IN CONVERSATION

By Bill Reid.

My article "E6/7 Weighing & Mixing" in the July CRCN brought some interesting response, as well as some very nice sample slides to back things up.

Ron Knowles (Area 11) sent a mixture of film makes, the interesting point being that he had taken exposures of the same subjects which gave a good idea how each film handled the same colours and processing, in the CRC Formula. Tony Chuter (Area 17) enclosed some samples of Ektachrome, 3M and Konicachrome which were `brilliant`. He thinks Ekta takes some beating, but also added that when he processed a cassette of Konica & 3M together in the same tank, it was quite an eye opener and would not have expected Konica to equal any of the other top products, "But it did". The particular roll he processed was from fresh Club sales and he wonders if Konica has benefited from the general up-grading that all film emulsions have had of late, or perhaps it`s just that previous formulae weighers & mixers have been using didn`t suit, while the CRC Formula is able to exploit the film`s potential. Whatever, Tony is now happy to use Konicachrome with confidence.

Another interesting point Tony brought up was two frames of his test card. This consists of an I. B. A. test card glued onto a large Kodak `grey` card, leaving a large grey boarder. The first frame had been exposed with the card placed on a window cill, close by had been a blue garden hammock, this gave a `blue` biased grey card. The second frame had been exposed with the card placed at the base of a tree immediately behind the first position. The result was completely different with a `true` grey card. This seems to prove that even a test card can give you a faulse rendering and before you blame the formula or film for some odd results, you should make sure the test card has been placed in `neutral` lighting.

Tony asked why I hadn`t answered how I got those two `blank` films with my first two trials with the CRC Formula! The fact is I really can`t say for sure. As all my bottles are perfectly labeled and assuming my weighing & mixing had been O.K. somehow I had managed to mix up a couple of the bottles, by that I don`t mean picking up the wrong one, but possibly had actually poured the into the wrong bottles to start with. This most likely being the 1st. Developer and Reversal, as with the film reversed it would leave nothing on the film to be developed. However I can`t prove that this was the case, but from now on the only bottle that will be on view will be the one label for the brew I am working on. Of course, I also had one session which gave very green results. I am sure this was the result of `poor` reversal, but not due to the reversal bath, but by probably being over-zealous with the short rinse stage. Our Treasurer, Colin Powell also suffered this problem and he has reverted to light reversal. Now if this cures the problem then that is fine, but as I see it, the advantage of E6/7 processing is being able to keep processing times and stages to the minimum and I don`t care for messing about with photoflood and water in close promixity, so I am all for chemical reversal, after all this is a chemical re-action and if you have carried out everything correctly then reversal should be as complete as for any other baths.

I was very reluctant to use chemical reversal and avoided it`s use even with kits that included it. One day while talking on the phone to Area 3 Co-ordinator, Roy Salmons, who produced the Photoworld kit, he assured me that it `should` work, so next time I tried it, the results were startling and I have never looked back and only too happy to leave photoflood and water basin packed away. The disappointment on turning to weighing and mixing was in having to revert to light reversal. However soon after this Tony Chuter introduced me to the Rayco formula for this brew and I was eager to try it, however a formula became available through the CRCN and I tried this with trials of the A.M. formula.

This proved quite disasterous either getting green results and in one case, an almost `solarised` effect. So for a time it was back to light reversal. Then along came the CRC Formula including a reversal bath. Well the first trials produced those two blank films, but apart from that I am now producing some super slides by using the CRC Formula exactly as given.

Like myself, John Wilson (Area 26) was on the point of going back to kits as we were doing so badly weighing and mixing with the A.M. formula. Our first aim in home processing is to get good pictures and to be able to use more films than we could afford with processed payed film. Therefore taking up W&M could only e worth while if it brought results as good, if not better than commercial kits. This proved difficult until the CRC formula came along.

John tells me he has now got his first really good results, though he is using a slightly modified version of the CRC formula, that Rita & Major Pearle published in the CRCN. However this brew is now very close to the CRC one and only seems to differ by the way of using Sodium and/or Potassium Hydroxide, not so much the substance but the quantities used, and his technique is to use only about three-quarters of the quantities and then add more at the end of the mixing & dissolving to get the right pH. He finds for the moment he has difficulty avoiding over`correction but expects to get the knack of it with practice.

On Reversal, John agrees that the rinse stage could cause problems. He finds that it takes a good minute to carry out this stage from taking the lid off the tank, to carrying out the rinse. Tony too shares this concern and both are interested in trying going directly from reversal to colour developer. Apparently, reversal doesn`t actually take place until the film meets the colour developer, therefore the two minutes in the reversal is to make sure the film is well saturated with the chemical reversal and it is this chemical on the film that creates the reaction and should the film be over-rinsed then poor or even no reversal could take place. Rinsing the tank makes no difference and will avoid excessive carry-over, but too long in the rinse water will effect the final reversal, so merely giving the spiral a shake may prove the best thing.

When I said keep the rinse within 30secs I should have made it clear that the 30secs was the actual time the film is soaked in the rinse,including emptying after all, then time the film is in the reversal doesn`t matter and a moment or two will make no difference as I am sure the 2 minutes is the minimum time to soak the emulsion. However it will be interesting seeing if we can omit the rinse altogether and there is no reason it shouldn`t work, though care must be taken that you don`t effect the pH value of the Colour Developer for proceeding films. I expect commercial kits have a buffer to avoid this problem, but for the moment don`t know if the CRC Formula includes enough buffer to handle this.

As Ron Croad has proved, the stated rinse does work and he is producing constant results. However as my problem shows up, we may be sailing a bit close to the wind and easily cause over-rinsing. If you are sure your tank will drain easily from pouring & shaking then it may be worth to omit the rinse, otherwise rinse only the tank and lid, but just give the spiral a shake, remembering to keep all this within the 30 seconds.

The rinse between Conditioner and Bleach also raises the same problem and I feel the same comments as above should apply. Glyn Willicombe (Area 20) also questions this and remarks such in the last Area 20 Slide Folio note book. He had a phone reply from Rita & Major Pearle (Area 13). major said "The spiral should be removed from the tank before the tank & lid are rinsed, rinsing the spiral would certainly impair reversal". This would seem to apply to the Conditioner also, which was what Glyn was interested in. Major also said "The conditioner should not be used with Ferricyanide bleach, the EDTA NaFe must be used with the CRC Formula. An Acetic acid stop bath must be used with the Ferricyanide bleach, but finds this combination could result in a `stain` of the unexposed ends of the film, with EDTA NaFe the film ends are quite clear".

This would seem to agree with my own findings. When using 3M film in the A.M. formula I found all the film ends had a `pink` cast. There is no reason why the Ferri bleach cannot be used with the CRC Formula, but it does actually turn a six bath brew into an eight bath one (Nine including the Stabiliser) and of course adds to the time and effort involved in processing your slides, plus there is a chance of getting stained film. I think it worth mentioning at this stage, Frank White`s interesting comments in the CRCN explaining how important the pH value of the Ferricyanide bleach is to avoiding `stain` of film ends.

I can understand members wishing to use up the supply of chemicals already in stock for the A.M. formula, but I feel that sticking to the CRC Formula as published will give you all the quality you want without adding possible problems. Among the variations some members are using, such as A.M. or CRC 1st. & Colour Developer, or simple bleach and fixer, some use a commercial reversal bath such as the concentrate Lingcolor Reversal. Lingcolor have always been well thought of and Tony says the keeping power of their concentrate reversal is exellent. However latest news is that you can no longer buy the reversal individually and must buy the whole lot of developers. This of course makes the total cost too much for many members, which is a pity, as I am sure this will loose Lingcolor many sales. However now that we have the exellent CRC Formula, plus a CRC reversal kit based on the same formula due out shortly, there is little need to buy anything else, whether you weigh & mix or just wish to use kits.

Again, on costs! both Tony and Glyn like Fujichrome film. Those of you who used this film under the Barfen CRX100 label will understand this. I found the combination of this film with the Barfen Flex-E6 kit gave me some of the best results I have ever had from kit processing. It`s a pity Barfen spoiled things by changing without telling anyone. Until recently Fujichrome in bulk length while expensive, compared to most makes, was still reasonable. However the latest price of £48 has put Tony & Glyn off buying it, or at least using it sparingly. I really don`t see the point of raising prices when all it means is less sales. Glyn adds that till recently he purchased Fujichrome in bulk from Jessop and it worked out cheaper than 3M from Club sales, but Jessop have increased the price of 100ft by £8 and adds that Jessop used to be the cheapest in the market, but now seems to increase prices every few months, not just on film, but on goods generally and finds some prices are no longer `discount` but actually the R.R.P. He wonders if this is the negative side of Jessop`s expansion into the market place instead of when as a single shop in Leicester they had rock-bottom prices and an excellent mail order business.

One film that seems to have gone astray is "Labachrome" a West German made film. This was introduced to us by Frank Beaumont of Area 13. I tried this film with the A. M. formula in my earliest trials with and while I got those very dense results, I was very impressed with the sharpness and colour balance, which was somewhere between 3M and Fujichrome. Tony has recently processed some which has lasted in his fridge some while, with the CRC formula, and has got excellent results.

About a year after Frank introduced the film he gave up his photographic business and as far as I know Kevin Craske took over some of his stock, but since then have heard no more of this film . It certainly deserves it`s place on the film market.

I haven`t mentioned pH meters as such. This has always been a debatable point with me -obviously pH values are very important and if too far out will give all sorts of problems. However from my earliest dealings with weighing & mixing I have been aware that most processing formulae is produced so as to give as close as possible a pH value by simply weighing & mixing to the formula. Up till now I have neither purchased or used a pH meter, the only time my brews have been checked is once by Tony Chuter and another time by Ron Croad. In both cases the values were as close as could be desires. Now the point I am making is, that while values must be at or near the given figure,as with most things, there is an acceptable allowance either side before any effect occurs. I don`t know what this is but obviously I must be getting nicely inside that figure.

The only pH check I have made myself is with pH paper that Lawrence Edwards sent me a while back. This only gives you an approximate indication and can only tell if you are really far out, but it does seem to give some confidence when you find that the colour change to the paper is close to the colours given for each pH value.

I am not saying you shouldn`t have a pH meter as I am sure knowing the values are spot on will give you more satisfaction and aid constant results, but this doesn`t not mean you must have one right away, you can always buy one at a later stage. The main thing is to get started in weighing & mixing and get those first results, after all that is what the CRC is all about. As well as the financial gain, in time. you have the satisfaction of knowing that every brew you use will be as fresh as it possibly can be and you can make up as little or as much as you require at the time. I have used all kinds over the years and mostly got fine results, but there is always that niggling that that things could go wrong when not knowing how old the kit was or if it had been stored properly, likewise, could some of those less better results been due to a faulty kit rather than anything I have done? It is nice to know that all my processing will now be carried out with the freshest of chemicals, only a day or two old, and no more than a week or two at the most.

UP-DATE

Since staring this article I have weighed & mixed and processed further films. After my previous successful sessions I have to report a disappointing result. In fact not much seems to have gone right this time.

With a 600ml brew I had six Scotch Chrome films to process. The first two came out with a `red-brown` appearance not unlike the strange `colourisation` effect I got last year, which I put down to poor chemical reversal. However in this case fully exposed frames were acceptable with the cast showing in the shadows. On first inspecting a sample slide, Ron Knowles thought I was being over-critical, but when enlarging the slide on his Simon table-top projector, he had to admit that the cast was there.

I`m almost ashamed to tell you what I did with the second pair of films! Well, I must out with it... I managed to pour in the bleach instead of the colour developer. I quickly emptied the tank and after a full wash started the process again from reversal, but all I got was a complete dense emulsion, hence two lost films.

With that I could only continue with the next pair and try harder. Thinking on the lines of `reversal` I next decided to restrict the rinse between reversal and Col. Developer to the minimum and simply fill the tank with water and pour out as soon as possible. It certainly appears to have avoided the re-brown effect, leaning slightly on the `green` side. Again on the sample slide Ron thought I was being over critical, but perhaps that wasn`t the best sample, but in truth the results were more acceptable than the red-brown ones. However these two problems seem to prove that while the CRC formula is an excellent one, there are still pitfalls to watch out for.

As luck had it, Kevin Craske phoned on another matter and I was able to put this to him. He thinks the red-brown was due to the `bleach` rather than the reversal. It has been long known that with EDTA (NaFe) type bleach you need to aerate the mixture to keep it active. Likewise I have already mentioned that this chemical takes some mixing and I have gone to some length to make sure the powder has mixed, but still I have noticed hard lumps of chemical at the bottom of the bottle after a day or two. Ron Croad and Tony Chuter have mentioned they add drops of `Ammonia` to aid this procedure. You use a lot of EDTA (NaFe) and it soon gets very dense and you need to both raise the temperature and add drops of water to get it to mix fully.

As Kevin recognises this problem and that of the reversal he has kindly offered to do a bit of research into these and report as soon as possible. Having had such excellent results previously it is difficult to understand this latest set back. In regards the reversal brew it has already been mentioned that there is some debate as to the need for adding the tiny amount of p-aminophenol solution as specified. While some agree that if its in the formula and easily available, it should be used. Ron Knowles suspects it and omits it, saying he finds it goes off too quickly, first developing `black` spots, then turning brown. I noticed the supply I have, which is just a few months old, does indeed have some black spots in it! so could this be the source of my problems this time? Even Kevin wonders if the infetisimal amount we use can really be doing anything, while Ron Knowles suggests that this may be one of those `obscure` chemicals that Kodak use/name to put others off the scent as to what they really are using in their formula!.

Having more processing to do soon I shall be looking into these two problems with others in the Club before proceeding any further. However, in case this might cause concern for those approaching their first use of the CRC Formula, I must explain that if you are using a completely fresh brew you should have no problems as far as the reversal is concerned and most likely if you give the bleach a good shake up in a bottle slightly larger than the amount you are using all should be well. After a while keep a check on the p-aminophenol solution and if you notice any black specs in it, then make up a fresh lot. While Ron seems to be having no problems while omitting this chemical I feel there is need to be more research before we can be sure that it is alright to do so.

In Conclusion

A little more light on using p-aminophenol has just come into my possession in an article that will now have to appear in full in the next Newsletter. In this article on a concentrate formulae based on the CRC formula, states in it`s notes that for the Reversal concentrate 2.7mls of p-amino solution is used. It then goes on ... "Since it doesn`t keep you have to throw away the other 97mls, which seems a waste. So if you can measure accurately down to half this quantity i.e. 0.5ml of Prop. Acid and 0.5gms of p-amino in 50mls of water then it would be better to do so". This makes me wonder if there is some truth in what Ron Knowles has been suggesting. However again I must add that my articles keeping you up to date with my ventures into weighing & mixing can only be from a very `novice` position and anything that I say or do must be considered in that vein. However I hope that it brings pertinent points of interest and that those of you who are more technically knowledgeable will take the time to respond and add some truth and guidance to the whole matter.