Brian Pritchard

Hello Richardson Sorry to take so lomg with the information - I had to dig the datasheets out from my loft. 2498 has a rating of 250 Daylight and 200 Tungsten When processed for 2 1/4 mins in D96 (Normal Motion Picture Developer) and 200 Daylight 160 Tungsten when processed as reversal. 2496 has a rating of 125 in tungsten developed for 1 minute at 95 deg F or 160 when reversal processed. You can also develop for 6 mins in D76 to give a gamma of 1.0. I have copies of the datasheets which I can scan if anyone wants them. Brian

Difficult to give an opinion without seeing a sample but I have known aluminum dust to cause blue spots. Brian

I have just listed on Ebay http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...E:L:LCA:GB:1123 This auction is for a Bolex 16mm Camera with f1.4 Switar 25mm lens, f1.8 Switar 16mm lens and f2.8 Yvar 75mm lens. There is a set of Bolex extension tubes 5mm, 10mm, 20mm, 40mm and 60mm. There are two lens caps and lens thread protectors and one body cap. IMPORTANT: The camera does NOT have a separate viewfinder. Brian

I believe that 8521 was introduced in 1995 and withdrawn in 1998. Brian

Thanks for the concern Hal but I use this address on my website so I get loads of spam anyway. I have a separate email address I don't spread around that I use for 'normal' communication. I also have other email addresses that I use when a website insists I give an email address before I can download etc. I do get 100 to 150 spam messages a day but it doesn't take long to de-spam it. Cheers Brian

I have a 50 ft roll of standard 8mm which you are welcome to for just the cost of postage. Email me at mail@brianpritchard.com with your postal address, please use subject '8mm film stock' so I can weed it out of the spam. Brian

He was quite right as it turns out. CRI was/is one of the biggest disasters of motion picture history. As well as being the most difficult process to run, streaks were very common, the majority of CRI's are nearly or actually unusable because of fading. You also lost the extra safety of having an interpos and a dupe negative. Not one of Kodak's best ideas! Brian

If my memory serves me correctly we used 2 x 100 watt lamps for our B/W Reversal process. One is sufficient but, of course with a continuous processing machine you cannot take the risk that the lamp fails so you have two lamps. I also remember making up RA-1 (Reversal Additive) for our ME-4 process and having to wear a full face mask and gloves because it was so dangerous. I believe that it comes as a solution now rather than the tablets we had to dissolve. Brian

Actually the re-exposure is not terribly critical as long as you give sufficient exposure. Excessive re-exposure, such as sunlight, will cause loss of density. The problem with chemical reversal agents is that they can be a menace in a processing laboratory as they will fog all films if the solution or the dust come into contact with other films. Brian

Of course it is impractical; I was just explaining what the Kodak information meant. I don't know of any lab that would carry out this procedure but an explanation was asked for and that is what I gave. Brian

You are right that in normal circumstances ECN2 is a standardised process; however if you want to push or pull the film you have to change the development time. Most labs would do this by changing the running speed of the machine. This does mean that when you change the machine speed all the other baths will change as well. Theoretically when pushing or pulling you would add or remove strands in the developer so that you are only changing the development time and not all the other baths. Brian

Actually all labs are able to run very short lengths - they regularly run control strips which are less than 2 ft long. However most do not want to be bothered and feel thay can't charge a realistic fee to make it worth while. When I worked at Humphries, many years ago, we all used Eastman colour neg in our still cameras and the rushes grader would attach the processed neg to a roll of rushes and make us a set of slides on colour print stock. They would all have the same grading but usually were quite acceptable; you just had to be extra careful with your exposure. Brian

I had a look through my collection of film datasheets. The closest I could get was Kodak Linagraph Shellburst Film 2476 (Estar-AH Base). This had an ASA of 250. It was a panchromatic emulsion with extended red sensitivity. It had a hardened emulsion for processing up to 130 degrees F, 54.5 degrees C. Development times in D19 were 12 minutes at 20 degrees C to 3/4 minute at 40.5 degrees C. In D76 the times were 7 minutes at 20 degrees and 2 1/4 minutes at 35 degreees C. These times give a contrast of 0.9. The uses mentioned in the datasheet were: Cinetheodolite photography, Spark-chamber photography, Bubble-chamber photography and cinefluorography. It was described as medium speed, medium granulartiy and very high resolving power. The datsheet is dated 4/1975. Brian

The usual way to detect Vinegar Syndrome is to use A-D strips (Acid Detection Strips) They change colour from blue to yellow as they detect the Acetic Acid. You can find information on Vinegar Syndrome on the IPI website They have a downloadable pdf file all about VS and storage of film. http://www.imagepermanenceinstitute.org/sh...b/downloads.asp Brian

All camera stocks are still manufacturered on acetate stock; there is always a danger of a camera jam in which case polyester will damage the camera. Most laboratory stocks are polyester although they usually are still avaliable as acetate mainly to special order. Brian

In general negatives have a greater ability to record tonal range than reversal stocks; this is because reversal stocks are processed to a higher contrast than negatives. Reversal stocks are processed to a projection contrast. Having said that higher contrast stocks will give a denser black and usually a cleaner white. Particularly in the case of black and white you have the ability to adjust the contrast of both the negative and the print whereas the final contrast of a reversal stock is determined by the first development contrast. Brian

Did you mean Les Ostinelli; he also worked at Humphries for a while? He died a couple of years ago. Brian

I don't see any problem in keeping the film wet before developing as long as the time is not excessive. Leaving the film in solution overnight will cause the emulsion to come off. Rem-jet is softened by any alkaline solution, developers are alkaline so this is why it is important to remove the backing before the film reaches the developer. Backing can be removed from the emulsion by polishing the emulsion with silver polixh and then re-washing to remove the very fine scratches you have put on the supercoat. I have spent many long hours doing this after a lab problem in processing. It works very well. Of course you have to handle the film carefully to avoid putting scratches on the base side. Perklone works quite well for removing backing on the base side although the best soultion is to rewsh the film back through the ECN process. Brian

It is a dark green filter that you view your scene through when shooting in Black and White. It enables you to judge the effect of the scene brightnesses without the distraction of colour. It effectively renders the scene as it would appear on panchromatic black and white film. In the days of black and white (when I was young) Kodak sold or quite often gave away, if you were sufficiently important, pan glasses. Brian

J2 over 86 is the perforator number and has no relevance to the stock identification. Brian

I've run 8mm on Photomecs and Calder machines. The important things are to make sure you don't have any tension build-ups on any of the racks and to make sure you use a 'tail'. You would normally do this when going from 35mm to 16mm but it is essential when going to 8mm. For those who haven't come across the expression, a 'tail' is a piece of machine leader that tapers from 35mm to 16mm or 16mm to 8mm and allows the film to settle in the right position on the rollers. You might also check that any flat rollers have soft touch tyres on them to avoid scratching the 8mm. I know of at least one lab that runs 8mm on a 35mm machine. Brian

Not so, Dominic is quite correct, of course. The rem-jet is first softened and then passes into a spray chamber where the backing is sprayed off and buffed. There are sprays impinging onto the emulsion side to prevent the backing getting onto the emulsion. The pre-bath is formulated so that the backing does NOT come off in it; otherwise there would be backing floating in the pre-bath which would get all over the film and be very difficult to remove. Brian

I understand from Howard, the manager, that half the staff go on Friday, the remaining staff stay on until the 24th July to complete the processing of the 'Frost' TV programme. I have been associated with them since the early 80's when they were part of the Humphries Group, they were taken over by Rank in 1985 and I amd my colleagues at Hendersons bought them when Rank were going to close them and renamed them Film Lab North, we sold them to Yorkshire TV when Hendersons went into administration in the late 90's. Film Lab North were one of the first labs in the world to offer a super 16 colour neg process and as such processed the colour neg from one of the Apollo Space missions for NASA. They still have the cans from space as well as a signed portrait of the astronauts. A great lab with very clean and tidy premises, very sad to see them go. Brian

Of course if you do not want to do these calculations then you just need to make a series of exposures of your gray card from normal reducing by 1/2 a stop each time. Ask your processing lab to measure the visual density of the dMin and each exposure. You only need to shoot enough frames to ensure that the camera is up to speed. You will then be able to get a close estimate of the required exposure. It didn't say on your post where you are from; if you are from the UK and you can't get the lab to do the measurements then do the exposure and get it processed and I will measure it for you if you send it to me. Brian