variable contrast b/w papers. Brian

The problem is really a financial one. Most labs have processing machines that use perhaps 1000L of develope,r if it is quite a fast machine. They would have to dump or store the current developer and then make up the new chemicals. Incidentally D76 is very similar to D96 the normal MP developer. Whilst they are processing your film they would not be able to process anything else. In addition they would have to run tests to establish running speed to get the required gamma on the stock(s) you are using. You would have to pay for the new chemicals, and if they had to dump the original bath you would have to pay for a new bath and probably the time involved for the technicians to do the work. Actually no lab is really happy with putting a new unseasoned bath in a machine; your special developer would probably stop them processing for a week. Brian

The calculation is based on the molecular weight of the chemical: Sodium carbonate is Na2Co3 which has a molecular weight of (2 X 23) + 12 + (3 x 16) = 106 Water is H2O which has a molecular weight of (2 X 1) +16 = 18. So decahydrate has a molecular weight of 106 + (10 X 18) = 286. The molecular weight of monohydrate is 106 + 18 = 124. The equivalent weight of decahydrate to monohydrate is 286/124 so you would need 52.5 x 286/124 gms of decahydrate = 121 gms. I have a formula that uses anhydrous Sodium Carbonate the amount is 45 gms. So using the above calculation monohydrate would need 45 X 124/106 = 52.6 gms which is what you have quoted. I hope this is clear. Brian

I also meant to mention that the Orwo rep in the UK is Tom Samuels - 01923 35 11 99. I have known Tom for many years and always found him most helpful. For those interested in the technical aspects of film perforations I have a page on my website: http://www.brianpritchard.com/Unsteadiness_in_16mm.htm This is an article by Leslie Wheeler from November 1958 and has a very good description of film perforating. Brian

Hello Bob Nice to talk to you the other day. I notice that in the data sheet on the Orwo website they say the standard pitch for 16mm is 0.2994 and not 0.2996. Perhaps there was a slip of the tongue when they said the slightly longer pitch? Brian

Don't forget that the edge numbers will be around the wrong way. Brian

I agree with with Mark, The Ilford manual of Photography is also a very good book. Brian

I left Filmatic in 1981 to become Technical Director at Humphries. I will assume the excellent quality was entirely down to me! :D Brian

Yes, it is. It is also odd that Filmatic was the first lab I worked at and Film and Photo will probably be the last! Brian

Hello John Yes they are still in business. They work with a very small staff; I go in occasionally to help with grading and sensitometry. Brian

There is also Deluxe. Brian