Other glass plates

Ilford R.40 Rapid Process Panchromatic glass plate

As well as the Selochrome stereo plates written about in my last post, I have also shot a number of different plates for night photography in recent months. I've used the last of the large format Selochrome plates written about in 2014 with some good results. Also mentioned in that blogpost were the Wratten & Wainwright Metallographic plates which were heavily fogged around the edges, so much so that I had all but written off using the plates. However, as I'd had a couple sitting in a plateholder for months, I decided to expose one on the same night as exposing this image on one of the Selochrome plates, and giving a moderately long exposure provided an image far less obscured by the fogging around the edges than I'd previously experienced.

Kodak Wratten & Wainwright Metallographic plate

As the Wratten & Wainwright box was sealed when I got it, I don't have a good theory as to why the plates shot recently should be less fogged than the others, except perhaps the fact that these plates would be from the central portion of the box, with a number of plates stacked on top (and below) the two illustrated here - although the edges of the plates themselves remain in the same relation to the edges of the box as those at the top or bottom of the stack.

Wratten & Wainwright glass plate

Incidentally both plates shown here exhibit true solarisation - the brightest highlights in the streetlamps have turned black. The term solarisation (when not describing a digital filter) is usually applied to what is more properly known as the Sabatier effect: the exposure in these highlight areas is such that the negative begins to lose density beyond the shoulder section of the characteristic curve (this phenomenon gets a brief mention in Ansel Adams' The Negative when describing his photograph The "Black Sun", Owens Valley, California). There's still a fair amount of fogging, and exposing for longer to combat this has resulted in what appears to be grain seen in the highlight areas, but this is scanner noise caused by the high density.

Late last year, I found two boxes of 4x5 inch plates, both Ilford R.40 Rapid Process Panchromatic - one box had been previously opened, but then resealed with black tape, and no plates had been used from it. I opened the other box for the information leaflet inside, which provided a date - August 1959.

Ilford R.40 Rapid Process Panchromatic glass plates

As described in the Ilford Manual of Photography (1946), Rapid Process Panchromatic plates were "For copying coloured originals. A plate of high contrast. The standard plate for colour separation screen negatives for photo-lithography." These were fifth highest in the list of plates by contrast in the Manual, and, as a process plate, it isn't given a speed: these plates were not intended for pictorial photography. The word Rapid in the name refers I think more to the speed of development rather than sensitivity - the information leaflet with the plates gives a development time of 2 1/2 minutes in ID13. The plates were introduced in 1918, and, according to Silver By The Ton, were rated 8 ASA in the post-1960 standard: other plates with the term Rapid in the name around the same time were rated 20 ASA.

Ilford R.40 Rapid Process Panchromatic test plate

For a test exposure, I rated one plate with an exposure index of 10 as a reasonable starting point, and with three successive exposures by progressively withdrawing the dark slide, gave the plate effective exposure indices of 10, 5, and 2.5 from right to left in the shot above. This was stand developed in RO9 One Shot, diluted 1+150 (to reduce contrast) for one hour. The results were very encouraging. The central section, with an effective rating of 5, looked best from the test plate. However, when shooting them at night, the first set of plates did appear to be overexposed, not helped by using a developer dilution of 1+100, rather than 1+150. The highlights in these negatives are very dense, and this again added noise when scanning in these areas, much like the Wratten & Wainwright plates: the image at the top of this post is one of the plates shot and developed in this fashion. I reduced my exposure times for the next shots by around one stop, and developed these plates at 1+150, as below.

Ilford R.40 Rapid Process Panchromatic plate

The Rapid Process Panchromatic plates are amongst the best I've used, in terms of the emulsion showing very little age-related deterioration; when coupled with getting the exposure right and developing to reduce the inherent contrast, the plates produce excellent results.

Ilford R.40 Rapid Process Panchromatic plate

Special Rapid Panchromatic plates

I've also recently used some quarter-plate size Special Rapid Panchromatic plates. First produced in 1919 at 32 ASA, these are "Fine grain. Fairly high contrast. General purpose plate. Widely used in scientific; and in the photo-mechanical trade for block making, offset work and photogravure." These are just above the middle of the contrast range of Ilford plates at the time. A leaflet inside the box was dated to 1946.

Special Rapid Panchromatic plate test

Rather than shooting these plates for the ongoing night photography project, I used most of the plates from the box on the LAPC photo walk last month; these were just fast enough to use handheld, rated around 10. The test plate above was also rated 10: with three successive exposures, the middle section at an exposure index of 5 provides a fuller negative. The plate below was one that I did shoot at night with a twenty-minute exposure which captured people queuing at a bar better than expected, if still very faint.

Special Rapid Panchromatic plate

Some time around 1950 Ilford's plate names gained prefixes with a letter and numerals: the Special Rapid Panchromatic above were later given the prefix R.20 as seen on this leaflet. I've wondered for some time about how these were constructed, what was the logic to them. The Hypersensitive Panchromatic and Fine Grain Panchromatic emulsions, being new just before the second world war, were not abbreviated in same way as other emulsions later: these were already abbreviated to HP and FP while the films went through their numerical iterations. Most other plates were given the alphabetical prefixes R, G and N (although not all - Selochrome didn't gain a prefix, but this was more of a brand name than a descriptor). Looking at the spectral sensitivity of the plates, as all panchromatic plates are given an R, it would appear that the letter are R denotes red sensitive; G plates are 'highly orthochromatic' with sensitivity extended into the yellow part of the spectrum that perhaps G is for green sensitive; and N for 'ordinary' plates would possibly mean not colour sensitive. I haven't found a logic to the numbers. One wonders if photographers stopped calling Soft Gradation Panchromatic plates that, and started referring to them simply as R.10 plates?

References
The Negative, Ansel Adams, 1981
Silver By The Ton, RJ Hercock and GA Jones,1979
The Ilford Manual of Photography, James Mitchell (ed.), 1946

Some large format glass plates

Ilford Selochrome 4x5 inch glass plate

In my posts about the ongoing glass plate night photography project, I've written about how some sizes are more common than others. Of all the relatively standard formats, 4x5 inches appear less frequently than quarterplate or the small metric and imperial sizes: in the past year I have only acquired two boxes in this size since using up the box of Air Ministry plates.

Wratten & Wainwright Metallographic Dry Plates

The first of these are Wratten and Wainwright Metallographic Dry Plates. Wratten and Wainwright were a British company bought by Eastman Kodak in 1912 (a few years earlier, Eastman Kodak had made approaches to buy or merge with Ilford, presumably to gain larger market share in the UK). The Wratten name was used as a Kodak brand for many years afterwards, notably for filters and safelights, as demonstrated by the instructions at the top of the box. The Art Nouveau typeface used on the box label suggested that the plates were old, as did the explicit use of the phrase 'Dry Plates'; dry plates had been around since the last quarter of the 19th century and superseded the wet plate process, such that it quickly became reasonable to assume that photographic plates were all of the dry variety, and none of the many other boxes of plates I've collected and used are described as 'dry plates'; indeed, even at the time one would never have found boxes of wet plates as a commodity, as the wet plate process required the photographer to coat a sheet of glass and then expose this in the camera before the emulsion had time to dry. The development of the dry photographic plate itself allowed the emergence of companies such as Eastman and Ilford to supply material to photographers, taking the step of preparing a light sensitive surface away from the photographer and into the business of mass production (however, as there are contemporary photographers who have revived the wet plate process prominently enough, when I mention shooting with glass plates, this becomes an occasional misunderstanding). The reverse of the card inside the box has the numbers '5/35' at the bottom, which may be a date of printing. I have used a later version of Metallographic plates before with some success.

Wratten & Wainwright Metallographic plate test

The test shot shows the Wratten & Wainwright Metallographic plates to be heavily fogged at the edges, but clear in the central portion. I did shoot a couple of these plates at night, but I was disappointed with the impenetrable fog around the edges of the plates. I had previously achieved some good images from the box of Air Ministry plates which were of a similar age, but as I have found as a very general rule, Kodak plates on the whole have tended not to age as well as Ilford plates; most of the glass plates I've used over the last couple of years have been either Kodak or Ilford, and I tend not to buy Kodak plates now unless in a rare size such as 4x5 inches (I do not have any information as to which manufacturer supplied the Air Ministry plates).

Wratten & Wainwright Metallographic glass plate

Ilford Selochrome 4x5 inch plates

Around the same time I also bought an unopened box of Ilford Selochrome 4x5 inch plates. These had a leaflet inside which was dated to 1951. The wrapper around the box has two different styles of label: on the side, the narrow label is a newer design, with Ilford written in a sans serif font. Like the Wratten and Wainwright plates, Selochrome is also orthochromatic (a panchromatic version of Selochrome was later made, at least as a roll film by Ilford, which I used on the last 127 Day). The Ilford Manual of Photography describe Selochrome as "a fast plate for general purposes. Of average contrast. Fine grain and highly orthochromatic." I shot a test at the same time as the Metallographic plate. The result below looks relatively high in contrast, but this is in part due to the image being scanned from a contact print. The plates have aged quite well, with a few spotting marks, appearing on some plates more than others. The image at the top of this post is the best example of a photograph shot on these plates. I also shot the same scene on one of the Wratten & Wainwright Metallographic plates for comparison.

Ilford Selochrome plate test

Ilford Selochrome 4x5 inch plate

Ilford Selochrome 4x5 inch plate

As well as 4x5 inch plates, I am also including in this post 9x12cm plates. As mentioned in my post on the Ica Trona 210, 9x12cm usually qualifies for large format. Last year, I wrote about finding three previously opened boxes of 9x12cm plates, which I got a few good results from two of the boxes. Earlier this year, I bought a job lot of three boxes of Ilford HP3, all previously unopened.

Ilford HP3 9x12cm glass plates

I could see from the box style before bidding on the lot that these were possibly late 1960s or early 70s. When the boxes arrived, one was not sealed, but was full; I opened one of the other boxes to find the leaflet inside. This was dated to 1973, just two years from the end of plate manufacture at Ilford. What the leaflet shows is just how many different types of plates (eight) were still being made at that late date. HP4 was introduced in 1966, but was made alongside HP3, and did not replace it for a number of years according to Photomemorabilia's Ilford Chronology, possibly HP3 as a plate emulsion was continued until glass plate manufacture ceased, and HP4 is not listed on the leaflet from the box. At this late date the HP name is also given in full: Hypersensitive Panchromatic. The boxes also contained 36 plates each - all previous boxes of photographic plates I've used contained, at least originally, one dozen (except for one half-dozen box). I suspect that at this stage it was uneconomical to sell plates in smaller amounts.

Ilford HP3 plate test

The test above shows that the plates are quite low in contrast, but there is little age deterioration beyond a loss in sensitivity. I rated the plate at 40 EI with three successive exposures, giving effective exposures of 40, 20 and 10. I shot some of the HP3 plates at night with my Voigtländer Avus where the low contrast was an advantage, but having three boxes of 36 plates, I was happy to divert some of the plates from my night photography project, and shot some with the Ica Trona handheld, rated 50, which I used to illustrated my post on the camera.

Ilford HP3 9x12cm plate, shot with Voigtländer Avus

Ilford HP3 9x12cm plate, shot with Voigtländer Avus

Ilford HP3 9x12cm plate, shot handheld with Ica Trona 210

Sources/further reading
Company details from Early Photography
Ilford Chronology on Photomemorabilia