Wednesday, 24 April 2013

Rolleicord ‘waddling’ while focusing

There is often discussion in fora on what to do when the front of a Rolleicord or a Rolleiflex gets a bang, moving the lens and film planes out of parallel. An expensive repair is the answer. However, only rarely does discussion of another problem that can cause loss of parallelism arise.

In the 1980s, I had a Rolleicord Va with what I can only describe as a ‘waddling’ front end. When focusing, one side of the front end moved ahead of the other; eventually, the other side seemed to catch up when I stopped turning the wheel but I was never sure the lens became parallel to the film after being so far off. This is the only Rollei I have seen with the problem out of those I have had or handled. The mechanism that the front board runs in and out of the back part of the camera appeared to be loose.

Makers of bellows or other cameras with collapsible fronts used emphasise that their construction ensured the film and lens planes were parallel. But what is the margin of error in, say, that Rolleicord?

Using standard formulae for circle of confusion and for depth of focus (i.e. the distance from the film plane at which an image is in sharp focus or lens-to-film tolerance), the total depth of focus at f16 is 1.7 mm, for a Rolleicord/flex. However, depth of focus, like depth of field, decreases as the size of the aperture is increased. By f3.5 it is 0.37 mm and by f2.8 only 0.3 mm. So I probably would not have noticed anything wrong with my waddling Rolleicord at small apertures. But at f3.5 and focused at the centre of the screen, it would only take one side to be 0.15 mm further away and the other to be 0.15 mm nearer the lens for the effect of lack of parallelism to become apparent.

Also germane to this point, is the discussion of the flatness of film after being left in a camera for some time and the superiority of the film path of the Minolta Autocord over the Rolleis. Again, the effect would be more apparent at large apertures, and in the f2.8 Rolleiflexes in particular.

With folding 35 mm cameras the tolerance is even tighter. One of the last cameras my father bought for his collection before he died was an Agfa Karat 36 with a Rodenstock Heligon f2 lens. I remember that the struts of this great camera were particularly impressive in the way that they ensured film and lens planes remained parallel when the front was extended. They needed to be; at f2 the depth of focus is only 0.12 mm — the thickness of a sheet of printer paper.

Thursday, 11 April 2013

Scanning Minox Transparencies

For a short time in the 1960s my wife had a Minox A (AIIIs) camera with separate meter. As well as monochrome films, she tried some Agfacolor CT18 reversal film. The results from the first two films were originally mounted in Minox's own slide mounts. They were then shown, using a home-made adapter, in a projector made by one of the other manufacturer's of sub-miniature cameras, possibly Minolta. Then I made an adapter to hold the small mounts in a conventional 2 x 2 projector. The results were not good in that they would take little enlargement — an 8 x 11 mm film size with 'grainy' film was not a recipe for high definition.

When it came to scanning the slides, I realised they would not fit into my Nikon film scanner. So I bought some Gepe 2 x 2 slides with Minox masks in order to scan them in those. A few transparencies were destroyed in the process. They had become stuck to the glass of the mounts and the emulsion was left behind; a few others were damaged. However, 59 survived the move and were scanned. The results, as expected were not wonderful but at least we had a record. I have written in previous posts of the 'grain' and 'dye clouds' of CT18. On an 8 x 11 slide the grain really shows.

More recently, I have tried removing a few of the transparencies from the Gepe mounts and scanning them in the Epson V500, using a variety of masks to prevent newton rings. I did so in order to see if I could get better scans without interference from the glass of the mounts. In short, it made little difference and I stuck with the original scans.

We also had a film that had not been cut and mounted. It was in the three lengths that came back from Agfa. These I held in the film-strip scanning device for the Nikon, scanning each shot in turn and moving the strip occasionally to avoid the horizontal bars that marked the edge of a 24 x 36 mm frame.
However, the curl on the film from top to bottom (like a steel tape measure) was fairly marked. Again more recently, I have rescanned these lengths in the V500. Newton rings proved to be a problem because no matter how I tried to mask and anchor the strip, the non-emulsion side often touched the glass of the scanner. Eventually, I did get a scan of all 34 shots on the film without newton rings and a little better than my original efforts.

Neat Image again proved useful in removing some of the graininess but one film in particular was markedly worse than the others, again raising the question of whether Agfa had real problems with quality control at the film making or processing stages. The colour though has survived very well from 1966.

Here is a scanned Minox slide:

Dissatisfaction with the Minox (a good-size enlargement was only 5 x 7 cm) led to its postage back to UK and its theft (most likely at Heathrow airport) in transit.

At least I could say out loud (as I say silently to myself): 'if only you had stuck to 35 mm and Kodachrome, I would not have had all this trouble in scanning YOUR slides'. I should have known better. The riposte was instant: 'Well, YOU persuaded me to buy that Minox and it did fit in my handbag'.

All our slides (and negatives are scanned). I only hope that the occasional requests from friends and relations to scan transparencies are for 35 mm Kodachromes.

Friday, 5 April 2013

The North: A Book Well Bought

An article in British Journal of Photography persuaded me to hit the Amazon buy button. The postman quickly delivered John Bulmer's 2012 book, The North. I had admired his work in the Sunday Times Magazine in the 1960s and 70s, and I highly recommend this collection from that time.

Contrary to the popular view of those who were not even there, the early 1960s was not swinging. We may have never had it so good but Britain was still only recovering from the impoverishment of the 1930s and the years of public and private austerity following the Second World War. Bulmer's book shows the world what it was really like.

Photographically brilliant, the documentation of what life was like in the north of England, will be a source for future historians of an era of slow recovery.

Seemingly unimportant details jog memories. On page 47, in the Black Country series, can be seen a narrow-necked milk bottle. Why is this significant? Well, sterilised milk was, and perhaps still is, sold in these bottles to distinguish it from the usual pasteurised milk milk in wider-necked bottles. Sterilised milk can be kept without refrigeration for much longer than pasteurised milk because it is first homogenised and then heated to a temperature above the boiling point of water for about 20 minutes. This heat treatment changes the taste of milk, producing a characteristic 'nutty' flavour. When sterilised milk was introduced most people in Britain did not like the flavour and stayed with pasteurised. However, for some reason, 'nutty' milk took off in the West Midlands and stayed popular for decades afterwards. Hence, the bottle of sterilised milk in the photograph of the Black Country.

In the same photograph, I wondered how Bulmer had managed to incorporate the ceiling light without burning out the highlight. I then realised that I was not looking at an electric light bulb but at gas mantles. The house did not have mains electricity in 1961.

Bulmer captured the essence of The North. I cannot recommend it too highly.


The North. John Bulmer. Liverpool: Bluecost Press. 2012. ISBN 9781908457080

John Bulmer's Website: